Zhou Yongchao, Zheng Wenxin, Zhang Wenming, Zhang Yiping, Fang Lei
Institute of Municipal Engineering, Zhejiang University, Zhejiang, Hangzhou, 310058, People's Republic of China.
Dept. of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
Environ Sci Pollut Res Int. 2022 Aug;29(38):58088-58096. doi: 10.1007/s11356-022-20033-3. Epub 2022 Apr 1.
Improving the removal rate of pentavalent antimony (Sb(V)) by electrocoagulation (EC) is of great significance to the environment. In this paper, the EC with composite scrap iron and manganese filings as an anode (Fe-Mn EC) was investigated for the high-efficiency elimination of Sb(V). The results showed that Fe-Mn EC can enhance the removal of Sb(V) by 11.18-17.36% compared with the traditional iron electrocoagulation (Fe EC). Meanwhile, Sb(V) removal increased with the growth of current concentration as well as Mn content in the anode. However, the Sb(V) removal rate was inhibited when Mn content exceeded 20%. Moreover, the flocs generated during the Fe and Fe-Mn EC (Fe flocs and Fe-Mn flocs) were analyzed both structurally and theoretically using XRD, SEM, BET, and adsorption experiment. The results indicated that the components of Fe-Mn flocs were mostly Mn-substituted FeOOH, which appeared as the structure of nanometer flakes and large internal surface areas. Meanwhile, the Fe-Mn flocs had the ability of much faster Sb(V) adsorption rate; its Sb(V) adsorption capacity was 2.5 times more than that of the Fe flocs. The thermodynamics constants of both Fe and Fe-Mn flocs proved that adsorption was associated with monolayer physical adsorption. To the best of our knowledge, this is the first report of the electrocoagulation with composite scrap iron-manganese as an anode to remove Sb, which provide a new idea and potential technical support for the removal of Sb(V).
提高电凝聚法（EC）对五价锑（Sb(V)）的去除率对环境具有重要意义。本文研究了以复合废铁和锰屑为阳极的电凝聚法（Fe-Mn EC）对Sb(V)的高效去除。结果表明，与传统铁电凝聚法（Fe EC）相比，Fe-Mn EC可将Sb(V)的去除率提高11.18-17.36%。同时，Sb(V)的去除率随着电流浓度以及阳极中锰含量的增加而提高。然而，当锰含量超过20%时，Sb(V)的去除率受到抑制。此外，利用XRD、SEM、BET和吸附实验对Fe和Fe-Mn EC过程中产生的絮体（Fe絮体和Fe-Mn絮体）进行了结构和理论分析。结果表明，Fe-Mn絮体的成分主要是锰取代的FeOOH，呈纳米片状结构且具有较大的内表面积。同时，Fe-Mn絮体对Sb(V)的吸附速率更快；其对Sb(V)的吸附容量是Fe絮体的2.5倍。Fe絮体和Fe-Mn絮体的热力学常数均证明吸附与单层物理吸附有关。据我们所知，这是首次报道以复合废铁-锰为阳极的电凝聚法去除锑，为去除Sb(V)提供了新思路和潜在的技术支持。
