Precipitation of organic arsenic compounds and their degradation products during struvite formation
Precipitation of organic arsenic compounds and their degradation products during struvite formation
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鸟粪石形成过程中有机砷化合物及其降解产物的沉淀
DOI：
10.1016/j.jhazmat.2016.05.057
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发表时间：
2016
影响因子：
13.6
通讯作者：
Yu Han-Qing
中科院分区：
文献类型：
--
作者：
Lin Jin-Biao;Yuan Shoujun;Wang Wei;Hu Zhen-Hu;Yu Han-Qing
洛克沙胂（ROX）和阿散酸（ASA）已广泛用作有机砷动物饲料添加剂。有机砷化合物及其降解产物砷酸盐 (As(V)) 和亚砷酸盐 (As(III)) 存在于厌氧反应器的废水中，该反应器用铵 (NH4+-N) 和磷酸盐 (PO43−-P) 一起处理受 ROX 或 ASA 污染的动物粪便。因此，废水中的砷物质可能参与了鸟粪石的形成过程。在这项研究中，研究了有机砷化合物及其降解产物As(V)和As(III)在鸟粪石结晶中的参与情况。结果表明，砷化合物并未显着影响 PO43−P 的回收率，但证实了鸟粪石形成过程中砷的沉淀。鸟粪石中砷化合物的沉淀受溶液 pH 值（9.0 至 11.0）的显着影响。随着pH值的增加，沉淀中ASA和ROX的含量下降，而As(III)和As(V)的含量增加。此外，鸟粪石中As(V)的砷含量高于As(III)、ASA和ROX。结果表明，当溶液含有砷物质时，鸟粪石可能受到污染，但可以通过控制溶液 pH 值并在鸟粪石形成过程中保持厌氧条件来最大程度地减少污染。
Roxarsone (ROX) and arsanilic acid (ASA) have been extensively used as organoarsenic animal feed additives. Organic arsenic compounds and their degradation products, arsenate (As(V)) and arsenite (As(III)), exist in the effluent from anaerobic reactors treating animal manure contaminated by ROX or ASA with ammonium (NH4+-N) and phosphate (PO43−-P) together. Therefore, arsenic species in the effluent might be involved in the struvite formation process. In this study, the involvement of organic arsenic compounds and their degradation products As(V) and As(III) in the struvite crystallization was investigated. The results demonstrated that arsenic compounds did not substantially affect the PO43−-P recovery, but confirmed the precipitation of arsenic during struvite formation. The precipitation of arsenic compounds in struvite was considerably affected by a solution pH from 9.0 to 11.0. With an increase in pH, the content of ASA and ROX in the precipitation decreased, but the contents of As(III) and As(V) increased. In addition, the arsenic content of As(V) in the struvite was higher than that of As(III), ASA and ROX. The results indicated that the struvite could be contaminated when the solution contains arsenic species, but that could be minimized by controlling the solution pH and maintaining anaerobic conditions during struvite formation.