In this study, a wave rectified alternating current (RAC) electrocoagulation process was developed for the oxidative sequestration of As(III) via simultaneous generating Fe(II) and O₂ in the synthesized anoxic groundwater. The optimal T_Fe-anode/T_MMO-anode:T_power-off ratio (T is the time-taken in corresponding stage) and reaction period for As(III) sequestration were 1:2:1 and 24 s, respectively. Elevating electric current applied on the alternate iron/MMO anodes (30–50 mA) and solution pH (6.0–9.0) promoted As(III) sequestration, whereas the presence of HCO₃^– and PO₄^3– deteriorated As(III) sequestration. The intermediate Fe(IV) primarily accounted for the oxidation of As(III) to As(V), which can be readily sequestrated by the freshly generated Fe(III) (oxyhydr)oxides. The energy required for As(III) sequestration in the RAC electrocoagulation process was only 0.11 kW·h m^–3, which is much less than those in the traditional DC/AC electrocoagulation processes. Generally, this study offers an energy-efficient strategy to improve access to safe groundwater for millions of people.

中文翻译：

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合成缺氧地下水中As（III）氧化螯合的节能电化学策略

在这项研究中，通过在合成的缺氧地下水中同时生成Fe（II）和O ₂，开发了一种波整流交流（RAC）电凝工艺用于氧化螯合As（III）。As（III）螯合的最佳T _Fe阳极/ T _MMO阳极：T_断电比（T为相应阶段所花费的时间）和反应时间分别为1：2：1和24 s。在交替的铁/ MMO阳极上施加的电流升高（30–50 mA）和溶液pH值（6.0–9.0）促进了As（III）的螯合，而HCO ₃ ^–和PO ₄ ^{3–的存在}As（III）螯合性能恶化。中间的Fe（IV）主要是将As（III）氧化为As（V），这很容易被新鲜生成的Fe（III）（羟基）氧化物螯合。RAC电凝过程中As（III）螯合所需的能量仅为0.11 kW·hm ^-3，比传统的DC / AC电凝过程中的能量要少得多。通常，这项研究提供了一种节能战略，以改善数百万人获得安全地下水的途径。