Removal of Arsenic from Strongly Acidic Wastewater Using Phosphorus Pentasulfide As Precipitant: UV-Light Promoted Sulfuration Reaction and Particle Aggregation
Removal of Arsenic from Strongly Acidic Wastewater Using Phosphorus Pentasulfide As Precipitant: UV-Light Promoted Sulfuration Reaction and Particle Aggregation
复制标题
使用五硫化二磷作为沉淀剂去除强酸性废水中的砷：紫外光促进硫化反应和颗粒聚集
DOI：
10.1021/acs.est.8b00206
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发表时间：
2018
影响因子：
11.4
通讯作者：
Hu Xingyun
中科院分区：
文献类型：
--
作者：
Peng Xianjia;Chen Jingyi;Kong Linghao;Hu Xingyun
高砷浓度的强酸性废水（H2SO4）是许多工业生产中产生的。通过传统的硫化物（例如，Na2S、FeS）将阳离子（Na+和Fe2+）引入溶液中，这可能阻止酸的再循环。采用新型硫化剂五硫化二磷（P2S5）对强酸性废水进行了脱砷研究。在黑暗条件下，As（III）的去除效果较好，但As（V）的去除速度较慢，这是该方法的主要缺陷。我们发现，这一缺陷可以有效地克服紫外线照射，通过加速的中间物种，一硫代砷酸盐（H3AsO3S）在砷（V）去除过程中的形成和转化。此外，紫外光照射促进了P2S5的水解，从而提高了砷的去除效率。此外，还促进了所形成的颗粒的聚集。与FeS和Na2S不同，P2S5引入H3PO4代替阳离子进入溶液，有利于强酸性废水中砷和酸的回收和再利用。
Strongly acidic wastewater (H2SO4) with a high arsenic concentration is produced by many industries. The removal of arsenic by traditional sulfide (e.g., Na2S, FeS) from strongly acidic wastewater introduces cations (Na+and Fe2+) to the solution, which may prevent the recycle of acid. In this study, a new sulfuration agent, phosphorus pentasulfide (P2S5) was employed, and its feasibility in arsenic removal from strongly acidic wastewater was investigated. In the dark, As(III) was efficiently removed, but the removal rate of As(V) was rather slow, which was the crucial defect for this method. We found that this defect can be efficiently overcome by UV irradiation through accelerating the formation and transformation of an intermediate species, monothioarsenate (H3AsO3S) in the As(V) removal process. In addition, the hydrolysis of P2S5was enhanced under UV irradiation, which resulted in the increase of the arsenic removal efficiencies. Besides, the aggregation of the formed particles was also promoted. Different from FeS and Na2S, P2S5introduces H3PO4instead of cations to the solution, which can facilitate the recycle and reuse of arsenic and acid in strongly acidic wastewater.