Engineered adsorbents for the removal of contaminants of emerging concern from water

CHAPTER 1

Engineered adsorbents for the removal of contaminants of emerging concern from water Bethzaely Fernández-Reyes, Krisiam Ortiz-Martínez, José A. Lasalde-Ramírez, Arturo J. Hernández-Maldonado Department of Chemical Engineering, University of Puerto Rico-Mayagüez Campus, Mayagüez, Puerto Rico, United States

Contents 1. Introduction 2. Porous and nonporous adsorbents 2.1 Carbon-based adsorbents

3 5 6 6 9 13 18 22 24 28 31 34 37

2.1.1 Activated carbon 2.1.2 Graphene oxide 2.1.3 Carbon nanotubes

2.2 Zeolites 2.3 Metaleorganic frameworks 2.4 Mesoporous silica 2.5 Clays 2.6 Composite adsorbents 3. Conclusions and areas of opportunity References

1. Introduction The persistent increase in concentration of contaminants of emerging concern (CECs) in waters around the globe is a problem that should be urgently addressed to avoid the possibility of adverse effects on health and the environment.1e6 A potential solution to this includes the implementation of advanced water treatment technologies, all working in tandem to remediate according to the diversity and complexity of CEC mixtures, which will vary according to region. One of those technologies involves separation of CECs from water via adsorption. This has been proven feasible and cost-effective, with capacity to remove contaminants Contaminants of Emerging Concern in Water and Wastewater ISBN 978-0-12-813561-7 https://doi.org/10.1016/B978-0-12-813561-7.00001-8

Copyright © 2020 Elsevier Inc. All rights reserved.

3

4

Contaminants of Emerging Concern in Water and Wastewater

present at even low-concentration levels (i.e., from mg L
1 to ng L
1).7e10 In contrast to other technologies, adsorption neither requires high pressure settings to function nor introduces toxic by-products to the environment with appropriate adsorbent regeneration.11,12 Adsorption is a surface phenomenon and the best way to improve or tailor it is by choosing a solid or composite matrix that offers the flexibility of chemical and physical functionalization. Another important aspect is the availability of porosity, at least in the mesorange to ensure that the adsorbateeadsorbent interactions are maximized and that size exclusion principles can be exploited. There is a great variety of porous adsorbents; these can be classified into two main categories: naturally occurring and engineered. The former is usually considered low-cost materials in comparison with the latter. However, many naturally occurring adsorbents frequently have restricted surface area and pore dimensions and, in most cases, exhibit limited adsorption capacity. Such drawbacks can be addressed methodically by designing adsorbents, either by the addition of engineering features such as functional groups (bottom up) or by the combination of different materials (e.g., composites) to enhance the adsorptive removal of CECs. There is a wide variety of functionalities that can be selectively or collectively incorporated onto the surface of an adsorbent. Functionalities such as acid/base moieties, hydrophobicity, metals, ion groups, and combinations therein are among the most commonly used. Some of the adsorbent inherent assets that need to be considered when these modifications are carried out are thermal-, chemical-, and hydrostability. Moreover, because the CECs are a vast group of chemical species that showcase substantial variation in physical-chemical properties (e.g., functional groups, solubility, pKa, molecular size, and partition coefficient),8 the successful design of the adsorbent will greatly depend on the heterogeneity of the sites of the surface, or set of surfaces in the case of composites, at ambient conditions. This chapter aims to offer a general perspective of efforts in the design and use of solid materials for the effective adsorptive removal of CECs from water. Emphasis will be given to engineered porous adsorbents, particularly those that belong to the following types: carbons, zeolites, metaleorganic frameworks (MOFs), mesoporous silica (MPS), and clays. Nonporous graphene oxides (GOs) will be discussed as well. Detailed analysis of their textural and chemical properties and ultimate adsorptive performance will be correlated to adsorption selectivity and capacity and to adsorption mechanisms.

Engineered adsorbents for the removal of contaminants of emerging concern from water

5

2. Porous and nonporous adsorbents Adsorbents are classified according to both the nature of their chemical structure and porosity. For instance, Fig. 1.1 presents a schematic comparison between pore structures and pore size distributions in noncrystalline, crystalline, pericrystalline, and clay materials.14 Noncrystalline materials lack an ordered inner structure (i.e., amorphous) and this family includes many carbon-based adsorbents (CBAs) that host a wide range of pore sizes (e.g., micro-, meso-, macroporosity); this family may also include nonporous materials such as GOs. On the other hand, crystalline adsorbents are those with an ordered inner structure and may possess not only pores

Figure 1.1 Pore size distributions according to families of adsorbent materials. Pore dimension ranges as defined by the International Union of Pure and Applied Chemistry.13

6

Contaminants of Emerging Concern in Water and Wastewater

but also a uniform pore size distribution. This family includes zeolites and MOFs. Zeolites are silico-aluminum materials showcasing cavities with sizes in the order of 2 nm, while MOFs are hybrid structures composed of metal nodes (or metal clusters) linked to each other by organic ligands. Pericrystalline materials have the peculiarity of an amorphous matrix but, at the same time, they contain ordered cavities. In this family, adsorbents are usually composed of silica, such as Mobil Crystalline Material (MCM) and Santa Barbara Amorphous (SBA) types. Finally, the clay family is composed of silicate materials formed by parallel layers with traces of metallic oxides and organic materials. Tunable galleries could be fashioned between the parallel layers to give a unique framework. Further sections will explain in detail the advantages and limitations of the families described above, as well as some of their variants. The potential of each one will also be addressed regarding their adsorption performance on the removal of CECs from aqueous phases.

2.1 Carbon-based adsorbents CBAs have been used in many studies for the adsorption of CECs from industrial and municipal wastewaters, landfill leachate, and contaminated groundwater.9 CBAs could be incorporated into water treatment processes as a single-stage approach to treat various CECs simultaneously or as a multistage approach to treat specific kinds of CECs.7,9 Properties such as surface area, ease of functionality, and pore size distribution are highly related to the three-dimensional matrix that the carbon structure adopts.8,15 Hence, CBAs are classified into three subfamilies depending on their structure: activated carbon (AC), GOs, and carbon nanotubes (CNTs). Fig. 1.2 shows examples of how CBA surfaces could in principle be modified. The following subsections will explain in detail each of the subfamily differences and performances as CEC adsorbents. 2.1.1 Activated carbon AC is among the most used adsorbents for CECs removal because of uptake capacity, large pore size distribution (micro-, meso-, macroporosity), and its ease of availability on the market.5,9,16e18 However, costs of production and regeneration, as well as its low selectivity toward some specific CECs, tends to limit its effective use in water remediation.9,16,18 AC production consists essentially of two core synthesis stages: pyrolysis of a precursor material, usually in a temperature range of 500d800⁰C, followed by a higher temperature activation or treatment

Engineered adsorbents for the removal of contaminants of emerging concern from water

7

Figure 1.2 Schematic representation of some of the possible modifications or functionalizations that can be made to carbon-based adsorbent surfaces.

(850d1000⁰C).9,19 AC could be made from biomass sources such as coal, lignite coal, coconut shells, wood, bamboo, nuts sawdust, cherry stones, rice husk, peach stones, coffee waste, potato, almond shells, peanut shell, among others.17,20 The raw material usually contains volatile organic matter that is released during the pyrolysis stage. At this stage, thermal treatment also causes reorganization of carbon atoms to yield more uniform pore structures.19 The secondary high temperature activation stage treatment usually involves physical or chemical processes. The former involves the use of a gas stream (e.g., O2, CO2, steam water), while the latter requires the use of an oxidative agent such as H3PO4, ZnCl2, H2SO4, H3BO3, KOH, or NaOH.19 This stage also boosts the generation of micro-, meso-, and macropores. CEC adsorption performance greatly depends on the raw material selection as the textural properties and surface chemistry of ACs vary significantly depending of the source.5,21 This was evident during tests made by Alvarez-Torrellas et al. for carbamazepine removal using AC made from peach stones (AC-PS) and rice husk (AC-RH), respectively.22 The differences in textural properties were highlighted as the key factor in the CEC uptake toward AC-PS, which is the AC with more micropores among the two variants. As pointed out by Alvarez-Torrellas et al., the adsorption driving force appeared to be based on a pore filling mechanism. In efforts to optimize the AC’s textural properties, and thus improve its adsorption capacity, different modification techniques have been carried out along with numerous chemical treatments. For instance, treatment with NH4-Cl tends to augment the parallel and extended channels within the

8

Contaminants of Emerging Concern in Water and Wastewater

AC inner structure.23 It was shown by Alahabadi et al. that the well-defined shape of the pore improved performance in the sequestration of chlortetracycline. This CEC contains multiple functional groups such as phenols, amino, chlorides, alcohols, and enones. Such functionalities could strongly interact with the carbon’s more uniform structure, leading toward complex interaction (i.e., pep and electron acceptor interaction), as stated by Alahabadi et al. In another study, Alvarez-Torrellas et al. found that physically activated ACs were better at the removal of 4-nitrophenol than the chemically treated ACs.20 Furthermore, the authors investigated the changes in the activation stage and also studied the physically activated variant after the incorporation of some functional groups onto its surface. The first variant, called PACS, was modified with H2SO2(s), and another variant named PAC-NUT was treated with HNO3 and urea. For the removal of the aforementioned CEC, Alvarez-Torrellas et al. observed a remarkable uptake capacity in PAC-NUT at low CEC concentrations in comparison to PACS. The results suggest that the treatment of HNO3 and urea creates a more basic AC surface, which tends to favor the adsorption via pep interaction and covalent bonding between the nitrogen and oxygen contained in the 4-nitrophenol. Performance of AC could also be affected by hydrophobicity changes.24,25 This was demonstrated in tests during the removal of caffeine using AC with different amounts of oxygenated groups.24 Two different approaches were considered to change the hydrophobicity of the material. The first one was based on liquid phase oxidation treatments (i.e., O-PC variant) to increase oxygen groups. The second method was to thermally treat the sample in an inert atmosphere (i.e., helium) to accomplish the opposite effect (reduction of oxygen groups) (He-PC variant). He-PC outperformed O-PC in caffeine uptake. The authors suggested that the oxygen on the O-PC’s surface decreases the hydrophobicity of the carbon, leading water molecules to interact competitively with the surface of the carbon. The oxygen groups tend to adsorb water, forming strong bonds, and this consequently leads to the formation of clusters that block pore entrance and therefore decrease caffeine adsorption. Hence, a competition between water and caffeine toward active adsorption sites should be present in the oxygenated variant. In another study, Shan et al. investigated the incorporation of magnetic properties through an AC/Fe3O4 hybrid material as an innovative and practical approach to improve adsorption.26 Several benefits can be

Engineered adsorbents for the removal of contaminants of emerging concern from water

9

acquired with such modification, particularly in operational terms (e.g., easier adsorbent separation from aqueous phase). There was a remarkable performance in carbamazepine uptake by the hybrid material in comparison to the other variants tested. According to Shan et al., the CEC appears to interact with Fe3O4 in a complex fashion, where pep interaction and hydrophobicity are also taking place as the driving forces. As evidenced by these reports and numerous others (see Table 1.1), AC has been methodically researched along the past years for water remediation. As stated above, ACs adsorption performance varies drastically depending on the biomass source and activation stage (i.e., chemical or physical treatment). Usually, macro- and mesoporous AC are employed for the adsorption of bulky molecules, while microporous AC seems to be more efficient for small molecules. Due to the presence of these vast types of pores (meso- and macropores), in some instances, molecules tend to reorganize inside the AC, increasing the probability of finding additional adsorption sites. Finally, the employed functionalization could affect the uptake capacity and the material’s performance toward the removal of CECs. 2.1.2 Graphene oxide The International Union of Pure and Applied Chemistry (IUPAC) defines graphene as a single carbon layer of graphite structure.35 As adsorption takes place on the top and bottom of the carbon sheet, the available surface area might be limited for some applications. However, graphene contains oxygenated groups such as hydroxyl, carboxyl, carbonyl, and epoxy, which enhance the stability of the material in water matrices.36 Furthermore, characteristic such as long-range p-conjugation on graphene provides high electric and thermal conductivity as well as a remarkable mechanical strength, which makes it attractive for different applications.37 The oxygenated groups in GO can certainly be considered an effective functionalization, but in some scenarios, it might also introduce limitations to graphene as an adsorbent. For instance, Wang and coworkers investigated the effect of the oxide grade on the adsorption of sulfamethoxazole using GO and reduced GO.38 GO is the most common adsorbent in the graphene family. It consists of a graphene monolayer with a large content of oxygenate groups. Reduced GO will be the treated version with a decrease in content of the aforementioned groups.37 A remarkable increase in the uptake capacity of the CEC was observed for the reduced GO variant, which was attributed to the pep interaction between the CEC and the adsorbent surface. Similar to the case of the ACs, the oxygens on GO seems

CECs [Coa (mg L
1)]

Qa (mg g
1) or [% Removal]

Peach stones AC [1216]

Caffeine, carbamazepine, diclofenac [100]

195e335 [30e52]

AC modified with high oxygenated groups [959] AC modified with low oxygenated groups [1064] Babassu coco AC [980] Dende coco AC [755] Coconut shell AC [1045] Babassu coco AC modified in inert atmosphere [1082] Dende coco AC modified in inert atmosphere [884] Coconut shell AC modified in inert atmosphere [1125] Pine wood AC activated with K2CO3 1:1 (w/w) [945] Pine wood AC activated with K2CO3 1:3 (w/w) [1509] NH4Cl-modified AC [1029] Chemically AC [1521] Physically AC with air [412]

Caffeine, carbamazepine, diclofenac [100]

126e179 [28e40]

Caffeine, carbamazepine, diclofenac [100]

200e267[30e54]

Caffeine Caffeine Caffeine Caffeine

205 164 250 235

Comments

Ref.

24

[27] [21] [38] [44]

Natural pH Natural pH Natural pH pH ¼ 3 pH ¼ 3 pH ¼ 3 pH ¼ 3

Caffeine [100]

165 [30]

pH ¼ 3

27

Caffeine [100]

306 [51]

pH ¼ 3

27

Acetaminophen, caffeine [120e480]

273e486 [1e25]

pH ¼ 5

28

Acetaminophen, caffeine [120e480]

422e459 [10e22]

pH ¼ 5

28

Chlortetracycline [20e200] 4-Nitrophenol [100] 4-Nitrophenol [100]

477 [49] 199 [50] 189 [67]

pH ¼ 6

23 20 20

[100] [100] [100] [100]

24 24 27 27 27 27

Contaminants of Emerging Concern in Water and Wastewater

Adsorbent [surface area (m2g
1)]

10

Table 1.1 Adsorption capacities of activated carbons (ACs) for single component contaminants of emerging concern (CECs) removal from aqueous solutions.

Rice husk AC [278] AC cloth [1911] AC [252] Powder AC [980] AC (activated with NaOH 5% w/w) AC (activated with KOH 5% w/w) AC (activated with ZnCl2 (2M)) AC (activated with HNO3 (5M)) AC (activated with NaCl (3M))

4-Nitrophenol [100]

202 [65]

20

4-Nitrophenol [100]

199 [64]

20

4-Nitrophenol [100]

123[20.2]

20

4-Nitrophenol [100]

236 [51]

20

Carbamazepine, ciprofloxacin hydrochloride [100] Carbamazepine, ciprofloxacin hydrochloride [100] Ibuprofen [10e103] Phenol Ciprofloxacin Amoxicillin, cephalexin, tetracycline, penicillin G [20e200] Amoxicillin, cephalexin, tetracycline, penicillin G [20e200] Amoxicillin, cephalexin, tetracycline, penicillin G [20e200] Amoxicillin, cephalexin, tetracycline, penicillin G [20e200] Amoxicillin, cephalexin, tetracycline, penicillin G [20e200]

242e264 [51e62]

pH ¼ 6.5

22

113e170 [34e41]

pH ¼ 6.5

22

479 [48.0] 22.12 5.13 [56e88]

pH ¼ 7.5 pH ¼ 6.5 pH ¼ 7 pH ¼ 2

29 30 31 32

[51e82]

pH ¼ 2

32

[56e75]

pH ¼ 2

32

[50e71]

pH ¼ 2

32

[52e73]

pH ¼ 2

32

Engineered adsorbents for the removal of contaminants of emerging concern from water

Physically AC with N2 flow saturated with H2O [403] Physically AC with N2 flow saturated with H3PO4 [428] Physically AC modified with H2SO4 [401] Physically AC modified with HNO3 and urea [679] Peach stones AC [1521]

Continued

11

[Coa


1

Qa (mg g
1) or [% Removal]

Comments

Ref.

Adsorbent [surface area (m g )]

CECs

Powder AC [1303]

24e51

pH ¼ 6

33

Mesoporous AC [214]

Lincomycin, sulfamethoxazole, iopromide [12,000] Carbamazepine, dorzolamide [5e75]

59e189 [8e28]

34

AC modified with Fe3O4 [486]

Carbamazepine, tetracycline [5e60]

46e128 [13e41]

pH ¼ 6 e8 pH ¼ 6

Co, initial concentration; Q, adsorption capacity. a Data estimated from isotherms plots.

(mg L )]

26

Contaminants of Emerging Concern in Water and Wastewater

2
1

12

Table 1.1 Adsorption capacities of activated carbons (ACs) for single component contaminants of emerging concern (CECs) removal from aqueous solutions.dcont'd

Engineered adsorbents for the removal of contaminants of emerging concern from water

13

to restrict this type of interaction (i.e., pep) as well, limiting the hydrophobic character of the surface, leading to a rather poor adsorbent performance. Wu et al. investigated an innovative way to effectively functionalize GO via the incorporation of rhamnolipid, a biosurfactant, for the removal of methylene blue.39 Although they confirmed that pep interaction and H-bonding between the rhamnolipids and that the CEC contributes to the adsorption process, they pointed out that electrostatic interaction was the principal adsorption mechanism. It has been demonstrated that GO generally attracts cationic and neutral CECs. Therefore, research has been performed to discover a method to enhance the adsorption toward anionic molecules, too. Cai and Larese-Casanova considered the incorporation of ethylenediamine onto GO as a positive charge functionality.40 They demonstrated that the presence of this positively charged molecule, when attached to the GO surface, enhances the adsorption toward anionic ibuprofen and cationic atenolol and neutral carbamazepine. The authors also suggested that electrostatic and pep interaction, H-bonding, and hydrophobicity play a vital role in the adsorption mechanisms. With this type of functionalization, a material with diverse adsorption sites was designed, with the capability of interacting with cationic, neutral, and anionic species. In another GO functionalization effort for CEC removal, Yamaguchi et al. evaluated a magnetic GO hybrid (i.e., MnFe2O4-GO) as a potential platform that could provide additional adsorption mechanisms that have not been included yet.41 The performance on the removal of glyphosate using the MnFe2O4-GO was extraordinary in comparison with GO and MnFe2O4 alone. The authors explained that the driving force was electrostatic interaction with a certain level of ion exchange capability. In general, GO adsorbents have considerable affinity toward cationic and neutral CECs because of the oxygenated groups present on its surface. Oxygenated groups could be deprotonated, providing a charge on the surface that could interact with CECs via electrostatic forces, H-bonding, etc. These aforementioned groups could also bring limitations in the material’s performance, which could be addressed by the incorporation of other attractive molecules. See Table 1.2 for further data on the use of GOs for the adsorption of CECs. 2.1.3 Carbon nanotubes CNTs consist of graphite cylindrical layers that exhibit high polarizability due to benzenoid rings.5,16,44 Oxidation, chemical grafting, and physical

14

Contaminants of Emerging Concern in Water and Wastewater

Table 1.2 Adsorption capacity of graphene oxide (GO) for single component contaminants of emerging concern (CECs) removal from aqueous solutions. Qa (mg g a
1 ) or [% CECs [Co Adsorbent [surface area Removal] Comments Ref. (mg L
1)] (m2 g
1)]

GO Reduced GO functionalized with MnFe2O4 microspheres [306] Reduced GO [530] GO [329] Graphene nanoplatelets pastes [10] GO functionalized with rhamnolipid [42] GO functionalized with ethylenediamine [14]

Graphene (commercially available) [132]

Powdered graphite [7]

Reduced GO from graphite powder [331]

Reduced GO from graphite flakes [325] Double oxidized GO [51]

Glyphosate [5 e80] Glyphosate [5 e80]

[33]

41

[97]

41

Sulfamethoxazole Sulfamethoxazole Sulfamethoxazole

13 3 3

38,b 38,b 38,b

Methylene blue [50e400] Ibuprofen, atenolol, carbamazepine [5 e200] Ketoprofen, carbamazepine, bisphenol A [2.5 e300] Ketoprofen, carbamazepine, bisphenol A [2.5 e300] Ketoprofen, carbamazepine, bisphenol A [2.5 e300] Ketoprofen, carbamazepine, bisphenol A [2.5 e300] Acetaminophen

493 [49]

pH ¼ 7

39

18e27 [20e28]

pH ¼ 7.2

40

16e26 [15e19]

pH ¼ 6.5

42

3e6 [16 e23]

pH ¼ 6.5

42

62e150 [16e26]

pH ¼ 6.5

42

54e125 [14e22]

pH ¼ 6.5

42

690 [14]

pH ¼ 8

43

Co, initial concentration; Q, adsorption capacity. a Data estimated from isotherms plots. b Data estimated from log plot.

Engineered adsorbents for the removal of contaminants of emerging concern from water

15

modification (e.g., impregnation or coating) are some of the pathways employed to modify these nanotubes.36 CNTs are classified into two categories: single-wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs). The former are composed of a single graphene layer (see Fig. 1.2), while the latter is composed of multiple, concentric nanotubes of the same layer with a high van der Waals index between them.5 CNTs have four available adsorption sites: internal, interstitial channel, grooves, and external.37 The effective surface that is available for CEC uptake in these adsorbents will depend on the nanotube arrangement (or category).5 Due to the aggregation of nanotubes in MWCNTs, the access of CECs to the voids might be inhibited and adsorption could be highly affected by the existence of steric effects.17,45 This behavior was evidenced in studies performed by Kim et al. for the removal of both antibiotics and contrast medium using both SWCNTs and MWCNTs.33 In this study, SWCNTs outperformed the uptake of the selected CECs. As suggested, a key factor governing this process was the availability of accessible, effective surface area. In an attempt to alter the surface chemistry of CNTs in favor of stronger interactions, Wei et al. incorporated oxygen-containing functional groups for the removal of antibiotics.46 A decrease in uptake capacity was observed with an increase of the oxygenated groups, a phenomenon that was also observed in AC and some GO subfamilies. The pep interactions between the CNT surface and the sulfonamide CECs were weakened as the result of the addition of these functional groups. In a separate work, Li et al. investigated ways to enhance the adsorption of triclosan by CNTs functionalized with hydroxyl and carboxyl groups.47 The dispersion of the CNTs was restricted by their hydrophobic character, and thus, the researchers decided to employ sonication to avoid aggregation of CNTs. This accelerated the adsorption of triclosan and increased the adsorption capacities of CNTs with and without functionalizations at neutral pH. In general, CNTs offer a platform where interaction like pep, Hbonding, and hydrophobicity are the key mechanisms in the process. Depending on the modification or functionalization, various adsorption mechanisms could be incorporated onto the surface, making it selective toward particular CECs. As shown in Table 1.3, the adsorption performance for CNTs could significantly change depending on the type. Furthermore, factors such as surface accessibility and the combination of technologies (e.g., sonication) seem to be noteworthy pathways to enhance the efficiency of this allotrope carbon.

Comments

Ref.

41e78 [21]

pH ¼ 6.5

22

pH w 7 pH w 7c pH w 7 pH w 7c pH w 7 pH w 7c

47

Adsorbent [surface area (m2g
1)]

CECs [Coa (mg L
1)]

Multi-wall carbon nanotube (MWCNT) (commercially available) [207] MWCNT

Carbamazepine, ciprofloxacin hydrochloride [100] Triclosan [1e13]

MWCNT functionalized with eOH group MWCNT functionalized with eCOOH group MWCNT (outer diameter 10e30 nm)

Triclosan [1e13]

MWCNT (outer diameter <10 nm) [140] MWCNT (outer diameter 8e15 nm) [140] MWCNT functionalized with eOH group [140] MWCNT functionalized with eCOOH group [140] MWCNT doped with N [53] Pristine capped CNT (outer diameter 8e15 nm) [147] Oxidized pristine capped CNT [151]

Sulfamethoxazole

117 [33] 133 [51] 101 [30] 117 [46] 82 [27] 103 [38] 122e183 [4e11] 11

Sulfamethoxazole

3

38,b

Sulfamethoxazole

11

38,b

Sulfamethoxazole

10.4

38,b

Sulfamethoxazole Sulfadimethoxine, sulfamethizole, sulfamethazine, sulfamethoxazole [0.05e1.20] Sulfadimethoxine, sulfamethizole, sulfamethazine, sulfamethoxazole [0.05e1.20] Lincomycin, sulfamethoxazole, iopromide [12,000]

4 5e12 [97e100] 4e11 [96e99] 146e198

pH ¼ 5

38,b 46

pH ¼ 5

46

pH ¼ 6

33

Single-wall carbon nanotube (SWCNT) (outer diameter 1.5 nm) [1020]

Triclosan [1e13] Ibuprofen, tetracycline [100]

47 47

38,b

Contaminants of Emerging Concern in Water and Wastewater

Qa (mg g
1) or [% Removal]

16

Table 1.3 Adsorption capacities of carbon nanotubes (CNTs) for single component contaminants of emerging concern (CECs) removal from aqueous solutions.

MWCNT [233] MWCNT (outer diameter 8e15 nm) [117] CNT (outer diameter 8e15 nm) [76] SWCNT (outer diameter 1e2 nm) [541] Carboxylic CNT functionalized with CoFe2O4 [132] Amino CNT functionalized with CoFe2O4 [134] Co, initial concentration; Q, adsorption capacity. a Data estimated from isotherms plots. b Data estimated from log plot.

Lincomycin, sulfamethoxazole, iopromide [12,000] Carbamazepine, dorzolamide [5e75] Ketoprofen, carbamazepine, bisphenol A [3e300] Diclofenac sodium, carbamazepine [4e5] Ketoprofen, carbamazepine, bisphenol A [2.5e300] Sulfamethoxazole, 17-b-estradiol [0.4e2.4] Sulfamethoxazole, 17-b-estradiol [0.4e2.4]

134e172

pH ¼ 6

33

71e213 [13e32] 24e60 [13e21] [63e71] 90e207 [12e20] 8e22 [34e91] 10e23 [39e96]

pH ¼ 8

34

pH ¼ 6.5

42

pH ¼ 6 pH ¼ 6.5

48 42

pH ¼ 5.7

49

pH ¼ 5.7

49

Engineered adsorbents for the removal of contaminants of emerging concern from water

MWCNT (outer diameter 15 nm) [235]

17

18

Contaminants of Emerging Concern in Water and Wastewater

2.2 Zeolites Zeolites have been considered for a wide variety of applications because of the material’s ease for functionalization and wider range of functionalization alternatives. Applications include catalysis, drug delivery, gas storage via adsorption, environmental remediation, lubricants, desiccants, and emulsification.50e53 By proper definition, zeolites are microporous aluminosilicates of a tectosilicate type that contain unique, highly ordered, and uniform pore structures.11,51,54e56 Depending on the aluminum content, zeolitic adsorbents might exhibit a highly hydrophilic character. This has been seen evidently as a limitation in the use of zeolites for technologies that require water treatment.57 Diminishing the aluminum content is sometimes not desired as this could significantly reduce the capability for effective functionalization of the zeolite; furthermore, dealumination techniques could significantly impact the material’s textural properties and hence result in lower adsorption capacity on a per mass or volume normalized basis. The particular atom coordination of a zeolitic material allows for the development of pores in the form of homogeneous cages and channels that lead to the arrangement of numerous structures and topologies as well as distinctive adsorption sites. The crystalline lattice offers exceptional thermal stability and excellent resistance to chemical, biological, and mechanical stresses. Fig. 1.3 shows examples of some modifications that have been carried on zeolitic surface. It should be noted that most of these modifications take place inside the pore structure of the zeolitic material (i.e., inside the cages and channels). The adsorption of CECs by zeolites is highly affected by the Si/Al ratio. This was demonstrated by Wu et al. in their studies for the removal of various nitrosamines precursors.58 The incorporation of the trivalent

Figure 1.3 Schematics of modifications or functionalizations that could be made to zeolite surfaces for the effective adsorption of contaminants of emerging concern (CECs).

Engineered adsorbents for the removal of contaminants of emerging concern from water

19

aluminum cation (Al3þ) into the framework generates a negatively charged structure deficiency which is balanced by presence of extraframework cation, including but not limited to Naþ, Liþ, Kþ, Ca2þ, Mg2þ, and NH4þ.11,51,55 Although some of these species undergo high coordination with water molecules (i.e., hydrophilicity), these could also provide additional specific surface potential electrostatic fields for the interaction for CECs. The aforementioned framework charge deficiency can be also exploited to introduce hydrophobicity onto the zeolite effective surface via addition of cationic surfactants. Goyal and coworkers applied this concept for modification of zeolite b and the removal of two phytoestrogens from water; they added hexadecyltrimethylammonium cations onto the zeolite.59 In another work, it was shown that the incorporation of the tetrasubstituted ammonium cation enhanced the hormones removal due to both hydrophobic and ionic interactions. Using as similar approach, Sun et al. modified zeolite surface with a monolayer, a patch bilayer, or a complete bilayer of surfactant for the removal of diclofenac.60 An increase in the CEC uptake was observed with an increase in surfactant loading. As the zeolite surface is being covered with the surfactant, the negative charge of the CEC interacts with the positively modified zeolite via the anion exchange mechanism, which seems to dominate this process. Despite the improvements in CEC uptake capacity brought by the incorporation of cationic surfactants, there is still room to further enhance the adsorbateeadsorbent interactions. For instance, Cabrera-Lafaurie et al. modified zeolite Y not only with a cationic surfactant but also added extraframework transition metals; the resulting still porous zeolitic material was tested for the removal of salicylic acid and carbamazepine.61 The material exhibited superior capacity for the uptake of salicylic acid, not only because of enhanced electrostatic interaction and hydrophobicity but also because of complexation between the transition metal and the CEC. Table 1.4 collects data for the adsorption capacity of zeolites for various CECs. It should be apparent from the data that the capacities are smaller in comparison to those exhibited by other adsorbent families; given the discussion shown above on the potential zeolitic surface for modification and tailoring, it is clear that more research is needed to exploit this as a mean to develop better CEC adsorption platforms.

Adsorbent [surface area (m g
1 )]

CECs [Coa (mg L
1)]

Zeolite Na-A HMOR zeolite Natural zeolite Surfactant-coated zeolite Zeolite Y [792]

Methylene blue [120] Mesosulfuron-methyl [8] Phenol [90] Orange II [250] Carbamazepine [1e22]

Zeolite Y functionalized with Co2þ [763] Zeolite Y functionalized with Ni2þ [718] Zeolite Y functionalized with Cu2þ [768] Zeolite Y surfactant modified [526] Zeolite Y surfactant modified functionalized with Co2þ [530] Zeolite Y surfactant modified functionalized with Ni2þ [232] Zeolite Y surfactant modified functionalized with Cu2þ [217] Zeolite Y [450]

Qa (mg g
1) or [% Removal]

Comments

Ref.

pH ¼ 6

62 62 62 62 61

Carbamazepine [1e22]

51 3 33 59 0.06 [0.3 e1.3] 0.13 [1.32]

pH ¼ 6

61

Carbamazepine [1e22]

0.08 [0.36]

pH ¼ 6

61

Carbamazepine [1e22]

0.1 [1]

pH ¼ 6

61

Carbamazepine, salicylic acid [1e22]

0.09e1.79 [4e27] 0.11e1.88 [5e29]

pH ¼ 6

61

pH ¼ 6

61

Carbamazepine, salicylic acid [1e22]

Carbamazepine, salicylic acid [1e22] Carbamazepine, salicylic acid [1e22]

Dimethylamine, trimethylamine, 3(dimethylaminomethyl)indole

0.08e1.1 [4e18] 0.07e2.29 [4e67]

pH ¼ 6

61

pH ¼ 6

61

[3e12]

pH ¼ 7

58

Contaminants of Emerging Concern in Water and Wastewater

2

20

Table 1.4 Adsorption capacities of zeolites for the single component contaminants of emerging concern (CECs) removal from aqueous solutions.

[8e27]

pH ¼ 7

58

[83e98]

pH ¼ 7

58

Dimethylamine, ethylmethylamine, trimethylamine, ddipropylamine, 4-dimethylaminoantipyrine Dimethylamine, ethylmethylamine, trimethylamine, diethylamine, dipropylamine, 3-(dimethylaminomethyl) indole Diclofenac [0e1184.6]

21 [15]

60

Diclofenac [0e1184.6]

35 [17]

60

Diclofenac [0e1184.6]

39 [17]

60

Tris(2-chloroethyl)phosphate [10] Daidzein, coumestrol [1e20]

110 41 [98e99] 52 126e157

Natural zeolite [37]

Methyl tertiary-butyl ether Meta-nitrophenol, ortho-nitrophenol, para-nitrophenol [10e500] Tetracycline, oxytetracycline

Zeolite 13X [896]

Phenol

5.1

Modernite [425]

Zeolite modified with monolayer of surfactant Zeolite modified with patch bilayer of surfactant Zeolite modified with bilayer of surfactant Zeolite b Zeolite b surfactant modified [300] Zeolite ferrierite [400] Nanozeolite [698]

Co, initial concentration; Q, adsorption capacity. a Data estimated from isotherms plots.

63e76

pH ¼ 4.8

63 59 64 65

pH ¼ 7e8 pH ¼ 6.5

66 30

Engineered adsorbents for the removal of contaminants of emerging concern from water

Bear river zeolite [375]

21

22

Contaminants of Emerging Concern in Water and Wastewater

2.3 Metaleorganic frameworks MOFs are materials whose structures are composed of metal nodes or clusters (usually transition metals) connected to organic linkers via coordination bonds.67e70 Many MOFs are highly crystalline structures with remarkable surface area (near the 10,000 m2 g
1 mark) and porosity,71 far superior when compared with first- and second-generation porous materials. The coordination nature of the bonds present in MOFs offers flexibility to produce a vast amount of structural topologies, with multidimensional and interpenetrated porosity.67,68,70,72 In addition to these characteristics, in principle, MOFs can be tuned chemically and from the bottom up to address specific applications. These features have made MOFs candidates for a wide range of uses including adsorption/storage, catalysis, sensors, among others.67,68,72e75 Despite all of the features of these materials, unfortunately, most of the first wave of MOF materials are susceptible to hydrolysis.72,76 Over the past decade, considerable research has been conducted to improve MOFs’ water stability and without compromising their structure and/or textural properties (i.e., porosity).72,74,77 Some approaches are based on increasing the hydrophobic character of their external or internal surface areas (i.e., pores). For example, some strategies are surface modifications, coreeshell structure, ligand modifications, carbon coating, and chemical vapor deposition (see Fig. 1.4). These modifications have recently resulted in a significant increase in the use of MOFs for water remediationerelated research.78e84 The revised compositions have not only resulted in improved structural hydrostability but also in an enhancement of the adsorptive driving forces, the latter due to the combination of specific interactions with the pep stacking interactions (i.e., due to significant amounts of framework concentrations on a per unit cell basis). Another approach for enhancing an MOF adsorption

Figure 1.4 Schematics of modifications or functionalizations to tailor a metaleorganic framework (MOF) surface for the effective adsorption of CECs.

Engineered adsorbents for the removal of contaminants of emerging concern from water

23

capacity is the incorporation of acidic and basic groups on the open metal sites (OMSs). Jhung and coworkers followed this to incorporate aminomethanesulfonic acid and ethylenediamine on coordinatively unsaturated sites of MIL-101(Cr) as sources of acid (SO3H) and basic (NH2) groups, respectively, and to produce adsorbents to remove naproxen and clofibric acid from water.85 These studies found a significant increase in the adsorption capacity of naproxen, and clofibric acid was observed in MOF modified with basic groups; the improvement was ascribed to the acide base and hydrogen bond interactions between the acidic CECs and the basic surface of the modified MOF. In another work, Jhung’s group modified a MIL-101(Cr) surface through the grafting of urea and melamine on the OMSs.86 It was shown that the incorporation of these NH2 groups favored the adsorption of various artificial sweeteners and nitroimidazole antibiotics. This was mainly explained by H-bonding between NH2 groups on the grafted MOFs and O
(SO2 or NO2) of the CECs. Likewise, MIL101(Cr) was modified with NO groups by oxidation of its surface with sulfuric and nitric acid. In contrast, with the NH2 groups, the NO2 groups on the grafted MOFs cannot form hydrogen bonds with these CECs, and as a result, the adsorption was adversely affected. As hydrogen bond interactions are considered an important mechanism in the adsorption of CECs, Jhung and coworkers also studied the adsorption of various CECs (with different properties such as size, polarity, and hydrophobicity) over MOFs containing different loadings of hydroxyl groups (OH and (OH)3).83 It was quantitatively determined that the capacity of adsorbed CECs increased as the number of H-acceptors in the CECs and H-donors (OH groups) in the MOF surface increased. Another commonly used modification of MOFs is an organic ligand exchange. Chen et al. used this approach to modulate the electrostatic interactions and the adsorption capacity and selectivity on UiO-66 for various dyes.87 In this particular case, the organic ligand 1,4-benzene dicarboxylic acid (H2-BDC) was changed to NH2-substituted derivative (NH2-BDC). This affected the electrostatic charges of the MOF and its textural properties (i.e., a decrease in the internal surface area and pore size, in addition to an increase in the external surface area). These changes favored the adsorption capacity and the selectivity toward the cationic dyes over the anionic dyes. The behavior was mainly credited to the increase of the external surface area and electrostatic attractions because the surface in these modified MOFs has a more negative surface charge. Using a similar approach, Jhung and coworkers exchanged the H2-BDC ligand on UiO-66

24

Contaminants of Emerging Concern in Water and Wastewater

for NH2-BDC and NaSO3H-BDC (for this modification, only 18% of the pristine ligands were exchanged to avoid collapsing of the MOF structure).88 In these studies, it was shown that an MOF exchanged with 18% of SO3H-BDC resulted in a better diclofenac adsorption capacity than the one exchanged with NH2-BDC. These results suggest that acidebase attractions between the acid groups (SO3H) of SO3H-UiO-66 and the basic groups (NH) of diclofenac favored the adsorption driving force. In contrast to the SO3H groups, the NH2 groups of NH2-UiO-66 resulted in base repulsions between NH group of diclofenac and the MOF surface. In general, the above MOF modification strategies have demonstrated that the adsorption capacity toward CECs could be improved by addition of acidebase, hydrogen bonds, and electrostatic interactions. However, in terms of removal capacity percentage, these materials remain somewhat below average compared with other adsorbent families which contain much lower surface areas and porosities than these MOFs (see Table 1.5).

2.4 Mesoporous silica The MPS family is based on inorganic, nontoxic, and highly abundant materials, known by their considerable surface area and ordered pore system.17,99,100 These pericrystalline materials showcase attractive structural topologies and formidable mechanical strength because of the unique arrangements and assemblies that the atoms can adopt (e.g., from a cubic to a hexagonal configuration).99 Furthermore, this family exhibits excellent physical and chemical properties along with good thermal stability.11 Usually, the main approaches employed to modify MPS surfaces and improve their adsorption performances have been grafting and cocondensation methods.100 The silanol (Si-OH) groups present on the MPS surface are responsible for the hydrophilic nature of this family, which can be seen as a limitation for water remediation. Simultaneously, those groups are keys to the aggregation of functional groups or the eventual immobilization of different CECs onto the structure.101 For instance, Hongsawat et al. functionalized a paramagnetic hexagonal MPS with a diversity of functional groups that included amino, nitrile, mercapto, phenyl, and octyl groups and tested the materials for the removal of ciprofloxacin.31 Despite the unique interaction that each functionality can bring into an adsorption mechanism, the authors suggested electrostatic interaction is, for most of the variants, the principal driving force. Nevertheless, the phenyl incorporation appeared to bolster

2
1

[Coa


1

Adsorbent [surface area (m g )]

CECs

MIL-100(Fe) [2776] MIL-101 (Cr) [3014]

Methylene blue [600] Naproxen, clofibric acid [13e150]

MIL-101 (Cr) [3392]

Naproxen, p-chloro-m-xylenol, bisphenol A, ketoprofen, triclosan [50] Saccharin [10] Naproxen, p-chloro-m-xylenol, bisphenol A, ketoprofen, triclosan [50] Naproxen, clofibric acid [13e150]

MIL-101 (Cr) [3030] MIL-101 (Cr) grafted with ethanolamine [3392] MIL-101 functionalized with aminomethanesulfonic [2322] ED-MIL-101 functionalized with ethylenediamine [2555] MIL-101 (Cr) grafted with triethanolamine [1838] MIL-101 grafted with urea [1970] MIL-101 grafted with urea [1970] MIL-101 grafted with melamine [1350] MIL-101 nitrated [1620] UiO-66 [838] UiO-66 [1082] UiO-66 [1125]

(mg L )]

Qa (mg g
1) or [% Removal]

1090 [68] 126e239 [16e64] 48e89 [19e35]

Comments

Ref.

T ¼ 35C

62 85 83

49 [21] 58e107 [23 e43] 78e146 [5e70]

86 83

Naproxen, clofibric acid [13e150]

63e265 [6e18]

85

Naproxen, p-chloro-m-xylenol, bisphenol A, ketoprofen, triclosan [50] Dimetridazole [10] Saccharin [10] Saccharin [10] Saccharin [10] Methylene blue, methyl orange [20] Diclofenac [30] Methylene blue [100]

79e156 [32 e63] 164 [48] 76 [38] 62 [29] 16 [10] 38e91 [37e91] 136 [45] 100 [25]

83

85

pH ¼ 6.30

pH ¼ 5.4 pH ¼ 7.5

89 86 86 86 87 88 90

Engineered adsorbents for the removal of contaminants of emerging concern from water

Table 1.5 Adsorption capacities of metaleorganic framework materials for single component contaminants of emerging concern (CECs) removal from aqueous solutions.

Continued

25

26

Table 1.5 Adsorption capacities of metaleorganic framework materials for single component contaminants of emerging concern (CECs) removal from aqueous solutions.dcont'd [Coa


1

Adsorbent [surface area (m g )]

CECs

UiO-66 changing ligand to aminocontaining terephthalic acid [617] UiO-66 functionalized with NH2 [902] UiO-66 functionalized with SO3 [910] ZIF-8 [1073] MIL-68(Al) [1417] MIL-53 [1438] MIL-53 functionalized with NH2 MOF-5 [92] HKUST-1[1726] HKUST-1[279] HKUST-1 embedded with polymercoated Fe3O4 microspheres [939] Cu3(BTC)2(H2O)3 CAU-1[1281]

Methylene blue, methyl orange [20]

29e98 [29e98]

Diclofenac [30] Diclofenac [30] Ibuprofen, diclofenac [20e100] Nitrobenzene 2,4-Dichlorophenoxyacetic acid [150] p-Nitrophenol [800] Methylene blue [30] Methylene blue [100] Methylene blue [3.2] Methylene blue [18]

83 [28] 209 [70] 18e75 [9e17] 1132 516 [34] 298 [7] 28 [1] 420 [34] 4 [23] 3

Methylene blue [3.7] Nitrobenzene [1000]

37 985 [19]

Co, initial concentration; Q, adsorption capacity. a Data estimated from isotherms plots.

(mg L )]

Qa (mg g
1) or [% Removal]

Comments

Ref.

87 pH ¼ 5.4 pH ¼ 5.4 pH ¼ 6.3 pH ¼ 3.5 pH ¼ 2 pH ¼ 7.5

pH ¼ 6.3

88 88 91 92 93 94 95 90 96 97 98 92

Contaminants of Emerging Concern in Water and Wastewater

2
1

Engineered adsorbents for the removal of contaminants of emerging concern from water

27

the interactions (e.g., via pep electron donor/acceptor), which turned out to favor the CECs removal. When using the silanol groups as the active site to graft both amines and metal (Fig. 1.5), however, the strategy significantly improves not only the hydrophobicity of MPS materials but also adsorption capacity via introduction of sites that promote specific interactions with CECs that include both electrostatic and complexation contributions. Ortíz-Martinez et al. evaluated the immobilization of various transition metals (e.g., Co, Ni, Cu) onto an amino-grafted SBA-15.102,103 This material strategy was employed to test for the removal of CECs such as naproxen, clofibric acid, caffeine, carbamazepine, as well as CEC metabolites salicylic acid, Odesmethylnaproxen, paraxanthine, and carbamazepine-10,11-epoxide. A significant affinity toward the smaller, acidic, and hydrophobic CECs was found for the variant that included copper as the active site. The observations were ascribed to a combination of various interactions, which are electrostatic, H-bond, and hydrophilicehydrophobic interactions along with the complex interaction by the transition metal and steric effect. Ortíz-Marínez et al. also found that the amino-grafted SBA-15 decorated with copper also showed remarkable selectivity for CEC metabolites over the parent compounds. A similar approach was followed by Zhang et al., who investigated the adsorption of tetracycline onto an amino-SBA-15 functionalized with iron.104 Outer- and inner-sphere surface complex interaction appeared to be the dominant mechanism because of the presence of the transition metal. Meanwhile, Teo et al. studied the adsorption of acetylsalicylic acid into an iron oxide-MPS MCM-41.105 They added different amounts of iron oxide

Figure 1.5 Scheme of modification or functionalization to mesoporous silica surfaces based on amine/metal grafting.

28

Contaminants of Emerging Concern in Water and Wastewater

to the surface to determine an optimal loading and found that this functional group could interact via strong electrostatic interaction with the CEC. In general, the silanol groups inherent to the surface of MPS materials, although responsible for its hydrophilicity, also bring a platform to introduce adsorption interactions (e.g., H-bond or ion exchange) that can result in the effective removal of various CECs, including metabolites. When combined to the large pore dimensions of many MPS materials, the organic and/or transition metal functionalized adsorbents might also provide an alternative to remove CECs that showcase large molecular dimensions. Table 1.6 summarizes adsorption capacities reported in the literature for various MPS materials.

2.5 Clays Clays are low-cost materials like carbons but are hydrophilic in nature. These materials are used in different industrial and engineering processes such as pharmacy, cosmetic, environmental remediation, adsorbent, catalyst, and ion exchange.18,110e115 Clays are a class of phyllosilicates composed of a mixture of carbonates, silicates, metal oxides, and metal ions. Because of the isomorphic substitution of metals (e.g., Siþ4 by Alþ3 or Alþ3 by Mgþ2 in tetrahedral and octahedral sites, respectively), their layers have charge deficiency.113,116 This allows for the intercalation metal cations or other positively charge moieties within the interlayer to balance charges, and through hydrolysis and other mechanisms, and form pore galleries in a two-dimensional structure. This way, enhancement of adsorption capacity can be obtained through tunable surface areas. For example, a montmorillonite was modified by Liu et al. with GO and iron pillars.117 The functionalization increased the surface area eightfold when compared to that of the unmodified clay. The resulting adsorbent was also evaluated for the removal of methylene blue and methyl orange. The dominant mechanism for the former CEC was described as based on electrostatic forces between the negative surface charge of the modified clay and the CEC’s positive charge. In contrast, pep staking seemed to be the driving force for the latter CEC. In addition to pillarized clay to develop galleries or pores, surfactants can also be added to provide hydrophobicity. Several studies have demonstrated that the incorporation of hydrophobic compounds can result in a prominent increase in adsorption capacity. Using this approach, Sun et al.

Adsorbent [surface area (m g )]

CECs

Nanoporous silica Phenyl-periodic mesoporous benzene-silica Methyl-MPS MPS [913]

Basic Blue 41 [60] Mesosulfuron-methyl [20] Methylene blue Carbamazepine, clofibric acid, caffeine, naproxen, salicylic acid [2.5e20] Carbamazepine, clofibric acid, caffeine, naproxen, salicylic acid [2.5e20] Carbamazepine, clofibric acid, caffeine, naproxen, salicylic acid [2.5e20] Carbamazepine, clofibric acid, caffeine, naproxen, salicylic acid [2.5e20] Carbamazepine, clofibric acid, caffeine, naproxen, salicylic acid [2.5e20] Ciprofloxacin Ciprofloxacin

113 10 16 0.07e0.52

62 62 62 102

0.01e0.21

102

0.06e0.15

102

0.01e0.17

102

0.08e0.48

102

1.54 2.96

pH ¼ 7 pH ¼ 7

31 31

Ciprofloxacin

1.93

pH ¼ 7

31

Ciprofloxacin

2.80

pH ¼ 7

31

Ciprofloxacin

3.47

pH ¼ 7

31

Engineered adsorbents for the removal of contaminants of emerging concern from water

Continued

29

Table 1.6 Adsorption capacity of various mesoporous silica (MPS) materials for the single component contaminants of emerging concern (CECs) removal from aqueous solutions. 2
1

MPS grafted with amines [375] MPS grafted with amines modified with Co [338] MPS grafted with amines modified with Ni [341] MPS grafted with amines modified with Cu [272] Magnetic hexagonal mesoporous [380] Magnetic hexagonal MPS grafted with mercapto group [492] Magnetic hexagonal MPS grafted with amino group [141] Magnetic hexagonal MPS grafted with phenyl group [345] Magnetic hexagonal MPS grafted with nitrile group [362]

[Coa


1

(mg L )]

Qa (mg g
1) or [% Removal]

Comments

Ref.

2
1


1

Comments

Ref.

Adsorbent [surface area (m g )]

CECs

Magnetic hexagonal MPS grafted with octyl group [403] Silica-alumina surface functionalized with NH2NH2/CH3CN [79] MPS [364] MPS [918] MPS modified with surfactant (chain length 16) [11] MPS modified with surfactant (chain length 14) [13] MPS modified with surfactant (chain length 12) [9] MPS [1087] MPS functionalized with Fe via hydrothermal method [721] MPS functionalized with Fe via impregnation method [517] SiO2/Al2O3 mixed oxide modified with Mn [101] MPS [492] MPS modified with amino group MPS modified with amino group and Fe [245]

Ciprofloxacin

1.94

pH ¼ 7

31

Salicylic acid [0.5e1000]

234 [20]

pH ¼ 3.5

106

Chlortetracycline [100] Enrofloxacin [0.32e20] Enrofloxacin [0.32e20]

409 [99] 6 [19] 14 [30]

pH ¼ 3.51 pH ¼ 7 pH ¼ 7

107 108 108

Enrofloxacin [0.32e20]

9 [26]

pH ¼ 7

108

Enrofloxacin [0.32e20]

6 [18]

pH ¼ 7

108

Acetylsalicylic acid [100e500] Acetylsalicylic acid [100e500]

0.05 6

105 105

Acetylsalicylic acid [100e500]

2

105

Methyl orange, salicylic acid [0.5e500]

94e140 [20e30] 9 5 74

Co, initial concentration; Q, adsorption capacity. a Data estimated from isotherms plots.

(mg L )]

Qa (mg g
1) or [% Removal]

Tetracycline [0e88.89] Tetracycline [0e88.89] Tetracycline [0e88.89]

pH ¼ 6.5 e8 pH ¼ 5 pH ¼ 5 pH ¼ 5

109 104 104 104

Contaminants of Emerging Concern in Water and Wastewater

[Coa

30

Table 1.6 Adsorption capacity of various mesoporous silica (MPS) materials for the single component contaminants of emerging concern (CECs) removal from aqueous solutions.dcont'd

Engineered adsorbents for the removal of contaminants of emerging concern from water

31

enhanced the adsorption capacity of illite clays via incorporation of a surfactant.118 Their studies found an increase in diclofenac uptake on addition of hydrophobic species onto the clay surface. Interestingly, an optimum surfactant incorporation quantity was found after no significant changes were observed with augmenting the surfactant amount. Ortiz-Martínez et al. modified an aluminum pillared clay by adding both surfactant and transition metals to improve selectivity toward certain CECs.119 In this case, a nickel-based variant adsorbed bisphenol A about 1.6 times more than other CECs including 2,4-dichlorophenol. This improvement was due to a combination of electrostatic forces, H-bonding, hydrophobicity, and complexation interactions with the mentioned transition metal. The clay-based adsorbent family remains prospective materials for remediation of CECs. Some of the modifications that have been successful in enhancing the material capacities include ion exchange, acid treatment, inclusion of amine groups, and incorporation of surfactants and transition metals. Because of the impressive cation exchange capacity of clays, the materials seem to have an affinity toward cationic CEC compounds. Table 1.7 presents some of adsorption capacities reported in the literature for various clays and CECs.

2.6 Composite adsorbents The search for adsorbent platforms with specific features and qualities for the removal of CECs has led to the generation of composites. For this chapter, a composite will be defined as the combination of two or more adsorbent materials (i.e., MPS and zeolite). Wei et al. conducted adsorption experiments of carbamazepine onto a granular CNT/alumina composite material.48 The combination provided a surface chemistry that provided several adsorption driving forces to take place, including hydrophobicity and van der Waals forces along with Lewis acidebase and pep interactions. González-Ramos et al. successfully synthesized a composite using AC and in situ crystal growth via aging of Faujasite zeolite seeds; the composite material also included with copper or nickel as extraframework cation species.130 The composites were tested for the removal of salicylic acid. Because of electrostatic repulsion between the zeolitic surface and salicylic acid molecule, Faujasite alone cannot adsorb the CEC. However, there was a significant adsorption capacity for AC/zeolite composite and an even better performance on the inclusion of the transition metal. Moreover, the variant that contains copper transition metal outperformed in

32

Table 1.7 Adsorption capacities of various clays adsorbents for the single component contaminants of emerging concern (CECs) removal from aqueous solutions. CECs [Coa (mg L
1)]

Qa (mg g
1) or [% Removal]

Montmorillonite modified with surfactant (C38H80ClN) [23] Montmorillonite pillared graphene oxide [972]

2,4-Dichlorophenol [100]

8 [96]

120

Methylene blue, methyl orange [3000] Paraquat, amitrole [40e300]

132e345 [48e93] 4e71 [29e76]

117

4-Chlorophenol [10e200]

Montmorillonite modified with zwitterionic surfactant [14] Montmorillonite modified with surfactant (C19H42NBr) [28] Montmorillonite modified with surfactant (C17H38NBr) [25] Montmorillonite pillared Fe [127] Montmorillonite modified with low surfactant coverage (C19H42NBr) [717] Montmorillonite modified with medium surfactant coverage (C19H42NBr) [717] Montmorillonite modified with high surfactant coverage (C19H42NBr) [717] Montmorillonite treated with 0.50M H2SO4 [229] Bentonite pillared Al functionalized with surfactant (C21H38NBr) and Cu [19] Bentonite pillared Al functionalized with surfactant (C21H38NBr) and Ni [14]

Comments

Ref.

57 [2]

pH ¼ 3 e7 pH ¼ 11

52

4-Chlorophenol [10e200]

53 [0.83]

pH ¼ 11

52

Levofloxacin [20e100] Diclofenac [148e1480]

48 [38] 0.15 [65]

pH ¼ 6.8

122 118

Diclofenac [148e1480]

133 [72]

118

Diclofenac [148e1480]

296.1 [68]

118

Crystal violet [80e300]

400 [46]

pH ¼ 5.9

123

Carbamazepine, clofibric acid, caffeine, salicylic acid [1e22] Carbamazepine, clofibric acid, caffeine, salicylic acid [1e22]

3.2e5.2 [50e79] 3.2e5.1 [48e78]

pH ¼ 6 e7 pH ¼ 6 e7

124

121

124

Contaminants of Emerging Concern in Water and Wastewater

Adsorbent [surface area (m2g
1)]

Bentonite pillared Al [258]

Illite modified with low surfactant coverage (C19H42NBr) [51] Illite modified with medium surfactant coverage (C19H42NBr) [51] Illite modified with high surfactant coverage (C19H42NBr) [51] Attapulgite functionalized with amino group [81] Palygorskite functionalized with amino group [59] Sepiolite functionalized with amino group [67] Palygorskite Palygorskite treated with HCl Palygorskite functionalized with Fe2O3 Kaolinite coated with Fe-Mn

pH ¼ 6 e7 pH ¼ 6 e7 pH ¼ 6 e7 pH ¼ 6 e7 pH ¼ 6 e7 pH <5.5 pH ¼ 7 e7.5

Diclofenac [148e592]

0.5e0.8 [11e13] 2.2e3.7 [41e67] 2.8e4.6 [52e84] 2.3e3.9 [41e72] 2.0e3.6 [36e67] [87e91] 215e276 [41e65] 5.3 [42]

Diclofenac [148e592]

8 [52]

118

Diclofenac [148e592]

15 [51]

118

Methylene blue [20e200] Methylene blue, metanil yellow [1,000e600,000] Methylene blue, metanil yellow Fenarimol [5] Fenarimol [5] Fenarimol [5] Basic Fuchsin, crystal violet [20 e50]

161.29 47e49

126 127

60 0.06 0.25 0.34 8e19 [61e77]

127 128 128 128 129

[1 [1 [1 [1

119 119 119 119 119 16 125 118

pH ¼ 7

33

Co, initial concentration; Q, adsorption capacity. a Data estimated from isotherms plots.

[1

Engineered adsorbents for the removal of contaminants of emerging concern from water

Bentonite pillared Al functionalized with surfactant (C21H38NBr) [59] Bentonite pillared Al functionalized with surfactant (C21H38NBr) and Ni [14] Bentonite pillared Al functionalized with surfactant (C21H38NBr) and Cu [19] Bentonite pillared Al functionalized with surfactant (C21H38NBr) and Co [5] Bentonite Smectite exchanged Na [720]

Bisphenol A, 2,4-dichlorophenol e18] Bisphenol A, 2,4-dichlorophenol e18] Bisphenol A, 2,4-dichlorophenol e18] Bisphenol A, 2,4-dichlorophenol e18] Bisphenol A, 2,4-dichlorophenol e18] Ciprofloxacin [20e40] Tramadol, doxepin

34

Contaminants of Emerging Concern in Water and Wastewater

comparison to the other composite variants. This remarkable performance was attributed to complexation between the transition metal and salicylic acid. In the case of the copper variant, the location of the metal and the possibility of a rearrangement in the electronic configuration are factors that could further enhance its performance. The presence of hydrophobic and electrostatic interactions was considered as well to be part of the overall adsorption mechanism. Other composites that have been reported so far for the adsorption of CECs are presented in Table 1.8 along with adsorption capacities reported for single component CEC adsorption.

3. Conclusions and areas of opportunity Although the adsorbent textural properties (e.g., specific surface area, pore size, etc.) certainly play a crucial role in the ultimate capacity, functionalization is the key to tailor selectivity. Given the variety and complexity of CECs matrices found around the globe, selective adsorption could become imperative; prioritizing on which CECs to remove could become critical for timely and effective remediation. In this chapter, the presentation of the state of the art in adsorbents for CEC removal was an attempt to convey the importance of functionalization to achieve better performance in terms of selectivity. Each of the families of adsorbents that were discussed above were not only particular in the chemical composition or phase sense but also in how each can get effectively functionalized for targeting a CEC or groups of CECs. Hydrophobicity, as a functionalization variable, is evidently vital either for the sake of stability of the porous structures of the adsorbent or just to get rid of water as a competitive adsorbate. However, the tailored combination of hydrophobicity and adsorbateeadsorbent interactions (i.e., Hbonding, electrostatic, complexation, pep interaction, pep stacking, etc.) will ultimately dictate selectivity and capacity. This will become more and more evident when considering tests of all of the aforementioned adsorbent families for CEC removal under realistic scenarios. And this refers not just about pH but also to dynamic or transient conditions, as well as uptakes of multicomponent CEC mixtures and in the presence of other major capacity inhibitors such as natural organic matter macromolecules.

[Coa


1

Adsorbent [surface area (m g )]

CECs

Imprinted zeolite Y carbon [559]

Salicylic acid [0.1e30]

2.57 [8.13]

Imprinted zeolite Y carbon functionalized with Cu2þ [527] Imprinted zeolite Y carbon functionalized with Ni2þ [532] Zeolite X with activated carbon (AC) [872] Zeolite X and AC Bentonite and chitosan and powdered AC with Fe nanoparticles [95] MWCNTs with CoFe2O4-NH2 magnetic nanoparticles [137] Chitosan and MWCNTs functionalized with CoFe2O4-NH2 [158] CNTs with alumina [237]

Salicylic acid [0.1e30]

8.96 [33.60]

Salicylic acid [0.1e30]

4.42 [18.50]

Phenol Phenol [552.1] Atenolol, ciprofloxacin, gemfibrozil [0.5e40] Tetrabromobisphenol-A [10 e60] Tetrabromobisphenol-A [10 e60] Diclofenac sodium, carbamazepine [4e5] Methylene blue, direct red 80 [100e1000] Methylene blue, direct red 80 [100e1000] Tetracycline [500]

34 30.5 24e26 [81e90]

Gelatin and MWCNT functionalized with nanomagnetite Gelatin and MWCNT Mesoporous silica-zeolite A functionalized with Fe [360]

(mg L )]

Qa (mg g
1) or [% Removal]

134

Continued

35

2
1

Engineered adsorbents for the removal of contaminants of emerging concern from water

Table 1.8 Adsorption capacities of adsorbent composites for the single component contaminants of emerging concern (CECs) removal from aqueous solution. Comments

Ref.

pH ¼ 7 e8 pH ¼ 7 e8 pH ¼ 7 e8 pH ¼ 6.6

130

pH ¼ 7

130 130 30 62 131

31

132

42

132

[63e73]

pH ¼ 6

48

611e877

133

540e581 [64e70]

133

526 [99]

pH ¼ 5

36

Table 1.8 Adsorption capacities of adsorbent composites for the single component contaminants of emerging concern (CECs) removal from aqueous solution.dcont'd [Coa


1

Comments

Ref.

160 [47] 77e10,7000 [51e52] [94]

pH ¼ 3.51

107 135

pH ¼ 7

136

Methylene blue [100] Methylene blue [100] Methylene blue [30]

498 [38] 196 [32] 40 [86]

pH ¼ 7.5 pH ¼ 7.5 pH ¼ 2

90 90 95

Progesterone [5] p-Nitrophenol [800]

34.8

Adsorbent [surface area (m g )]

CECs

Illite/smectite mixture [41] Palygorskiteemontmorillonite [104]

Chlortetracycline [100] Bisphenol A, ciprofloxacin [0.01e1500] Diclofenac [2]

Montmorillonite loaded with poly vinylpyridineco-styrene HKUST-1 with 5% UiO-66 [719] UiO-66 with 5% HKUST-1[625] MOF-5 with polyoxometalate (WellseDawson acid) [395] Membrane of PTFE modified with ZIF-8 [23] Sandwich membrane of polymer and aminocontaining MIL-53 Co, initial concentration; Q, adsorption capacity. a Data estimated from isotherms plots.

Qa (mg g
1) or [% Removal]

(mg L )]

137 94

Contaminants of Emerging Concern in Water and Wastewater

2
1

Engineered adsorbents for the removal of contaminants of emerging concern from water

37

References 1. Malchi, T.; Maor, Y.; Tadmor, G.; Shenker, M.; Chefetz, B. Irrigation of Root Vegetables with Treated Wastewater: Evaluating Uptake of Pharmaceuticals and the Associated Human Health Risks. Environmental Science and Technology 2014, 48 (16), 9325e9333. 2. Naidu, R.; Arias Espana, V. A.; Liu, Y.; Jit, J. Emerging Contaminants in the Environment: Risk-Based Analysis for Better Management. Chemosphere 2016, 154, 350e357. 3. Noguera-Oviedo, K.; Aga, D. S. Lessons Learned from More Than Two Decades of Research on Emerging Contaminants in the Environment. Journal of Hazardous Materials 2016, 316, 242e251. 4. Pose-Juan, E.; Fernández-Cruz, T.; Simal-Gándara, J. State of the Art on Public Risk Assessment of Combined Human Exposure to Multiple Chemical Contaminants. Trends in Food Science and Technology 2016, 55, 11e28. 5. Rodriguez-Narvaez, O. M.; Peralta-Hernandez, J. M.; Goonetilleke, A.; Bandala, E. R. Treatment Technologies for Emerging Contaminants in Water: A Review. The Chemical Engineering Journal 2017, 323, 361e380. 6. Yang, G. C. C. Global Challenges and Solutions of Emerging Contaminants: An Editorial Overview and beyond. Chemosphere 2017, 168, 1222e1229. 7. Prasse, C.; Stalter, D.; Schulte-Oehlmann, U.; Oehlmann, J.; Ternes, T. A. Spoilt for Choice: A Critical Review on the Chemical and Biological Assessment of Current Wastewater Treatment Technologies. Water Research 2015, 87, 237e270. 8. Adeleye, A. S.; Conway, J. R.; Garner, K.; Huang, Y.; Su, Y.; Keller, A. A. Engineered Nanomaterials for Water Treatment and Remediation: Costs, Benefits, and Applicability. The Chemical Engineering Journal 2016, 286, 640e662. 9. De Gisi, S.; Lofrano, G.; Grassi, M.; Notarnicola, M. Characteristics and Adsorption Capacities of Low-Cost Sorbents for Wastewater Treatment: A Review. Sustainable Materials and Technologies 2016, 9, 10e40. 10. Richardson, S. D.; Kimura, S. Y. Water Analysis: Emerging Contaminants and Current Issues. Analytical Chemistry 2016, 88 (1), 546e582. 11. Sharma, S.; Bhattacharya, A. Drinking Water Contamination and Treatment Techniques. Applied Water Science 2017, 7 (3), 1043e1067. 12. Wang, Y.; Zhu, J.; Huang, H.; Cho, H.-H. Carbon Nanotube Composite Membranes for Microfiltration of Pharmaceuticals and Personal Care Products: Capabilities and Potential Mechanisms. Journal of Membrane Science 2015, 479, 165e174. 13. Rouquerol, J.; Avnir, D.; Fairbridge, C. W.; Everett, D. H.; Haynes, J. H.; Pernicone, N.; Ramsay, J. D. F.; Sing, K. S. W.; Unger, K. K. Recommendations for the Characterization of Porous Solids. Pure and Applied Chemistry 1994, 66 (8), 1739e1758. 14. Szostak, R. Molecular Sieves: Principles of Synthesis and Identification; Blackie Academic & Professional: London; New York, 1998. 15. Dichiara, A. B.; Benton-Smith, J.; Rogers, R. E. Enhanced Adsorption of Carbon Nanocomposites Exhausted with 2,4-dichlorophenoxyacetic Acid after Regeneration by Thermal Oxidation and Microwave Irradiation. Environmental Science Nano 2014, 1 (2), 113e116. 16. Ahmed, M. B.; Zhou, J. L.; Ngo, H. H.; Guo, W. Adsorptive Removal of Antibiotics from Water and Wastewater: Progress and Challenges. The Science of the Total Environment 2015, 532, 112e126. 17. Akhtar, J.; Amin, N. A. S.; Shahzad, K. A Review on Removal of Pharmaceuticals from Water by Adsorption. Desalination and Water Treatment 2016, 57 (27), 12842e12860.

38

Contaminants of Emerging Concern in Water and Wastewater

18. Leudjo Taka, A.; Pillay, K.; Yangkou Mbianda, X. Nanosponge Cyclodextrin Polyurethanes and Their Modification with Nanomaterials for the Removal of Pollutants from Waste Water: A Review. Carbohydrate Polymers 2017, 159, 94e107. 19. Chowdhury, Z. K. Activated Carbon: Solutions for Improving Water Quality; American Water Works Association, 2013. 20. Álvarez-Torrellas, S.; Martin-Martinez, M.; Gomes, H. T.; Ovejero, G.; García, J. Enhancement of P-Nitrophenol Adsorption Capacity through N2-Thermal-Based Treatment of Activated Carbons. Applied Surface Science 2017, 414, 424e434. 21. Nielsen, L.; Biggs, M. J.; Skinner, W.; Bandosz, T. J. The Effects of Activated Carbon Surface Features on the Reactive Adsorption of Carbamazepine and Sulfamethoxazole. Carbon 2014, 80, 419e432. 22. Álvarez-Torrellas, S.; Peres, J. A.; Gil-Álvarez, V.; Ovejero, G.; García, J. Effective Adsorption of Non-biodegradable Pharmaceuticals from Hospital Wastewater with Different Carbon Materials. The Chemical Engineering Journal 2017, 320, 319e329. 23. Alahabadi, A.; Hosseini-Bandegharaei, A.; Moussavi, G.; Amin, B.; Rastegar, A.; Karimi-Sani, H.; Fattahi, M.; Miri, M. Comparing Adsorption Properties of NH4Clmodified Activated Carbon towards Chlortetracycline Antibiotic with Those of Commercial Activated Carbon. Journal of Molecular Liquids 2017, 232, 367e381. 24. Álvarez-Torrellas, S.; García Lovera, R.; Escalona, N.; Sepúlveda, C.; Sotelo, J. L.; García, J. Chemical-activated Carbons from Peach Stones for the Adsorption of Emerging Contaminants in Aqueous Solutions. The Chemical Engineering Journal 2015, 279, 788e798. 25. Bahamon, D.; Carro, L.; Guri, S.; Vega, L. F. Computational Study of Ibuprofen Removal from Water by Adsorption in Realistic Activated Carbons. Journal of Colloid and Interface Science 2017, 498, 323e334. 26. Shan, D.; Deng, S.; Zhao, T.; Wang, B.; Wang, Y.; Huang, J.; Yu, G.; Winglee, J.; Wiesner, M. R. Preparation of Ultrafine Magnetic Biochar and Activated Carbon for Pharmaceutical Adsorption and Subsequent Degradation by Ball Milling. Journal of Hazardous Materials 2016, 305, 156e163. 27. Couto, O. M.; Matos, I.; da Fonseca, I. M.; Arroyo, P. A.; da Silva, E. A.; de Barros, M. A. S. D. Effect of Solution pH and Influence of Water Hardness on Caffeine Adsorption onto Activated Carbons. Canadian Journal of Chemical Engineering 2015, 93 (1), 68e77. 28. Galhetas, M.; Mestre, A. S.; Pinto, M. L.; Gulyurtlu, I.; Lopes, H.; Carvalho, A. P. Chars from Gasification of Coal and Pine Activated with K2CO3: Acetaminophen and Caffeine Adsorption from Aqueous Solutions. Journal of Colloid and Interface Science 2014, 433, 94e103. 29. Guedidi, H.; Lakehal, I.; Reinert, L.; Lévêque, J.-M.; Bellakhal, N.; Duclaux, L. Removal of Ionic Liquids and Ibuprofen by Adsorption on a Microporous Activated Carbon: Kinetics, Isotherms, and Pore Sites. Arabian Journal of Chemistry 2017; https:// doi.org/10.1016/j.arabjc.2017.04.006. 30. Cheng, W. P.; Gao, W.; Cui, X.; Ma, J. H.; Li, R. F. Phenol Adsorption Equilibrium and Kinetics on Zeolite X/activated Carbon Composite. Journal of the Taiwan Institute of Chemical Engineers 2016, 62, 192e198. 31. Hongsawat, P.; Prarat, P.; Ngamcharussrivichai, C.; Punyapalakul, P. Adsorption of Ciprofloxacin on Surface Functionalized Superparamagnetic Porous Silicas. Desalination and Water Treatment 2014, 52. 32. Pouretedal, H. R.; Sadegh, N. Effective Removal of Amoxicillin, Cephalexin, Tetracycline and Penicillin G from Aqueous Solutions Using Activated Carbon Nanoparticles Prepared from Vine Wood. Journal of Water Process Engineering 2014, 1, 64e73.

Engineered adsorbents for the removal of contaminants of emerging concern from water

39

33. Kim, H.; Hwang, Y. S.; Sharma, V. K. Adsorption of Antibiotics and Iopromide onto Single-Walled and Multi-Walled Carbon Nanotubes. The Chemical Engineering Journal 2014, 255, 23e27. 34. Ncibi, M. C.; Sillanpää, M. Optimizing the Removal of Pharmaceutical Drugs Carbamazepine and Dorzolamide from Aqueous Solutions Using Mesoporous Activated Carbons and Multi-Walled Carbon Nanotubes. Journal of Molecular Liquids 2017, 238, 379e388. 35. Fitzer, E.; Kochling, K.-H.; Boehm, H. P.; Marsh, H. Recommended Terminology for the Description of Carbon as a Solid (IUPAC Recommendations 1995). Pure and Applied Chemistry 1995, 67 (3), 473e506. 36. Zhang, Y.; Wu, B.; Xu, H.; Liu, H.; Wang, M.; He, Y.; Pan, B. Nanomaterialsenabled Water and Wastewater Treatment. NanoImpact 2016, 3e4, 22e39. 37. Cai, Z.; Sun, Y.; Liu, W.; Pan, F.; Sun, P.; Fu, J. An Overview of Nanomaterials Applied for Removing Dyes from Wastewater. Environmental Science and Pollution Research 2017, 24 (19), 15882e15904. 38. Wang, F.; Ma, S.; Si, Y.; Dong, L.; Wang, X.; Yao, J.; Chen, H.; Yi, Z.; Yao, W.; Xing, B. Interaction Mechanisms of Antibiotic Sulfamethoxazole with Various Graphene-Based Materials and Multiwall Carbon Nanotubes and the Effect of Humic Acid in Water. Carbon 2017, 114, 671e678. 39. Wu, Z.; Zhong, H.; Yuan, X.; Wang, H.; Wang, L.; Chen, X.; Zeng, G.; Wu, Y. Adsorptive Removal of Methylene Blue by Rhamnolipid-Functionalized Graphene Oxide from Wastewater. Water Research 2014, 67, 330e344. 40. Cai, N.; Larese-Casanova, P. Application of Positively-Charged EthylenediamineFunctionalized Graphene for the Sorption of Anionic Organic Contaminants from Water. Journal of Environmental Chemical Engineering 2016, 4 (3), 2941e2951. 41. Ueda Yamaguchi, N.; Bergamasco, R.; Hamoudi, S. Magnetic MnFe2O4eGraphene Hybrid Composite for Efficient Removal of Glyphosate from Water. The Chemical Engineering Journal 2016, 295, 391e402. 42. Liu, F.-f.; Zhao, J.; Wang, S.; Du, P.; Xing, B. Effects of Solution Chemistry on Adsorption of Selected Pharmaceuticals and Personal Care Products (PPCPs) by Graphenes and Carbon Nanotubes. Environmental Science and Technology 2014, 48 (22), 13197e13206. 43. Moussavi, G.; Hossaini, Z.; Pourakbar, M. High-rate Adsorption of Acetaminophen from the Contaminated Water onto Double-Oxidized Graphene Oxide. The Chemical Engineering Journal 2016, 287, 665e673. 44. Sarkar, B.; Mandal, S.; Tsang, Y. F.; Kumar, P.; Kim, K.-H.; Ok, Y. S. Designer Carbon Nanotubes for Contaminant Removal in Water and Wastewater: A Critical Review. The Science of the Total Environment 2018, 612, 561e581. 45. Jung, C.; Son, A.; Her, N.; Zoh, K.-D.; Cho, J.; Yoon, Y. Removal of Endocrine Disrupting Compounds, Pharmaceuticals, and Personal Care Products in Water Using Carbon Nanotubes: A Review. Journal of Industrial and Engineering Chemistry 2015, 27, 1e11. 46. Wei, J.; Sun, W.; Pan, W.; Yu, X.; Sun, G.; Jiang, H. Comparing the Effects of Different Oxygen-Containing Functional Groups on Sulfonamides Adsorption by Carbon Nanotubes: Experiments and Theoretical Calculation. The Chemical Engineering Journal 2017, 312, 167e179. 47. Li, H.; Zhang, W.; Zhang, Z.; Zhang, X. Sorption of Triclosan to Carbon Nanotubes: The Combined Effects of Sonication, Functionalization and Solution Chemistry. The Science of the Total Environment 2017, 580, 1318e1326. 48. Wei, H.; Deng, S.; Huang, Q.; Nie, Y.; Wang, B.; Huang, J.; Yu, G. Regenerable Granular Carbon Nanotubes/Alumina Hybrid Adsorbents for Diclofenac Sodium and

40

49. 50. 51. 52.

53.

54. 55. 56. 57. 58. 59. 60. 61.

62. 63.

64.

Contaminants of Emerging Concern in Water and Wastewater

Carbamazepine Removal from Aqueous Solution. Water Research 2013, 47 (12), 4139e4147. Wang, F.; Sun, W.; Pan, W.; Xu, N. Adsorption of Sulfamethoxazole and 17b-Estradiol by Carbon Nanotubes/CoFe2O4 Composites. The Chemical Engineering Journal 2015, 274, 17e29. Corma, A. From Microporous to Mesoporous Molecular Sieve Materials and Their Use in Catalysis. Chemical Reviews 1997, 97 (6), 2373e2420. Sandoval-Díaz, L.-E.; González-Amaya, J.-A.; Trujillo, C.-A. General Aspects of Zeolite Acidity Characterization. Microporous and Mesoporous Materials 2015, 215, 229e243. Nourmoradi, H.; Avazpour, M.; Ghasemian, N.; Heidari, M.; Moradnejadi, K.; Khodarahmi, F.; Javaheri, M.; Moghadam, F. M. Surfactant Modified Montmorillonite as a Low Cost Adsorbent for 4-chlorophenol: Equilibrium, Kinetic and Thermodynamic Study. Journal of the Taiwan Institute of Chemical Engineers 2016, 59, 244e251. Serri, C.; de Gennaro, B.; Catalanotti, L.; Cappelletti, P.; Langella, A.; Mercurio, M.; Mayol, L.; Biondi, M. Surfactant-modified Phillipsite and Chabazite as Novel Excipients for Pharmaceutical Applications? Microporous and Mesoporous Materials 2016, 224, 143e148. Martucci, A.; Rodeghero, E.; Pasti, L.; Bosi, V.; Cruciani, G. Adsorption of 1,2dichloroethane on ZSM-5 and Desorption Dynamics by in situ Synchrotron Powder X-Ray Diffraction. Microporous and Mesoporous Materials 2015, 215, 175e182. Jha, B.; Singh, D. Basics of Zeolites. In Fly Ash Zeolites 2016, Vol. 78; pp 5e31. Bhatnagar, A.; Anastopoulos, I. Adsorptive Removal of Bisphenol A (BPA) from Aqueous Solution: A Review. Chemosphere 2017, 168, 885e902. Davis, M. E. Ordered Porous Materials for Emerging Applications. Nature 2002, 417, 813. Wu, Q.; Shi, H.; Ma, Y.; Adams, C.; Jiang, H.; Wang, J.; Eichholz, T.; Timmons, T. Removal of N-Nitrosamine Precursors in Drinking Water System Using Adsorption Methods. Separation and Purification Technology 2015, 156 (Part 3), 972e979. Goyal, N.; Bulasara, V. K.; Barman, S. Removal of Emerging Contaminants Daidzein and Coumestrol from Water by Nanozeolite Beta Modified with Tetrasubstituted Ammonium Cation. Journal of Hazardous Materials 2018, 344, 417e430. Sun, K.; Shi, Y.; Wang, X.; Li, Z. Sorption and Retention of Diclofenac on Zeolite in the Presence of Cationic Surfactant. Journal of Hazardous Materials 2017, 323 (Part A), 584e592. Cabrera-Lafaurie, W. A.; Román, F. R.; Hernández-Maldonado, A. J. Removal of Salicylic Acid and Carbamazepine from Aqueous Solution with Y-Zeolites Modified with Extraframework Transition Metal and Surfactant Cations: Equilibrium and Fixed-Bed Adsorption. Journal of Environmental Chemical Engineering 2014, 2 (2), 899e906. Tan, K. L.; Hameed, B. H. Insight into the Adsorption Kinetics Models for the Removal of Contaminants from Aqueous Solutions. Journal of the Taiwan Institute of Chemical Engineers 2017, 74, 25e48. Grieco, S. A.; Ramarao, B. V.; Schulte, J.; Kiemle, D. Adsorption Equilibrium and Mechanisms of Tris(2-Chloroethyl)phosphate (TCEP) on Zeolite-b under Environmentally Relevant and Competitive Conditions with Methyl Tert-Butyl Ether (MTBE). Environmental Technology and Innovation 2017, 8, 172e181. Martucci, A.; Leardini, L.; Nassi, M.; Sarti, E.; Bagatin, R.; Pasti, L. Removal of Emerging Organic Contaminants from Aqueous Systems: Adsorption and Location of Methyl-Tertiary-Butyl-Ether on Synthetic Ferrierite. Mineralogical Magazine 2014, 78 (5), 1161e1175.

Engineered adsorbents for the removal of contaminants of emerging concern from water

41

65. Pham, T.-H.; Lee, B.-K.; Kim, J. Improved Adsorption Properties of a Nano Zeolite Adsorbent toward Toxic Nitrophenols. Process Safety and Environmental Protection 2016, 104 (Part A), 314e322. 66. Lye, J. W. P.; Saman, N.; Sharuddin, S. S. N.; Othman, N. S.; Mohtar, S. S.; Md Noor, A. M.; Buhari, J.; Cheu, S. C.; Kong, H.; Mat, H. Removal Performance of Tetracycline and Oxytetracycline from Aqueous Solution via Natural Zeolites: An Equilibrium and Kinetic Study. Clean, Soil, Air, Water 2017, 45 (10), 1600260en/a. 67. Kuppler, R. J.; Timmons, D. J.; Fang, Q.-R.; Li, J.-R.; Makal, T. A.; Young, M. D.; Yuan, D.; Zhao, D.; Zhuang, W.; Zhou, H.-C. Potential Applications of MetalOrganic Frameworks. Coordination Chemistry Reviews 2009, 253 (23e24), 3042e3066. 68. Furukawa, H.; Cordova, K. E.; O’Keeffe, M.; Yaghi, O. M. The Chemistry and Applications of Metal-Organic Frameworks. Science 2013, 341 (6149). 69. Khan, N. A.; Hasan, Z.; Jhung, S. H. Adsorptive Removal of Hazardous Materials Using Metal-Organic Frameworks (MOFs): A Review. Journal of Hazardous Materials 2013, 244e245, 444e456. 70. Hasan, Z.; Jhung, S. H. Removal of Hazardous Organics from Water Using MetalOrganic Frameworks (MOFs): Plausible Mechanisms for Selective Adsorptions. Journal of Hazardous Materials 2015, 283, 329e339. 71. Hçnicke, I. M.; Senkovska, I.; Bon, V.; Baburin, I. A.; Bçnisch, N.; Raschke, S.; Evans, J. D.; Kaskel, S. Balancing Mechanical Stability and Ultrahigh Porosity in Crystalline Framework Materials. Angewandte Chemie International Edition 2018, 57, 13780e13783. 72. Burtch, N. C.; Jasuja, H.; Walton, K. S. Water Stability and Adsorption in Metale Organic Frameworks. Chemical Reviews 2014, 114 (20), 10575e10612. 73. Tan, F.; Liu, M.; Li, K.; Wang, Y.; Wang, J.; Guo, X.; Zhang, G.; Song, C. Facile Synthesis of Size-Controlled MIL-100(Fe) with Excellent Adsorption Capacity for Methylene Blue. The Chemical Engineering Journal 2015, 281, 360e367. 74. Ahmed, I.; Jhung, S. H. Applications of Metal-Organic Frameworks in Adsorption/ separation Processes via Hydrogen Bonding Interactions. The Chemical Engineering Journal 2017, 310 (Part 1), 197e215. 75. Kumar, P.; Pournara, A.; Kim, K.-H.; Bansal, V.; Rapti, S.; Manos, M. J. Metalorganic Frameworks: Challenges and Opportunities for Ion-Exchange/sorption Applications. Progress in Materials Science 2017, 86, 25e74. 76. Bezverkhyy, I.; Weber, G.; Bellat, J.-P. Degradation of Fluoride-free MIL-100(Fe) and MIL-53(Fe) in Water: Effect of Temperature and pH. Microporous and Mesoporous Materials 2016, 219, 117e124. 77. Piscopo, C. G.; Polyzoidis, A.; Schwarzer, M.; Loebbecke, S. Stability of UiO-66 under Acidic Treatment: Opportunities and Limitations for Post-synthetic Modifications. Microporous and Mesoporous Materials 2015, 208, 30e35. 78. Hasan, Z.; Jeon, J.; Jhung, S. H. Adsorptive Removal of Naproxen and Clofibric Acid from Water Using Metal-Organic Frameworks. Journal of Hazardous Materials 2012, 209e210, 151e157. 79. Huang, Z.; Lee, H. K. Performance of Metal-Organic Framework MIL-101 after Surfactant Modification in the Extraction of Endocrine Disrupting Chemicals from Environmental Water Samples. Talanta 2015, 143, 366e373. 80. Ayati, A.; Shahrak, M. N.; Tanhaei, B.; Sillanpää, M. Emerging Adsorptive Removal of Azo Dye by MetaleOrganic Frameworks. Chemosphere 2016, 160, 30e44. 81. DeFuria, M. D.; Zeller, M.; Genna, D. T. Removal of Pharmaceuticals from Water via pep Stacking Interactions in Perfluorinated MetaleOrganic Frameworks. Crystal Growth and Design 2016, 16 (6), 3530e3534.

42

Contaminants of Emerging Concern in Water and Wastewater

82. Sarker, M.; Ahmed, I.; Jhung, S. H. Adsorptive Removal of Herbicides from Water over Nitrogen-Doped Carbon Obtained from Ionic liquid@ZIF-8. The Chemical Engineering Journal 2017, 323, 203e211. 83. Song, J. Y.; Jhung, S. H. Adsorption of Pharmaceuticals and Personal Care Products over Metal-Organic Frameworks Functionalized with Hydroxyl Groups: Quantitative Analyses of H-Bonding in Adsorption. The Chemical Engineering Journal 2017, 322, 366e374. 84. Zhuo, N.; Lan, Y.; Yang, W.; Yang, Z.; Li, X.; Zhou, X.; Liu, Y.; Shen, J.; Zhang, X. Adsorption of Three Selected Pharmaceuticals and Personal Care Products (PPCPs) onto MIL-101(Cr)/natural Polymer Composite Beads. Separation and Purification Technology 2017, 177, 272e280. 85. Hasan, Z.; Choi, E.-J.; Jhung, S. H. Adsorption of Naproxen and Clofibric Acid over a MetaleOrganic Framework MIL-101 Functionalized with Acidic and Basic Groups. The Chemical Engineering Journal 2013, 219, 537e544. 86. Seo, P. W.; Khan, N. A.; Hasan, Z.; Jhung, S. H. Adsorptive Removal of Artificial Sweeteners from Water Using MetaleOrganic Frameworks Functionalized with Urea or Melamine. ACS Applied Materials and Interfaces 2016, 8 (43), 29799e29807. 87. Chen, Q.; He, Q.; Lv, M.; Xu, Y.; Yang, H.; Liu, X.; Wei, F. Selective Adsorption of Cationic Dyes by UiO-66-NH2. Applied Surface Science 2015, 327, 77e85. 88. Hasan, Z.; Khan, N. A.; Jhung, S. H. Adsorptive Removal of Diclofenac Sodium from Water with Zr-Based MetaleOrganic Frameworks. The Chemical Engineering Journal 2016, 284, 1406e1413. 89. Seo, P. W.; Khan, N. A.; Jhung, S. H. Removal of Nitroimidazole Antibiotics from Water by Adsorption over MetaleOrganic Frameworks Modified with Urea or Melamine. The Chemical Engineering Journal 2017, 315, 92e100. 90. Azhar, M. R.; Abid, H. R.; Sun, H.; Periasamy, V.; Tadé, M. O.; Wang, S. One-pot Synthesis of Binary Metal Organic Frameworks (HKUST-1 and UiO-66) for Enhanced Adsorptive Removal of Water Contaminants. Journal of Colloid and Interface Science 2017, 490, 685e694. 91. Bhadra, B. N.; Ahmed, I.; Kim, S.; Jhung, S. H. Adsorptive Removal of Ibuprofen and Diclofenac from Water Using Metal-Organic Framework-Derived Porous Carbon. The Chemical Engineering Journal 2017, 314, 50e58. 92. Xie, L.; Liu, D.; Huang, H.; Yang, Q.; Zhong, C. Efficient Capture of Nitrobenzene from Waste Water Using MetaleOrganic Frameworks. The Chemical Engineering Journal 2014, 246, 142e149. 93. Jung, B. K.; Hasan, Z.; Jhung, S. H. Adsorptive Removal of 2,4dichlorophenoxyacetic Acid (2,4-D) from Water with a MetaleOrganic Framework. The Chemical Engineering Journal 2014, 234, 99e105. 94. Jia, Z.; Jiang, M.; Wu, G. Amino-MIL-53(Al) Sandwich-Structure Membranes for Adsorption of P-Nitrophenol from Aqueous Solutions. The Chemical Engineering Journal 2017, 307, 283e290. 95. Liu, X.; Gong, W.; Luo, J.; Zou, C.; Yang, Y.; Yang, S. Selective Adsorption of Cationic Dyes from Aqueous Solution by Polyoxometalate-Based MetaleOrganic Framework Composite. Applied Surface Science 2016, 362, 517e524. 96. Lin, S.; Song, Z.; Che, G.; Ren, A.; Li, P.; Liu, C.; Zhang, J. Adsorption Behavior of MetaleOrganic Frameworks for Methylene Blue from Aqueous Solution. Microporous and Mesoporous Materials 2014, 193, 27e34. 97. Xu, Y.; Jin, J.; Li, X.; Song, C.; Meng, H.; Zhang, X. Adsorption Behavior of Methylene Blue on Fe3O4-Embedded Hybrid Magnetic MetaleOrganic Framework. Desalination and Water Treatment 2016, 57 (52), 25216e25225.

Engineered adsorbents for the removal of contaminants of emerging concern from water

43

98. Li, L.; Li, J. C.; Rao, Z.; Song, G. W.; Hu, B. Metal Organic Framework [Cu3(BTC)2(H2O)3] for the Adsorption of Methylene Blue from Aqueous Solution. Desalination and Water Treatment 2014, 52 (37e39), 7332e7338. 99. Hoffmann, F.; Cornelius, M.; Morell, J.; Fröba, M. Silica-based Mesoporous OrganiceInorganic Hybrid Materials. Angewandte Chemie International Edition 2006, 45 (20), 3216e3251. 100. Casado, N.; Pérez-Quintanilla, D.; Morante-Zarcero, S.; Sierra, I. Current Development and Applications of Ordered Mesoporous Silicas and Other SoleGel SilicaBased Materials in Food Sample Preparation for Xenobiotics Analysis. Trends in Analytical Chemistry 2017, 88, 167e184. 101. Vunain, E.; Mishra, A. K.; Mamba, B. B. Dendrimers, Mesoporous Silicas and Chitosan-Based Nanosorbents for the Removal of Heavy-Metal Ions: A Review. International Journal of Biological Macromolecules 2016, 86, 570e586. 102. Ortiz-Martínez, K.; Guerrero-Medina, K. J.; Román, F. R.; HernándezMaldonado, A. J. Transition Metal Modified Mesoporous Silica Adsorbents with Zero Microporosity for the Adsorption of Contaminants of Emerging Concern (CECs) from Aqueous Solutions. The Chemical Engineering Journal 2015, 264, 152e164. 103. Ortiz-Martínez, K.; Vargas-Valentín, D. A.; Hernandez-Maldonado, A. J. Adsorption of Contaminants of Emerging Concern from Aqueous Solutions Using Cu2þ Amino Grafted SBA-15 Mesoporous Silica: Multi-Component and Metabolites Adsorption. Industrial and Engineering Chemistry 2018, 57 (18), 6426e6439. 104. Zhang, Z.; Li, H.; Liu, H. Insight into the Adsorption of Tetracycline onto Amino and Amino-Fe(3þ) Gunctionalized Mesoporous Silica: Effect of Functionalized Groups. Journal of Environmental Sciences 2018, 65, 171e178. 105. Teo, H. T.; Siah, W. R.; Yuliati, L. Enhanced Adsorption of Acetylsalicylic Acid over Hydrothermally Synthesized Iron Oxide-Mesoporous Silica MCM-41 Composites. Journal of the Taiwan Institute of Chemical Engineers 2016, 65, 591e598. 106. Arshadi, M.; Mousavinia, F.; Abdolmaleki, M. K.; Amiri, M. J.; Khalafi-Nezhad, A. Removal of Salicylic Acid as an Emerging Contaminant by a Polar Nano-Dendritic Adsorbent from Aqueous Media. Journal of Colloid and Interface Science 2017, 493, 138e149. 107. Wang, W.; Tian, G.; Zong, L.; Zhou, Y.; Kang, Y.; Wang, Q.; Wang, A. From Illite/ smectite Clay to Mesoporous Silicate Adsorbent for Efficient Removal of Chlortetracycline from Water. Journal of Environmental Sciences 2017, 51, 31e43. 108. Liang, Z.; Zhaob, Z.; Sun, T.; Shi, W.; Cui, F. Adsorption of Quinolone Antibiotics in Spherical Mesoporous Silica: Effects of the Retained Template and its Alkyl Chain Length. Journal of Hazardous Materials 2016, 305, 8e14. 109. Arshadi, M.; Mousavinia, F.; Amiri, M. J.; Faraji, A. R. Adsorption of Methyl Orange and Salicylic Acid on a Nano-Transition Metal Composite: Kinetics, Thermodynamic and Electrochemical Studies. Journal of Colloid and Interface Science 2016, 483, 118e131. 110. Guégan, R. Intercalation of a Nonionic Surfactant (C10E3) Bilayer into a NaMontmorillonite Clay. Langmuir 2010, 26 (24), 19175e19180. 111. Zhang, D.; Zhou, C.-H.; Lin, C.-X.; Tong, D.-S.; Yu, W.-H. Synthesis of Clay Minerals. Applied Clay Science 2010, 50 (1), 1e11. 112. Leardini, L.; Martucci, A.; Braschi, I.; Blasioli, S.; Quartieri, S. Regeneration of HighSilica Zeolites after Sulfamethoxazole Antibiotic Adsorption: A Combined in situ High-Temperature Synchrotron X-Ray Powder Diffraction and Thermal Degradation Study. Mineralogical Magazine 2014, 78 (5), 1141e1159. 113. Schampera, B.; Tunega, D.; Solc, R.; Woche, S. K.; Mikutta, R.; Wirth, R.; Dultz, S.; Guggenberger, G. External Surface Structure of Organoclays Analyzed by Transmission Electron Microscopy and X-Ray Photoelectron Spectroscopy in Combination

44

114.

115.

116. 117.

118. 119.

120.

121. 122. 123. 124.

125. 126.

127.

Contaminants of Emerging Concern in Water and Wastewater

with Molecular Dynamics Simulations. Journal of Colloid and Interface Science 2016, 478, 188e200. Lelario, F.; Gardi, I.; Mishael, Y.; Dolev, N.; Undabeytia, T.; Nir, S.; Scrano, L.; Bufo, S. A. Pairing Micropollutants and Clay-Composite Sorbents for Efficient Water Treatment: Filtration and Modeling at a Pilot Scale. Applied Clay Science 2017, 137, 225e232. Yang, Q.; Gao, M.; Zang, W. Comparative Study of 2,4,6-trichlorophenol Adsorption by Montmorillonites Functionalized with Surfactants Differing in the Number of Head Group and Alkyl Chain. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2017, 520, 805e816. Park, Y.; Ayoko, G. A.; Horváth, E.; Kurdi, R.; Kristof, J.; Frost, R. L. Structural Characterisation and Environmental Application of Organoclays for the Removal of Phenolic Compounds. Journal of Colloid and Interface Science 2013, 393, 319e334. Liu, L.; Zhang, B.; Zhang, Y.; He, Y.; Huang, L.; Tan, S.; Cai, X. Simultaneous Removal of Cationic and Anionic Dyes from Environmental Water Using Montmorillonite-Pillared Graphene Oxide. Journal of Chemical and Engineering Data 2015, 60 (5), 1270e1278. Sun, K.; Shi, Y.; Chen, H.; Wang, X.; Li, Z. Extending Surfactant-Modified 2:1 Clay Minerals for the Uptake and Removal of Diclofenac from Water. Journal of Hazardous Materials 2017, 323 (Part A), 567e574. Ortiz-Martínez, K.; Reddy, P.; Cabrera-Lafaurie, W. A.; Román, F. R.; HernándezMaldonado, A. J. Single and Multi-Component Adsorptive Removal of Bisphenol A and 2,4-dichlorophenol from Aqueous Solutions with Transition Metal Modified InorganiceOrganic Pillared Clay Composites: Effect of pH and Presence of Humic Acid. Journal of Hazardous Materials 2016, 312, 262e271. Huang, L.; Zhou, Y.; Guo, X.; Chen, Z. Simultaneous Removal of 2,4dichlorophenol and Pb(II) from Aqueous Solution Using Organoclays: Isotherm, Kinetics and Mechanism. Journal of Industrial and Engineering Chemistry 2015, 22, 280e287. Gu, Z.; Gao, M.; Lu, L.; Liu, Y.; Yang, S. Montmorillonite Functionalized with Zwitterionic Surfactant as a Highly Efficient Adsorbent for Herbicides. Industrial and Engineering Chemistry Research 2015, 54 (18), 4947e4955. Liu, Y.; Dong, C.; Wei, H.; Yuan, W.; Li, K. Adsorption of Levofloxacin onto an Iron-Pillared Montmorillonite (Clay Mineral): Kinetics, Equilibrium and Mechanism. Applied Clay Science 2015, 118, 301e307. Sarma, G. K.; Sen Gupta, S.; Bhattacharyya, K. G. Adsorption of Crystal Violet on Raw and Acid-Treated Montmorillonite, K10, in Aqueous Suspension. Journal of Environmental Management 2016, 171, 1e10. Cabrera-Lafaurie, W. A.; Román, F. R.; Hernández-Maldonado, A. J. Transition Metal Modified and Partially Calcined InorganiceOrganic Pillared Clays for the Adsorption of Salicylic Acid, Clofibric Acid, Carbamazepine, and Caffeine from Water. Journal of Colloid and Interface Science 2012, 386 (1), 381e391. Thiebault, T.; Guégan, R.; Boussafir, M. Adsorption Mechanisms of Emerging Micropollutants with a Clay Mineral: Case of Tramadol and Doxepine Pharmaceutical Products. Journal of Colloid and Interface Science 2015, 453, 1e8. Zhou, Q.; Gao, Q.; Luo, W.; Yan, C.; Ji, Z.; Duan, P. One-Step Synthesis of AminoFunctionalized Attapulgite Clay Nanoparticles Adsorbent by Hydrothermal Carbonization of Chitosan for Removal of Methylene Blue from Wastewater. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2015, 470, 248e257. Moreira, M. A.; Ciuffi, K. J.; Rives, V.; Vicente, M. A.; Trujillano, R.; Gil, A.; Korili, S. A.; de Faria, E. H. Effect of Chemical Modification of Palygorskite and

Engineered adsorbents for the removal of contaminants of emerging concern from water

128. 129. 130.

131. 132. 133.

134.

135.

136. 137.

45

Sepiolite by 3-aminopropyltriethoxisilane on Adsorption of Cationic and Anionic Dyes. Applied Clay Science 2017, 135, 394e404. Ouali, A.; Belaroui, L. S.; Bengueddach, A.; Galindo, A. L.; Peña, A. Fe2O3e palygorskite Nanoparticles, Efficient Adsorbates for Pesticide Removal. Applied Clay Science 2015, 115, 67e75. Khan, T. A.; Khan, E. A.; Shahjahan. Removal of Basic Dyes from Aqueous Solution by Adsorption onto Binary Iron-Manganese Oxide Coated Kaolinite: Non-linear Isotherm and Kinetics Modeling. Applied Clay Science 2015, 107, 70e77. González-Ramos, K. M.; Fernández-Reyes, B.; Román, F. R.; Hernándezþ 2þ Maldonado, A. J. A Hierarchical Porous Carbon e Mþ or Cu2þ) n [FAU] (Mn ¼Ni Adsorbent: Synthesis, Characterization and Adsorption of Salicylic Acid from Water. Microporous and Mesoporous Materials 2014, 200, 225e234. Arya, V.; Philip, L. Adsorption of Pharmaceuticals in Water Using Fe3O4 Coated Polymer Clay Composite. Microporous and Mesoporous Materials 2016, 232, 273e280. Zhou, L.; Ji, L.; Ma, P.-C.; Shao, Y.; Zhang, H.; Gao, W.; Li, Y. Development of Carbon nanotubes/CoFe2O4 Magnetic Hybrid Material for Removal of Tetrabromobisphenol A and Pb(II). Journal of Hazardous Materials 2014, 265, 104e114. Saber-Samandari, S.; Saber-Samandari, S.; Joneidi-Yekta, H.; Mohseni, M. Adsorption of Anionic and Cationic Dyes from Aqueous Solution Using Gelatin-Based Magnetic Nanocomposite Beads Comprising Carboxylic Acid Functionalized Carbon Nanotube. The Chemical Engineering Journal 2017, 308, 1133e1144. Guo, Y.; Huang, W.; Chen, B.; Zhao, Y.; Liu, D.; Sun, Y.; Gong, B. Removal of Tetracycline from Aqueous Solution by MCM-41-Zeolite A Loaded Nano Zero Valent Iron: Synthesis, Characteristic, Adsorption Performance and Mechanism. Journal of Hazardous Materials 2017, 339, 22e32. Berhane, T. M.; Levy, J.; Krekeler, M. P. S.; Danielson, N. D. Adsorption of Bisphenol A and Ciprofloxacin by Palygorskite-Montmorillonite: Effect of Granule Size, Solution Chemistry and Temperature. Applied Clay Science 2016, 132e133, 518e527. Kohay, H.; Izbitski, A.; Mishael, Y. G. Developing Polycation-Clay Sorbents for Efficient Filtration of Diclofenac: Effect of Dissolved Organic Matter and Comparison to Activated Carbon. Environmental Science and Technology 2015, 49 (15), 9280e9288. Ragab, D.; Gomaa, H. G.; Sabouni, R.; Salem, M.; Ren, M.; Zhu, J. Micropollutants Removal from Water Using Microfiltration Membrane Modified with ZIF-8 Metal Organic Frameworks (MOFs). The Chemical Engineering Journal 2016, 300, 273e279.