Efficient Removal of Trace Se(VI) by Millimeter-Sized Nanocomposite

Apr 17, 2017 - To address this problem, the millimeter-sized nanocomposite nZVI@D201 was fabricated by in situ preparation of nanoscale zerovalent iro...
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Efficient Removal of Trace Se(VI) by Millimeter-Sized Nanocomposite of Zerovalent Iron Confined in Polymeric Anion Exchanger Chao Shan,†,‡ Xing Wang,† Xiaohong Guan,§ Fei Liu,† Weiming Zhang,†,‡ and Bingcai Pan*,†,‡ †

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China ‡ Research Center for Environmental Nanotechnology (ReCENT), Nanjing University, Nanjing 210023, China § State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China S Supporting Information *

ABSTRACT: The removal of trace Se(VI) from water is a great challenge because its adsorption or ion-exchange is significantly inhibited by other coexisting anions at much greater levels. To address this problem, the millimeter-sized nanocomposite nZVI@D201 was fabricated by in situ preparation of nanoscale zerovalent iron (nZVI) confined in the pore channels of a polymeric anion exchanger (D201). Preferable removal of trace Se(VI) in the presence of sulfate by nZVI@D201 over D201, nZVI, and their mixture was attributed to the significant roles of pore confinement effect and the Donnan membrane effect from the polymeric host. Moreover, the removal of trace Se(VI) by nZVI@D201 was insignificantly affected by pH (3−10), dissolved oxygen, coexisting anions, and humic acid at their environmental levels. The XPS spectrum revealed that the Se immobilized in nZVI@D201 was mainly Se(IV) (84.9%), indicating the synergistic removal mechanism involving ion-exchange, adsorption, and reduction. Through the periodic/complete regeneration, nZVI@D201 could be sustainably utilized for Se(VI) removal. In addition, column experiments showed that nZVI@D201 exhibited great potential for practical trace Se(VI) removal in fixed-bed systems. larger specific surface area and higher reactivity.13,14 However, the aggregation and high mobility of nZVI limit its full-scale application in flow-through systems.15,16 Moreover, an extra process is required to separate the sludge of nZVI and its corrosion products from water after the treatment with nZVI. Nowadays, encapsulation of nZVI in porous materials has been considered to be an effective approach to solve the above issues.17−19 In our recent studies,10,20 a strongly basic anionexchanger, that is, D201, has been employed to fabricate a nanocomposite by in situ formation of nZVI inside the nanosized pore channels of the cross-linked polymeric host. Owing to the nondiffusible positive charge provided by the -N+(CH3)3 groups fixated on the host skeleton, an anionic pollutant such as NO3− could be favorably preconcentrated into the pore spaces prior to their further removal by the embedded ZVI nanoparticles.10,21 Considering that Se(VI) exists in the anionic form of SeO42− over a wide range of pH (3−11),22 it can be reasonably expected that the resultant nanocomposite would be promising for Se(VI) removal through combining the Donnan membrane effect of the host and the higher reactivity of ZVI nanoparticles confined in the pore channels. A

1. INTRODUCTION Although selenium is an essential trace element, excessive intake of Se could lead to serious health issues.1 Hence, the concentration of Se in drinking water is strictly limited. The maximum contaminant level (MCL) of Se in drinking water is set to be 10 μg/L by both the European Union and the national standard of China. To respond to such stringent regulations, efficient technologies for trace Se removal from water are in great demand. In the aquatic environment, Se is usually present in its inorganic forms including selenate [Se(VI)] and selenite [Se(IV)], which have distinct properties.2 Se(IV) is readily adsorbed on metal oxides, clays, and minerals via formation of inner-sphere complexes.3 In contrast, Se(VI) is weakly adsorbed via outer-sphere complexation, which is subject to severe interference induced by coexisting anions.4 Although numerous studies have reported satisfactory performance of Se(IV) removal using various techniques, the removal of trace Se(VI) remains the real challenge because its adsorption or ionexchange is greatly inhibited by the presence of other coexisting anions at much greater levels.5,6 Consequently, chemical reduction of Se(VI) to Se(IV) is an effective pretreatment approach prior to its effective sequestration via adsorption.7−9 Zerovalent iron (ZVI) has been extensively explored as a cost-effective material for water decontamination through synergistic reduction and adsorption.10−12 Especially, nanosized ZVI (nZVI) has attracted increasing attention because of its © XXXX American Chemical Society

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February 5, 2017 April 8, 2017 April 17, 2017 April 17, 2017 DOI: 10.1021/acs.iecr.7b00507 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

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Industrial & Engineering Chemistry Research

were withdrawn at desired time intervals and filtered through 0.45 μm membrane for Se analysis. The dosage of nZVI@D201 (0.20 g/L) was optimized according to preliminary experiments (Figure S1), by varying the dosage from 0.050 to 0.50 g/L. All the kinetic experiments were conducted in duplicate. 2.4. Effect of Solution Chemistry on Se(VI) Removal by nZVI@D201. 2.4.1. Effect of pH. To investigate the effect of pH on Se(VI) removal percentage, the initial pH of Se(VI) solution (also with 200 mg/L SO42−) was adjusted to integer values from 3 to 11 by using 0.50 M NaOH or HCl. The batch experiments of Se(VI) removal by nZVI@D201 were carried out in Erlenmeyer flasks in a thermostatic shaker at 25 °C and 250 rpm for 24 h. As for the effect of pH on the removal kinetics, additional experiments were conducted with the same method as in the kinetics study at initial pHs of 3, 5, 7, and 9, respectively. 2.4.2. Effect of DO. The effect of DO on the removal of Se(VI) by nZVI@D201 was investigated by the same method of the removal kinetics study but under aeration with N2, O2, and air, respectively. Prior to the addition of nZVI@D201, the solution was prepurged for 30 min, respectively. During the removal process, the solution was continuously purged to provide stable DO, which was measured by a DO fluorescent electrode. 2.4.3. Effect of Coexisting Anions and HA. The influence of coexisting anions were investigated in batch experiment mode (described in previous section) by introducing the corresponding sodium salts of chloride, carbonate, sulfate, nitrate, silicate, and phosphate into the Se(VI) solution, respectively, and the concentration of the coexisting anions was at gradient levels of 0, 0.1, 1, and 10 mM, respectively. Likewise, the HA stock solution was spiked into the Se(VI) solution (containing 200 mg/L SO42−) to obtain HA concentration of 0, 2, 4, 6, or 8 mg/ L (as TOC), respectively. 2.5. Regeneration and Reuse of nZVI@D201. In order to evaluate the reusability of nZVI@D201, an economic regeneration strategy, that is, five cycles of periodic regeneration followed by one-cycle complete regeneration, was adopted in this study. In each cycle, the removal process was carried out in Erlenmeyer flasks according to the same procedures as in the batch experiment for 24 h. After the removal process, the nZVI@D201 beads were separated from the solution, exposed to ultrasound treatment in 3% KBH4 solution for 30 min, shaken in the same solution at 25 °C and 250 rpm for 3.5 h to resuscitate the ZVI in the nanocomposite, and finally washed with deoxygenated water. The regenerated nZVI@D201 beads were shaken in 5 mM HCl for 10 min to remove the trace residual alkali and washed with deoxygenated water for the next cycle. After five cycles of Se(VI) removal and periodic regeneration, a complete regeneration was performed. The exhausted nZVI@D201 was shaken in 2.0 M HCl for 24 h to remove the substances inside the pore channels, and then was washed with deoxygenated water until reaching circumneutral pH (∼7). The recovered host beads were reused to impregnate ZVI following the same procedure for nZVI@ D201, and examined for next Se(VI) removal. 2.6. Fixed-Bed Experiments. Fixed-bed column experiments were carried out with a glass column (10 mm in diameter and 120 mm in length). Three materials, D201, nZVI@D201, and HFO@D201 (5.0 mL), were packed in three individual columns. The feeding solution containing Se(VI) and other ionic substances flowed down the column at a constant volumetric rate of 25 mL/h, equivalent to the empty

synergistic process of Se(VI) removal involving anionexchange, adsorption, and chemical reduction could be anticipated by employing the resultant nanocomposite. However, the performance and mechanism of Se(VI) removal by the proposed material has never been reported. Hence, the main objective of the present study is to investigate the performance and mechanism of trace Se(VI) removal by the nanocomposite nZVI@D201. The effect of pH, dissolved oxygen (DO), coexisting anions, and humic acid (HA) on the removal of Se(VI) by nZVI@D201 was particularly concerned. The removal mechanism was preliminarily revealed through characterizing the nanocomposite before and after reaction with Se(VI) with various techniques. Moreover, the regeneration and reuse of nZVI@D201 for sustainable Se(VI) removal was developed. In addition, the practical applicability of nZVI@D201 for Se(VI) removal in flow-through systems was considered by fixed-bed column experiments.

2. MATERIALS AND METHODS 2.1. Materials. The Se(VI) stock solution (10 mM) was prepared with ultrapure water using Na2SeO4 (Xiya Reagent, Chengdu, China). D201, a macroporous strongly basic anion exchanger, was purchased from Zhejiang Zhengguang Industrial Co., Ltd. (Hangzhou, China). Before using, the D201 beads were sieved to 0.6−0.8 mm, washed with 1.0 M NaOH, DI water, and 1.0 M HCl in turn, extracted with ethanol, and finally desiccated at 50 °C. The stock solution of HA was prepared by dissolving humic acid sodium salt (ARCOS, Belgium) in ultrapure water, adjusted with 1.0 M HCl to pH 7, and then filtered through a 0.45 μm membrane filter. The total organic carbon (TOC) of the HA stock solution was determined with a combustion-type TOC analyzer (TOC-L, Shimadzu, Japan). All other reagents were of analytical purity and purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China) unless otherwise stated. All the solutions were prepared with ultrapure water (18.2 MΩ cm). 2.2. Preparation of nZVI@D201. The nanocomposite nZVI@D201 was fabricated according to our previous study.10 Briefly, 2.0 g of preprocessed D201 was added into a 200 mL solution containing 2.0 M FeCl3 and 2.0 M HCl. The anionic FeCl4− was loaded through ion-exchange on D201 with the counterion Cl−. After 12 h of rotation in a shaker, the solid beads were rinsed five times with ethanol. Then, the nZVI@ D201 nanocomposite was obtained by ultrasonication in KBH4 solution (1.5% by weight), where the preloaded FeCl4− was reduced to Fe0. Finally, the resultant beads were filtered out, washed with deoxygenated water, and dried under vacuum for subsequent use. The bare nZVI was prepared by KBH4 reduction following the method of the previous study.23 Meanwhile, another nanocomposite, HFO@D201, with the same polymeric skeleton but containing nanohydrated Fe(III) oxide (HFO), was also prepared according to the method of our previous study24 and employed for comparison with nZVI@D201. 2.3. Removal of Se(VI) by nZVI@D201. The kinetics of Se(VI) removal by nZVI@D201 was studied as follows: 0.10 g of nZVI@D201 composite was added into 500 mL solution containing 200 μg/L Se(VI) and 200 mg/L SO42− with initial pH of 6.0 ± 0.1. Note that the sulfate addition was aimed to simulate the coexisting anions commonly present in natural waters, which is crucial to the performance of Se(VI) removal.5,6 Under continuous mechanic agitation, aliquots B

DOI: 10.1021/acs.iecr.7b00507 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

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charged quaternary ammonium groups of the D201 host, the high pHpzc of nZVI@D201 (9.5, Figure S2) ensured that the surface of nZVI@D201 was positively charged over a wide range of pH ( SiO32− > NO3− > SO42− > CO32− > Cl− (note that the formulas herein were given in their most deprotonated forms for simplicity). In the absence of any other anions, the removal of Se(VI) by nZVI@D201 was close to 100%. The presence of Cl− (up to 10 mM) did not exert noticeable influence on Se(VI) removal. SO42− and CO32− below 1 mM did not pose inhibitory influence on Se(VI) removal and marginally decreased the Se(VI) removal by 2% at the 10 mM level. The slight inhibition induced by SO42− was attributed to its competitive adsorption with SeO42−. However, the removal of Se(VI) was still above 98% at SO 4 2− concentration 4000 times higher than Se(VI), indicating the significant role of embedded ZVI nanoparticles taking into account that SO42− ions suppress Se(VI) removal by the D201 host (Figure S3). As for the CO32− anion at higher levels, the possible formation of FeCO3 on the surface of ZVI might be responsible for the slight decrease in Se(VI) removal (∼2%) by covering the active sites.17 The effect of NO3− below 1 mM was negligible. However, the removal of Se(VI) decreased to 60% in the presence of 10 mM NO3−. This could be ascribed to the electron acceptor nature of NO3−, which would compete with Se(VI) for electron.17 The presence of PO43− and SiO32− at 1 and 10 mM significantly inhibited Se(VI) removal by nZVI@ D201, because both anions could form inner-sphere complexes with iron (oxy)hydroxides and inhibit Se(VI) adsorption on ZVI surface.37 The inhibitory effect of PO43− was especially pronounced due to its superior adsorption affinity for iron

Figure 4. Effect of dissolved oxygen on the removal of Se(VI) by nZVI@D201. T = 25 °C, pH0 = 6.0 ± 0.1, [Se(VI)]0 = 200 μg/L, [SO42−] = 200 mg/L, nZVI@D201 dosage = 0.20 g/L.

curves in the N2- and air-aerated systems overlapped with each other, indicating that the removal of Se(VI) by nZVI@D201 was not affected by DO from 2.8 to 8.3 mg/L, which covered most of the DO range in natural waters. In the O2-aerated system, as DO increased to 24.5 mg/L, the rate constant of Se(VI) removal was decreased by 34% (Table S2). On one side, DO as an electron acceptor would compete with Se(VI) for electrons. On the other side, higher DO accelerated the oxygenadsorption corrosion of ZVI, and the increasing Fe oxides deposited on the ZVI surface were expected to hinder the electron transfer between ZVI and Se(VI).32 The XRD pattern of nZVI@D201 after reaction with Se(VI) (Figure S4) showed that the corrosion products of the embedded ZVI were mainly lepidocrocite and magnetite. Lepidocrocite could inhibit the electron transfer due to its poor conductivity, while magnetite has good conductivity and could facilitate electron transfer electron for Se(VI) reduction.33 Previous studies27,34 suggested that Fe2+ from ZVI corrosion enabled the transformation of E

DOI: 10.1021/acs.iecr.7b00507 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

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Industrial & Engineering Chemistry Research (oxy)hydroxides over SiO32−.38 In short, Cl−, SO42−, and CO32− posed negligible effects on Se(VI) removal by nZVI@ D201. In contrast, high level of NO3− inhibited Se(VI) removal through competition for electron, while SiO32− and PO43− significantly inhibited Se(VI) removal via occupation of adsorption sites. Nevertheless, all the six anions at environmental levels posed insignificant effect on Se(VI) removal. 3.2.5. Effect of HA. Due to the ubiquity of humic substances in natural waters, the effect of HA on the removal of Se(VI) by nZVI@D201 was investigated. It could be seen from Figure S5 that Se(VI) removal slightly decreased with the increase of HA concentration. However, even when the concentration of HA was up to 8 mg TOC/L, the removal of Se(VI) was still above 95% and the corresponding residual Se was below the MCL of 10 μg/L. Typically, HA is negatively charged, and its adsorption onto the corrosion products on the ZVI surface might be responsible for the slight inhibitory effect.39,40 On the other side, HA could form complexes with soluble Fe species.41,42 The formed complexes of large molecules and steric structures might hinder the mass transfer of Se(VI) and block some reactive sites. Nevertheless, in this study, the favorable performance might be attributed to the size exclusion effect, and the nanoporous structure of nZVI@D201 is supposed to hinder HA permeation inside the polymeric phase and interaction with the embedded ZVI nanoparticles.43 3.3. Mechanism of Se(VI) Removal by nZVI@D201. As shown in Figure 6a, after reaction with Se(VI), the distribution of Fe on the cross section of nZVI@D201 did not exhibit obvious difference from the original nanocomposite. The distribution of Se (Figure 6b) was highly consistent with that of Fe, indicating the immobilization of Se was mostly induced by the embedded ZVI. To further explore the mechanism of Se(VI) removal by nZVI@D201, the oxidation states of the immobilized Se were characterized. The fitted XPS highresolution spectrum of Se 3p of nZVI@D201 preloaded with Se(VI) is illustrated in Figure 7. It can be seen that the oxidation states of the immobilized Se consisted of Se(IV), Se(0), and Se(−II), accounting for 84.9%, 10.7%, and 4.4%, respectively. In contrast, no Se(VI) was detected, indicating that Se(VI) reduction is an important step during its sequestration by nZVI@D201. Previous studies7,15,44 showed that Fe(II) bound to the surface of core−shell structured ZVI/ corrosion products was highly reactive, capable of reducing Se(VI) to Se(IV). In addition, magnetite and lepidocrocite were formed during the reaction of nZVI@D201with Se(VI) (Figure S4), which had high adsorption affinity for Se(IV) via formation of inner-sphere complexes.45 Thereby, the largest proportion (84.9%) of Se was immobilized in the valence of Se(IV). Part of the adsorbed Se(IV) was further reduced to Se0 and even Se(−II) in the solid phase by ZVI.11 To sum up, the removal of Se(VI) by nZVI@D201 consisted of a synergetic process involving ion-exchange, adsorption, and reduction. 3.4. Regeneration and Reuse of nZVI@D201. The regeneration of nZVI@D201 and its reuse for Se(VI) removal was evaluated (Figure S6). The removal of Se was above 97% during the first four cycles, suggesting the effectiveness of periodic regeneration. However, it decreased to 77.6% in the fifth cycle, which could be caused by the gradual loss of Fe (from 14.8% to 12.2%) and accumulation of Se (up to 0.85%) in nZVI@D201 during the reuse cycles (Table S3). Considering the low cost of Fe source compared with the anion-exchanger host, the exhausted nZVI@D201 was completely regenerated, after which its Fe content returned

Figure 6. Elemental distribution of Fe (a) and Se (b) along the diameter on the cross section of nZVI@D201 after reaction with Se(VI). For the removal process, T = 25 °C, pH0 = 6.0 ± 0.1, [Se(VI)]0 = 200 μg/L, [SO42−] = 200 mg/L, nZVI@D201 dosage = 0.20 g/L, and contact time = 24 h.

Figure 7. Fitted high-resolution Se 3p XPS spectrum of nZVI@D201 after reaction with Se(VI).

to 14.4%, and its XRD pattern (Figure S7) solely showed similar characteristic Fe0 peak at 44.9° to the fresh nZVI@ D201. Moreover, the reprepared nZVI@D201 exhibited excellent Se(VI) removal, just like the fresh one (Figure S6). F

DOI: 10.1021/acs.iecr.7b00507 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

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Industrial & Engineering Chemistry Research 3.5. Fixed-Bed Column Experiments. The fixed-bed column experiments were carried out to further examine the applicability of nZVI@D201 for trace Se(VI) removal in flowthrough systems. Two widely used materials, D201 and HFO@ D201, were also employed for comparison. As seen from the breakthrough profiles of Se(VI) removal by the three materials (Figure 8), the effective treatable volume of D201, HFO@

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Figure 8. Breakthrough profile of Se during the removal of Se(VI) from synthetic feeding solution by nZVI@D201 in column reactor at 25 °C. EBCT = 12 min.

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D201 could serve as a promising nanocomposite for trace Se(VI) removal from water.

ASSOCIATED CONTENT

* Supporting Information S

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.iecr.7b00507. Method of potentiometric titration, details of pseudofirst-order kinetic model, pseudo-first-order kinetic parameters for Se(VI) removal by nZVI@D201 at different initial pHs and under different aeration conditions, variations of Fe and Se contents in nZVI@ D201 during the regeneration and reuse for Se(VI) removal, effect of nZVI@D201 dosage on the removal of Se(VI), potentiometric titration curves of D201, nZVI@ D201, and HFO@D201, effect of coexisting sulfate on the removal of Se(VI) by D201, XRD pattern of nZVI@ D201 after reaction with Se(VI), effect of humic acid on the removal of Se(VI) by nZVI@D201, regeneration and reuse of nZVI@D201 for Se(VI) removal, XRD pattern of nZVI@D201 after complete regeneration, and variation of Fe concentration and pH of the effluent from the nZVI@D201 column (PDF)

AUTHOR INFORMATION

Corresponding Author

D201 and nZVI@D201 before the breakthrough point was ∼520, ∼490, and ∼1240 bed volumes (BV). Column mode performance of D201 and nZVI@D201 is consistent with their batch removal experiments. As for HFO@D201, although HFO is an excellent sorbent for most inorganic anions,24,46 the adsorption of Se(VI) on HFO is via nonspecific outer-sphere complexation, and the coexisting anions would exert a negative role in Se(VI) removal. The above result further demonstrated the significant role of the synergistic process, that is, ionexchange, adsorption, and reduction, in Se(VI) removal by nZVI@D201. In addition, the concentration of Fe in the effluent was below 0.07 mg/L, which was far below the corresponding MCL (0.3 mg/L), and the effluent pH was stably maintained at around 7.4 (Figure S8). Generally speaking, nZVI@D201 exhibits great potential for trace Se(VI) removal in fixed-bed systems.

*E-mail: [email protected]. Tel: +86-25-8968-0390.

4. CONCLUSIONS In this study, the removal of trace Se(VI) by nZVI@D201 was systematically investigated in terms of both performance and mechanism. The removal of trace Se(VI) by nZVI@D201 was much more efficient than that by D201, nZVI, and their mixture, indicating the synergistic effect of the polymeric anionexchanger host and the embedded ZVI nanoparticles. The removal of trace Se(VI) by nZVI@D201 was effective over a wide pH range (3−10). The effects of DO, coexisting anions, and humic acid at their environmental levels on the removal of Se(VI) by nZVI@D201 were negligible. The removal of Se(VI) by nZVI@D201 was proven to proceed by a synergistic mechanism involving ion-exchange, adsorption, and reduction. Moreover, nZVI@D201 could be sustainably utilized for Se(VI) removal through the performance-dependent periodic or complete regeneration. In addition, nZVI@D201 exhibited great potential for trace Se(VI) removal in a fixed-bed system in comparison with D201 and HFO@D201. Therefore, nZVI@

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ORCID

Xiaohong Guan: 0000-0001-5296-423X Bingcai Pan: 0000-0003-3626-1539 Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This study was financially supported by National Key Research and Development Program of China (Grant No. 2016YFA0203104), Natural Science Foundation of China (Grant No. 51378279/51608255), Natural Science Foundation of Jiangsu Province (Grant No. BK20160653), China Postdoctoral Science Foundation (Grant No. 2016M600398), and Jiangsu Postdoctoral Science Foundation (Grant No. 1601040B). REFERENCES

(1) Tang, C.; Huang, Y.; Zhang, Z.; Chen, J.; Zeng, H.; Huang, Y. H. Rapid Removal of Selenate in a Zero-Valent Iron/Fe3O4/Fe2+ Synergetic System. Appl. Catal., B 2016, 184, 320−327. (2) Li, Y.; Cheng, W.; Sheng, G.; Li, J.; Dong, H.; Chen, Y.; Zhu, L. Synergetic Effect of a Pillared Bentonite Support on Se(VI) Removal by Nanoscale Zero Valent Iron. Appl. Catal., B 2015, 174−175, 329− 335. (3) Hayes, K. F.; Roe, A. L.; Brown, G. E.; Hodgson, K. O.; Leckie, J. O.; Parks, G. A. In Situ X-Ray Absorption Study of Surface Complexes: Selenium Oxyanions on α-FeOOH. Science 1987, 238, 783−786. (4) Yamani, J. S.; Lounsbury, A. W.; Zimmerman, J. B. Adsorption of Selenite and Selenate by Nanocrystalline Aluminum Oxide, Neat and Impregnated in Chitosan Beads. Water Res. 2014, 50, 373−381. (5) Jegadeesan, G.; Mondal, K.; Lalvani, S. B. Selenate Removal from Sulfate Containing Aqueous Solutions. Environ. Technol. 2005, 26, 1181−1187. G

DOI: 10.1021/acs.iecr.7b00507 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

Article

Industrial & Engineering Chemistry Research (6) Nishimura, T.; Hashimoto, H.; Nakayama, M. Removal of Selenium(VI) from Aqueous Solution with Polyamine-Type Weakly Basic Ion Exchange Resin. Sep. Sci. Technol. 2007, 42, 3155−3167. (7) Tang, C.; Huang, Y. H.; Zeng, H.; Zhang, Z. Reductive Removal of Selenate by Zero-Valent Iron: The Roles of Aqueous Fe2+ and Corrosion Products, and Selenate Removal Mechanisms. Water Res. 2014, 67, 166−174. (8) Murphy, A. P. Removal of Selenate from Water by Chemical Reduction. Ind. Eng. Chem. Res. 1988, 27, 187−191. (9) Mondal, K.; Jegadeesan, G.; Lalvani, S. B. Removal of Selenate by Fe and NiFe Nanosized Particles. Ind. Eng. Chem. Res. 2004, 43, 4922− 4934. (10) Jiang, Z.; Lv, L.; Zhang, W.; Du, Q.; Pan, B.; Yang, L.; Zhang, Q. Nitrate Reduction Using Nanosized Zero-Valent Iron Supported by Polystyrene Resins: Role of Surface Functional Groups. Water Res. 2011, 45, 2191−2198. (11) Zhang, Y. Q.; Wang, J. F.; Amrhein, C.; Frankenberger, W. T. Removal of Selenate from Water by Zerovalent Iron. J. Environ. Qual. 2005, 34, 487−495. (12) Fuller, S. J.; Stewart, D. I.; Burke, I. T. Chromate Reduction in Highly Alkaline Groundwater by Zerovalent Iron: Implications for Its Use in a Permeable Reactive Barrier. Ind. Eng. Chem. Res. 2013, 52, 4704−4714. (13) Crane, R. A.; Scott, T. B. Nanoscale Zero-Valent Iron: Future Prospects for an Emerging Water Treatment Technology. J. Hazard. Mater. 2012, 211-212, 112−125. (14) Yirsaw, B. D.; Megharaj, M.; Chen, Z.; Naidu, R. Environmental Application and Ecological Significance of Nano-Zero Valent Iron. J. Environ. Sci. 2016, 44, 88−98. (15) Guan, X.; Sun, Y.; Qin, H.; Li, J.; Lo, I. M. C.; He, D.; Dong, H. The Limitations of Applying Zero-Valent Iron Technology in Contaminants Sequestration and the Corresponding Countermeasures: The Development in Zero-Valent Iron Technology in the Last Two Decades (1994−2014). Water Res. 2015, 75, 224−248. (16) Saleh, N.; Kim, H.-J.; Phenrat, T.; Matyjaszewski, K.; Tilton, R. D.; Lowry, G. V. Ionic Strength and Composition Affect the Mobility of Surface-Modified Fe0 Nanoparticles in Water-Saturated Sand Columns. Environ. Sci. Technol. 2008, 42, 3349−3355. (17) Dong, H.; Chen, Y.; Sheng, G.; Li, J.; Cao, J.; Li, Z.; Li, Y. The Roles of a Pillared Bentonite on Enhancing Se(VI) Removal by ZVI and the Influence of Co-Existing Solutes in Groundwater. J. Hazard. Mater. 2016, 304, 306−312. (18) Liu, T.; Yang, X.; Wang, Z.-L.; Yan, X. Enhanced Chitosan Beads-Supported Fe0-Nanoparticles for Removal of Heavy Metals from Electroplating Wastewater in Permeable Reactive Barriers. Water Res. 2013, 47, 6691−6700. (19) Wu, X.; Yang, Q.; Xu, D.; Zhong, Y.; Luo, K.; Li, X.; Chen, H.; Zeng, G. Simultaneous Adsorption/Reduction of Bromate by Nanoscale Zerovalent Iron Supported on Modified Activated Carbon. Ind. Eng. Chem. Res. 2013, 52, 12574−12581. (20) Liu, F.; Shan, C.; Zhang, X.; Zhang, Y.; Zhang, W.; Pan, B. Enhanced Removal of EDTA-Chelated Cu(II) by Polymeric AnionExchanger Supported Nanoscale Zero-Valent Iron. J. Hazard. Mater. 2017, 321, 290−298. (21) Lofrano, G.; Carotenuto, M.; Libralato, G.; Domingos, R. F.; Markus, A.; Dini, L.; Gautam, R. K.; Baldantoni, D.; Rossi, M.; Sharma, S. K.; Chattopadhyaya, M. C.; Giugni, M.; Meric, S. Polymer Functionalized Nanocomposites for Metals Removal from Water and Wastewater: An Overview. Water Res. 2016, 92, 22−37. (22) Santos, S.; Ungureanu, G.; Boaventura, R.; Botelho, C. Selenium Contaminated Waters: An Overview of Analytical Methods, Treatment Options and Recent Advances in Sorption Methods. Sci. Total Environ. 2015, 521-522, 246−260. (23) Sun, Y.; Li, X.; Cao, J.; Zhang, W.; Wang, H. P. Characterization of Zero-Valent Iron Nanoparticles. Adv. Colloid Interface Sci. 2006, 120, 47−56. (24) Zhang, Q.; Pan, B.; Chen, X.; Zhang, W.; Pan, B.; Zhang, Q.; Lv, L.; Zhao, X. S. Preparation of Polymer-Supported Hydrated Ferric

Oxide Based on Donnan Membrane Effect and Its Application for Arsenic Removal. Sci. China, Ser. B: Chem. 2008, 51, 379−385. (25) Cumbal, L.; Sengupta, A. K. Arsenic Removal Using PolymerSupported Hydrated Iron(III) Oxide Nanoparticles: Role of Donnan Membrane Effect. Environ. Sci. Technol. 2005, 39, 6508−6515. (26) Comba, S.; Di Molfetta, A.; Sethi, R. A Comparison Between Field Applications of Nano-, Micro-, and Millimetric Zero-Valent Iron for the Remediation of Contaminated Aquifers. Water, Air, Soil Pollut. 2011, 215, 595−607. (27) Yoon, I. H.; Kim, K. W.; Bang, S.; Kim, M. G. Reduction and Adsorption Mechanisms of Selenate by Zero-Valent Iron and Related Iron Corrosion. Appl. Catal., B 2011, 104, 185−192. (28) Noubactep, C. An Analysis of the Evolution of Reactive Species in Fe0/H2O Systems. J. Hazard. Mater. 2009, 168, 1626−1631. (29) Shih, Y. H.; Hsu, C. Y.; Su, Y. F. Reduction of Hexachlorobenzene by Nanoscale Zero-Valent Iron: Kinetics, pH Effect, and Degradation Mechanism. Sep. Purif. Technol. 2011, 76, 268−274. (30) Dong, J.; Zhao, Y.; Zhao, R.; Zhou, R. Effects of pH and Particle Size on Kinetics of Nitrobenzene Reduction by Zero-Valent Iron. J. Environ. Sci. 2010, 22, 1741−1747. (31) Alowitz, M. J.; Scherer, M. M. Kinetics of Nitrate, Nitrite, and Cr(VI) Reduction by Iron Metal. Environ. Sci. Technol. 2002, 36, 299− 306. (32) Yin, W.; Wu, J.; Li, P.; Wang, X.; Zhu, N.; Wu, P.; Yang, B. Experimental Study of Zero-Valent Iron Induced Nitrobenzene Reduction in Groundwater: The Effects of pH, Iron Dosage, Oxygen and Common Dissolved Anions. Chem. Eng. J. 2012, 184, 198−204. (33) Huang, Y. H.; Tang, C.; Zeng, H. Removing Molybdate from Water using a Hybridized Zero-Valent Iron/Magnetite/Fe(II) Treatment System. Chem. Eng. J. 2012, 200−202, 257−263. (34) Ritter, K.; Odziemkowski, M. S.; Simpgraga, R.; Gillham, R. W.; Irish, D. E. An In Situ Study of the Effect of Nitrate on the Reduction of Trichloroethylene by Granular Iron. J. Contam. Hydrol. 2003, 65, 121−136. (35) Tang, S.; Wang, X.; Mao, Y.; Zhao, Y.; Yang, H.; Xie, Y. F. Effect of Dissolved Oxygen Concentration on Iron Efficiency: Removal of Three Chloroacetic Acids. Water Res. 2015, 73, 342−352. (36) Huang, Y. H.; Zhang, T. C. Effects of Dissolved Oxygen on Formation of Corrosion Products and Concomitant Oxygen and Nitrate Reduction in Zero-Valent Iron Systems with or without Aqueous Fe2+. Water Res. 2005, 39, 1751−1760. (37) Su, C. M.; Puls, R. W. Arsenate and Arsenite Removal by Zerovalent Iron: Effects of Phosphate, Silicate, Carbonate, Borate, Sulfate, Chromate, Molybdate, and Nitrate, Relative to Chloride. Environ. Sci. Technol. 2001, 35, 4562−4568. (38) Bergendahl, J. A.; Thies, T. P. Fenton’s Oxidation of MTBE with Zero-Valent Iron. Water Res. 2004, 38, 327−334. (39) Klausen, J.; Vikesland, P. J.; Kohn, T.; Burris, D. R.; Ball, W. P.; Roberts, A. L. Longevity of Granular Iron in Groundwater Treatment Processes: Solution Composition Effects on Reduction of Organohalides and Nitroaromatic Compounds. Environ. Sci. Technol. 2003, 37, 1208−1218. (40) Murphy, E. M.; Zachara, J. M.; Smith, S. C. Influence of Mineral-Bound Humic Substances on the Sorption of Hydrophobic Organic Compounds. Environ. Sci. Technol. 1990, 24, 1507−1516. (41) Liu, T.; Rao, P.; Lo, I. M. C. Influences of Humic Acid, Bicarbonate and Calcium on Cr(VI) Reductive Removal by ZeroValent Iron. Sci. Total Environ. 2009, 407, 3407−3414. (42) Tsang, D. C. W.; Graham, N. J. D.; Lo, I. M. C. Humic Acid Aggregation in Zero-Valent Iron Systems and Its Effects on Trichloroethylene Removal. Chemosphere 2009, 75, 1338−1343. (43) Lin, B.; Hua, M.; Zhang, Y.; Zhang, W.; Lv, L.; Pan, B. Effects of Organic Acids of Different Molecular Size on Phosphate Removal by HZO-201 Nanocomposite. Chemosphere 2017, 166, 422−430. (44) Noubactep, C. Metallic Iron for Environmental Remediation: a Review of Reviews. Water Res. 2015, 85, 114−123. H

DOI: 10.1021/acs.iecr.7b00507 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

Article

Industrial & Engineering Chemistry Research (45) Martinez, M.; Gimenez, J.; de Pablo, J.; Rovira, M.; Duro, L. Sorption of Selenium(IV) and Selenium(VI) onto Magnetite. Appl. Surf. Sci. 2006, 252, 3767−3773. (46) You, X. L.; Guaya, D.; Farran, A.; Valderrama, C.; Cortina, J. L. Phosphate Removal from Aqueous Solution Using a Hybrid Impregnated Polymeric Sorbent Containing Hydrated Ferric Oxide (HFO). J. Chem. Technol. Biotechnol. 2016, 91, 693−704.

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DOI: 10.1021/acs.iecr.7b00507 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX