Health risk assessment of organic micropollutants in greywater for potable reuse

Health risk assessment of organic micropollutants in greywater for potable reuse

Accepted Manuscript Health risk assessment of organic micropollutants in greywater for potable reuse Ramiro Etchepare , Jan Peter van der Hoek PII: S...
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Accepted Manuscript Health risk assessment of organic micropollutants in greywater for potable reuse Ramiro Etchepare , Jan Peter van der Hoek PII:

S0043-1354(14)00746-5

DOI:

10.1016/j.watres.2014.10.048

Reference:

WR 10967

To appear in:

Water Research

Received Date: 31 May 2014 Revised Date:

11 August 2014

Accepted Date: 21 October 2014

Please cite this article as: Etchepare, R., van der Hoek, J.P., Health risk assessment of organic micropollutants in greywater for potable reuse, Water Research (2014), doi: 10.1016/ j.watres.2014.10.048. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

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Potable water Households

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Greywater

Yes

Log D ≥ 3

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No

Established drinking water guideline available ?

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No evaluation

Multiple barriers treatment

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Organic micropollutants in greywater

Yes

Selection of more problematic compounds Tier 1 Calculation of RQ value

No

Toxicity information available ?

Yes

Tier 2

No Tier 3

Calculation of a benchmark value

1

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Health risk assessment of organic micropollutants in greywater for potable reuse

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Ramiro Etcheparea,b, Jan Peter van der Hoekc,d

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a

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b

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c

Laboratório de Tecnologia Mineral e Ambiental, Departamento de Engenharia de Minas, PPGE3M, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970, Porto Alegre-RS, Brazil. Corresponding author: [email protected] CAPES Foundation, Ministry of Education of Brazil, Brasília – DF 70.040-020, Brazil.

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Delft University of Technology, Department Water Management, Stevinweg 1, 2628 CN Delft, The Netherlands, [email protected] d

Waternet, Strategic Centre, Korte Ouderkerkerdijk 7, 1096 AC Amsterdam, The Netherlands, [email protected]

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Abstract

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In light of the increasing interest in development of sustainable potable reuse systems, additional

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research is needed to elucidate the risks of producing drinking water from new raw water sources.

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This article investigates the presence and potential health risks of organic micropollutants in

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greywater, a potential new source for potable water production introduced in this work. An

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extensive literature survey reveals that almost 280 organic micropollutants have been detected in

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greywater. A three-tiered approach is applied for the preliminary health risk assessment of these

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chemicals. Benchmark values are derived from established drinking water standards for compounds

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grouped in Tier 1, from literature toxicological data for compounds in Tier 2, and from a Threshold of

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Toxicological Concern approach for compounds in Tier 3. A risk quotient is estimated by comparing

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the maximum concentration levels reported in greywater to the benchmark values. The results show

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that for the majority of compounds, risk quotient values were below 0.2, which suggests they would

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not pose appreciable concern to human health over a lifetime exposure to potable water. Thirteen

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compounds were identified with risk quotients above 0.2 which may warrant further investigation if

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greywater is used as a source for potable reuse. The present findings are helpful in prioritizing

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upcoming greywater quality monitoring and defining the goals of multiple barriers treatment in

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future water reclamation plants for potable water production.

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Key words: greywater, organic micropollutants, risk assessment, potable reuse, toxicological data

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1. Introduction Treatment of wastewater for potable reuse is an emerging strategy being implemented worldwide to

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supplement water resource portfolios, especially in arid and semi-arid regions, coastal communities

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faced with saltwater intrusions and regions where the quantity and/or quality of the water supply

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may be compromised. Many examples of potable reuse treatment trains are reported throughout

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the world and recent discussions among water reuse experts have addressed the reliance on the

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existing systems to produce acceptable and safe water to consume (Rodriguez et al., 2009;

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Tchobanoglous et al., 2011; Pisani and Menge, 2013; Gerrity et al., 2013).

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Due to an expected higher level of initial contamination in the source wastewater in comparison to

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conventional source waters, potable reuse systems are being scrutinized more carefully by water

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regulators. Accordingly, multi-barrier treatment systems are being applied to attain high levels of

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chemical and microbial contaminant removal and to satisfy established drinking water regulations.

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The evaluation of potable reuse schemes should be in line with the World Health Organization

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guidelines for Water Safety Plans (WSP), which are usually applied for conventional drinking water

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supplies (WHO, 2011). WSP are based on the human health risk assessment of the potable water

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supply chain and take into consideration the hazards within the system, from the catchment to the

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consumer, in relation to the risk of producing unsafe water. Although in most cases pathogen

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removal requirements drive unit process selection and integration, another important major public

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health concern is the potential health impacts from long-term, and in some cases, short-term

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exposure to low concentration of chemicals and micropollutants present in the reclaimed water

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(WHO, 2011). Therefore it is important to characterize contaminant loads and associated risks for all

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potential drinking water sources, to adequately determine total removal required, identify

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appropriate treatment trains and ultimately satisfy public health criteria.

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Municipal wastewater treatment plant (WWTP) effluents have been the main source of water for

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potable reuse schemes in large-scale installations (Gerrity et al., 2013). However, a general trend is

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visible towards more decentralized and closed loop (onsite) systems as separating wastewater at the

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source and treating separately the different flows will offer possibilities to recover clean water,

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nutrients and energy (Jefferson et al. 2000; Cook et al., 2009, van der Hoek et al., 2014). An example

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of this is in the urban (domestic) environment, where “green buildings” are being commissioned in

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growing number (Zuo et al., 2014) and water efficiency is accomplished through the collection,

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treatment and reuse of rainwater, black water and greywater (Johnson, 2000). Additionally,

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individual or cluster of housing estates and isolated communities, where there is no connection to

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the public water supply and sewerage, may be benefitted with more readily available sources of

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water for potable uses (Mwenge Kahinda et al., 2007; Cook et al., 2009).

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In the present paper, greywater (GW), used here to refer to domestic wastewater excluding any

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input from toilets (Jefferson et al., 2000), is introduced as an alternative potential source of water for

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potable reuse. GW has been estimated to account for about 60-80% of domestic wastewater

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(Eriksson et al., 2002b; Hernández Leal, 2010), yet, its chemical nature is quite different. For example,

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the COD:BOD ratio can be as high as 4:1 (Boyjoo et al., 2013), indicating a high chemical content. It

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must also be pointed out that GW can be highly variable in composition, being highly dependent on

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the activities in the household, as well as the inhabitants’ lifestyles and use of chemical products.

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Many previous works have been published on the characteristics of GW in relation to conventional

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physical (temperature, colour, turbidity, electrical conductivity, suspended solids), chemical (BOD,

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COD, TOC, pH, nutrients, heavy metals) and microbiological (bacteria, protozoa, viruses, helminths)

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parameters and were recently reviewed and compiled by Boyjoo et al. (2013).

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Despite its much lower pathogen content (absence of feces) and organic matter content, surprisingly,

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GW has only been proposed for non-potable reuse applications, especially irrigation (Surendran and

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Wheatley, 1998; Smith and Bani-Melhem, 2012; USEPA, 2012; Alfiya et al., 2013). Therefore the

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associated risks are generally divided into two categories: environmental risks and human health

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risks. Environmental risk assessments (ERA) related to detrimental effects of reclaimed water on soil

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characteristics (Travis et al., 2010; Turner et al., 2013), plants growth (phytotoxicity – Garland et al.,

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2000; Pinto et al., 2010), surface/groundwater quality and aquatic/terrestrial organisms (van Wezel

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et al., 2002; Eriksson et al., 2006) are highly important to address environmental contamination

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issues. Eriksson et al. (2002b) is one of the scarce studies addressing ERA of organic micropollutants

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(OMPs) present in GW. Since using reclaimed GW for toilet flushing and car washing is also becoming

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common, more information is available regarding (microbial) health risks for non-potable reuse

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(Dixon et al., 1999; Maimon et al., 2010; O'Toole et al., 2012; Barker et al., 2013). Nevertheless, the

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main challenge still waiting for advanced research development is to turn GW into potable water

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quality (Oron et al., 2014) and very few studies have investigated the nature, loads and associated

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health risks of OMPs in GW related to the use of GW as a new source for drinking water production.

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The latter consists the focus of the present study.

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At Delft University of Technology, in the Netherlands, a team of scientists, students and companies is

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working on the Green Village, a temporary pilot site on the campus, which will be used to test new

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technologies prior to their implementation in the development of the Green Campus, a more

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ambitious project planned at the University (van der Hoek et al., 2014). The Green Village will not be

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connected to water supply, the sewerage and cable systems. The aim is to develop it as an autarkic

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and decentralized system, producing its own potable water (from GW) and electricity, and clean its

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organic waste streams in a sustainable way. The present work is a first attempt, undertaken as part

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of the Green Village project, at compiling a hazard assessment and risk characterization to identify

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and understand the risks of potable water production from GW due to the presence of OMPs.

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Although most studies investigating GW reuse and associated risks have focused on non-potable

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applications and conventional water quality parameters, this work is intended to provide in-depth

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and up-to-date compiled data on OMPs found in GW. This paper includes a preliminary health risk

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assessment (screening level) by means of a theoretical and empirical framework (three-tiered

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approach) of OMPs that may pose a risk to human health in reclaimed potable water and ends with a

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discussion of the suitability of treatment barriers to mitigate problematic compounds. In part the

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present study is aimed at helping prioritize further investigations in this subject.

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2. Materials and methods

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If GW is to be treated and reused as potable water, a preliminary health risk assessment has to be

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conducted to identify and determine which OMPs, at the concentrations present in GW, may pose a

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potential health risk if not properly removed. The present work includes a risk characterization

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conducted in four consecutive steps. First, an extensive literature review on the presence and

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concentrations of OMPs in GW was conducted. Second, solute properties of the identified

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compounds were obtained in order to prioritize the most relevant and problematic compounds and

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exclude from the analysis those that are expected to be easily removed in conventional water and

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wastewater treatment plants. Third, a three-tiered approach was applied to derive benchmark values

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for the compounds with the aid of either statutory drinking water guidelines or toxicological

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threshold values. Finally, measured maximum GW concentrations reported were compared to the

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respective benchmark values and a risk quotient (RQ) was calculated. The detailed methodology used

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for each of these steps is described in sections 2.1 through 2.4. and illustrated in Figure 1. Mixture

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interactions were not quantified since the risk assessment methods for compounds with different

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mode of action are a complex matter still under debate.

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Figure 1. Flow chart indicating the risk assessment conducted in the present study. GW, greywater;

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Log D, distribution coefficient; RQ, risk quotient.

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2.1 Presence of organic micropollutants in greywater

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A comprehensive literature review on the presence and concentrations of OMPs in GW was

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performed. The survey did not include organic macro-pollutants, inorganic compounds such as

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nutrients and metals since they have been extensively studied elsewhere, but was confined to

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organic chemicals present in micro and nano-scale concentrations. The review covered the period

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from 1991 to 2014, by consulting published (inter)national articles, conference proceedings,

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academic theses and official reports.

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2.2 Selection of compounds for assessment

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As it is not feasible to include every chemical in a toxicological assessment, the OMPs identified in

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GW were prioritized based on their ability to easily pass conventional water treatment barriers, as

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components not removed in conventional systems are likely to pose the most threat in potable reuse

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of GW.

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The n-octanol-water partition coefficient (log Kow) is a solute property related to hydrophobicity

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which has been used as log cut-off to prioritize compounds in toxicological assessments (Schriks et

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al., 2010). Compounds with a log Kow above 3 are less likely to pass water treatment plants that

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include an activated-carbon adsorption stage than those with lower values (Westerhoff et al., 2005).

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pH-corrected log Kow values are referred to as log D or distribution coefficient. The log D appears to

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be a more accurate and conservative tool to predict the adsorption of ionic solutes than the log Kow

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(Hu et al., 1997; Ridder et al., 2010). For neutral solutes, log Kow = log D, but for ionic solutes log D <

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log Kow. In the present work, log D values were obtained with the aid of the estimation program

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Marvin Sketch 6.2 and compounds with a log D ≥ 3 were excluded from further assessment. An

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exception was made for 4 alkylphenol ethoxylates (octylphenol tetra-ethoxylate; octylphenol hexa-

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ethoxylate; octylphenol hepta-ethoxylate; and octylphenol octa-ethoxylate) which were not found on

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the estimation software. For these compounds the log D values were obtained from literature (Ahel

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and Giger, 1993).

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2.3 Derivation of benchmark values with a three-tiered approach

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Due to the potential toxicity of low doses of OMPs after mid- to long-term exposure and the

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associated threat to public health, it was necessary to determine the concentrations of the selected

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contaminants at which potential adverse health effects may occur. A three-tiered approach, as

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similarly proposed by Rodriguez et al (2007), was applied in order to derive benchmark values.

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Compounds with an established drinking water guideline or standard value, were allocated to “Tier

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1”. Compounds without drinking water standards, but for which toxicity information is available were

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allocated to “Tier 2”. Those compounds for which toxicity information is not available were allocated

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to “Tier 3”.

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2.3.1 Tier 1: Regulated compounds

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Conventionally, raw and treated potable water quality have been analysed by comparing the

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measured concentration of a particular substance or parameter with the respective benchmark value

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based on drinking water standards or guidelines. Because different states and nations regulate

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different contaminants or may assign their own standard values for the same contaminant, it is

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important to define the guidelines pertinent to a specific context. For the risk assessment of potable

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reuse of GW in the Netherlands, the applicable maximum contaminant levels (benchmark values)

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were extracted from the following drinking water guidelines, in order of priority: the Dutch Drinking

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Water Decree (Staatsblad, 2011), the Guidelines for Drinking Water Quality (WHO, 2011), the

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European Council Directive 98/83/EC (EC, 1998) and the 2011 Edition of the Drinking Water

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Standards and Health Advisories (USEPA, 2011). However, since the established standards for the

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parameters “pesticides” and “other anthropogenic compounds” in the Dutch Drinking Water Decree

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were considered too generic to be used in the present risk assessment, their respective target values

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were not used to derive benchmark values for pesticides and anthropogenic compounds. These

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compounds were assessed individually.

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2.3.2 Tier 2: Unregulated compounds with toxicity value

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The first step of Tier 2 was to obtain toxicological threshold values for the assessed compounds

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expressed as TDI (tolerable daily intake), ADI (acceptable daily intake) and/or RfD (reference dose)

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from data sets and documents available from World Health Organization (WHO), U.S. EPA and other

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reliable (inter)national sources which are presented in Table 1. If not available, a provisional TDI was

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derived based on the lowest (sub) chronic no observed (adverse) effect levels (NO(A)ELs) obtained in

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rodent studies divided by an assessment factor (AF) of either:

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100 – includes combined factor of 10 for interspecies extrapolation and factor of 10 for

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inter-individual differences, •

200 – includes an additional factor of 2 to extrapolate from subchronic to chronic exposure,

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600 – includes an additional factor of 6 to extrapolate from subacute to chronic exposure,

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or

depending on which was most applicable to the data available (Van Leeuwen and Vermeire, 2007).

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Toxicological threshold values refer to the daily exposure likely to be without deleterious effects in

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humans and therefore cannot be taken directly as drinking water standards but instead must be used

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to derive benchmark values as described by the WHO (2011). In the present study the benchmark

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values for drinking water were calculated using Equation 1. This method allocates 20% of the

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reference intake value (TDI/ADI/RfD) for drinking water, to allow for exposure from other sources,

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then multiplies this allocation by the typical average body weight of an adult (60 kg) and divides it by

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a daily drinking water consumption of 2 L. Equation 2 was used to calculate the benchmark value

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corresponding to a conservative cancer risk of 10-5 for carcinogenic compounds which have not been

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assigned a toxicological threshold value but have a reported oral slope factor (SF) value instead

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(WHO, 2011).

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Table 1. Sources to obtain toxicological threshold values

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Equation 1:

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ℎ   = 198 199 200

     

Where:

T = toxicological threshold value (TDI/ADI/RfD) bw = body weight (60 kg)

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P = fraction of the TDI allocated to drinking water (20%)

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C = daily drinking water consumption (2 L)

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Equation 2: ℎ   =

       

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Where:

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Risk level = 10-5

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SF = Slope factor 2.3.3 Tier 3: Compounds without toxicity value

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For compounds without toxicity information, target values were derived from a Threshold of

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Toxicological Concern (TTC) approach. The TTC is a conservative level of human intake or exposure

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that is considered to be of negligible risk to human health, despite the absence of chemical-specific

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toxicity data. The widely accepted TTC values proposed by Munro et al. (1996) and Kroes et al. (2004)

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are set as:

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•

0.0025 μg/kg bw/day for substances that raise concern for potential genotoxicity;

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0.3 μg/kg bw/day for organophosphates;

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1.5, 9 and 30 μg/kg bw/day for Cramer class III, II and I substances, respectively.

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Thus, these values were applied for the present Tier 3 compounds. The thresholds for non-genotoxic

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compounds were elaborated using a dataset published by Munro et al. (1996), related to chemical

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classes as defined by Cramer et al. (1978) and are based on the 5th percentiles of NOELs covering

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chronic oral exposure. Possible genotoxic compounds and the Cramer class classification of

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compounds were identified in the present work through structural alerts aided by the OECD QSAR

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3.2 application toolbox (URL 1). The present approach also considered the exclusion of compounds

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for which no TTC could be derived such as high potency carcinogens (i.e. aflatoxin-like, azoxy- or N-

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nitroso- compounds, benzidines, hydrazines), metal containing compounds, proteins, steroids,

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polyhalogenated-dibenzodioxin, -dibenzofuran, and –bisphenyl (Kroes et al., 2004).

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The TTC values were further translated to benchmark values by taking into account the body weight

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and daily ingestion of drinking water (Equation 3). The same body weight (60 kg), allocation factor

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(20%) and water consumption rate (2 L) of Tier 2 were applied in Equation 3.

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Equation 3

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2.4 Calculation of a risk quotient

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To evaluate the potential health risks and toxicological relevance of the assessed compounds, the

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maximum concentration levels identified in GW were divided by the benchmark value and expressed

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as a RQ. Compounds with a RQ ≥ 1 may be of potential human health concern if treated GW were to

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be consumed over a lifetime period. These compounds would be of high-priority at the selection and

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design of future GW treatment plants for potable water production. As similarly proposed by Schriks

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et al. (2010), compounds in GW with a RQ value ≥ 0.2 and < 1, are considered to also warrant further

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investigation. Compounds in GW with a RQ value < 0.2 are presumed to present less appreciable

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concern to human health.

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3. Results

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3.1 Organic micropollutants in greywater

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OMPs became a focus for GW research in the 1990’s after two articles (Burrows et al., 1991; Santala

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et al., 1998) reported the presence of detergents and long-chain fatty acids detected through a GC-

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MS screening. A more comprehensive study in this field of research, which identified as many as 900

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xenobiotic organic compounds (XOCs) as potentially present in GW, was performed by Eriksson et al.

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(2002), using tables of contents of Danish household products (bathroom and laundry chemicals).

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The XOCs are expected to be present in GW because they originate from the various chemicals and

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personal care products used in households such as cleaning agents (detergents, soaps, shampoos),

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fragrances, UV-filters, perfumes and preservatives. Subsequent screening of bathroom GW from an

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apartment building in Denmark confirmed almost 200 different XOCs (Eriksson et al., 2003).

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However, as the study also detected some unexpected chemicals not directly connected to

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household chemicals (e.g. flame retardants and illicit drugs), it can be concluded that an inventory of

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the use of household chemicals cannot compensate for a full characterization of the compounds

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actually present in GW. In a later study investigating the concentrations of several selected organic

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hazardous substances in GW from housing areas in Sweden, Palmquist & Hanæus (2005, 2006) found

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that 46 out of more than 80 organic substances were present in concentrations above the detection

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limits.

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Quite recently, Donner et al. (2010) reviewed the knowledge with respect to the presence of XOCs in

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GW and investigated the sources, presence and potential fate of xenobiotic micropollutants in on-

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site GW treatment systems. However, Donner’s investigation focused on non-potable reuse of GW

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and was limited to a few compounds selected from those listed either as Priority Substances or

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Priority Hazardous Substances under the European Water Framework Directive (WFD) (EU, 2000). So

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far the WFD has established environmental quality standards (EQS) for 41 dangerous chemical

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substances (33 of them classified as priority substances). However, these are only a fraction of the

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compounds that are potentially hazardous as this list does not include, for instance, any

264

pharmaceutical compounds or personal care products.

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In spite of these findings, the number of publications on the monitoring and analysis of OMPs in GW

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is still scarce. There are, to the best of our knowledge, 12 published studies on this topic, where GW

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was produced, sampled and analysed from 7 different locations (5 housing estates, 1 camping site

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and 1 sport club) spread in Sweden, Denmark and the Netherlands (Eriksson et al., 2003; Andersson

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and Dalsgaard, 2004; Nielsen and Pettersen, 2005; Palmquist & Hanæus, 2005, 2006; Larsen, 2006;

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Ledin et al., 2006; Andersen et al., 2007; Hernández Leal et al., 2010; Eriksson et al., 2009; Revitt et

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al., 2011; Temmink et al., 2011). In total, 278 OMPs have been detected in GW considering all

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available literature data. The full list of the OMPs identified and their concentrations is provided in

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supplementary information, Table S1. Identified compounds were grouped into eleven substance

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classes: 1) Plasticisers and softeners; 2) Preservatives; 3) UV filters; 4) Surfactants and emulsifiers; 5)

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Flavours and fragrances; 6) Polycyclic aromatic hydrocarbons (PAHs); 7) Polychlorinated biphenyls

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(PCBs); 8) Solvents; 9) Brominated flame retardants; 10) Organotin compounds; and 11)

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Miscellaneous.

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The outcome of the prioritization of OMPs found in GW resulted in the identification of 89

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compounds (log D < 3) out of the original list. These compounds were selected for further

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assessment. Of these 89 chemicals surfactants contributed 5, fragrances and flavours 26, plasticisers

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4, preservatives 17, solvents 10, organotin compounds 3, UV filter 1, PAH 1, and other miscellaneous

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compounds 22. These OMPs and their respective CAS numbers and log D values are listed in Table S2

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(supplementary data).

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3.3 Preliminary health risk assessment of selected OMPs in GW

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The final list of OMPs in GW with their respective benchmark values and RQ values is provided in

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Table 2. For only 5 compounds (benzene, dichloromethane, ethylbenzene, pentachlorophenol and

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trichloromethane) statutory drinking water guideline values were available and these compounds

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were grouped into Tier 1. The benchmark values of Tier 1 ranged from 1 µg/L (benzene) to 300 µg.L-1

290

(ethylbenzene and trichloromethane, respectively) and originated from the Dutch Drinking Water

291

Decree, the WHO Guidelines for Drinking Water Quality and the USEPA, according to the order of

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priority set in the present work. Toxicological data were found for 39 compounds (Tier 2). An

293

established TDI, ADI or RfD was available for 27 compounds and in 11 cases when there was no TDI,

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ADI or RfD available, an established NO(A)EL was utilized to derive a TDI value with the aid of

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assessment factors. Specifically for the carcinogenic 2,4,6-trichlorophenol there was a SF available

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from EPA-IRIS. The remaining 45 compounds with no toxicological data were grouped into Tier 3. The

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latter comprised 29 compounds allocated to Cramer class I, 14 compounds allocated to Cramer Class

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III and 2 compounds with genotoxic structural alerts.

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Calculated benchmark values varied from 0.15 µg.L-1 (for the possible genotoxic benzenesulfonic

300

acid, methyl ester and sulfuric acid, dimethyl ester) to 72,000 µg.L-1 (for the preservative citric acid).

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The highest observed benchmark values (eight of them >10,000 µg.L-1) referred to preservatives and

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fragrances/flavours, which in general are also chemicals utilized as food additives. The lowest

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observed benchmark values related to compounds allocated to Tier 3 (from 0.15 to 180 µg.L-1), with

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exception for benzene (1 µg.L-1), dichloromethane (5 µg.L-1) and pentachlorophenol (1 µg.L-1) in Tier

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1; 2,4,6-trichlorophenol (25 µg.L-1), 2,4-dichlorophenol (18 µg.L-1), 2-ethyl-1-hexanol (6 µg.L-1), 2-

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hexanone, 3,4-dimethylphenol (6 µg.L-1), nicotine (4.8 µg.L-1), and tri(2-chloroethyl) phosphate (78

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µg.L-1) in Tier 2.

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For 5 compounds the RQ value was above 1, namely: benzene (Tier 1); 2-ethyl-1-hexanol (Tier 2);

309

benzenesulfonic acid methyl ester; dodecanoic acid; and tetracanoic acid (Tier 3). Accordingly, these

310

compounds may be of potential human health concern if not reduced in treatment barriers and are

311

considered to be of higher priority for further studies on the risk assessment and the selection of

312

technologies to be applied in future GW treatment plants for drinking water production. For 8

313

compounds (dichloromethane; trichloromethane; nicotine; acetamide; indole; decanamide, N-(2-

314

hydroxyethyl)-; sulfuric acid, dimethyl ester; and methyl dihydrojasmonate), the RQ value was above

315

0.2 (and below 1). These compounds are also considered to warrant further investigation.

316

Table 2. Selected OMP, maximum detected levels and calculated RQ values

317

4. Discussion

318

Potable reuse of GW is a novel and potentially beneficial research topic given the increasingly urgent

319

need to identify and validate new raw water sources for safe drinking water production worldwide.

320

An important concern in the development of GW potable reuse schemes appears to be the lack of

321

knowledge about the presence and risks of OMPs. The occurrence of OMPs has been much better

322

characterized in WWTP influents and effluents and in surface waters than in GW (Pal et al., 2010;

323

Deblonde et al., 2011; Luo et al., 2014), and very little is known about OMPs in industrial

324

wastewaters. WWTPs that treat domestic (household) sewage, hospital effluents, industrial

325

wastewaters, as well as wastewaters from livestock and agriculture are considered to be the main

326

source of OMPs to aquatic systems (Kasprzyk-Hordern et al., 2009). Most of previous studies on GW

327

characterization and treatment have been limited to the assessment of conventional water quality

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parameters for non-potable reuse applications. Accordingly, the first challenge facing those who wish

329

to treat GW to potable water quality is to identify the chemicals which potentially represent a threat

330

to human health in future applications. The present study combined available data in literature with

331

risk characterization methods in order to improve our understanding regarding the presence of

332

OMPs in GW and the risks they may pose to human health.

333

The results presented in Table S1 (supplementary data) confirmed the presence of OMPs directly

334

associated with household chemicals, especially personal care products. Several miscellaneous

335

compounds, probably indirectly associated with household chemicals have also been identified (e.g.

336

brominated flame retardants, organotin compounds, and drugs). Nevertheless, pharmaceuticals

337

active compounds, which have been consistently detected in hospital effluents (Verlicchi et al., 2010)

338

and WWTPs (Deblonde et al., 2011; Luo et al., 2014) and raised environmental and human health

339

concern due to their persistency and potential in endocrine disruption (Daughton and Ternes, 1999),

340

were virtually not present. Two exceptions were the pharmaceuticals acetaminophen and salicylic

341

acid, but maximum detected levels in GW (1.5 µg.L-1 and 0.6 µg.L-1, respectively) are about 500

342

(acetaminophen) and 3,500 (salicylic acid) times lower than the corresponding maximum levels

343

reported in WWTP effluents (Pal et al., 2010 - Table 3). As administrated pharmaceutical compounds

344

are excreted from the human body via feces and urine, separate collection and treatment of GW in

345

households can contribute to keeping these substances away from reclaimed (potable) water.

346

Table 3 compares the concentrations of some of the OMPs compiled in the present study with

347

maximum concentrations reported for WWTP influents and effluents (based on recent review

348

papers/compiled literature data). Besides pharmaceuticals, in general, much higher loads of OMPs

349

associated to industrial chemicals and wastewaters are observed in WWTPs influents (among them:

350

bisphenol-A = 11.8 µg.L-1; 4-nonylphenol = 101.6 µg.L-1; 4-octylphenol = 8.7 µg.L-1; dibutylphtalate =

351

46.8 µg.L-1) when compared to GW (bisphenol-A = 1.2 µg.L-1;

352

octylphenol = 0.16 µg.L-1; dibutylphtalate = 3.1 µg.L-1), while concentrations of personal care

353

products are slightly higher in GW. Intermittent contributions from agricultural and/or livestock

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4-nonylphenol = 38 µg.L-1; 4-

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runoff and hospital discharges may also cause spikes in pharmaceuticals and steroid hormones in

355

WWTP influents and effluents (Verlicchi et al., 2010; Sim et al., 2011) and industrial discharges may

356

contain organic compounds and other materials that are typically absent in GW (e.g.

357

aminopolycarboxylate complexing agents - Reemtsma and Jekel, 2006). On the other hand, another

358

important factor is rainfall. Kasprzyk-Hordern et al. (2009) found that the concentrations of a

359

selection of 55 OMPs in the WWTP influent were doubled when the flow was halved during dry

360

weather conditions, suggesting that rainwater could dilute the concentrations of the compounds

361

within the sewage. Therefore, the common practice in potable reuse schemes of cotreatment of

362

hospital, industrial, agriculture, stormwater and domestic wastewaters at a municipal WWTP (Gerrity

363

et al., 2013) is not a sustainable approach for reducing the risks of OMPs because it is based on

364

dilution of different discharges and does not provide an adequate segregation of pollutants and, in

365

particular, of different classes of OMPs.

366

Table 3. Maximum concentrations of OMPs in GW (present study) in comparison with maximum

367

levels reported in WWTP influents and effluents. The literature data of WWTPs were compiled from

368

recent review papers (Pal et al., 2010; Deblonde et al., 2012; Luo et al., 2014)

369

A preliminary health-based risk assessment of 89 prioritized OMP (with log D < 3) in GW was

370

performed to determine benchmark values. The first step was a conventional evaluation of

371

contaminants and consisted of identifying compounds with an established drinking water guideline

372

or standard value (Tier 1). The need to develop additional tiers arose because no current guidelines

373

exist for a majority of the chemicals identified in this study. As the fulfillment of the criteria for

374

establishment of a guideline value may take place several years after a potential contaminant is

375

identified (WHO, 2011), an attempt was made to characterize the risks of selected compounds with

376

no established guidelines. There were 39 chemicals in this study for which relevant toxicity

377

information (ADI, TDI, RfD, NOA(E)L) exists (Tier 2), thus benchmark values were derived from this

378

available information. Health authorities recommend using maximum acceptable or tolerable levels

379

such as ADI, RfD and TDI as guidelines for contaminants that may accumulate in the body. Since its

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introduction in 1957 by the Council of Europe and later by the Joint Expert Committee on Food

381

Additives-JECFA (WHO, 2002), the ADI has been proven to be a valid and practical tool in the risk

382

assessment and are the basis for many regulatory standards (WHO, 2011).

383

The remaining compounds were those without established drinking water criteria or toxicity data

384

(Tier 3). The benchmark values developed in this study for compounds in Tier 3 ranged from 0.15 to

385

180 µg.L-1. The widely accepted TTC approach used to derive these benchmark values (Kroes et al.,

386

2004; Munro et al., 1996) was considered appropriately conservative and protective to human

387

health, since it has been applied frequently by regulatory bodies for risk assessment of substances at

388

low dose oral exposure for which limited or no toxicity data are present (Leeman et al., 2014; EFSA,

389

2012; EU, 2012). However, it should be noted that more conservative TTC approaches than the one

390

applied in the present study have also been proposed. Mons et al. (2013), for example, set TTC

391

values for all chemicals other than genotoxic and steroid endocrine compounds at 1.5 µg/person per

392

day (target value in drinking water equal to 0.1 µg.L-1), to achieve drinking water of impeccable

393

quality in line with the so-called Q21 approach. On the other hand, the thresholds should be as

394

accurate as feasible and not over conservative to prevent unnecessary low thresholds. In this respect

395

it is noted that recently new thresholds have been proposed above the current (accepted) thresholds

396

used in this study (Munro et al., 2008; Tluczkiewicz et al., 2011; Leeman et al., 2014). These new

397

possibilities for the TTC approach must be further elucidated and validated by international

398

regulatory agencies before they can be put into practice.

399

Five pesticides were assessed in the present study (2,4,6-trichlorophenol, 2,4-dichlorophenol, 2,5-

400

dichlorophenol, malathion and pentachlorophenol). The benchmark values derived for them in this

401

study ranged from 1 to 120 µg.L-1 and were far above the established standard (0.1 µg.L-1) for

402

pesticides set by the Dutch Drinking Water Decree and the European Council Directive 98/83/EC.

403

Although the present results suggest that these statutory standards might be overly pragmatic and

404

stringent, it is advisable that drinking water produced from GW complies with the pesticide

405

mandatory target value of 0.1 µg.L-1.

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The calculated RQ values for the majority of OMPs were below 1, indicating that these compounds

407

are presumed to present little appreciable danger to human health. However, a few compounds

408

(benzene; 2-ethyl-1-hexanol; benzenesulfonic acid, methyl ester; dodecanoic acid and tetracanoic

409

acid) had RQ values above 1, which suggests that these compounds may pose a more appreciable

410

concern. Further investigations should focus on reducing the concentrations of these more

411

problematic compounds from GW by the application of advanced treatment barriers in order to

412

reach the target safe levels. Different wastewater treatments may be appropriate only for some of

413

these OMPs due to the variability of their physico-chemical properties (e.g. hydrophobicity,

414

molecular weight, and chemical structure – Table S3) and therefore, a multiple barriers treatment is

415

advisable. In Windhoek, for instance, direct drinking water reclamation from wastewater has already

416

been applied successfully for more than 40 years based on the multiple barriers concept to reduce

417

associated risks and improve the water quality (du Pisani and Menge, 2013). The treatment train

418

consists of the following partial barriers for OMPs removal: pre-ozonation, enhanced coagulation +

419

dissolved air flotation + rapid sand filtration, and subsequent ozone, biological activated

420

carbon/granular activated carbon.

421

Based on these considerations, to remove OMPs from GW for potable reuse, a triple barrier

422

consisting of a membrane bioreactor (MBR, coupled with an ultrafiltration membrane), ozone-based

423

advanced oxidation process (AOP) and activated carbon adsorption (AC) appears to be promising

424

(van der Hoek et al., 2014). MBRs are able to effectively remove a wide spectrum of OMPs that are

425

resistant to conventional biological processes (Tadkaew et al., 2011; Trinh et al., 2012). Ozone-based

426

AOP and AC have demonstrated to be effective for removing the prioritized compounds found in the

427

present study (Rosal et al., 2010; Hernández Leal et al., 2011; Lee et al., 2012; Jurado-Sánchez et al.,

428

2014). The application of AC is also supported by results obtained herein, which showed that 189 out

429

of the 278 compounds detected in GW have Log D values above 3 (high sorption), and thus are

430

expected to be removed by this treatment stage. In the Netherlands, this treatment train will be

431

tested and extensively studied in the aforementioned Green Village project at Delft University of

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Technology. The clean water supply of its test laboratory site will be provided using GW and

433

rainwater generated on site as raw water sources by reclaiming them in a pilot scale multiple barrier

434

treatment concept for drinking water production.

435

Looking towards the future, the results presented in this article can help researchers, water

436

engineers and stakeholders to prioritize further investigations about the use of GW as potable water

437

supply.

438

Conclusions

440 441

An extensive literature review showed that, in total, 278 OMP have been detected in GW from 7 different sites located in Denmark, Sweden and the Netherlands;

•

442 443

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The study shows a practical tool to assess the health risks of relevant OMPs by deriving benchmark values for a group of (prioritized) compounds (log D < 3);

•

The preliminary health risk assessment, performed with the aid of a three tiered approach, showed that for only a minority of selected OMPs, established drinking water standards are

445

available. Benchmark values for non-regulated compounds were derived based on either

446

toxicological available data or TTC approach;

447

•

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444

The RQ values obtained (based on the maximum concentration levels detected in the limited available GW sources and on calculated benchmark values) revealed that from the

449

toxicological point of view, the majority of assessed chemicals would not pose appreciable

450 451 452

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human health concern in an exposure scenario to drinking water over a life-time period;

•

A group of 5 compounds with RQ value > 1 as well as 8 compounds with the RQ value between 0.2 and 1 suggest that advanced multiple treatment barriers would be required in

453

future potable water reclamation plants to reduce the concentration of these compounds to

454

safe levels.

455

Acknowledgements

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The authors wish to thank CAPES (Brazilian institution), that directly sponsored these doctoral studies

457

at Delft University of Technology (Scholarship n° 8106-13-4). Special thanks to students, professors

458

and researchers of TU Delft (Section Sanitary Engineering) and particularly, to Marisa Buyers-Basso

459

for her helpful comments on the manuscript and English revision.

460

References

461 462

Ahel, M., Giger, W., 1993. Partitioning of alkylphenols and alkylphenol polyethoxylates between water and organic solvents. Chemosphere 26 (8), 1471-1478.

463 464 465

Alfiya, Y., Gross, A., Sklarz, M., Friedler, E., 2013. Reliability of on-site greywater treatment systems in Mediterranean and arid environments – a case study. Water Science and Technology, 67 (6), 13891395.

466 467

Andersen H.R, Lunsbye M., Wedel H.V., Eriksson E., Ledin A., 2007. Estogenic personal care products in a greywater reuse system. Water Science and Technology 56 (12), 45–9.

468 469 470 471

Andersson, M., Dalsgaard, A., 2004. Demonstrationsprojekt med genanvendelse af gra° t spildevand fra en større gra°vandsproducent Økologisk byfornyelse og spildevandrensning Nr. 46 http://www2.mst.dk/Udgiv/publikationer/2004/87-7614-149-7/html/default.htm (In Danish). Accessed April 2014.

472 473 474

Barker S.F., O'Toole J., Sinclair M.I., Leder K., Malawaraarachchi M., Hamilton A.J., 2013. A probabilistic model of norovirus disease burden associated with greywater irrigation of home produced lettuce in Melbourne, Australia. Water Research 47, 1421–1432.

475 476

Boyjoo, Y., Pareek, V.K., Ang, M., 2013. A review of greywater characteristics and treatment processes. Water Science and Technology 67 (7), 1403-1424.

477 478 479

Burrows, W.D., Schmidt, M.O., Carnevale, R.M., and Schaub, S.A., 1991. Nonpotable reuse: Development of health criteria and technologies for shower water recycle. Water Science and Technology 24 (9), 81-88.

480 481

Cramer, G.M., Ford, R.A. Hall, R.L., 1978. Estimation of toxic hazard – A decision tree approach. Food and Cosmetics Toxicology 16, 255-276.

482 483 484 485

Cook, S., Tjandraatmadja, G., Ho, A., Sharma, A., 2009. Definition of decentralised systems in the south east Queensland context. CSIRO: Water for a Healthy Country National Research Flagship. Urban Water Security Research Alliance, Technical Report No. 12. Available from: http://www.urbanwateralliance.org.au/ publications.html (accessed in July 2014).

486 487

Daughton, C.G., Ternes, T.A., 1999. Pharmaceuticals and Personal Care Products in the Environment: Agents of Subtle Change? Environmental Health Perspectives 107 (6), 907–938.

488 489

Deblonde T., Cossu-Leguille, C., Hartemann, P., 2011. Emerging pollutants in wastewater: a review of the literature. International Journal of Hygiene and Environmental Health 214, 442–448.

490 491

Dixon, A., Butler, D., Fewkes, A., 1999. Guidelines for greywater re-use: health issues. Water Environmental Journal 13, 322–6.

492 493 494

Donner, E., Eriksson, E., Revitt, D.M., Scholes, L., Holten-Lutzhof, H.C., Ledin, A., 2010. Presence and fate of priority substances in domestic greywater treatment and reuse systems. Science of the Total Environment 408 (12), 2444-2451.

AC C

EP

TE D

M AN U

SC

RI PT

456

20

ACCEPTED MANUSCRIPT

EC (European Commission), 1998. Council Directive 98/83/EC of 3 November 1998 on the Quality of Water Intended for Human Consumption. Official Journal of the European Communities. L:1998:330:0032:0054:EN: Accessed January 2014: http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri¼OJ.

499 500 501

EFSA (European Food Safety Authority), 2012. Scientific Opinion on Exploring options for providing advice about possible human health risks based on the concept of Threshold of Toxicological Concern (TTC). EFSA Journal 10 (7), 2750.

502 503 504

Eriksson, E., Auffarth, K., Eilerse, A.M., Henze, M., Ledin, A., 2003. Household chemicals and personal care products as sources for xenobiotic organic compounds in grey wastewater. Water SA 29, 135146.

505 506

Eriksson, E., Auffarth, K.P.S., Henze, M., Ledin, A., 2002a. Characteristics of grey wastewater. Urban Water 4 (1), 85-104.

507 508

Eriksson, E., Andersen, H.R., Madsen, T. S., Ledin, A., 2009. Greywater pollution variability and loadings. Ecological Engineering 35, 661-669.

509 510 511 512

Eriksson, E., Baun, A., Henze, M., and Ledin, A., 2002b. Environmental risk assessment of xenobiotic organic compounds in grey wastewater. In: Potential and problems related to reuse of water in households, PhD thesis, Technical University of Denmark, 2002b. Available online at: http://www.er.dtu.dk/publications/ (accessed in July 2014).

513 514

Eriksson, E., Baun, A., Henze, M., Ledin, A., 2006. Phytotoxicity of grey wastewater evaluated by toxicity tests. Urban Water Journal 3 (1), 13-20.

515 516 517 518 519

EU (European Union), 2012. Opinion on use of the threshold of toxicological concern (TTC) approach for human safety assessment of chemical substances with focus on cosmetics and consumer products. Scientific committee on Consumer Safety (SCCS), Scientific Committee on Health and Environmental Risks (SCHER) and Scientific Committee on Emerging and Newly identified Health Risks (SCENIHR); SCCP/1171/08.

520 521 522

EU (European Union), 2000. Directive 2000/60/EC of the European Parliament and the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Journal of the European Communities 22.12.2000, L327/1 – L327/73.

523 524 525

Garland, J.L., Levine, L.H., Yorio, N.C., Adams, J.L., Cook, K.L., 2000. Graywater processing in recirculating hydroponic systems: Phytotoxicity, surfactant degradation, and bacterial dynamics. Water Research 31 (12), 3075-3086.

526 527

Gerrity, D., Pecson, B., Trussell, R.S., Trussell, R.R., 2013. Potable reuse treatment trains throughout the world. Journal of Water Supply: Research and Technology – AQUA 62 (6), 321-338.

528 529

Gracia, R.S., Cortes, S., Sarasa, J., Ormad, P., Ovelleiro, J.L., 2000. TiO2-catalysed ozonation of raw ebro river water. Water Research 44 (5), 1525-1532.

530 531 532

Hernández Leal, L., Vieno, N., Temmink, H., Zeeman, G., Buisman, C.J.N., 2010. Occurrence of xenobiotics in gray water and removal in three biological treatment systems. Environmental Science and Technology 44, 6835-6842.

533 534

Hernández Leal, L., Temmink, H., Zeeman, G., & Buisman, C., 2011. Removal of micropollutants from aerobically treated greywater via ozone and activated carbon. Water Research 45, 2887-2896.

535 536

Hernández Leal, L., 2010. Removal of micropollutants from grey water combining biological and physical/chemical processes. Thesis, Wageningen University, The Netherlands.

537 538 539

Hoek, J.P van der, Tenorio, J., Hellinga, C., Lier, J. van, Wijk, A. van, 2014. Green Village Delft Integration of an Autarkic Water Supply in a Local Sustainable Energy System. Journal of Water Reuse and Desalination. Accepted manuscript.

AC C

EP

TE D

M AN U

SC

RI PT

495 496 497 498

21

ACCEPTED MANUSCRIPT

Hu, J.J., Aizawa, T., Magara, Y., 1997. Evaluation of adsorbability of pesticides in water on powdered activated carbon using octanol-water partitioning coefficient. Water Science and Technology 35 (7), 219–226.

543 544 545

Ikhlaq, A., Brown, D.R., Kasprzyk-Hordern, B., 2012. Mechanisms of catalytic ozonation on alumina and zeolites in water: Formation of hydroxyl radicals, 2012. Applied Catalysis B: Environmental 123– 124 94– 106.

546 547

Jefferson, B., Laine, A., Parsons, S., Stephenson, T., Judd, S., 2000. Technologies for domestic wastewater recycling. Urban Water 1 (4), 285-292.

548 549

Johnson, S.D., 2000. The economic case for “High performance buildings”. Corporate Environmental Strategy 7 (4), 350-361.

550 551 552

Jurado-Sánchez, B., Ballesteros, E., Gallego, M., 2014. Occurrence of carboxylic acids in different steps of two drinking-water treatment plants using different disinfectants. Water Research 51, 186197.

553 554 555

Kasprzyk-Hordern B., Dinsdale, R.M., Guwy, A.J., 2009. The removal of pharmaceuticals, personal care products, endocrine disruptors and illicit drugs during wastewater treatment and its impact on the quality of receiving waters. Water Research 43, 363–380.

556 557 558 559

Kroes, R., Renwick, A.G., Cheeseman, M., Kleiner, J., Mangelsdorf, I., Piersma, A., Schilter, B., Schlatter, J., van Schothorst, F., Vos, J.G., Würtzen, G., 2004. Structure-based thresholds of toxicological concern (TTC): guidance for application to substances present at low levels in the diet. Food and Chemical Toxicology 42, 65-83.

560 561 562

Larsen N.J., 2006 Demonstrationsprojekt i fuldskala for rensning af gråt spildevand Økologisk byfornyelse og spildevandsrensning [No. 59 http://www2.mst.dk/Udgiv/publikationer/2006/877052-149-2/html/default.htm (In Danish)]. Accessed April 2014.

563 564 565 566

Ledin, A., Auffarth, K., Eriksson, E., Smith, M., Eilersen, A.-M., Mikkelsen, P.S., Dalsgaard, A., Henze, M., 2006. Udvikling af metode til karakterisering af gra° t spildevand. Økologisk byfornyelse og spildevandsrensning [No. 58. http://www.mst.dk/Udgivelser/Publikationer/2006/07/87- 7052-1166.htm. (In Danish)]. Accessed April 2014.

567 568 569

Lee, C.O., Howe, K.J., Thomson, B.M., 2012. Ozone and biofiltration as an alternative to reverse osmosis for removing PPCPs and micropollutants from treated wastewater. Water Research 46, 1005-1014.

570 571 572

Leeman, W.R., Krul, L., Houben, G.F., 2014. Reevaluation of the Munro dataset to derive more specific TTC thresholds. Regulatory Toxicology and Pharmacology. doi: http://dx.doi.org/10.1016/j.yrtph.2014.04.015

573 574

Lin, L. Xie, M. Liang, Y., He, Y., Chan, J.Y., Luan, T., 2012. Degradation of cypermethrin, malathion and dichlorovos in water and on tea leaves with O3/UV/TiO2 treatment. Food Control 28, 374-379.

575 576 577

Luo, Y., Guoa, W., Ngo, H.H., Nghiemb, L.D., Hai, F.I., Zhang, J., Liang, S., Wang, X.C., 2014. A review on the occurrence of micropollutants in the aquatic environment and their fate and removal during wastewater treatment. Science of the Total Environment 473–474, 619–641.

578 579

Maimon A, Tal A, Friedler E, Gross A., 2010. Safe on-site reuse of greywater for irrigation – a critical review of current guidelines. Environmental Science Technology 44, 3213–20.

580 581 582

Munro, I.C., Ford, R.A., Kennepohl, E., Sprenger, J.G., 1996. Correlation of structural class with NoObserved-Effect Levels: A proposal for establishing a threshold of concern. Food and Chemical Toxicology 34, 829-867.

583 584

Munro, I.C., Renwick, A.G., Danielewska-Nikiel, B., 2008. The Threshold of Toxicological Concern (TTC) in risk assessment. Toxicology Letters 180, 151-156.

AC C

EP

TE D

M AN U

SC

RI PT

540 541 542

22

ACCEPTED MANUSCRIPT

Mwenge Kahinda, J., Taigbenu, A.E., Boroto, J.R., 2007. Domestic rainwater harvesting to improve water supply in rural South Africa. Physics and Chemistry of the Earth 32, 1050-1057.

587 588 589 590

Nielsen, M., Pettersen, T., 2005. Genanvendelse af gråt spildevand på campingpladser — Fase 2 og 3 Økologisk byfornyelse og spildevandsrensning [No. 57. Report to the Danish EPA] http://www2.mst.dk/Udgiv/publikationer/2005/87-7614-899-8/html/default.htm (In Danish). Accessed April 2014.

591 592

Oron, G., Adel, M., Agmon, V, Friedler, E., Halperin, R., Leshem, E., Weinberg, D., 2014. Greywater use in Israel and worldwide: Standards and prospects. Water Research 58, 92–101.

593 594 595

Pal, A., Gin, K.Y.H., Lin, A.Y.C., Reinhard, M., 2010. Impacts of emerging organic contaminants on freshwater resources: review of recent occurrences, sources, fate and effects. Science of the Total Environment 408, 6062–6069.

596 597

Palmquist, H., Hanaeus, J., 2005. Hazardous substances in separately collected grey- and blackwater from ordinary Swedish households. Science of the Total Environment 348, 151-163.

598 599

Palmquist, H., Hanaeus, J., 2006. Organic Hazardous Substances in Graywater from Swedish Households. Journal of Environmental Engineering 132, 901-908.

600 601

Pinto, U., Maheshwari, B.L. Grewal, H.S., 2010. Effects of greywater irrigation on plant growth, water use and soil properties. Resources, Conservation and Recycling 54, 429–435.

602 603 604

Pisani, P., Menge, J.G., 2013. Direct potable reclamation in Windhoek: a critical review of the design philosophy of new Goreangab drinking water reclamation plant. Water Science and Technology: Water Supply 13 (2), 214-226.

605 606

Reemtsma, T., Jekel, M. (Eds.), 2006. Organic pollutans in the water cycle – Properties, occurrence, analysis and environmental relevance of polar compounds. Wiley VCH, Germany, 350p.

607 608 609 610 611

Revitt, M., Eriksson, E., Donner, E., 2011. The implications of household greywater treatment and reuse for municipal wastewater flows and micropollutant loads. Water Research (45), 1549-1560. Ridder de D.J., Villacorte, L. Verliefde, A.R.D. Verberk, J.Q.J.C., Heijman, S.G.J., Amy, G.L., van Dijk, J.C., 2010. Modeling equilibrium adsorption of organic micropollutants onto activated carbon. Water Research 44, 3077–3086.

612 613 614

Rodriguez, C., Van Buynder, P., Devine, B., Cook, A., Weinstein, P., 2009. Indirect potable reuse schemes: a sustainable water supply alternative. Journal of Environmental Research and Public Health 8 (6), 1174-1209.

615 616 617

Rodriguez, C., Weinstein, P., Cook, A., Devine, B., Buynder, P.V., 2007. A Proposed Approach for the Assessment of Chemicals in Indirect Potable Reuse Schemes, Journal of Toxicology and Environmental Health, Part A: Current Issues, 70 (19), 1654-1663.

618 619 620

Rosal, R., Rodríguez, A., Perdigón-Melón, J.A., Petre, A., García-Calvo, E., Gómez, M.J., Agüera, A., Fernández-Alba, A.R., 2010. Occurrence of emerging pollutants in urban wastewater and their removal through biological treatment followed by ozonation. Water Research 44, 578-588.

621 622 623

Santala, E., Uotila, J., Zaitsev, G., Alasiurua, R., Tikka, R., and Tengvall, J., 1998. Microbiological greywater treatment and recycling in an apartment building. AWT98 -Advanced Wastewater Treatment, Recycling and Reuse: Milan 14-16 September 1998. pp. 319-324.

624 625

Schriks, M., Heringa, M.B., Margaretha, K., Voogt, P., van Wezel, A., 2010. Toxicological relevance of emerging contaminants for drinking water quality. Water Research (44) 461–476.

626 627

Sim, W., Lee, J., Shin, S., Song, K., Oh, J., 2011. Assessment of fates of estrogens in wastewater and sludge from various types of wastewater treatment plants. Chemosphere 82, 1448–1453.

AC C

EP

TE D

M AN U

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585 586

23

ACCEPTED MANUSCRIPT

Smith, E., Bani-Melhem, K., 2012. Grey water characterization and treatment for reuse in an arid environment. Water Science and Technology 66 (1), 72-78.

630 631 632

Staatsblad, 2011. Besluit van 23 mei 2011, houdende bepalingen inzake de productie en distributie van drinkwater en de organisatie van de openbare drinkwatervoorziening (Drinkwaterbesluit). http://wetten.overheid.nl/BWBR0030111/geldigheidsdatum_28-05-2014, accessed May 2014.

633 634

Surendran, S., Wheatley, A.D., 1998. Grey-water reclamation for non-potable re-use. Water Environment 12, 406-413.

635 636

Tadkaew, N., Hai, F.I., McDonald, J.A., Khan, S.J., Nghiema, L.D. Removal of trace organics by MBR treatment: The role of molecular properties. Water Research 45, 2439-2451.

637 638

Tchobanoglous, G., Leverenz, H., Nellor, M.H., Crook, J., 2011. Direct potable reuse: A path forward. WateReuse Research and WateReuse California, Washington, DC.

639 640 641 642

Temmink, H., Hernández Leal, L., Graaf, M., Zeeman, G., Buisman, C., 2011. Personal care products and pharmaceuticals in new sanitation concepts. Conference Proceedings International Water Week Amsterdam “Presenting integrated solutions for a changing world”, 2011, Amsterdam, The Netherlands.

643 644 645

Tluczkiewicz I., Buist, H.E., Martin, M.T., Mangelsdorf, I., Escher, S.E., 2011. Improvement of the Cramer classification for oral exposure using the database TTC RepDose – A strategy description. Regulatory Toxicology and Pharmacology 61, 340–350

646 647

Travis, M.J., Wiel-Shafran, A., Weisbrod, N., Adar, E., Gross, A., 2010. Greywater reuse for irrigation: Effect on soil properties. Science of the Total Environment 408, 2501–2508

648 649 650

Trinh, T. van den Akker, B, Coleman, H.M., Stuetz, R.M., Le-Clech, P., Khan, S.J., 2012. Removal of endocrine disrupting chemicals and microbial indicators by a decentralised membrane bioreactor for water reuse. Journal of Water Reuse and Desalination 2 (2), 67–73.

651 652

Turner, R.D.R, Will, J.D., Dawes, L.A., Gardner, E.A., Lyons, D.J., 2013. Phosphorus as a limiting factor on sustainable greywater irrigation. Science of the Total Environment 456–457, 287–298.

653 654 655

URL 1. OECD Organization of Economic Co-operation and Development. OECD Quantitative Structure-Activity Relationships Project. http://www.oecd.org/chemicalsafety/riskassessment/theoecdqsartoolbox.htm, accessed May 2014.

656 657 658

USEPA (United States Environmental Protection Agency), 2011. 2011-Edition of the Drinking Water Standards and Health Advisories. EPA 820-R-11-002 Office of Water U.S. Environmental Protection Agency Washington, DC.

659 660

USEPA (United States Environmental Protection Agency), 2012. Guidelines for water reuse. US Environmental Protection Agency. Office of Wastewater Management, Washington, DC.

661 662 663

van der Hoek, J.P., Tenorio, J., Hellinga, C., Lier, J. van, Wijk, A. van, 2014. Green Village Delft Integration of an Autarkic Water Supply in a Local Sustainable Energy System. Journal of Water Reuse and Desalination. In Press, doi:10.2166/wrd.2014.057.

664 665

Van Leeuwen, C.J., Vermeire, T., 2007. Risk Assessment of Chemicals, second ed., Springer, ISBN 9784020-6101-1.

666 667

van Wezel, A.P., Jager, T., 2002. Comparison of two screening level risk assessment approaches for six disinfectants and pharmaceuticals. Chemosphere 47, 1113–1128.

668 669 670

Verlicchi P., Galletti, A., Petrovic, M., Barceló, D., 2010. Hospital effluents as a source of emerging pollutants: an overview of micropollutants and sustainable treatment options. Journal of Hydrology 389, 416–428.

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Wang, J., Junyang Cheng, Can Wang, Shaoxia Yang, Wanpeng Zhu, 2013. Catalytic ozonation of dimethyl phthalate with RuO2/Al2O3 catalysts prepared by microwave irradiation. Catalysis Communications 41, 1-5.

674 675 676

Westerhoff, P., Yoon, Y., Snyder, S., Wert, E., 2005. Fate of endocrine-disruptor, pharmaceutical, and personal care product chemicals during simulated drinking water treatment processes. Environmental Science and Technology 37 (17), 6649–6663.

677 678

WHO (World Health Organization), 2011. Guidelines for Drinking-water Quality. World Health Organization.

679 680 681

WHO (World Health Organization), 2002. Evaluation of certain food additives and contaminants : fifty-seventh report of the Joint FAO/WHO Expert Committee on Food Additives. Joint FAO/WHO Expert Committee on Food Additives.

682 683 684

WHO-IPCS (World Health Organization - International Programme on Chemical Safety), 1994. Environmental health criteria for phenol (161). First draft prepared by Ms G. K. Montizan: WHO, Printed in Finland, 1994. 21p.

685 686

Zuo, J., Zhao, Z.Y., 2014. Green building research–current status and future agenda: A review. Renewable and Sustainable Energy Reviews 30, 271–281.

SC

RI PT

671 672 673

M AN U

687

AC C

EP

TE D

688

ACCEPTED MANUSCRIPT Table 1. Sources to obtain toxicological threshold values

RI PT

URL http://inchem.org/pages/ehc.html http://ec.europa.eu/dgs/health_consumer/dyna/press_r oom/index_en.cfm http://ec.europa.eu/health/scientific_committees/enviro nmental_risks/index_en.htm http://www.ema.europa.eu/ema/ http://www.efsa.europa.eu/ http://inchem.org/pages/jecfa.html http://webnet.oecd.org/hpv/ui/Search.aspx

SC

http://www.bfr.bund.de/de/start.html

http://ec.europa.eu/social/main.jsp?catId=148&langId=e n&intPageId=684 http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris. showSubstanceList&list_type=alpha&view=A

AC C

EP

TE D

M AN U

Sources of toxicological assessment data Environmental Health Criteria monographs (WHO) European Comission – Health and Consumer Protection (ECHCP) European Comission - Scientific Committee on Health and Environmental Risks (SCHER) European Medicines Agency (EMA) European Safe Food Authority (EFSA) Joint FAO/WHO Expert Committee on Food Additives (JECFA) Organization for Economic Cooperation and Development– Exisiting chemicals database (OECD) TheGerman Federal Institute for Risk Asessment (BFR) – The Scientific committee on occupational exposure limits (SCOEL) U.S. EPA Integrated Risk Information System (EPAIRIS)

ACCEPTED MANUSCRIPT

Table 2. Selected OMP, maximum detected levels and calculated RQ values

9.85 4.4 2.1 0.04 250

1 µg.L -1 5 µg.L -1 300 µg.L -1 1 µg.L -1 300 µg.L

SC

M AN U

1.7 7.4 0.10 0.16 8.5 0.6 0.24 15.3 0.05 5.9 170 1.5 0.5 20.7 0.5 1 17 11.4 0.5 15 2.8 1

-1

Source

Benchmark -1 value, µg.L

RQ

Staatsblad (2011) USEPA (2011) WHO (2011) USEPA (2011) WHO (2011)

1 5 300 1 300

9.85 0.88000 0.00700 0.04000 0.83333

EFSA (NOAEL); AF = 600 OECD (NOEL); AF = 600 EPA-IRIS (SF) EPA-IRIS (RfD) JECFA (ADI) EPA-IRIS (RfD) EPA-IRIS (RfD) ECHCP (NOAEL); AF = 200 EPA-IRIS (RfD) EPA-IRIS (RfD) EPA report (NOAEL); AF = 200 EMA (ADI) JECFA (ADI) BFR (ADI) JECFA (ADI) OECD (NOAEL); AF = 600 Daston (2004) (NOEL); AF = 600 EFSA (TDI) JECFA (ADI) OECD (NOAEL); AF = 100 JECFA (ADI) EFSA (TDI)

750 500 25 18 6 30 300 30,000 6 300 1,500 300 12,000 600 30,000 10,000 1,000 12,000 6,000 72,000 3,000 600

0.00227 0.01480 0.00400 0.00889 1.41667 0.02000 0.00080 0.00051 0.00833 0.01967 0.11333 0.00500 0.00004 0.03450 0.00002 0.00010 0.01700 0.00095 0.00008 0.00021 0.00093 0.00167

RI PT

Drinking water standard/ toxicity threshold value

EP AC C

Tier 1 Benzene Dichloromethane Ethylbenzene Pentachlorophenol Trichloromethane Tier 2 1,3-Dioxolane 1-Dodecanamine, N,N-dimethyl2,4,6-Trichlorophenol 2,4-Dichlorophenol 2-Ethyl-1-hexanol 2-Hexanone 2-Methylphenol 2-Phenyl-5-benzimidazolesulfonic acid 3,4-Dimethylphenol 3-Methylphenol 4-Methyl-phenol Acetaminophen Anise camphor Benzalkonium chloride Benzoic acid Benzoic acid, 4-hydroxyButylparaben Camphor Carvone Citric acid Citronellol Coumarin

Maximum detected level, -1 µg.L

75 mg/kg bw/day 50 mg/kg bw/day 0.011 per mg/kg bw/day 0.003 mg/kg bw/day 0.5 mg/kg bw/day 0.005 mg/kg 0.05 mg/kg bw/day 40 mg/kg bw/day 0.001 mg/kg bw/day 0.05 mg/kg bw/day 50 mg/kg bw/day 0.05 mg/kg bw/day 2 mg/kg bw/day 0.1 mg/kg bw/day 5 mg/kg bw/day 1,000 mg/kg bw/day 100 mg/kg bw/day 2 mg/kg bw/day 1 mg/kg bw/day 1,200 mg/kg bw/day 0.5 mg/kg bw/day 0.1 mg/kg bw/day

TE D

Compounds

ACCEPTED MANUSCRIPT

6,000 4,800 300 1,500 10,000 15,000 450 3,000 120 24,000 10,000 120 4.8 600 12,000 480 78

0.00050 0.00792 0.02967 0.00953 0.00410 0.00007 0.00133 0.00513 0.01583 0.00136 0.00370 0.00035 0.25000 0.03500 0.00175 0.00292 0.00513

1.5 µg/kg bw/day 1.5 µg/kg bw/day 1.5 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 1.5 µg/kg bw/day 30 µg/kg bw/day 1.5 µg/kg bw/day 30 µg/kg bw/day 0.0025 µg/kg bw/day 30 µg/kg bw/day

TTC (Cramer class III) TTC (Cramer class III) TTC (Cramer class III) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class III) TTC (Cramer class I) TTC (Cramer class III) TTC (Cramer class I) TTC (potential genotoxic) TTC (Cramer class I)

9 9 9 180 180 180 180 180 180 180 180 180 180 9 180 9 180 0.15 180

0.13333 0.06667 0.01778 0.00056 0.00222 0.00167 0.01000 0.13778 0.00389 0.00167 0.00833 0.00778 0.07056 0.12222 0.00056 0.95556 0.02222 7.33333 0.00500

SC

RI PT

WHO-IPCS (2006) (TDI) EPA-IRIS (RfD) JECFA (NOAEL); AF:200 EFSA (NOAEL); AF = 200 EFSA (NOAEL); AF = 600 JECFA (ADI) EMA (ADI) JECFA (ADI) EPA-IRIS (RfD) JECFA (ADI) EFSA (NOAEL); AF = 600 EPA-IRIS (RfD) EFSA (ADI) WHO (ADI) JECFA (ADI) EPA-IRIS (RfD) SCHER (TDI)

EP

TE D

1.2 0.6 0.16 0.1 0.4 0.3 1.8 24.8 0.7 0.3 1.5 1.4 12.7 1.1 0.1 8.6 4 1.1 0.9

1 mg/kg bw/day 0.8 mg/kg bw/day 10 mg/kg bw/day 50 mg/kg bw/day 1 10 mg/kg bw/day 2.5 mg/kg bw/day 0.075 mg/kg bw/day 0.5 mg/kg bw/day 0.02 mg/kg bw/day 4 mg/kg bw/day 1 10 mg/kg bw/day 0.02 mg/kg bw/day 0.0008 mg/kg bw/day 0.1 mg/kg bw/day 2 mg/kg bw/day 0.08 mg/kg bw/day 13 µg/kg bw/day

M AN U

3 38 8.9 14.3 41 1 0.6 15.4 1.9 32.6 37 0.042 1.2 21 21 1.4 0.4

AC C

Dibutyl tin Diethyl phthalate Dihydromyrcenol Dodecanamide, N,N-bis(2-hydroxyethyl)Ethylparaben Eugenol Isoeugenol Linalool Malathion Menthol Methylparaben Naphthalene Nicotine Phenol Propylparaben Toluene Tri(2-chloroethyl) phosphate Tier 3 1,2-Ethanediamine, N-ethyl1,8-Nonanediol, 8-methyl2,5-Dichlorophenol 2,5-Dimethylphenol 2,6-Dimethylphenol 2-Hexanol 2-Methyl-butanoic acid, methyl ester 2-Phenoxy ethanol 3-Hexanol 3-Hexanone 3-Methyl-butanoic acid, methyl ester 4-Heptanone 4-Methoxy-benzoic acid 4-Methyl-pentanoic acid, methyl ester 6-Methyl-5-hepten-2-one Acetamide Acetic acid, phenoxyBenzenesulfonic acid, methyl ester Butanoic acid, butyl ester

ACCEPTED MANUSCRIPT

0.3 0.6 0.1 1.2 2808 0.1

AC C

TTC (Cramer class III) TTC (Cramer class III) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class III) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class III) TTC (Cramer class I) TTC (Cramer class III) TTC (Cramer class I) TTC (Cramer class III) TTC (Cramer class III) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class III)

9 9 180 180 180 9 180 180 180 180 9 180 9 180 9 9 180 180 180 9

0.05556 0.35556 0.00667 0.02722 3.77778 0.01111 0.00444 0.05611 0.00500 0.00111 0.42222 0.04444 0.43333 0.00944 0.11 0.01111 0.01667 0.00611 0.00333 0.12222

1.5 µg/kg bw/day 30 µg/kg bw/day 0.0025 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day

TTC (Cramer class III) TTC (Cramer class I) TTC (potential genotoxic) TTC (Cramer class I) TTC (Cramer class I) TTC (Cramer class I)

9 180 0.15 180 180 180

0.03333 0.00333 0.66667 0.00667 15.6 0.00056

SC

RI PT

1.5 µg/kg bw/day 1.5 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 1.5 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 1.5 µg/kg bw/day 30 µg/kg bw/day 1.5 µg/kg bw/day 30 µg/kg bw/day 1.5 µg/kg bw/day 1.5 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 30 µg/kg bw/day 1.5 µg/kg bw/day

M AN U

TE D

0.5 3.2 1.2 4.9 680 0.1 0.8 10.1 0.9 0.2 3.8 8 3.9 1.7 0.99 0.1 3 1.1 0.6 1.1

EP

Caffeine Decanamide, N-(2-hydroxyethyl)Decanoic acid Dimethyl phthalate Dodecanoic acid Eucalyptol Geraniol Hexanoic acid, methyl ester Homomyrtenol Hydroxycitronellol Indole Isobutylparaben Methyl dihydrojasmonate Mono 2-ethylhexyl phthalate Monobutyl tin Monooctyl tin Octanoic acid Pentanoic acid, methyl ester Phenylethyl alcohol Propanoic acid, 2-methyl-, 2,2-dimethyl-1-(2-hydroxy-1methylethyl)propyl ester Propanoic acid, 2-methyl-, 3-hydroxy-2,2,4-trimethylpentyl ester Salicylic acid Sulfuric acid, dimethyl ester Terpineol Tetracanoic acid α-Methyl-benzene methanol

ACCEPTED MANUSCRIPT Table 3. Maximum concentrations of OMPs in GW (present study) in comparison with maximum levels reported in WWTP influents and effluents. The literature data of WWTPs were compiled from recent review papers (Pal et al., 2010; Deblonde et al., 2012; Luo et al., 2014) WWTPs Effluent Influent -1 -1 (µg.L ) (µg.L )

GW (present -1 study) (µg.L )

Class

Acetaminhophen

Pharmaceutical

1.5

56.9

777

Salicylic acid

Pharmaceutical

0.6

63.7

2,098

Caffeine

Food additive/stimulant

0.5

209

43.5

Benzophenone

Personal care product

4.9

0.9

0.23

Galaxolide

Personal care product

19.1

25

2.77

Tonalide

Personal care product

5.8

1.93

0.32

Triclosan

Personal care product

35.7

23.9

6.88

4-Nonylphenol

Surfactants

38

101.6

7.8

4-Octylphenol

Surfactants

0.16

8.7

1.3

Bisphenol-A

Plasticizer

1.2

11.8

4.09

Butylbenzyl phtalate

Plasticizer

9

37.87

3.13

Di-(2-ethylhexyl) phthalate

Plasticizer

Dibutyl phthalate

Plasticizer

Diethyl phtalate

Plasticizer

Di-isobutyl phthalate

Plasticizer

Dimethyl phtalate

Plasticizer

Dimethyl phthalate

Plasticizer

SC

M AN U

TE D EP AC C

RI PT

Compound

160

122

54

3.1

46.8

4.13

38

50.7

2.58

8

20.48

-

4.9

3.32

0.115

4.9

6.49

1.52

ACCEPTED MANUSCRIPT

Log D ≥ 3 No

No

Yes

M AN U

Established drinking water guideline available ?

SC

Yes

Yes

TE D

Toxicity information available ?

Tier 1

Tier 2

Selection/calculation of a benchmark value

Tier 3

Calculation of RQ value

EP

No

AC C

No evaluation

RI PT

List of OMPs found in GW

ACCEPTED MANUSCRIPT Highlights Greywater is a potentially novel raw water source for potable reuse. The presence and concentrations of organic micropollutants in greywater was compiled. A risk assessment identified the more problematic compounds for potable reuse.

RI PT

The majority of assessed compounds pose no appreciable danger to human health.

AC C

EP

TE D

M AN U

SC

Useful for future monitoring of greywater and design of potable water reuse plants.

ACCEPTED MANUSCRIPT

Table S1. OMPs found in GW (µg.L-1 or indicated if different)

BO90 tenant owner's society / Copenhagen, Denmark1

Vibyasen housing area / Sollentuna, Sweden2

Plasticisers and softeners 8.5

Butylbenzyl phthalate

<1

Decanedioic acid, bis(2-ethylhexyl) ester

1.0

Di-(2-ethylhexyl) phthalate

9.8-39 3.1

Diethyl phthalate

<1-13

Di-isobutyl phthalate

<1-3

Dimethyl phthalate

4.9

Di-n-butyl phthalate

<1

Mono 2-ethylhexyl phthalate Preservatives 2,4,6-Trichlorophenol 2,4-Dichlorophenol 2,5-Dichlorophenol 2-Phenoxy ethanol Acetic acid, phenoxyBenzoic acid

Gals Klint Campingsite / Copenhagen, Denmark7

0.42

0.22

7.5-20

28

14

4.2-38

7.2-9.4

27

29

<1.0-8

3.4-6.0

4.9

1.8

<1.0

<0.5

0.15

0.98

1.8-9.4

4.4-6.2

2.7

1.8

14.2 1.0 1.7

EP

Hexadecanoic acid, methyl ester Hexanedioic acid, bis(2-ethylhexyl) ester

Vasbadet swimming club / Brondby, Denmark6

<1-1.4

AC C

Dipentyl-phtalate

1.4-3.3

Nordhavnsgarden apartment Housing estate building / Sneek, The /Copenhagen, Netherlands5 Denmark4

8.4-160

TE D

Dibutyl phthalate

<1.0-9.0

M AN U

2-Ethyl-1-hexanol

Gebers housing estate / Skarpnäck, Sweden3

SC

Compound name

RI PT

Source of GW / Location

<0.02-0.10

0.066

0.06-0.13

0.16

0.06-0.13

0.16

24.8 4 0.5

Benzoic acid, 4-hydroxy-

1

Butylated hydroxyanisole

0.5

ACCEPTED MANUSCRIPT

Butylated hydroxytoluene

4.5

Butylparaben

<0.2-17 15

Dichlorophenol

RI PT

Citric acid

0.06-0.13

Ethylparaben

0.6

<0.1-41 0.1-8

Malathion

1.9

Methylparaben

2.6

Octanoic acid

3 0.4

Propylparaben Triclosan

0.6

UV filters 2-Ethylhexyl salicylate 2-Phenyl-5-benzimidazolesulfonic acid

1-Dodecene 1-Hexadecene 3-Hexanol 3-Hexanone 3-Methylphenol 4-Methoxy-benzoic acid

0.5

0,075-0.3

0.1-37

<0.1-21

nd-5.5 6.3-35.7

nd-4.7 0.1-15.3 nd-8.9 0.3-17.4 0.3-4.9 nd-146 3.9-67.7

EP

Parasol MCX Fragrances and flavours

4.2

AC C

Octocrylene

0.56-5.9

TE D

4-Methylbenzylidene-camphor

M AN U

Phenol, 2,6-bis(1,1-dimethylethyl)-4-(methoxymethyl)-

Benzophenone-3

SC

Isobutylparaben

Avobenzone

0.19-4.4

0.4

0.7 0.3 0.1 12.7

4-Methylphenol

3.1

6-Methyl-5-hepten-2-one

0.1

Anise camphor (trans-anethole)

0.5

21

5.9

0.5

Camphor

9.1-11.4

Carvone

0.5

Citronellol

2.8

Coumarin

1.0

Decanoic acid

1.2

Dihydroabietate

1.1

Dihydromyrcenol

8.9

Dodecanal

0.9

Dodecanoic acid, methyl ester

2.2

Eucalyptol

0.1

Eugenol

1.0

Farnesol

1.0

Galaxolide

Hexyl cinnamic aldehyde Hexyl cinnamic aldehyde Homomyrtenol Hydroxycitronellol Indole Isoeugenol Linalool Linalyl propanoate Menthol

5.7-19.1

0.6

76.9 0.7

EP

Hexadecanoic acid

0.9

0.2

AC C

Geranyl acetone

0.8

TE D

Geraniol

SC

0.9

Caffeine

M AN U

Butanoic acid, butyl ester

RI PT

ACCEPTED MANUSCRIPT

3.8

0.6 15.4 1.3 32.6

Menthone

0.9

Methyl abietate

1.4

Methyl dihydrojasmonate

3.9

0.6-11.5

Phenylethyl alcohol

0.6

Squalene

133

Terpineol

1.2

Tetradecanoic acid, methyl ester

3.1

Thymol

2.5

RI PT

ACCEPTED MANUSCRIPT

Tonalide α-Methyl-benzene methanol

0.1

1.6

1-Dodecanamine, N,N-dimethyl-

7.4

1-Dodecanol

11.3

1-Hexadecanol

63.7 117

2-(Dodecyloxy)-ethanol

37.3

2-(Tetradecyloxy)-ethanol

18.7

4-nonylphenol (NP)

0.4

4-NP hexa-ethoxylate 4-NP mono-ethoxylate 4-NP octa-ethoxylate 4-NP penta-ethoxylate 4-NP tetra-ethoxylate 4-NP tri-ethoxylate 4-octylphenol (OP)

EP

4-NP hepta-ethoxylate

AC C

4-NP di-ethoxylate

2.82-5.95

TE D

1-Octadecanol

M AN U

15-Octadecanoic acid

SC

Surfactants

0.56-1.1

4.02-15.9

<0.05-5

9.14-24.1

<0.05-5.2

18.9-40.9

<0.4-9

2.75-6.73

<0.05-3.7

<0.1

<0.05-3.3

15.5-49.7

<0.04-6.5

21.1-61.4

<0.025-2.3

11.8-36.2

<0.025-3.3

0.08-0.16

0.07-0.15

0.37-4.74

<0.005-0.07

0.24-0.6

<0.005-0.11

4-OP hepta-ethoxylate

0.17-0.44

<0.05

4-OP hexa-ethoxylate

0.26-0.81

<0.05

4-OP mono-ethoxylate

0.08-0.21

0.13-0.38

4-OP tri-ethoxylate 4-OP di-ethoxylate

nd-5.8

0.35-1.63

0.8-38

0.9

0.76

ACCEPTED MANUSCRIPT

<0.001-0.14

<0.05

4-OP penta-ethoxylate

0.41-2.6

<0.05

4-OP tetra-ethoxylate

0.4-3.1

<0.05

9-Methyltetradecanoic acid

RI PT

4-OP octa-ethoxylate

2.7

9-Octadecenoic acid

144-15863

9-Octadecenoic acid

27.4

9-Octadecenoic acid, (Z)-, methyl ester

18.0

SC

Benzalkonium chloride

8.1

Decanoic acid

5.5-755

Dodecanamide, N-(2-hydroxyethyl)-

0.8

Dodecanamide, N,N-bis(2-hydroxyethyl)-

14.3 5.9-680

Elicosanoic acid

19.7-189

Hexacanoic acid

291-7020

Hexanoic acid Isopropyl myristate Octadecanoic acid Octadecanoic acid, 2-hydroxyethyl ester Octadecanoic acid, 2-methylpropyl ester Octadecanoic acid, butyl ester Octadecanoic acid, methyl ester Octanoic acid p-Octylphenolmethyl Tetracanoic acid

8.2

4.5

291-7020 1.6

EP

Hexadecanoic acid, hexadecyl ester

4.2-3569 0.9

AC C

Hexadecanoic acid, 1,2-ethanediyl ester

TE D

Dodecanoic acid

M AN U

Bisphenol-A Cyclododecane

0.3

0.2 4.6 8.1-283 0.2 4.4-2808

Tetracosanoic acid, methyl ester

0.6

Tetradecanoic acid

12.6

2.1-20.7 0.42-1.2

Tetradecanoic acid, 12-methyl-

1.8

Tetradecanoic acid, 12-methyl-, methyl ester

1.8

Tetradecanoic acid, dodecyl ester

1.2

PAHs 0.26

0.018-0.072

Acenaphthylene

-

0.15

Anthracene

-

0.023-0.041

0.02-0.04

<0.01

Benzo(a)pyrene Benzo(ghi)perylene

0.04 0.01-0.02

Fluoranthene Fluorene Naphthalene

<4.5

Phenanthrene Pyrene

PCB#156 PCB#157 PCB#167 Solvents 1,13-Tetradecadiene 1,3-Dioxolane 1,8-Nonanediol, 8-methyl1-Decene 1-Docosene

EP

PCB#118

AC C

PCB#105

0.03-0.03

0.033-0.035

<0.01

0.048-0.065

<0.1

0.029-0.042

0.04

0.1-0.12

0.04-0.05

<0.01

TE D

PCB

1.8 1.7 0.6 0.6 1.6

1-Nonadecene

0.8

1-Tetradecene

0.5

2-Hexadecanol

6.1

<0.01

<0.01

M AN U

Chrysene

SC

Acenaphthene

RI PT

ACCEPTED MANUSCRIPT

<0.02

0.022-0.029 ng/L

<0.02

0.073-0.12 ng/L

<0.02

0.019-0.032 ng/L

<0.02

0.022-0.026 ng/L

<0.02

0.011-0.015 ng/L

3-Dodecene

0.4

3-Eicosene

7.3

3-Octadecene

0.5

4-Dodecene

0.5

4-Heptanone

1.4

5-Eicosene

5.2

5-Octadecene

0.4

7-Tetradecene

0.2

Acetamide Benzene

8.6 <1.9

Cyclohexadecane

21.1

Cyclotetradecane

4.8

Decane

4.2

Dodecane

1.2

Eicosane

4.1

Octadecane Sulfuric acid, dimethyl ester Toluene Tridecane Xylene, mXylene, oOrganotin compounds Dibutyl tin Dioctyl tin

0.2 1.1 0.1

EP

Nonane

1.9-2.1

1.4 2.0

AC C

Ethylbenzene

SC

0.6

M AN U

0.3

2-Hexanone

TE D

2-Hexanol

RI PT

ACCEPTED MANUSCRIPT

3.5 0.6

252-3000 ng/L

28.2 ng/L

20-21 ng/L

Monobutyl tin

431-990 ng/L

Monooctyl tin

29-100 ng/L

89.8 ng/L

<1.4-9.85

ACCEPTED MANUSCRIPT

Tributyl tin

209-287 ng/L

6.4 ng/L

PentaBDE

0.17-0.76

0.0048-0.018

PentaBDE 100

0.026-0.11

<0.001-0.0027

0.12-0.64

0.0039-0.015

HexaBDE

0.002-0.007

<0.001-0.0016

TetraBDE

0.066-0.24

0.0048-0.014

TetraBDE 47

0.049-0.22

0.0048-0.014

1,1-Dodecanediol, diacetate

0.8

1,2-Ethanediamine, N-ethyl-

1.2

11-Hexadecenoic acid

0.5

11-Hexadecenoic acid, methyl ester

3.7

1-Octadecene

2.4

2,5-Dimethylphenol

3,4-Dimethylphenol 3-Methyl-butanoic acid, methyl ester 3-Methylphenol 4-Heptanone, 3-ethyl4-Methyl-pentanoic acid, methyl ester 4-Methylphenol 7-Hexadecenoic acid, methyl ester, (Z)8,11-Octadecadienoic acid, methyl ester 9,12-Octadecadienoic acid, methyl ester 9-Hexadecenoic acid

0.1 0.4

1.8

0.05

0.24 0.05

1.5

EP

2-Methylphenol

5.9

5.9

0.2

AC C

2-Methyl-butanoic acid, methyl ester

TE D

2,6-Dimethylphenol

M AN U

Miscellaneous

SC

PentaBDE 99

RI PT

Brominated Flame Retardants

1.1

170 4.2 15.5 7.5 18.7

9-Hexadecenoic acid, eicosyl ester, (Z)-

5.1

9-Hexadecenoic acid, methyl ester, (Z)-

31.3

3.2

9-Octadecenamide, (Z)-

0.6

9-Octadecenoic acid, (E-), octadecyl ester

10.6

9-Octadecenoic acid, (Z)-, 9-hexadecenyl ester, (Z)-

2.9

9-Octadecenoic acid, (Z)-, 9-octadecenyl ester, (Z)-

2.0

9-Octadecenoic acid, (Z)-, octadecyl ester

7.8

9-Octadecenoic acid, methyl ester, (E)-

2.2

Acetaminophen

1.5

Acetic acid, octadecyl ester

2.5

Benzenesulfonic acid, methyl ester

1.1

Cholest-4-en-3-one

0.9 2.4

Cholesta-3,5-diene

12.8

Cholesterol

28.6

Cholesterol acetate

4.9

Decanamide, N-(2-hydroxyethyl)Dichloromethane Docosanoic acid, methyl ester Dodecanoic acid, dodecyl ester Dodecanoic acid, hexadecyl ester Dodecanoic acid, tetradecyl ester Eicosanoic acid Eicosanoic acid, methyl ester Glycerol β-palmitate

0.5

0.2 3.2

EP

Coprostanol

0.9 2.1

AC C

Cis-1,2-dichloroethylene

TE D

Cholest-5-en-3-one

SC

4.8

9-Hexadecenoic acid, tetradecyl ester

M AN U

9-Hexadecenoic acid, octadecyl ester, (Z)-

RI PT

ACCEPTED MANUSCRIPT

5.3 3.0 1.3 0.6 3.8

Heptadecanoic acid, methyl ester

1.7

Hexadecanamide

0.7

Hexadecanoic acid, 14-methyl-, methyl ester

1.1

4.4

5.3

Hexadecenoic acid, methyl ester

3.9

Hexanoic acid, methyl ester

10.1

Lanosta-8,24-dien-3β-ol

0.6

Nicotine

1.2

Octadecanoic acid, 2-[(1-oxohexadecyl)oxy]ethyl ester

2.8

Octadecenoic acid, methyl ester

9.7

Pentadecanoic acid, methyl ester

1.8

Pentanoic acid, methyl ester

1.1

Phenol Phenol, m-tert-butyl-

0.9 0.5

Propanoic acid, 2-methyl-, 2,2-dimethyl-1-(2-hydroxy-1-methylethyl)propyl ester

1.1

Propanoic acid, 2-methyl-, 3-hydroxy-2,2,4-trimethylpentyl ester

0.3

Provitamin D3

3.1

Tetradecanoic acid, 9-methyl-, methyl ester Tetradecanoic acid, hexadecyl ester Tri(2-chloroethyl) phosphate Trichloromethane Tridecanoic acid, methyl ester Triphenyl phosphate β-Sitosterol

0.6

<0.1-1 0.5

6.5

EP

Tetrachloromethane

0.4

<0.1-250

AC C

Salicylic acid

2.2

TE D

Propanoic acid, 2-methyl-, 1-(1,1-dimethylethyl)-2-methyl-1,3-propanediyl ester

SC

3.4

Hexadecanoic acid, tetradecyl ester

M AN U

Hexadecanoic acid, octadecyl ester

RI PT

ACCEPTED MANUSCRIPT

1.2

0.5 0.7

0.34

21

ACCEPTED MANUSCRIPT Eriksson et al. (2003); Ledin et al.(2006); Larsen (2006).

2

Palmquist and Hanaeus (2005).

3

Palmquist and Hanaeus (2006).

4

Andersen et al. (2007); Eriksson et al. (2009); Revitt et al. (2011).

5

Hernández Leal et al. (2010); Temmink et al. (2011).

6

Andersson and Dalsgaard (2004).

7

Nielsen and Pettersen (2005).

AC C

EP

TE D

M AN U

SC

RI PT

1

ACCEPTED MANUSCRIPT

Table S2: List of prioritized OMP in the present study

1,2-Ethanediamine, N-ethyl-

Log D Compound

110-72-5

-3.43

Dibutyl tin

CAS

Log D

1002-53-5

2.19

75-09-2

1.29

84-66-2

2.69

18479-58-8

2.82

131-11-3

1.98

0.02

Dichloromethane

1.84

Diethyl phthalate

1-Dodecanamine, N,N-dimethyl-

112-18-5

2.71

Dihydromyrcenol

2,4,6-trichlorophenol

88-06-2

2.14

Dimethyl phthalate

2,4-dichlorophenol

120-83-2

2.6

Dodecanamide, N,N-bis(2-hydroxyethyl)-

120-40-1

2.74

2,5-dichlorophenol

583-78-8

2.49

Dodecanoic acid

143-07-7

2.06

2.5-dimethylphenol

95-87-4

2.7

Ethylbenzene

100-41-4

2.93

2.6-dimethylphenol

576-26-1

2.7

Ethylparaben

120-47-8

2

2-Ethyl-1-hexanol

104-76-7

2.5

Eucalyptol

470-82-6

2.35

2-Hexanol

626-93-7

1.67

Eugenol

97-53-0

2.61

2-Hexanone

591-78-6

1.7

Geraniol

106-24-1

2.5

2-Methyl-butanoic acid, methyl ester

868-57-5

1.61

Hexanoic acid, methyl ester

106-70-7

1.96

2-methylphenol

95-48-7

2.18

Homomyrtenol

128-50-7

1.81

2-Phenoxy ethanol

122-99-6

1.13

Hydroxycitronellol

107-74-4

1.69

27503-81-7

0.09

Indole

120-72-9

2.07

3,4-dimethylphenol

95-65-8

2.7

isobutylparaben

4247-02-3

2.88

3-Hexanol

623-37-0

1.74

Isoeugenol

97-54-1

2.63

3-Hexanone

589-38-8

1.95

Linalool

78-70-6

2.65

3-Methyl-butanoic acid, methyl ester

556-24-1

1.35

Malathion

121-75-5

1.86

Menthol

89-78-1

2.66

3-methylphenol 4-Heptanone 4-Methoxy-benzoic acid 4-Methyl-pentanoic acid, methyl ester 4-Methyl-phenol (p-cresol)

108-39-4

M AN U

TE D

EP

2-phenyl-5-benzimidazolesulfonic acid

SC

646-06-0 54725-73-4

1,8-Nonanediol, 8-methyl-

AC C

1,3-Dioxolane

CAS

RI PT

Compound

2.18

123-19-3

2.4

100-09-4

-1.44

2412-80-8

1.8

106-44-5

2.18

Methyl dihydrojasmonate

24851-98-7

2.92

99-76-3

1.64

Mono 2-ethylhexyl phthalate

4376-20-9

1.19

Monobutyl tin

78763-54-9

-0.14

Methylparaben

1

6-Methyl-5-hepten-2-one

110-93-0

2.02

Monooctyl tin

NA

1.45

Acetamide

60-35-5

-1.03

Naphthalene

91-20-3

2.96

ACCEPTED MANUSCRIPT

54-11-5

-0.31

Acetic acid, phenoxy-

122-59-8

-2.01

Octanoic acid

124-07-2

0.51

Anise camphor (trans-anethole)

4180-23-8

2.94

Pentachlorophenol

87-86-5

2.79

BaCl (Benzalkonium chloride) Benzene

8001-54-5

1.69

Pentanoic acid, methyl ester

624-24-8

1.51

71-43-2

1.97

Phenol

108-95-2

1.67

Benzenesulfonic acid, methyl ester

80-18-2

1.53

60-12-8

1.49

Benzoic acid

65-85-0

-1.48

Phenylethyl alcohol (b-Methylphenethyl alcohol) Propanoic acid, 2-methyl-, 2,2-dimethyl-1-(2-hydroxy-1methylethyl)propyl ester

74367-33-2

2.7

Benzoic acid, 4-hydroxy-

99-96-7

-1.58

Propanoic acid, 2-methyl-, 3-hydroxy-2,2,4-trimethylpentyl ester

77-68-9

2.81

Butanoic acid, butyl ester

109-21-7

2.39

Propylparaben

94-13-3

2.52

Butylparaben

94-26-8

2.96

Salicylic acid

69-72-7

-1.52

Caffeine

58-08-2

-0.55

Sulfuric acid, dimethyl ester

77-78-1

-0.09

Camphor

76-22-2

2.55

Terpineol

98-55-5

2.17

RI PT

Nicotine

SC

0.9

M AN U

103-90-2

99-49-0

2.55

tetracanoic acid

544-63-8

2.31

Citric acid

77-92-9

-9.47

Toluene

108-88-3

2.49

Citronellol

26489-01-0

2.75

Tri(2-chloroethyl) phosphate

115-96-8

2.11

Coumarin

91-64-5

1.78

Trichloromethane

67-66-3

1.83

α-Methyl-benzenemethanol

98-85-1

1.62

TE D

Carvone

2128117

2.32

Decanoic acid

334-48-5

1.17

NA, not available

EP

Decanamide, N-(2-hydroxyethyl)-

AC C

1

Acetaminophen (paracetamol)

ACCEPTED MANUSCRIPT

Table S3. Physico-chemical characteristics of more problematic (RQ > 0.2) OMPs identified in GW

2.5 -1.03 1.97 1.53 2.32 1.29 4.48 2.07 2.92 1.16 -0.09 5.37 1.83

b

Formula

Surface tension -1 (mN.m )

C6H18O C2H5NO C6H6 C7H8O3S C12H25NO2 CH2Cl2 C12H24O2 C8H7N C13H22O3 C10H14N2 C2H6O4S C14H28O2 CHCl3

47 na 28.2 na na na 26.6 na na na 40.1 na 27.1

EP

TE D

Data from estimation software: aMarvin Sketch 6.2 and bEPI SuiteTM; na = not available.

AC C

b

Vapour pressure (mmHg)

b

RI PT

2-Ethyl-1-hexanol Acetamide Benzene Benzenesulfonic acid methyl ester Decanamide, N-(2-hydroxyethyl)Dichloromethane Dodecanoic acid Indole Methyl dihydrojasmonate Nicotine Sulfuric acid, dimethyl ester Tetracanoic acid Trichloromethane

Molecular b weight -1 (g.mol ) 130.23 59.07 78.11 172.20 215.34 84.93 200.32 117.15 226.32 162.24 126.13 228.38 119.38

0.205 0.0369 90 0.00175 1.08E-008 433 0.00111 0.0124 0.000857 0.0329 0.68 0.00016 192

SC

Log a Kow

M AN U

Compound

b

Water solubility -1 (mg.L ) 1,285.3 2,000 1,339 3,174.2 2,427.7 11,665 10.972 561.53 154.88 4.2E+5 43,569 1.0548 8,630.2