State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, P.R. China.
Research Center for Environmental Nanotechnology (ReCENT), Nanjing University , Nanjing 210023, China.
Environ Sci Technol. 2017 Jun 6;51(11):6326-6334. doi: 10.1021/acs.est.7b00724. Epub 2017 May 19.
Water decontamination from As(III) is an urgent but still challenging task. Herein, we fabricated a bifunctional nanocomposite HFO@PS-Cl for highly efficient removal of As(III), with active chlorine covalently binding spherical polystyrene host for in situ oxidation of As(III) to As(V), and Fe(III) hydroxide (HFO) nanoparticles (NPs) embedded inside for specific As(V) removal. HFO@PS-Cl could work effectively in a wide pH range (5-9), and other substances like sulfate, chloride, bicarbonate, silicate, and humic acid exert insignificant effect on As(III) removal. As(III) sequestration is realized via two pathways, that is, oxidation to As(V) by the active chlorine followed by specific As(V) adsorption onto HFO NPs, and As(III) adsorption onto HFO NPs followed by oxidation to As(V). The exhausted HFO@PS-Cl could be refreshed for cyclic runs with insignificant capacity loss by the combined regeneration strategy, that is, alkaline solution to rinse the adsorbed As(V) and NaClO solution to renew the host oxidation capability. In addition, fixed-bed experiments demonstrated that the HFO@PS-Cl column could generate >1760 bed volume (BV) effluent from a synthetic As(III)-containing groundwater to meet the drinking water standard (<10 μg As/L), whereas other two HFO nanocomposites, HFO@PS-N and HFO@D201 could only generate 450 and 600 BV effluents under otherwise identical conditions.
从 As(III) 中进行水的脱污是一项紧迫但仍然具有挑战性的任务。在此，我们制备了一种双功能纳米复合材料 HFO@PS-Cl，用于高效去除 As(III)，其中活性氯通过共价键结合到球形聚苯乙烯主链上，用于原位将 As(III)氧化为 As(V)，并且 Fe(III)氢氧化物 (HFO)纳米颗粒 (NPs) 嵌入其中，用于特定的 As(V)去除。HFO@PS-Cl 可以在很宽的 pH 范围内（5-9）有效工作，并且像硫酸盐、氯化物、碳酸氢盐、硅酸盐和腐殖酸等其他物质对 As(III)去除的影响很小。As(III)的螯合通过两种途径实现，即活性氯将 As(III)氧化为 As(V)，然后通过特定的 As(V)吸附到 HFO NPs 上，以及 As(III)吸附到 HFO NPs 上，然后被氧化为 As(V)。通过联合再生策略，即用碱性溶液冲洗吸附的 As(V)和 NaClO 溶液来恢复主链的氧化能力，可以对耗尽的 HFO@PS-Cl 进行再生，以进行循环运行，而不会有明显的容量损失。此外，固定床实验表明，HFO@PS-Cl 柱可以从含 As(III)的地下水产生 >1760 倍床体积（BV）的出水，以满足饮用水标准（<10 μg As/L），而其他两种 HFO 纳米复合材料 HFO@PS-N 和 HFO@D201 在其他相同条件下只能产生 450 和 600 BV 的出水。
