Journal of the Taiwan Institute of Chemical Engineers ( IF 5.5 ) Pub Date : 2021-07-18 , DOI: 10.1016/j.jtice.2021.06.039 Yanan Ning 1 , Kai Li 1 , Zekun Zhao 1 , Dong Chen 1 , Yifan Li 1 , Yijie Liu 1 , Qipeng Yang 1 , Bo Jiang 1
To address future phosphorus scarcity and organophosphorus pesticides discharge associated environmental problems, a filter-press type electrochemical system was developed for acephate, a typical organophosphorus pesticide, degradation and simultaneous recovery of phosphorus. In this reaction system, boron-doped diamond (BDD) mediated anodic oxidation could transform acephate into ortho-phosphate (o-PO4) and then o-PO4 was precipitated with Ca2+ at the cathode surface in the form of hydroxyapatite induced by the local basic environment. The phosphorus recovery efficiency raised from 57 % to 92 % within 180 min by elevating current density from 5 to 30 mA/cm2, accompanying the enhanced acephate mineralization efficiency from 77% to 97%. These enhancement trends were attributed to the increased yield of BDD(•OH) and higher local pH near the cathode, respectively, at higher current density applied. Phosphorus recovery efficiency swelled by 15% with solution pH decreasing from 9.0 to 4.0 since anodic oxidation of acephate into o-PO4 was favorable in the acid solution. Moreover, phosphorus recovery was seriously depressed in the initial reaction stage with the presence of Mg2+, whereas bicarbonate posed the negative effect over the whole reaction process. Unexpectedly, the presence of Cl− inhibited the degradation of acephate since highly oxidative •OH was consumed by Cl−. In general, the electrochemical strategy of “anodic oxidation-cathodic precipitation” has been demonstrated practicable for phosphorus recovery from the organophosphorus wastewater.
中文翻译:
有机磷农药的同步电化学降解和磷的回收:阳极氧化和阴极沉淀的协同作用
为了解决未来磷稀缺和有机磷农药排放相关的环境问题,开发了一种压滤式电化学系统,用于降解和同时回收磷的典型有机磷农药乙酰甲胺磷。在该反应体系中,掺硼金刚石 (BDD) 介导的阳极氧化可将乙酰磷灰石转化为正磷酸盐 (o-PO 4 ),然后 o-PO 4与 Ca 2+在阴极表面以羟基磷灰石诱导的形式沉淀。由当地的基本环境决定。通过将电流密度从 5 mA/cm 2提高到 30 mA/cm 2,磷回收效率在 180 分钟内从 57 % 提高到 92 %,伴随着乙酰甲胺磷矿化效率从 77% 提高到 97%。这些增强趋势分别归因于在施加更高电流密度时BDD( • OH)产量增加和阴极附近更高的局部 pH 值。由于在酸溶液中乙酰甲胺磷阳极氧化为 o-PO 4是有利的,磷回收效率随着溶液 pH 值从 9.0 降低到 4.0 增加了 15% 。此外,Mg 2+的存在在初始反应阶段严重抑制了磷的回收率,而碳酸氢盐对整个反应过程产生了负面影响。出乎意料的是,Cl -的存在抑制了乙酰甲胺磷的降解,因为它具有高度氧化性•OH 被 Cl -消耗。总的来说,“阳极氧化-阴极沉淀”的电化学策略已被证明可用于从有机磷废水中回收磷。