当前位置: X-MOL 学术Environ. Sci. Technol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Reductive Removal and Recovery of As(V) and As(III) from Strongly Acidic Wastewater by a UV/Formic Acid Process
Environmental Science & Technology ( IF 11.4 ) Pub Date : 2022-06-20 , DOI: 10.1021/acs.est.2c02129
Linghao Kong 1, 2 , Jinmin Zhao 1, 2, 3 , Xingyun Hu 1, 2 , Feng Zhu 1, 2, 3 , Xianjia Peng 1, 2, 3
Affiliation  

The removal of arsenic (As(V) and As(III)) from strongly acidic wastewater using traditional neutralization or sulfuration precipitation methods produces a large amount of arsenic-containing hazardous wastes, which poses a potential threat to the environment. In this study, an ultraviolet/formic acid (UV/HCOOH) process was proposed to reductively remove and recover arsenic from strongly acidic wastewater in the form of valuable elemental arsenic (As(0)) products to avoid the generation of hazardous wastes. We found that more than 99% of As(V) and As(III) in wastewater was reduced to highly pure solid As(0) (>99.5 wt %) by HCOOH under UV irradiation. As(V) can be efficiently reduced to As(IV) (H2AsO3 or H4AsO4) by hydrogen radicals (H) generated from the photolysis of HCOOH through dehydroxylation or hydrogenation. Then, As(IV) is reduced to As(III) by H or through its disproportionation. The reduction of As(V) to H4AsO4 by H and the disproportionation of H4AsO4 are the main reaction processes. Subsequently, As(III) is reduced to As(0) not only by H through stepwise dehydroxylation but also through the disproportionation of intermediate arsenic species As(II) and As(I). With additional density functional theory calculations, this study provides a theoretical foundation for the reductive removal of arsenic from acidic wastewater.

中文翻译:

紫外/甲酸工艺从强酸性废水中还原去除和回收 As(V) 和 As(III)

传统的中和或硫化沉淀法从强酸性废水中去除砷(As(V)和As(III))会产生大量含砷危险废物,对环境构成潜在威胁。在这项研究中,提出了一种紫外线/甲酸 (UV/HCOOH) 工艺,以还原方式从强酸性废水中以有价值的元素砷 (As(0)) 产品的形式去除和回收砷,以避免产生危险废物。我们发现,在紫外线照射下,HCOOH 将废水中超过 99% 的 As(V) 和 As(III) 还原为高纯度固体 As(0) (>99.5 wt%)。As( V )可以通过氢自由基H ) 由 HCOOH 通过脱羟基或氢化光解产生。然后,As(IV) 被 H 或通过歧化作用还原为 As(III)。H 将As(V)还原为H 4 AsO 4和H 4 AsO 4歧化是主要的反应过程。随后,As(III) 不仅通过 H 通过逐步脱羟基而且通过中间体砷物质 As(II) 和 As(I) 的歧化被还原为 As(0)。通过额外的密度泛函理论计算,本研究为酸性废水中砷的还原去除提供了理论基础。
更新日期:2022-06-20
down
wechat
bug