Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, China.
Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, China; Shanghai Institute of Pollution Control and Ecological Security, 1239 Siping Road, Shanghai, 200092, China.
Chemosphere. 2021 Jul;274:129790. doi: 10.1016/j.chemosphere.2021.129790. Epub 2021 Jan 27.
The co-presence of arsenic (As) and antimony (Sb) in water bodies has been commonly reported. The toxicity of As and Sb varies with different speciation. Herein, we designed a dual-functional electrochemical filter toward "one-step" detoxification and sequestration of highly toxic As(III) and Sb(III). The key to this technology is a functional anodic filter consists of nanoscale goethite and carbon nanotubes (CNT). Results showed that 97.9% As(III) and 91.9% Sb(III) transformation and 86.4% As and 70.1% Sb removal efficiency can be obtained over 2 h continuous filtration under optimized conditions. The As removal kinetics and efficiency enhanced with flow rate and applied voltage (e.g., the As removal efficiency increased from 62.9% at 0 V to 86.4% at 2.5 V). This enhancement in kinetics and efficiency can be explained by the synergistic effects of the flow-through design, plentiful exposed sorption sites, electrochemical reactivity, and nanoscale goethite. Moreover, the proposed technology works effectively across a wide pH range. Only negligible inhibition was observed in the presence of nitrate, chloride, and carbonate. Exhausted hybrid filters can be effectively regenerated by using chemical wash with NaOH solution. This study not only revealed the different adsorption behaviors of As(III) and Sb(III) on the hybrid filters, but also provided new insights into rational design of continuous-flow filters toward simultaneous decontamination of As(III) and Sb(III).
水体中砷（As）和锑（Sb）的共存现象已被广泛报道。As 和 Sb 的毒性因不同的形态而异。在此，我们设计了一种双重功能的电化学过滤器，用于“一步”解毒和固定高毒性的 As(III)和 Sb(III)。该技术的关键是一种功能性阳极过滤器，由纳米级针铁矿和碳纳米管（CNT）组成。结果表明，在优化条件下，经过 2 小时的连续过滤，可实现 97.9%的 As(III)和 91.9%的 Sb(III)转化以及 86.4%的 As 和 70.1%的 Sb 去除效率。在流速和施加电压（例如，从 0 V 时的 62.9%提高到 2.5 V 时的 86.4%）增加的情况下，As 的去除动力学和效率得到增强。这种动力学和效率的增强可以通过流通式设计、丰富的暴露吸附位点、电化学反应性和纳米级针铁矿的协同作用来解释。此外，所提出的技术在很宽的 pH 范围内都能有效工作。在存在硝酸盐、氯化物和碳酸盐的情况下，仅观察到可忽略的抑制作用。用过的混合过滤器可以通过使用 NaOH 溶液进行化学清洗来有效再生。本研究不仅揭示了 As(III)和 Sb(III)在混合过滤器上的不同吸附行为，而且为合理设计用于同时去除 As(III)和 Sb(III)的连续流过滤器提供了新的见解。
