- Email: [email protected]
Environmentally sustainable acid mine drainage remediation: Use of natural alkaline material
Journal of Water Process Engineering 33 (2020) 101064
Contents lists available at ScienceDirect
Journal of Water Process Engineering journal homepage: www.elsevier.com/locate/jwpe
Environmentally sustainable acid mine drainage remediation: Use of natural alkaline material
T
A. García-Valero*, S. Martínez-Martínez, A. Faz, J. Rivera, J.A. Acosta Sustainable Use, Management and Reclamation of Soil and Water Research Group. Universidad Politécnica de Cartagena, Paseo Alfonso XIII 48, 30203, Cartagena, Spain
A R T I C LE I N FO
A B S T R A C T
Keywords: Acid mine drainage Alkaline material Marl Sandstone Calcareous crust
Acid Mine Drainage (AMD) is an important source of pollution to the environment, characterized by a very low pH and high metal(loid)s concentration. The objective of this research was to evaluate the effect of three alkaline materials: marl, sandstone and calcareous crust on AMD neutralization and metal precipitation. To achieve this objective, a batch test was design, where a 5/10 alkaline material(g)/AMD(mL) ratio was used. In order to optimize the process, three particle sizes (2–10, 10–20 and 20−30 mm) of each material were used, and water samples were collected during the neutralization time. Due to the extreme pH of AMD used (pH < 2.5), it was necessary to carry out an AMD pretreatment, which consisted of adding 2.5 g of Ca(OH)2 per liter of AMD to raise a pH of 4. This pretreatment was essential because when AMD (pH < 4) was in contact with alkaline material a fast disintegration had place and a viscous substance was forming which prevented water rehabilitation. The results showed that the three alkaline materials reduced Fe, As, Cd, Cu, Pb and Zn concentrations in AMD, due mainly to their high carbonates content, which allowed metal(loid)s precipitation. The removal percentages were 100 % for Fe, Cu and Pb for marl, sandstone and calcareous crust, and about 60 % for Zn and Cd when sandstone was used. The optimal size particle was 20−30 mm for marl, while for sandstone with a size particle of 10−20 mm a considerable reduction of metal(loid)s in AMD was observed. Besides, the contact time required to neutralization of AMD and metal(loid)s reduction was lower for marl and sandstone than calcareous crust. Therefore, the results of this study showed that anyone of these alkaline materials could be used in AMD treatment depending on availability in the study area.
1. Introduction Mining and the aftermath of mining activity once the resource has expired tends to make a potential environmental and health risk causing negative impacts in the surrounding areas [1,2]. The extractive activity has a noticeable impact in the environment causing air pollution in open-pit mining because of the land movement and emissions of toxic gases in smelter [3], and changes in landscapes, modification of habitats, contamination of surface and groundwater, degradation of land resources, erosion and sedimentation processes, release of metal (oid)s and formation of acid mine drainage (AMD) [4], despite the economic positives that co-exist when the mine is operational [5]. One of the main environmental problems of sulfide mining is the generation of AMD [6], which is the result of sulfide-bearing rock oxidization to form sulfuric acid in the presence of atmospheric oxygen and water [7]. The resulting effluents are characterized by extreme acidity and a high level of dissolved metals [8] that, due to the corrosive nature, interacts with rocks containing different types of mineral
⁎
ore and easily provoking the solubility of toxic metals. As consequence the concentration of dissolved metals is increased in the receiving surface water stream and negatively affecting the stream biota [9] and damaging waterways and altering landscapes [10]. Soils contaminated with AMD have a deficit of necessary elements vital for the proper plant growth, therefore, revegetation and rehabilitation difficulties are longterm environmental impacts of AMD [11]. If left untreated AMD can contaminate ground and surface water and thereby damage ecosystems and potentially impact human health [12]. Thus, in order to preserve and protect the environment and enhance ecological sustainability, proper prevention of AMD generation should be one of the important preconditions [9]. The degree of environmental pollution by AMD is dependent on its composition and pH, which in turn may vary depending on both the geology of the mine sites and mining processes used [9]. Neutralization of acid water occurs in natural systems in association with some geological strata, which allow precipitate metals either as carbonates or as hydroxides. However, excess quantities of acid that are beyond the
Corresponding author. E-mail address: [email protected] (A. García-Valero).
https://doi.org/10.1016/j.jwpe.2019.101064 Received 9 July 2019; Received in revised form 8 November 2019; Accepted 16 November 2019 2214-7144/ © 2019 Elsevier Ltd. All rights reserved.
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
sealed and transport to the laboratory where was kept in refrigeration until it was analyzed. The period of sampling was on February 2018 when there is a low evapotranspiration with an average high temperature of 19.3 °C and an average low temperature of 9.9 °C, and an average rainfall of 22 mm during this month, which does not affect the characteristics of lake water. In order to select the materials to be used for AMD reclamation, geological and soil maps from areas close to mining area were evaluated. The geological study of the area revealed that huge amounts of carbonated sedimentary rocks such as marls and sandstones are available in the Sierra del Puerto, a mountain range located 40 km north of mining area (Fig. 1). In addition, many of the soil from Campo de Cartagena, which is the most important agricultural area close to mining activity, are composed by pretrocalcic horizons, which has been broken and placed in soil surface by farmers to allow proper rooting of crops, this material is called calcareous crust and it is consider a waste without any use (Fig. 1). Therefore, the alkaline materials used as acidneutralizing agents were marl, sandstone and calcareous crust for its high content of carbonates. They are used as acid-neutralizing agent which can be used as a complexing, binding or ions exchange agent for metal ions in liquid solution; it meaning metal(loid)s can precipitate [30]. About 10 kg of each of these materials were sampled, each material was mixed and homogenized and they were sieved in three size particles: 30−20 mm, 20−10 mm and 10−2 mm, which were used in the AMD treatment.
natural neutralizing systems are often produced. Therefore, the release of this toxic water onto land and natural water streams is unavoidable thus, causing dire environmental consequences [13]. If AMD is not managed properly, it causes considerable environmental degradation, water and soil contamination, severe health impact on nearby communities, biodiversity loss and aquatic ecosystem, whose negative environmental impacts pass from generation to generation [9]. Acid mine drainage can be treated with different technologies. The methods used to treat AMD can be classified as active or passive systems based on their requirements for chemical addition, infrastructure, maintenance and monitoring [14]. The active treatment methods include continuous addition of chemicals and substrates to precipitate metals, membrane processes, ion exchange, etc., that have been applied to reduce its negative impact on the receiving environment [13,15–18]. However, chemical treatment of AMD, which is composed of several dissolved toxic metals, is too complex, expensive and difficult to management, therefore one of the current research line is to use inexpensive materials for AMD reclamation. The passive treatments use systems which favors pseudo-natural processes [19], as such as chemical, biological and physical removal processes that occur naturally in the environment [20] and involves systems as constructed wetlands or bioreactors [9]. In fact, a variety of techniques have been tested and/or employed to control AMD at its source, including the use of limestone and alkaline industrial waste products, such as fly as cement kiln dust, green liquor dregs and bauxite residues [21]. The importance of calcareous materials in supplying carbonates to neutralize acidity, and contributing to buffer capacity of geological media is well recognized [22]. Marls are composed mainly of clay minerals and carbonates in different concentration, usually between 20 and 65 % [23,24] and they, together with limestones, are the most abundant rocks in the study area, Murcia Region. Sandstones are generally formed by various types of carbonate cements [25], specifically in Murcia Region they have a carbonated composition because of their grains and cements are usually calcium carbonate by the erosion of limestone rocks. Other common alkaline materials in Murcia Region, and in other areas with arid and semiarid climate, are the calcareous crusts that are formed as consequence of carbonate calcium precipitation, which usually are found in the foothills of the mountains and plainlands in this area. Therefore, the main objective of this study was to evaluate the efficiency of alkaline materials for AMD neutralization and metals precipitation, considering the following parameters to be optimized: a) type of alkaline material to be used, b) optimum particle size, and c) neutralization velocity.
2.2. Experiment design for acid mine drainage neutralization and metals/ arsenic immobilization The test to AMD reclamation consisted on put in contact acid water with different alkaline materials. Firstly, a previous test was performed to evaluate the behavior of alkaline material when they were contact with AMD of pH 2.5, the result was a high and fast degradation of the material and the formation of a sludge which prevented water sampling and analysis. This was caused by a fast degradation of carbonates of the alkaline materials and the formations of slurry with the rest of minerals, in addition the high concentration of iron in the AMD precipitated on the surface of this slurry prevent the water flow. In order to prevent this high and fast degradation of alkaline materials and formation of sludge, a pretreatment was carried out: AMD pH was increased up to 4 with calcium hydroxide (Ca(OH)2). Besides, in order to know the optimum amount of calcium hydroxide to be used, the pretreatment was carried out with a concentration from 0.5 g Ca(OH)2 L−1 to 5 g L−1 (data no showed), being 2.5 g Ca(OH)2 L−1 the selected concentration because it showed a pH close to 4 in AMD. Once the pretreatment was optimized, the main experimental setup was performed contacting the AMD at pH 4 with the three different alkaline materials and with three particles size: 30−20 mm, 20−10 mm and 10−2 mm (Fig. 2). Five hundred grams of each alkaline material were added into 1000 mL of AMD. pH and electrical conductivity (E.C.) were continually measured and 10 mL were extracted in different time (0, 15, 30, 60, 225, 345 s for marl; 0, 15, 30, 48, 240 s for sandstone; 0, 60, 120, 255, 555, 1155s for calcareous crust). Different sampling time was used because of the time of pH neutralization were different for each material. In each AMD sample metal(loid)s concentration was analyzed.
2. Materials and methods 2.1. Study area and sampling collection The study area is located in Murcia Region, SE Spain, this Region has a semiarid Mediterranean climate, with an average annual temperature of 18 °C and an average annual rainfall of 275 mm, and evapotranspiration rate exceeds 600 mm year −1 [26,27]. The AMD used in this study came from the Sierra Minera of Cartagena-La Unión (southeast of Spain), specifically from Brunita quarry where lead and zinc ores were mined, and whose mining operations finished in 1990, being operative for more than 2500 years [28]. Although the mining activity was abandoned thirty years ago, millions of tons of waste were accumulated on the surface of the land forming mining ponds and [29] causing changes in the visual characteristics of the area and produced physiographic modifications and alterations in the landscape [7]. These mining ponds are composed by high amounts of Fe-oxyhydroxides, sulphates, and potentially leachable metal(loid)s due to extreme acidic conditions and salinity. Once the mining was ceased, the groundwater was contaminated creating a red lake in the former Brunita quarry. The AMD used in this study were sampled from this lake (Fig. 1) and it was collected with a polyethylene container of 20 L, which was hermetically
2.3. Analytical methods 2.3.1. Analytical methods for acid mine drainage Acid mine drainage samples were filtered with a 0.45 μm paper filter before analysis. pH was determined using GLP21-CRISON, and E.C. using GLP31- CRISON. A mass spectrometer (ICP-MS) model Agilent 7500a was used to determine the total metal(loid)s concentrations (Fe, As, Cd, Cu, Pb and Zn) [31]. These metal(loid)s were selected because they were main metals extracted by the mining activity (pyrite, 2
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
Fig. 1. Sampling points in southeast of Murcia Region.
2.4. Statistical analysis
arsenopyrite, galena and sphalerite) and the main responsible of surface and groundwater pollution [32,33].
Microsoft Excel was used to perform a descriptive statistical analysis of the data. For the purpose of showing the metal(loid)s concentration when increased pH scatter plots were represented from a polynomial equation. Bar graphs were used to showed metals/arsenic concentration in AMD when it was treated with the three alkaline materials and with three different size particle from a polynomial equation. Speed of metal (loid)s reduction when AMD was treated with marl, sandstone and calcareous crust was represented with scatter plots.
2.3.2. Analytical methods for characterization of alkaline materials Alkaline materials samples were dried for 48 h at 45 °C. A split of each sample was ground using an agate mortar (RetschRM 100). The pH was measured in 1:1 water/alkaline material suspension [34] while the E.C. was measured in a 1:5 alkaline material/water suspension [35]. The equivalent calcium carbonate was determined using the Bernard´s calcimeter and the total metal(loid)s concentrations in alkaline materials were digested using HNO3 and H3ClO4 [36] and determinate by ICP-MS, model Agilent 7500a. Instrument optimization evaluation and quality control included the use of reference soil material from the Federal Institute for Material Research (BAM-U110), obtaining recoveries of 93–101 % for Cd, 95–98 % for Pb, 97–104 % for As, 96–105 % for Fe, 98–106 % for Zn, and 99–102 % for Cu, blanks and reference standards during the analyses, and sample replicates. The mineral composition of alkaline materials was determined by Xray diffraction (XRD) and scanning electron microscopy (SEM). X-ray diffraction analysis was conducted on randomly oriented ground samples, using a D8 X-ray diffractometer (Bruker, Germany) with Cu-Ka radiation operated at 40 kV and 30 mA. The morphology and the in situ chemical composition of samples were observed and determined using a XLS-30 SEM (Philips, The Netherlands) equipped with energy dispersive system (EDS). The sample for SEM analysis was mounted on an aluminum stub and coated with platinum for 3 min using a Denton™ vacuum system prior to submicroscopic observations. The SEM was operated at 15 keV and 1.94 A filament current. In situ chemical composition of particles was recorded in EDAX spectrum collected either in spot (∼1 mm) or full field of view mode for 400 s. Semi-quantitative ( ± 5 %) elemental composition of particles was corrected for Z (atomic number), A (absorption), and F (fluorescence) factors.
3. Results and discussion 3.1. Characteristics of acid mine drainage and alkaline materials pH, E.C. and concentration of metal(loid)s in AMD and alkaline materials are showed in Table 1. The acid mine drainage use in this study was catalogued as highly acid [37] and salty [38]. The results indicated that the concentrations of Fe, Cu, Zn, As, Cd, and Pb were high and similar to those reported in other studies [6,14]. In contrast, alkaline materials were characterized by a basic pH and no salinity [39]. Concentrations of Fe, Cu, Zn, As, Cd and Pb were low and similar to those found in sedimentary soils and rocks of Murcia Region [27]. The content of carbonates was very high for marl, sandstone and calcareous crust with values of 48, 65, 92 %, respectively, which suggests a high potential to be used as neutralization agent to increase pH in acidic water and therefore suitable to be used as a material to treat AMD [22]. Minerals identified in sandstone and marl were calcite (CaCO3), dolomite (MgCa(CO3)2) and quartz (SiO2). SEMEDAX analysis showed that the matrix of sandstone was mainly composed by sand size grains of quartz (50−2000 mm) cemented by calcite and dolomite minerals (Fig. 3a), while the matrix of marl was 3
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
removal efficiency is due to below pH 7 in AMD, Zn and Cd exists as Zn2+ and Cd2+ [14] forming an insoluble precipitate [40], probably ZnCO3 and CdCO3 [41–43]. Other studies had reported that Zn tends to precipitate as hydroxide Zn(OH)2 at a minimum pH of 8.4 when concrete is used [44]. In addition, other authors showed that in a pH range of 7–8.2 ionic zinc gets converted to a hydroycarbonate precipitate, hydrozoncite (Zn5(CO3)2(OH)6)) [14]. On the other hand, the lowest concentration of Zn in treated water was found for marl, while the highest was reported when calcareous crust was used, despite of its higher carbonate concentration and permeability [23]. However, this could occur because carbonates in marl were less cemented than in calcareous crust, and therefore, the surface to precipitate metal(loid)s was bigger. Oppositely, the reduction of Fe, Cu and Pb concentrations in AMD was higher at pH 5.5, finding the lowest concentrations of these three metals in AMD at pH 6.5 when marl was applied. The removal of these metals from AMD was relatively rapid with a sharp decline observed for all alkalis investigated. The remarkable removal efficiency of Fe, Cu and Pb was attributed to the availability of exchange sites for these elements [38] and the co-precipitation of Cu and Pb with Fe [44]. Evidently, as suggested these materials were effective in fully removing metals from acidic mine drainage, whose main mechanisms implied were the co-precipitation with carbonates when pH was increased [9]. The behavior of As was totally different to the previous metals, increasing its concentration with the pH for calcareous crust, while a slight decrease was observed when marl was used. In addition, sandstone had not significant variations in As concentrations when pH was increased. Other studies carried out with limestone showed As concentration significantly dropped [45]. This proves that the behavior of As in AMD is different depending on the material used for neutralization. Besides, in As-rich AMD waters, As is usually immobilized by coprecipitation with iron hydroxysulfates. However, this mechanism involves microbial mediated reactions that lead to incomplete removal of As [46]. Fig. 2. Schematic diagram of the laboratory experiments.
3.3. Influence of particle size of alkaline materials on treatment of AMD Table 1 Physicochemical characteristics and metal(loid)s contents in alkaline materials and acid mine drainage.
pH EC (dS m−1) Fe Cu Zn As Cd Pb Carbonates (%)
Marl*
Sandstone*
Calcareous Crust*
AMD**
8.1 1.61 254 16.9 258 0.16 0.13 24 48
9.6 0.53 352 12.5 264 0.14 0.20 29 65
8.8 0.31 375 12.8 242 0.11 0.25 42 92
2.3 7.90 863,916 3,306 160,188 190 466 43 nd
The particle size is one of the main factors affecting the efficiency of metal(loid)s removal processes. The effect of particle size of alkaline materials on the treatment efficiency of metal(loid)s, when pH of the AMD was 6.5, is shown in Fig. 5. The concentrations of all metal(loid)s were reduced for all particle size when marl was used. Fe, Cu and Pb were totally eliminated from AMD. However, Zn, As and Cd were reduced but they were not totally eliminated, obtaining the lower concentrations in AMD when the particle size of the marl was the highest (20−30 mm). This result can be due to because highest particles of marls are composed by higher concentration of carbonates and lower of clay than smaller one, which promotes the co-precipitation of Zn, As and Cd with carbonates. Oppositely, other studies have shown that smaller particles have larger specific surface area, allowing more contact with alkaline materials and, therefore, AMD neutralization [8]. Besides, all contaminants’ removal efficiency decreased when increase in particle size because smaller particles increase dissolution of CaCO3 in materials [30]. For sandstone, particles size of 20−30 mm, concentrations of Fe, Cu and Pb were not totally eliminated although they were considerably reduced. The other two particles size achieved concentrations close to cero for Fe, Cu and Pb in the AMD, mainly when 10−20 mm was the particle size used. The rest of metal(loid)s were decreased for all particle size with small variations among them. The heterogeneous behavior of metals removal when the particles sizes are used is due to sandstone with coarse, medium and fine grains have different microstructures and cementation degrees. Sandstones with medium and fine grains bear rich clay minerals, while sandstones with coarse grains contain very few clay minerals [47]. Besides, other research showed
* metal(loid)s mg kg−1. ** metal(loid)s μg L−1, nd: undetermined.
characterized by clay size grain of quartz (< 2 mm) cemented by carbonate minerals (Fig. 3b). In contrast, calcareous crust was mainly composed by a matrix of consolidated calcite, covered by small particles of quartz (< 10 mm) (Fig. 3c). 3.2. Effect of alkaline materials on AMD reclamation The behavior of metals and arsenic when pH in AMD was increased using different alkaline materials with a particle size of 10−20 mm is showed in Fig. 4. Both Zn and Cd concentrations had a progressive decrease for the three alkaline materials as pH was elevated. The results pointed out that Zn and Cd significantly decreased at 6.5 as a result of the high neutralizing ability of these alkaline materials. This high 4
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
Fig. 3. Scanning electronic microscope images for sandstone (a), marl (b), calcareous crust (b).
concentrations in AMD by 33–80 %, and Zn concentrations by over 95 %, while fly ash treatment reduced Cu concentrations by 99 % [10]. For marl and sandstone used in this study, Zn and Cd were removal about 60 % in AMD while calcareous crust had a removal efficiency of 40 % to Zn. Although the efficiencies were high for all alkaline materials, marl showed the best results likely because of its less cementation. However, Zn, As and Cd were not completely eliminated, therefore an additional treatment using chemicals should be evaluate to increase the removal effectivity [9]. However, at industrial scale the use of these materials as passive treatment could be enough to minimize the environmental impacts of AMD. This passive treatment would consist in the construction of alkaline channels, using calcareous crust, sandstone and marl, where the AMD would circulate by gravity, only it would be recommendable increase the contact time between these materials and the AMD to ensure acid neutralization and metals precipitation. In addition, a monitoring plan should be designed to assess the state of the alkaline material to replace it when excessive degradation is observed or when the efficiency of metal removal is below expected.
that sandstones are heavily compacted, being carbonates and clay minerals the predominant pore-filling diagenetic cements [25,45]. In addition, the intergranular pores, intragranular pores, microfractures and micropores of sandstones [25] could explain the different behavior of each size particle. Finally, the three particle sizes had a different effect on metals precipitation when calcareous crust was used (Fig. 5). Concentrations of Cu, Zn, Cd and As were higher for 10−20 mm particle size than for the other two particle sizes, however, metals in AMD were not completely eliminated in any case. In contrast, concentrations of Fe and Pb were almost eliminated from AMD, especially Pb, the main reason for this behavior is likely due to that calcareous crust grains are rapidly coated with a thin layer of iron prevented a efficient precipitation of the rest of metals [45]. 3.4. Effectiveness of acid neutralization and metals/arsenic immobilization Taking into account the concentrations of the studied metal(loid)s before and after AMD treatment by alkaline materials (marl, sandstone and calcareous crust) and for a size particle of 10−20 mm, metals mainly removed were Pb, Fe and Cu, with a removal percentage close to 100 % (Table 2). Other research evaluated the effectiveness of alkalis such as lime, sodium hydroxide or sodium carbonate, concluded that 99.7 % of Fe was removed [14]. Others found that 63.6 % of Fe was removal when stainless steel slag was applied compared to 99.7 % Fe removal when basic oxygen furnace slag was used [11]. In addition, it was evaluated the potential use of pervious concrete for treating AMD and reported a removal efficiency of 98 % for Fe in an AMD collected from a gold mine and 87 % for a AMD from a coalfield [44]. Similarly, significant reductions were obtained with cement kiln dust, lime kiln dust, red mud bauxite, coal fly ash, and blast furnace slag, which removed over 99 % of Cd, Cu, Fe, and Zn [9]. Considering the results of the total efficiencies in the treatment of AMD with powdered limestone and limewater Ca(OH)2 [45], the lower As efficiencies of removal were identified in accordance with our results (Table 2). Another study showed that recycled concrete aggregates treatment decreased Cu
3.5. Influence of contact time between alkaline materials-AMD Evolution of metals and arsenic concentrations vs contact time for the three alkaline materials used for AMD reclamation is showed in Fig. 6. Six minutes contact time was necessary to most of metal(loid)s concentration decreased in AMD when marl was used, although in the first minute the highest reductions were observed. Copper decreased considerably in the first minute, as well as Fe. Cadmium was progressively reduced and As and Pb were eliminated in AMD after 6 min contact time. Sandstone had a similar behavior than marl to minimize metal(loid)s from AMD; however, the necessary time to get similar reductions was 4 min. When AMD was treated with calcareous crust, Fe and Pb were eliminated at 19 min. Copper quickly decreased in the first two minutes while Cd and Zn showed a progressive decrease. The longer time of 5
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
Fig. 4. Variations of metals and arsenic concentration with the increase of pH in AMD.
4. Conclusions
neutralization compared with the previous materials is due to calcareous crust is more difficult to disintegrate since it is more compact and harder than marls and sandstone, and therefore, react more slowly than the previous alkali materials in spite of its high carbonates concentration. Other studies performed with carbide lime, which contains 94.3 % of CaO and with a metals concentration about 0.5–2.5 g L−1, needed between 5−70 min of reaction time to decrease metals [40].Similarly, the use of eggshells required 40 min to achieve complete removal of Fe [30].
Results showed that all alkaline materials tested (marl, sandstone and calcareous crust) can be used for AMD rehabilitation due to its high capability to increase pH and decrease metal(loid)s concentration by precipitation. However, Fe, Cu, Zn, As, Cd and Pb concentrations in AMD treated with marl were lower than those reported when sandstone and calcareous crust were used. In addition, the behavior of metals was different, Zn and Cd decreased progressively from pH 4 to pH 6.5, while Fe, Cu and Pb did it suddenly when pH was 5.5. Oppositely, arsenic 6
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
Fig. 5. Influence of particle size of alkaline materials on treatment of AMD.
iron prevented an efficient precipitation of the rest of metals. The removal efficiency of the three alkaline materials with a size particle of 10−20 mm was close to 100 % for Pb, Fe and Cu. However, sandstone reduced Zn and Cd about 60 % in AMD, and calcareous crust had a removal efficiency of 40 % for Zn. In order to increase the removal efficacy of these metals, additional treatment using chemicals should be evaluate. However, at large scale it would be recommendable increase the contact time between these materials and the AMD to ensure acid neutralization and metals precipitation. Marl and sandstone showed the shortest contact time with AMD for full neutralization allowing a fast precipitation of metal(loid)s. Oppositely, although calcareous crust has a carbonates concentration of 98 %, needed longer contact time to achieve the neutralization and metals precipitation, which was due to a more compact structure and harder consistence than marls and sandstone.
Table 2 Effectiveness of acid neutralization and metals/arsenic immobilization. Effectiveness (%)
Marl Sandstone Calcareous Crust
Fe
Cu
Zn
As
Cd
Pb
100 98 100
99 98 92
69 62 40
29 0 0
70 68 60
100 100 100
behavior was different to the previous metals, which depended on alkaline material used to treat AMD. The optimal particle size for metals removing from AMD when marl was used was 20−30 mm, however Fe, Cu and Pb were removed from AMD for all particle sizes, while Zn, As and Cd had lower concentrations for this size, which suggested that the higher amount of carbonate in the largest particles of marl promoted a higher co-pecipitation of metals. Sandstone allowed a high reduction of metal(loid)s in AMD for all particle size, being Fe, Cu and Pb specially decreased for 10−20 mm; however, Zn, Cd and As had similar reductions in AMD for the three particle size. Finally, although Fe and Pb were similarly removed for all particle size when AMD was treated with calcareous crust, the behavior of the rest of metal(loid)s was variable, which was likely due to calcareous crust grains are rapidly coated with a thin layer of
Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
7
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
[6]
[7]
[8]
[9]
[10] [11] [12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
Fig. 6. Metals and arsenic precipitation when AMD contact with alkaline materials.
[25]
References
[26]
[1] R. Zornoza, D.M. Carmona, J.A. Acosta, S. Martínez-Martínez, N. Weiss, Á. Faz, The effect of former mining activities on contamination dynamics in sediments, surface water and vegetation in El Avenque stream, SE Spain, Water Air Soil Pollut. 223 (2012) 519–532, https://doi.org/10.1007/s11270-011-0879-5. [2] E.J. Lam Esquenazi, B.F. Keith Norambuena, Í.L.M.B. Montofre Bacigalupo, M.E. Gálvez Estay, Necessity of intervention policies for tailings identified in the Antofagasta Region, Chile, Rev. Int. Contam. Ambient. 35 (2019) 515–539, https:// doi.org/10.20937/rica.2019.35.03.01. [3] E.L. Esquenazi, B.K. Norambuena, Í.M. Bacigalupo, M.G. Estay, Evaluation of soil intervention values in mine tailings in northern Chile, PeerJ 2018 (2018) 1–30, https://doi.org/10.7717/peerj.5879. [4] M. Gabarrón, A. Faz, S. Martínez-Martínez, J.A. Acosta, Change in metals and arsenic distribution in soil and their bioavailability beside old tailing ponds, J. Environ. Manage. 212 (2018) 292–300, https://doi.org/10.1016/j.jenvman.2018. 02.010. [5] D. Cozzolino, S. Chandra, J. Roberts, A. Power, P. Rajapaksha, N. Ball, R. Gordon, J. Chapman, There is gold in them hills: predicting potential acid mine drainage
[27]
[28]
[29]
[30]
8
events through the use of chemometrics, Sci. Total Environ. 619–620 (2018) 1464–1472, https://doi.org/10.1016/j.scitotenv.2017.11.063. R.A. Crane, D.J. Sapsford, Selective formation of copper nanoparticles from acid mine drainage using nanoscale zerovalent iron particles, J. Hazard. Mater. 347 (2018) 252–265, https://doi.org/10.1016/j.jhazmat.2017.12.014. J.A. Acosta, A. Abbaspour, G.R. Martínez, S. Martínez-Martínez, R. Zornoza, M. Gabarrón, A. Faz, Phytoremediation of mine tailings with Atriplex halimus and organic/inorganic amendments: a five-year field case study, Chemosphere. 204 (2018) 71–78, https://doi.org/10.1016/j.chemosphere.2018.04.027. C. Zhang, F. Xia, J. Long, B. Peng, An integrated technology to minimize the pollution of chromium in wet-end process of leather manufacture, J. Clean. Prod. 154 (2017) 276–283, https://doi.org/10.1016/j.jclepro.2017.03.216. K.K. Kefeni, T.A.M. Msagati, B.B. Mamba, Acid mine drainage: prevention, treatment options, and resource recovery: a review, J. Clean. Prod. 151 (2017) 475–493, https://doi.org/10.1016/j.jclepro.2017.03.082. S.N. Jones, B. Cetin, Evaluation of waste materials for acid mine drainage remediation, Fuel. 188 (2017) 294–309, https://doi.org/10.1016/j.fuel.2016.10.018. T. Name, C. Sheridan, Remediation of acid mine drainage using metallurgical slags, Miner. Eng. 64 (2014) 15–22, https://doi.org/10.1016/j.mineng.2014.03.024. B. Vital, J. Bartacek, J.C. Ortega-Bravo, D. Jeison, Treatment of acid mine drainage by forward osmosis: Heavy metal rejection and reverse flux of draw solution constituents, Chem. Eng. J. 332 (2018) 85–91, https://doi.org/10.1016/j.cej.2017.09. 034. Y. Nleya, G.S. Simate, S. Ndlovu, Sustainability assessment of the recovery and utilisation of acid from acid mine drainage, J. Clean. Prod. 113 (2016) 17–27, https://doi.org/10.1016/j.jclepro.2015.11.005. G. Kaur, S.J. Couperthwaite, B.W. Hatton-Jones, G.J. Millar, Alternative neutralisation materials for acid mine drainage treatment, J. Water Process Eng. 22 (2018) 46–58, https://doi.org/10.1016/j.jwpe.2018.01.004. F. Bilek, S. Wagner, Long term performance of an AMD treatment bioreactor using chemolithoautotrophic sulfate reduction and ferrous iron precipitation under in situ groundwater conditions, Bioresour. Technol. 104 (2012) 221–227, https://doi.org/ 10.1016/j.biortech.2011.11.022. M.S. Oncel, A. Muhcu, E. Demirbas, M. Kobya, A comparative study of chemical precipitation and electrocoagulation for treatment of coal acid drainage wastewater, J. Environ. Chem. Eng. 1 (2013) 989–995, https://doi.org/10.1016/j.jece. 2013.08.008. M. Peiravi, S.R. Mote, M.K. Mohanty, J. Liu, Bioelectrochemical treatment of acid mine drainage (AMD) from an abandoned coal mine under aerobic condition, J. Hazard. Mater. 333 (2017) 329–338, https://doi.org/10.1016/j.jhazmat.2017.03. 045. S. Ryu, G. Naidu, M.A. Hasan Johir, Y. Choi, S. Jeong, S. Vigneswaran, Acid mine drainage treatment by integrated submerged membrane distillation–sorption system, Chemosphere. 218 (2019) 955–965, https://doi.org/10.1016/j. chemosphere.2018.11.153. H.E. Ben Ali, C.M. Neculita, J.W. Molson, A. Maqsoud, G.J. Zagury, Performance of passive systems for mine drainage treatment at low temperature and high salinity: a review, Miner. Eng. 134 (2019) 325–344, https://doi.org/10.1016/j.mineng.2019. 02.010. A. Alsaiari, H.L. Tang, Field investigations of passive and active processes for acid mine drainage Treatment: Are anions a concern? Ecol. Eng. 122 (2018) 100–106, https://doi.org/10.1016/j.ecoleng.2018.07.035. M.G. Sephton, J.A. Webb, Application of Portland cement to control acid mine drainage generation from waste rocks, Appl. Geochem. 81 (2017) 143–154, https:// doi.org/10.1016/j.apgeochem.2017.03.017. A. Kastyuchik, A. Karam, M. Aïder, Effectiveness of alkaline amendments in acid mine drainage remediation, Environ. Technol. Innov. 6 (2016) 49–59, https://doi. org/10.1016/j.eti.2016.06.001. F. Lamas, F. Lamas-López, R. Bravo, Influence of carbonate content of marls used in dams: Geotechnical and statistical characterization, Eng. Geol. 177 (2014) 32–39, https://doi.org/10.1016/j.enggeo.2014.05.007. A.H. Vakili, R. Narimousa, M. Salimi, M.S. Farhadi, M. Dezh, Effect of freeze-thaw cycles on characteristics of marl soils treated by electroosmosis application, Cold Reg. Sci. Technol. 167 (2019) 102861, , https://doi.org/10.1016/j.coldregions. 2019.102861. J. Lai, D. Li, G. Wang, C. Xiao, J. Cao, C. Wu, C. Han, X. Zhao, Z. Qin, Can carbonate cementation be inhibited in continental red bed sandstone? J. Pet. Sci. Eng. 179 (2019) 1123–1135, https://doi.org/10.1016/j.petrol.2019.05.015. A. Faz, R. Arnaldos, H. Conesa, G. García, Soils affected by mining and industrial activities in Cartagena (SE Spain): classification problems, Eur. Soil Bur. Research r (2001) 165–170 https://pdfs.semanticscholar.org/6975/ 8b62727baad8a3ec090d105f89b3de5a083d.pdf. S. Martínez-Martínez, J.A. Acosta, A.F. Cano, D.M. Carmona, R. Zornoza, C. Cerda, Assessment of the lead and zinc contents in natural soils and tailing ponds from the Cartagena-La Unión mining district, SE Spain, J. Geochemical Explor. 124 (2013) 166–175, https://doi.org/10.1016/j.gexplo.2012.09.004. F.J. Morales Yago, La sierra de Cartagena-La Unión (Murcia): un ejemplo de actividad turística a través del patrimonio minero, Papeles Geogr. 61 (2015) 77, https://doi.org/10.6018/geografia/2015/218891. P. Martínez-Pagán, A. Faz, J.A. Acosta, D.M. Carmona, S. Martínez-Martínez, A multidisciplinary study for mining landscape reclamation: a study case on two tailing ponds in the Region of Murcia (SE Spain), Phys. Chem. Earth. 36 (2011) 1331–1344, https://doi.org/10.1016/j.pce.2011.02.007. A.M. Muliwa, T.Y. Leswifi, M.S. Onyango, Performance evaluation of eggshell waste material for remediation of acid mine drainage from coal dump leachate, Miner. Eng. 122 (2018) 241–250, https://doi.org/10.1016/j.mineng.2018.04.009.
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
[41] S.K. Thakur, N.K. Tomar, S.B. Pandeya, Influence of phosphate on cadmium sorption by calcium carbonate, Geoderma. 130 (2006) 240–249, https://doi.org/10. 1016/j.geoderma.2005.01.026. [42] S.M. Pourmortazavi, Z. Marashianpour, M.S. Karimi, M. Mohammad-Zadeh, Electrochemical synthesis and characterization of zinc carbonate and zinc oxide nanoparticles, J. Mol. Struct. 1099 (2015) 232–238, https://doi.org/10.1016/j. molstruc.2015.06.044. [43] M.S. Tizo, L.A.V. Blanco, A.C.Q. Cagas, B.R.B. Dela Cruz, J.C. Encoy, J.V. Gunting, R.O. Arazo, V.I.F. Mabayo, Efficiency of calcium carbonate from eggshells as an adsorbent for cadmium removal in aqueous solution, Sustain. Environ. Res. 28 (2018) 326–332, https://doi.org/10.1016/j.serj.2018.09.002. [44] A.N. Shabalala, S.O. Ekolu, S. Diop, F. Solomon, Pervious concrete reactive barrier for removal of heavy metals from acid mine drainage − column study, J. Hazard. Mater. 323 (2017) 641–653, https://doi.org/10.1016/j.jhazmat.2016.10.027. [45] Z.M. Migaszewski, A. Gałuszka, S. Dołęgowska, Arsenic in the Wiśniówka acid mine drainage area (south-central Poland) – mineralogy, hydrogeochemistry, remediation, Chem. Geol. 493 (2018) 491–503, https://doi.org/10.1016/j.chemgeo.2018. 06.027. [46] P. Le Pape, F. Battaglia-Brunet, M. Parmentier, C. Joulian, C. Gassaud, L. FernandezRojo, J.M. Guigner, M. Ikogou, L. Stetten, L. Olivi, C. Casiot, G. Morin, Complete removal of arsenic and zinc from a heavily contaminated acid mine drainage via an indigenous SRB consortium, J. Hazard. Mater. 321 (2017) 764–772, https://doi. org/10.1016/j.jhazmat.2016.09.060. [47] H. Li, H. Li, B. Gao, W. Wang, C. Liu, Study on pore characteristics and microstructure of sandstones with different grain sizes, J. Appl. Geophys. 136 (2017) 364–371, https://doi.org/10.1016/j.jappgeo.2016.11.015.
[31] W. APHA, AWWA, Standard Methods for Examination of Water and Wastewater, 22ndAmerican Public Health Association, Washington, 2012http://www. standardmethods.org/. [32] J.A. Acosta, A. Faz, S. Martínez-Martínez, R. Zornoza, D.M. Carmona, S. Kabas, Multivariate statistical and GIS-based approach to evaluate heavy metals behavior in mine sites for future reclamation, J. Geochemical Explor. 109 (2011) 8–17, https://doi.org/10.1016/j.gexplo.2011.01.004. [33] M. Gabarrón, A. Faz, J.A. Acosta, Use of multivariable and redundancy analysis to assess the behavior of metals and arsenic in urban soil and road dust affected by metallic mining as a base for risk assessment, J. Environ. Manage. 206 (2018) 192–201, https://doi.org/10.1016/j.jenvman.2017.10.034. [34] M. Peech, Methods of Soil Analysis, Black, Wisconsin, USA, (1965). [35] M. Andrades, Prácticas de Edafología y Climatología, Logroño, La Rioja, España, (1996). [36] D.E. Risser, Baker J.A, Testing soils for toxic metals, Soil Testi, soil sciences society of america spec, Publ, Madison, WI (1990). [37] O. Aduvire, Drenaje acido de mina generación y tratamiento, Madrid, Spain, (2006). [38] I. Moodley, C.M. Sheridan, U. Kappelmeyer, A. Akcil, Environmentally sustainable acid mine drainage remediation: research developments with a focus on waste/byproducts, Miner. Eng. 126 (2018) 207–220, https://doi.org/10.1016/j.mineng. 2017.08.008. [39] USDA NRCS, Natural Resources Conservation Service, (1996) Nrcs.usda.gov. [40] A. Othman, A. Sulaiman, S.K. Sulaiman, Carbide lime in acid mine drainage treatment, J. Water Process Eng. 15 (2017) 31–36, https://doi.org/10.1016/j.jwpe. 2016.06.006.
9
Contents lists available at ScienceDirect
Journal of Water Process Engineering journal homepage: www.elsevier.com/locate/jwpe
Environmentally sustainable acid mine drainage remediation: Use of natural alkaline material
T
A. García-Valero*, S. Martínez-Martínez, A. Faz, J. Rivera, J.A. Acosta Sustainable Use, Management and Reclamation of Soil and Water Research Group. Universidad Politécnica de Cartagena, Paseo Alfonso XIII 48, 30203, Cartagena, Spain
A R T I C LE I N FO
A B S T R A C T
Keywords: Acid mine drainage Alkaline material Marl Sandstone Calcareous crust
Acid Mine Drainage (AMD) is an important source of pollution to the environment, characterized by a very low pH and high metal(loid)s concentration. The objective of this research was to evaluate the effect of three alkaline materials: marl, sandstone and calcareous crust on AMD neutralization and metal precipitation. To achieve this objective, a batch test was design, where a 5/10 alkaline material(g)/AMD(mL) ratio was used. In order to optimize the process, three particle sizes (2–10, 10–20 and 20−30 mm) of each material were used, and water samples were collected during the neutralization time. Due to the extreme pH of AMD used (pH < 2.5), it was necessary to carry out an AMD pretreatment, which consisted of adding 2.5 g of Ca(OH)2 per liter of AMD to raise a pH of 4. This pretreatment was essential because when AMD (pH < 4) was in contact with alkaline material a fast disintegration had place and a viscous substance was forming which prevented water rehabilitation. The results showed that the three alkaline materials reduced Fe, As, Cd, Cu, Pb and Zn concentrations in AMD, due mainly to their high carbonates content, which allowed metal(loid)s precipitation. The removal percentages were 100 % for Fe, Cu and Pb for marl, sandstone and calcareous crust, and about 60 % for Zn and Cd when sandstone was used. The optimal size particle was 20−30 mm for marl, while for sandstone with a size particle of 10−20 mm a considerable reduction of metal(loid)s in AMD was observed. Besides, the contact time required to neutralization of AMD and metal(loid)s reduction was lower for marl and sandstone than calcareous crust. Therefore, the results of this study showed that anyone of these alkaline materials could be used in AMD treatment depending on availability in the study area.
1. Introduction Mining and the aftermath of mining activity once the resource has expired tends to make a potential environmental and health risk causing negative impacts in the surrounding areas [1,2]. The extractive activity has a noticeable impact in the environment causing air pollution in open-pit mining because of the land movement and emissions of toxic gases in smelter [3], and changes in landscapes, modification of habitats, contamination of surface and groundwater, degradation of land resources, erosion and sedimentation processes, release of metal (oid)s and formation of acid mine drainage (AMD) [4], despite the economic positives that co-exist when the mine is operational [5]. One of the main environmental problems of sulfide mining is the generation of AMD [6], which is the result of sulfide-bearing rock oxidization to form sulfuric acid in the presence of atmospheric oxygen and water [7]. The resulting effluents are characterized by extreme acidity and a high level of dissolved metals [8] that, due to the corrosive nature, interacts with rocks containing different types of mineral
⁎
ore and easily provoking the solubility of toxic metals. As consequence the concentration of dissolved metals is increased in the receiving surface water stream and negatively affecting the stream biota [9] and damaging waterways and altering landscapes [10]. Soils contaminated with AMD have a deficit of necessary elements vital for the proper plant growth, therefore, revegetation and rehabilitation difficulties are longterm environmental impacts of AMD [11]. If left untreated AMD can contaminate ground and surface water and thereby damage ecosystems and potentially impact human health [12]. Thus, in order to preserve and protect the environment and enhance ecological sustainability, proper prevention of AMD generation should be one of the important preconditions [9]. The degree of environmental pollution by AMD is dependent on its composition and pH, which in turn may vary depending on both the geology of the mine sites and mining processes used [9]. Neutralization of acid water occurs in natural systems in association with some geological strata, which allow precipitate metals either as carbonates or as hydroxides. However, excess quantities of acid that are beyond the
Corresponding author. E-mail address: [email protected] (A. García-Valero).
https://doi.org/10.1016/j.jwpe.2019.101064 Received 9 July 2019; Received in revised form 8 November 2019; Accepted 16 November 2019 2214-7144/ © 2019 Elsevier Ltd. All rights reserved.
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
sealed and transport to the laboratory where was kept in refrigeration until it was analyzed. The period of sampling was on February 2018 when there is a low evapotranspiration with an average high temperature of 19.3 °C and an average low temperature of 9.9 °C, and an average rainfall of 22 mm during this month, which does not affect the characteristics of lake water. In order to select the materials to be used for AMD reclamation, geological and soil maps from areas close to mining area were evaluated. The geological study of the area revealed that huge amounts of carbonated sedimentary rocks such as marls and sandstones are available in the Sierra del Puerto, a mountain range located 40 km north of mining area (Fig. 1). In addition, many of the soil from Campo de Cartagena, which is the most important agricultural area close to mining activity, are composed by pretrocalcic horizons, which has been broken and placed in soil surface by farmers to allow proper rooting of crops, this material is called calcareous crust and it is consider a waste without any use (Fig. 1). Therefore, the alkaline materials used as acidneutralizing agents were marl, sandstone and calcareous crust for its high content of carbonates. They are used as acid-neutralizing agent which can be used as a complexing, binding or ions exchange agent for metal ions in liquid solution; it meaning metal(loid)s can precipitate [30]. About 10 kg of each of these materials were sampled, each material was mixed and homogenized and they were sieved in three size particles: 30−20 mm, 20−10 mm and 10−2 mm, which were used in the AMD treatment.
natural neutralizing systems are often produced. Therefore, the release of this toxic water onto land and natural water streams is unavoidable thus, causing dire environmental consequences [13]. If AMD is not managed properly, it causes considerable environmental degradation, water and soil contamination, severe health impact on nearby communities, biodiversity loss and aquatic ecosystem, whose negative environmental impacts pass from generation to generation [9]. Acid mine drainage can be treated with different technologies. The methods used to treat AMD can be classified as active or passive systems based on their requirements for chemical addition, infrastructure, maintenance and monitoring [14]. The active treatment methods include continuous addition of chemicals and substrates to precipitate metals, membrane processes, ion exchange, etc., that have been applied to reduce its negative impact on the receiving environment [13,15–18]. However, chemical treatment of AMD, which is composed of several dissolved toxic metals, is too complex, expensive and difficult to management, therefore one of the current research line is to use inexpensive materials for AMD reclamation. The passive treatments use systems which favors pseudo-natural processes [19], as such as chemical, biological and physical removal processes that occur naturally in the environment [20] and involves systems as constructed wetlands or bioreactors [9]. In fact, a variety of techniques have been tested and/or employed to control AMD at its source, including the use of limestone and alkaline industrial waste products, such as fly as cement kiln dust, green liquor dregs and bauxite residues [21]. The importance of calcareous materials in supplying carbonates to neutralize acidity, and contributing to buffer capacity of geological media is well recognized [22]. Marls are composed mainly of clay minerals and carbonates in different concentration, usually between 20 and 65 % [23,24] and they, together with limestones, are the most abundant rocks in the study area, Murcia Region. Sandstones are generally formed by various types of carbonate cements [25], specifically in Murcia Region they have a carbonated composition because of their grains and cements are usually calcium carbonate by the erosion of limestone rocks. Other common alkaline materials in Murcia Region, and in other areas with arid and semiarid climate, are the calcareous crusts that are formed as consequence of carbonate calcium precipitation, which usually are found in the foothills of the mountains and plainlands in this area. Therefore, the main objective of this study was to evaluate the efficiency of alkaline materials for AMD neutralization and metals precipitation, considering the following parameters to be optimized: a) type of alkaline material to be used, b) optimum particle size, and c) neutralization velocity.
2.2. Experiment design for acid mine drainage neutralization and metals/ arsenic immobilization The test to AMD reclamation consisted on put in contact acid water with different alkaline materials. Firstly, a previous test was performed to evaluate the behavior of alkaline material when they were contact with AMD of pH 2.5, the result was a high and fast degradation of the material and the formation of a sludge which prevented water sampling and analysis. This was caused by a fast degradation of carbonates of the alkaline materials and the formations of slurry with the rest of minerals, in addition the high concentration of iron in the AMD precipitated on the surface of this slurry prevent the water flow. In order to prevent this high and fast degradation of alkaline materials and formation of sludge, a pretreatment was carried out: AMD pH was increased up to 4 with calcium hydroxide (Ca(OH)2). Besides, in order to know the optimum amount of calcium hydroxide to be used, the pretreatment was carried out with a concentration from 0.5 g Ca(OH)2 L−1 to 5 g L−1 (data no showed), being 2.5 g Ca(OH)2 L−1 the selected concentration because it showed a pH close to 4 in AMD. Once the pretreatment was optimized, the main experimental setup was performed contacting the AMD at pH 4 with the three different alkaline materials and with three particles size: 30−20 mm, 20−10 mm and 10−2 mm (Fig. 2). Five hundred grams of each alkaline material were added into 1000 mL of AMD. pH and electrical conductivity (E.C.) were continually measured and 10 mL were extracted in different time (0, 15, 30, 60, 225, 345 s for marl; 0, 15, 30, 48, 240 s for sandstone; 0, 60, 120, 255, 555, 1155s for calcareous crust). Different sampling time was used because of the time of pH neutralization were different for each material. In each AMD sample metal(loid)s concentration was analyzed.
2. Materials and methods 2.1. Study area and sampling collection The study area is located in Murcia Region, SE Spain, this Region has a semiarid Mediterranean climate, with an average annual temperature of 18 °C and an average annual rainfall of 275 mm, and evapotranspiration rate exceeds 600 mm year −1 [26,27]. The AMD used in this study came from the Sierra Minera of Cartagena-La Unión (southeast of Spain), specifically from Brunita quarry where lead and zinc ores were mined, and whose mining operations finished in 1990, being operative for more than 2500 years [28]. Although the mining activity was abandoned thirty years ago, millions of tons of waste were accumulated on the surface of the land forming mining ponds and [29] causing changes in the visual characteristics of the area and produced physiographic modifications and alterations in the landscape [7]. These mining ponds are composed by high amounts of Fe-oxyhydroxides, sulphates, and potentially leachable metal(loid)s due to extreme acidic conditions and salinity. Once the mining was ceased, the groundwater was contaminated creating a red lake in the former Brunita quarry. The AMD used in this study were sampled from this lake (Fig. 1) and it was collected with a polyethylene container of 20 L, which was hermetically
2.3. Analytical methods 2.3.1. Analytical methods for acid mine drainage Acid mine drainage samples were filtered with a 0.45 μm paper filter before analysis. pH was determined using GLP21-CRISON, and E.C. using GLP31- CRISON. A mass spectrometer (ICP-MS) model Agilent 7500a was used to determine the total metal(loid)s concentrations (Fe, As, Cd, Cu, Pb and Zn) [31]. These metal(loid)s were selected because they were main metals extracted by the mining activity (pyrite, 2
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
Fig. 1. Sampling points in southeast of Murcia Region.
2.4. Statistical analysis
arsenopyrite, galena and sphalerite) and the main responsible of surface and groundwater pollution [32,33].
Microsoft Excel was used to perform a descriptive statistical analysis of the data. For the purpose of showing the metal(loid)s concentration when increased pH scatter plots were represented from a polynomial equation. Bar graphs were used to showed metals/arsenic concentration in AMD when it was treated with the three alkaline materials and with three different size particle from a polynomial equation. Speed of metal (loid)s reduction when AMD was treated with marl, sandstone and calcareous crust was represented with scatter plots.
2.3.2. Analytical methods for characterization of alkaline materials Alkaline materials samples were dried for 48 h at 45 °C. A split of each sample was ground using an agate mortar (RetschRM 100). The pH was measured in 1:1 water/alkaline material suspension [34] while the E.C. was measured in a 1:5 alkaline material/water suspension [35]. The equivalent calcium carbonate was determined using the Bernard´s calcimeter and the total metal(loid)s concentrations in alkaline materials were digested using HNO3 and H3ClO4 [36] and determinate by ICP-MS, model Agilent 7500a. Instrument optimization evaluation and quality control included the use of reference soil material from the Federal Institute for Material Research (BAM-U110), obtaining recoveries of 93–101 % for Cd, 95–98 % for Pb, 97–104 % for As, 96–105 % for Fe, 98–106 % for Zn, and 99–102 % for Cu, blanks and reference standards during the analyses, and sample replicates. The mineral composition of alkaline materials was determined by Xray diffraction (XRD) and scanning electron microscopy (SEM). X-ray diffraction analysis was conducted on randomly oriented ground samples, using a D8 X-ray diffractometer (Bruker, Germany) with Cu-Ka radiation operated at 40 kV and 30 mA. The morphology and the in situ chemical composition of samples were observed and determined using a XLS-30 SEM (Philips, The Netherlands) equipped with energy dispersive system (EDS). The sample for SEM analysis was mounted on an aluminum stub and coated with platinum for 3 min using a Denton™ vacuum system prior to submicroscopic observations. The SEM was operated at 15 keV and 1.94 A filament current. In situ chemical composition of particles was recorded in EDAX spectrum collected either in spot (∼1 mm) or full field of view mode for 400 s. Semi-quantitative ( ± 5 %) elemental composition of particles was corrected for Z (atomic number), A (absorption), and F (fluorescence) factors.
3. Results and discussion 3.1. Characteristics of acid mine drainage and alkaline materials pH, E.C. and concentration of metal(loid)s in AMD and alkaline materials are showed in Table 1. The acid mine drainage use in this study was catalogued as highly acid [37] and salty [38]. The results indicated that the concentrations of Fe, Cu, Zn, As, Cd, and Pb were high and similar to those reported in other studies [6,14]. In contrast, alkaline materials were characterized by a basic pH and no salinity [39]. Concentrations of Fe, Cu, Zn, As, Cd and Pb were low and similar to those found in sedimentary soils and rocks of Murcia Region [27]. The content of carbonates was very high for marl, sandstone and calcareous crust with values of 48, 65, 92 %, respectively, which suggests a high potential to be used as neutralization agent to increase pH in acidic water and therefore suitable to be used as a material to treat AMD [22]. Minerals identified in sandstone and marl were calcite (CaCO3), dolomite (MgCa(CO3)2) and quartz (SiO2). SEMEDAX analysis showed that the matrix of sandstone was mainly composed by sand size grains of quartz (50−2000 mm) cemented by calcite and dolomite minerals (Fig. 3a), while the matrix of marl was 3
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
removal efficiency is due to below pH 7 in AMD, Zn and Cd exists as Zn2+ and Cd2+ [14] forming an insoluble precipitate [40], probably ZnCO3 and CdCO3 [41–43]. Other studies had reported that Zn tends to precipitate as hydroxide Zn(OH)2 at a minimum pH of 8.4 when concrete is used [44]. In addition, other authors showed that in a pH range of 7–8.2 ionic zinc gets converted to a hydroycarbonate precipitate, hydrozoncite (Zn5(CO3)2(OH)6)) [14]. On the other hand, the lowest concentration of Zn in treated water was found for marl, while the highest was reported when calcareous crust was used, despite of its higher carbonate concentration and permeability [23]. However, this could occur because carbonates in marl were less cemented than in calcareous crust, and therefore, the surface to precipitate metal(loid)s was bigger. Oppositely, the reduction of Fe, Cu and Pb concentrations in AMD was higher at pH 5.5, finding the lowest concentrations of these three metals in AMD at pH 6.5 when marl was applied. The removal of these metals from AMD was relatively rapid with a sharp decline observed for all alkalis investigated. The remarkable removal efficiency of Fe, Cu and Pb was attributed to the availability of exchange sites for these elements [38] and the co-precipitation of Cu and Pb with Fe [44]. Evidently, as suggested these materials were effective in fully removing metals from acidic mine drainage, whose main mechanisms implied were the co-precipitation with carbonates when pH was increased [9]. The behavior of As was totally different to the previous metals, increasing its concentration with the pH for calcareous crust, while a slight decrease was observed when marl was used. In addition, sandstone had not significant variations in As concentrations when pH was increased. Other studies carried out with limestone showed As concentration significantly dropped [45]. This proves that the behavior of As in AMD is different depending on the material used for neutralization. Besides, in As-rich AMD waters, As is usually immobilized by coprecipitation with iron hydroxysulfates. However, this mechanism involves microbial mediated reactions that lead to incomplete removal of As [46]. Fig. 2. Schematic diagram of the laboratory experiments.
3.3. Influence of particle size of alkaline materials on treatment of AMD Table 1 Physicochemical characteristics and metal(loid)s contents in alkaline materials and acid mine drainage.
pH EC (dS m−1) Fe Cu Zn As Cd Pb Carbonates (%)
Marl*
Sandstone*
Calcareous Crust*
AMD**
8.1 1.61 254 16.9 258 0.16 0.13 24 48
9.6 0.53 352 12.5 264 0.14 0.20 29 65
8.8 0.31 375 12.8 242 0.11 0.25 42 92
2.3 7.90 863,916 3,306 160,188 190 466 43 nd
The particle size is one of the main factors affecting the efficiency of metal(loid)s removal processes. The effect of particle size of alkaline materials on the treatment efficiency of metal(loid)s, when pH of the AMD was 6.5, is shown in Fig. 5. The concentrations of all metal(loid)s were reduced for all particle size when marl was used. Fe, Cu and Pb were totally eliminated from AMD. However, Zn, As and Cd were reduced but they were not totally eliminated, obtaining the lower concentrations in AMD when the particle size of the marl was the highest (20−30 mm). This result can be due to because highest particles of marls are composed by higher concentration of carbonates and lower of clay than smaller one, which promotes the co-precipitation of Zn, As and Cd with carbonates. Oppositely, other studies have shown that smaller particles have larger specific surface area, allowing more contact with alkaline materials and, therefore, AMD neutralization [8]. Besides, all contaminants’ removal efficiency decreased when increase in particle size because smaller particles increase dissolution of CaCO3 in materials [30]. For sandstone, particles size of 20−30 mm, concentrations of Fe, Cu and Pb were not totally eliminated although they were considerably reduced. The other two particles size achieved concentrations close to cero for Fe, Cu and Pb in the AMD, mainly when 10−20 mm was the particle size used. The rest of metal(loid)s were decreased for all particle size with small variations among them. The heterogeneous behavior of metals removal when the particles sizes are used is due to sandstone with coarse, medium and fine grains have different microstructures and cementation degrees. Sandstones with medium and fine grains bear rich clay minerals, while sandstones with coarse grains contain very few clay minerals [47]. Besides, other research showed
* metal(loid)s mg kg−1. ** metal(loid)s μg L−1, nd: undetermined.
characterized by clay size grain of quartz (< 2 mm) cemented by carbonate minerals (Fig. 3b). In contrast, calcareous crust was mainly composed by a matrix of consolidated calcite, covered by small particles of quartz (< 10 mm) (Fig. 3c). 3.2. Effect of alkaline materials on AMD reclamation The behavior of metals and arsenic when pH in AMD was increased using different alkaline materials with a particle size of 10−20 mm is showed in Fig. 4. Both Zn and Cd concentrations had a progressive decrease for the three alkaline materials as pH was elevated. The results pointed out that Zn and Cd significantly decreased at 6.5 as a result of the high neutralizing ability of these alkaline materials. This high 4
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
Fig. 3. Scanning electronic microscope images for sandstone (a), marl (b), calcareous crust (b).
concentrations in AMD by 33–80 %, and Zn concentrations by over 95 %, while fly ash treatment reduced Cu concentrations by 99 % [10]. For marl and sandstone used in this study, Zn and Cd were removal about 60 % in AMD while calcareous crust had a removal efficiency of 40 % to Zn. Although the efficiencies were high for all alkaline materials, marl showed the best results likely because of its less cementation. However, Zn, As and Cd were not completely eliminated, therefore an additional treatment using chemicals should be evaluate to increase the removal effectivity [9]. However, at industrial scale the use of these materials as passive treatment could be enough to minimize the environmental impacts of AMD. This passive treatment would consist in the construction of alkaline channels, using calcareous crust, sandstone and marl, where the AMD would circulate by gravity, only it would be recommendable increase the contact time between these materials and the AMD to ensure acid neutralization and metals precipitation. In addition, a monitoring plan should be designed to assess the state of the alkaline material to replace it when excessive degradation is observed or when the efficiency of metal removal is below expected.
that sandstones are heavily compacted, being carbonates and clay minerals the predominant pore-filling diagenetic cements [25,45]. In addition, the intergranular pores, intragranular pores, microfractures and micropores of sandstones [25] could explain the different behavior of each size particle. Finally, the three particle sizes had a different effect on metals precipitation when calcareous crust was used (Fig. 5). Concentrations of Cu, Zn, Cd and As were higher for 10−20 mm particle size than for the other two particle sizes, however, metals in AMD were not completely eliminated in any case. In contrast, concentrations of Fe and Pb were almost eliminated from AMD, especially Pb, the main reason for this behavior is likely due to that calcareous crust grains are rapidly coated with a thin layer of iron prevented a efficient precipitation of the rest of metals [45]. 3.4. Effectiveness of acid neutralization and metals/arsenic immobilization Taking into account the concentrations of the studied metal(loid)s before and after AMD treatment by alkaline materials (marl, sandstone and calcareous crust) and for a size particle of 10−20 mm, metals mainly removed were Pb, Fe and Cu, with a removal percentage close to 100 % (Table 2). Other research evaluated the effectiveness of alkalis such as lime, sodium hydroxide or sodium carbonate, concluded that 99.7 % of Fe was removed [14]. Others found that 63.6 % of Fe was removal when stainless steel slag was applied compared to 99.7 % Fe removal when basic oxygen furnace slag was used [11]. In addition, it was evaluated the potential use of pervious concrete for treating AMD and reported a removal efficiency of 98 % for Fe in an AMD collected from a gold mine and 87 % for a AMD from a coalfield [44]. Similarly, significant reductions were obtained with cement kiln dust, lime kiln dust, red mud bauxite, coal fly ash, and blast furnace slag, which removed over 99 % of Cd, Cu, Fe, and Zn [9]. Considering the results of the total efficiencies in the treatment of AMD with powdered limestone and limewater Ca(OH)2 [45], the lower As efficiencies of removal were identified in accordance with our results (Table 2). Another study showed that recycled concrete aggregates treatment decreased Cu
3.5. Influence of contact time between alkaline materials-AMD Evolution of metals and arsenic concentrations vs contact time for the three alkaline materials used for AMD reclamation is showed in Fig. 6. Six minutes contact time was necessary to most of metal(loid)s concentration decreased in AMD when marl was used, although in the first minute the highest reductions were observed. Copper decreased considerably in the first minute, as well as Fe. Cadmium was progressively reduced and As and Pb were eliminated in AMD after 6 min contact time. Sandstone had a similar behavior than marl to minimize metal(loid)s from AMD; however, the necessary time to get similar reductions was 4 min. When AMD was treated with calcareous crust, Fe and Pb were eliminated at 19 min. Copper quickly decreased in the first two minutes while Cd and Zn showed a progressive decrease. The longer time of 5
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
Fig. 4. Variations of metals and arsenic concentration with the increase of pH in AMD.
4. Conclusions
neutralization compared with the previous materials is due to calcareous crust is more difficult to disintegrate since it is more compact and harder than marls and sandstone, and therefore, react more slowly than the previous alkali materials in spite of its high carbonates concentration. Other studies performed with carbide lime, which contains 94.3 % of CaO and with a metals concentration about 0.5–2.5 g L−1, needed between 5−70 min of reaction time to decrease metals [40].Similarly, the use of eggshells required 40 min to achieve complete removal of Fe [30].
Results showed that all alkaline materials tested (marl, sandstone and calcareous crust) can be used for AMD rehabilitation due to its high capability to increase pH and decrease metal(loid)s concentration by precipitation. However, Fe, Cu, Zn, As, Cd and Pb concentrations in AMD treated with marl were lower than those reported when sandstone and calcareous crust were used. In addition, the behavior of metals was different, Zn and Cd decreased progressively from pH 4 to pH 6.5, while Fe, Cu and Pb did it suddenly when pH was 5.5. Oppositely, arsenic 6
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
Fig. 5. Influence of particle size of alkaline materials on treatment of AMD.
iron prevented an efficient precipitation of the rest of metals. The removal efficiency of the three alkaline materials with a size particle of 10−20 mm was close to 100 % for Pb, Fe and Cu. However, sandstone reduced Zn and Cd about 60 % in AMD, and calcareous crust had a removal efficiency of 40 % for Zn. In order to increase the removal efficacy of these metals, additional treatment using chemicals should be evaluate. However, at large scale it would be recommendable increase the contact time between these materials and the AMD to ensure acid neutralization and metals precipitation. Marl and sandstone showed the shortest contact time with AMD for full neutralization allowing a fast precipitation of metal(loid)s. Oppositely, although calcareous crust has a carbonates concentration of 98 %, needed longer contact time to achieve the neutralization and metals precipitation, which was due to a more compact structure and harder consistence than marls and sandstone.
Table 2 Effectiveness of acid neutralization and metals/arsenic immobilization. Effectiveness (%)
Marl Sandstone Calcareous Crust
Fe
Cu
Zn
As
Cd
Pb
100 98 100
99 98 92
69 62 40
29 0 0
70 68 60
100 100 100
behavior was different to the previous metals, which depended on alkaline material used to treat AMD. The optimal particle size for metals removing from AMD when marl was used was 20−30 mm, however Fe, Cu and Pb were removed from AMD for all particle sizes, while Zn, As and Cd had lower concentrations for this size, which suggested that the higher amount of carbonate in the largest particles of marl promoted a higher co-pecipitation of metals. Sandstone allowed a high reduction of metal(loid)s in AMD for all particle size, being Fe, Cu and Pb specially decreased for 10−20 mm; however, Zn, Cd and As had similar reductions in AMD for the three particle size. Finally, although Fe and Pb were similarly removed for all particle size when AMD was treated with calcareous crust, the behavior of the rest of metal(loid)s was variable, which was likely due to calcareous crust grains are rapidly coated with a thin layer of
Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
7
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
[6]
[7]
[8]
[9]
[10] [11] [12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
Fig. 6. Metals and arsenic precipitation when AMD contact with alkaline materials.
[25]
References
[26]
[1] R. Zornoza, D.M. Carmona, J.A. Acosta, S. Martínez-Martínez, N. Weiss, Á. Faz, The effect of former mining activities on contamination dynamics in sediments, surface water and vegetation in El Avenque stream, SE Spain, Water Air Soil Pollut. 223 (2012) 519–532, https://doi.org/10.1007/s11270-011-0879-5. [2] E.J. Lam Esquenazi, B.F. Keith Norambuena, Í.L.M.B. Montofre Bacigalupo, M.E. Gálvez Estay, Necessity of intervention policies for tailings identified in the Antofagasta Region, Chile, Rev. Int. Contam. Ambient. 35 (2019) 515–539, https:// doi.org/10.20937/rica.2019.35.03.01. [3] E.L. Esquenazi, B.K. Norambuena, Í.M. Bacigalupo, M.G. Estay, Evaluation of soil intervention values in mine tailings in northern Chile, PeerJ 2018 (2018) 1–30, https://doi.org/10.7717/peerj.5879. [4] M. Gabarrón, A. Faz, S. Martínez-Martínez, J.A. Acosta, Change in metals and arsenic distribution in soil and their bioavailability beside old tailing ponds, J. Environ. Manage. 212 (2018) 292–300, https://doi.org/10.1016/j.jenvman.2018. 02.010. [5] D. Cozzolino, S. Chandra, J. Roberts, A. Power, P. Rajapaksha, N. Ball, R. Gordon, J. Chapman, There is gold in them hills: predicting potential acid mine drainage
[27]
[28]
[29]
[30]
8
events through the use of chemometrics, Sci. Total Environ. 619–620 (2018) 1464–1472, https://doi.org/10.1016/j.scitotenv.2017.11.063. R.A. Crane, D.J. Sapsford, Selective formation of copper nanoparticles from acid mine drainage using nanoscale zerovalent iron particles, J. Hazard. Mater. 347 (2018) 252–265, https://doi.org/10.1016/j.jhazmat.2017.12.014. J.A. Acosta, A. Abbaspour, G.R. Martínez, S. Martínez-Martínez, R. Zornoza, M. Gabarrón, A. Faz, Phytoremediation of mine tailings with Atriplex halimus and organic/inorganic amendments: a five-year field case study, Chemosphere. 204 (2018) 71–78, https://doi.org/10.1016/j.chemosphere.2018.04.027. C. Zhang, F. Xia, J. Long, B. Peng, An integrated technology to minimize the pollution of chromium in wet-end process of leather manufacture, J. Clean. Prod. 154 (2017) 276–283, https://doi.org/10.1016/j.jclepro.2017.03.216. K.K. Kefeni, T.A.M. Msagati, B.B. Mamba, Acid mine drainage: prevention, treatment options, and resource recovery: a review, J. Clean. Prod. 151 (2017) 475–493, https://doi.org/10.1016/j.jclepro.2017.03.082. S.N. Jones, B. Cetin, Evaluation of waste materials for acid mine drainage remediation, Fuel. 188 (2017) 294–309, https://doi.org/10.1016/j.fuel.2016.10.018. T. Name, C. Sheridan, Remediation of acid mine drainage using metallurgical slags, Miner. Eng. 64 (2014) 15–22, https://doi.org/10.1016/j.mineng.2014.03.024. B. Vital, J. Bartacek, J.C. Ortega-Bravo, D. Jeison, Treatment of acid mine drainage by forward osmosis: Heavy metal rejection and reverse flux of draw solution constituents, Chem. Eng. J. 332 (2018) 85–91, https://doi.org/10.1016/j.cej.2017.09. 034. Y. Nleya, G.S. Simate, S. Ndlovu, Sustainability assessment of the recovery and utilisation of acid from acid mine drainage, J. Clean. Prod. 113 (2016) 17–27, https://doi.org/10.1016/j.jclepro.2015.11.005. G. Kaur, S.J. Couperthwaite, B.W. Hatton-Jones, G.J. Millar, Alternative neutralisation materials for acid mine drainage treatment, J. Water Process Eng. 22 (2018) 46–58, https://doi.org/10.1016/j.jwpe.2018.01.004. F. Bilek, S. Wagner, Long term performance of an AMD treatment bioreactor using chemolithoautotrophic sulfate reduction and ferrous iron precipitation under in situ groundwater conditions, Bioresour. Technol. 104 (2012) 221–227, https://doi.org/ 10.1016/j.biortech.2011.11.022. M.S. Oncel, A. Muhcu, E. Demirbas, M. Kobya, A comparative study of chemical precipitation and electrocoagulation for treatment of coal acid drainage wastewater, J. Environ. Chem. Eng. 1 (2013) 989–995, https://doi.org/10.1016/j.jece. 2013.08.008. M. Peiravi, S.R. Mote, M.K. Mohanty, J. Liu, Bioelectrochemical treatment of acid mine drainage (AMD) from an abandoned coal mine under aerobic condition, J. Hazard. Mater. 333 (2017) 329–338, https://doi.org/10.1016/j.jhazmat.2017.03. 045. S. Ryu, G. Naidu, M.A. Hasan Johir, Y. Choi, S. Jeong, S. Vigneswaran, Acid mine drainage treatment by integrated submerged membrane distillation–sorption system, Chemosphere. 218 (2019) 955–965, https://doi.org/10.1016/j. chemosphere.2018.11.153. H.E. Ben Ali, C.M. Neculita, J.W. Molson, A. Maqsoud, G.J. Zagury, Performance of passive systems for mine drainage treatment at low temperature and high salinity: a review, Miner. Eng. 134 (2019) 325–344, https://doi.org/10.1016/j.mineng.2019. 02.010. A. Alsaiari, H.L. Tang, Field investigations of passive and active processes for acid mine drainage Treatment: Are anions a concern? Ecol. Eng. 122 (2018) 100–106, https://doi.org/10.1016/j.ecoleng.2018.07.035. M.G. Sephton, J.A. Webb, Application of Portland cement to control acid mine drainage generation from waste rocks, Appl. Geochem. 81 (2017) 143–154, https:// doi.org/10.1016/j.apgeochem.2017.03.017. A. Kastyuchik, A. Karam, M. Aïder, Effectiveness of alkaline amendments in acid mine drainage remediation, Environ. Technol. Innov. 6 (2016) 49–59, https://doi. org/10.1016/j.eti.2016.06.001. F. Lamas, F. Lamas-López, R. Bravo, Influence of carbonate content of marls used in dams: Geotechnical and statistical characterization, Eng. Geol. 177 (2014) 32–39, https://doi.org/10.1016/j.enggeo.2014.05.007. A.H. Vakili, R. Narimousa, M. Salimi, M.S. Farhadi, M. Dezh, Effect of freeze-thaw cycles on characteristics of marl soils treated by electroosmosis application, Cold Reg. Sci. Technol. 167 (2019) 102861, , https://doi.org/10.1016/j.coldregions. 2019.102861. J. Lai, D. Li, G. Wang, C. Xiao, J. Cao, C. Wu, C. Han, X. Zhao, Z. Qin, Can carbonate cementation be inhibited in continental red bed sandstone? J. Pet. Sci. Eng. 179 (2019) 1123–1135, https://doi.org/10.1016/j.petrol.2019.05.015. A. Faz, R. Arnaldos, H. Conesa, G. García, Soils affected by mining and industrial activities in Cartagena (SE Spain): classification problems, Eur. Soil Bur. Research r (2001) 165–170 https://pdfs.semanticscholar.org/6975/ 8b62727baad8a3ec090d105f89b3de5a083d.pdf. S. Martínez-Martínez, J.A. Acosta, A.F. Cano, D.M. Carmona, R. Zornoza, C. Cerda, Assessment of the lead and zinc contents in natural soils and tailing ponds from the Cartagena-La Unión mining district, SE Spain, J. Geochemical Explor. 124 (2013) 166–175, https://doi.org/10.1016/j.gexplo.2012.09.004. F.J. Morales Yago, La sierra de Cartagena-La Unión (Murcia): un ejemplo de actividad turística a través del patrimonio minero, Papeles Geogr. 61 (2015) 77, https://doi.org/10.6018/geografia/2015/218891. P. Martínez-Pagán, A. Faz, J.A. Acosta, D.M. Carmona, S. Martínez-Martínez, A multidisciplinary study for mining landscape reclamation: a study case on two tailing ponds in the Region of Murcia (SE Spain), Phys. Chem. Earth. 36 (2011) 1331–1344, https://doi.org/10.1016/j.pce.2011.02.007. A.M. Muliwa, T.Y. Leswifi, M.S. Onyango, Performance evaluation of eggshell waste material for remediation of acid mine drainage from coal dump leachate, Miner. Eng. 122 (2018) 241–250, https://doi.org/10.1016/j.mineng.2018.04.009.
Journal of Water Process Engineering 33 (2020) 101064
A. García-Valero, et al.
[41] S.K. Thakur, N.K. Tomar, S.B. Pandeya, Influence of phosphate on cadmium sorption by calcium carbonate, Geoderma. 130 (2006) 240–249, https://doi.org/10. 1016/j.geoderma.2005.01.026. [42] S.M. Pourmortazavi, Z. Marashianpour, M.S. Karimi, M. Mohammad-Zadeh, Electrochemical synthesis and characterization of zinc carbonate and zinc oxide nanoparticles, J. Mol. Struct. 1099 (2015) 232–238, https://doi.org/10.1016/j. molstruc.2015.06.044. [43] M.S. Tizo, L.A.V. Blanco, A.C.Q. Cagas, B.R.B. Dela Cruz, J.C. Encoy, J.V. Gunting, R.O. Arazo, V.I.F. Mabayo, Efficiency of calcium carbonate from eggshells as an adsorbent for cadmium removal in aqueous solution, Sustain. Environ. Res. 28 (2018) 326–332, https://doi.org/10.1016/j.serj.2018.09.002. [44] A.N. Shabalala, S.O. Ekolu, S. Diop, F. Solomon, Pervious concrete reactive barrier for removal of heavy metals from acid mine drainage − column study, J. Hazard. Mater. 323 (2017) 641–653, https://doi.org/10.1016/j.jhazmat.2016.10.027. [45] Z.M. Migaszewski, A. Gałuszka, S. Dołęgowska, Arsenic in the Wiśniówka acid mine drainage area (south-central Poland) – mineralogy, hydrogeochemistry, remediation, Chem. Geol. 493 (2018) 491–503, https://doi.org/10.1016/j.chemgeo.2018. 06.027. [46] P. Le Pape, F. Battaglia-Brunet, M. Parmentier, C. Joulian, C. Gassaud, L. FernandezRojo, J.M. Guigner, M. Ikogou, L. Stetten, L. Olivi, C. Casiot, G. Morin, Complete removal of arsenic and zinc from a heavily contaminated acid mine drainage via an indigenous SRB consortium, J. Hazard. Mater. 321 (2017) 764–772, https://doi. org/10.1016/j.jhazmat.2016.09.060. [47] H. Li, H. Li, B. Gao, W. Wang, C. Liu, Study on pore characteristics and microstructure of sandstones with different grain sizes, J. Appl. Geophys. 136 (2017) 364–371, https://doi.org/10.1016/j.jappgeo.2016.11.015.
[31] W. APHA, AWWA, Standard Methods for Examination of Water and Wastewater, 22ndAmerican Public Health Association, Washington, 2012http://www. standardmethods.org/. [32] J.A. Acosta, A. Faz, S. Martínez-Martínez, R. Zornoza, D.M. Carmona, S. Kabas, Multivariate statistical and GIS-based approach to evaluate heavy metals behavior in mine sites for future reclamation, J. Geochemical Explor. 109 (2011) 8–17, https://doi.org/10.1016/j.gexplo.2011.01.004. [33] M. Gabarrón, A. Faz, J.A. Acosta, Use of multivariable and redundancy analysis to assess the behavior of metals and arsenic in urban soil and road dust affected by metallic mining as a base for risk assessment, J. Environ. Manage. 206 (2018) 192–201, https://doi.org/10.1016/j.jenvman.2017.10.034. [34] M. Peech, Methods of Soil Analysis, Black, Wisconsin, USA, (1965). [35] M. Andrades, Prácticas de Edafología y Climatología, Logroño, La Rioja, España, (1996). [36] D.E. Risser, Baker J.A, Testing soils for toxic metals, Soil Testi, soil sciences society of america spec, Publ, Madison, WI (1990). [37] O. Aduvire, Drenaje acido de mina generación y tratamiento, Madrid, Spain, (2006). [38] I. Moodley, C.M. Sheridan, U. Kappelmeyer, A. Akcil, Environmentally sustainable acid mine drainage remediation: research developments with a focus on waste/byproducts, Miner. Eng. 126 (2018) 207–220, https://doi.org/10.1016/j.mineng. 2017.08.008. [39] USDA NRCS, Natural Resources Conservation Service, (1996) Nrcs.usda.gov. [40] A. Othman, A. Sulaiman, S.K. Sulaiman, Carbide lime in acid mine drainage treatment, J. Water Process Eng. 15 (2017) 31–36, https://doi.org/10.1016/j.jwpe. 2016.06.006.
9