School of Chemical Engineering and Energy, Zhengzhou University, 100 Science Avenue, 450001, PR China.
School of Chemical Engineering and Energy, Zhengzhou University, 100 Science Avenue, 450001, PR China.
Sci Total Environ. 2018 Mar;616-617:1235-1241. doi: 10.1016/j.scitotenv.2017.10.194. Epub 2017 Oct 23.
In order to evaluate the influence of roxarsone (ROX) on the livestock wastewater treatment, a lab-scale pilot employing an anoxic-oxic (A-O) process was investigated by adding different concentrations of ROX at different periods. The mass balance of arsenic (As) in the A-O system was established through the analysis of As speciation and As migration in the gas, liquid and solid phases. The results showed that around 80% of total ROX (initial concentration was 50mgROXL) was eliminated in the anoxic reactor (R1) in which at least about 11% of total ROX was transformed to inorganic As (iAs) due to the direct breaking of the C-As bond of ROX. Inorganic As (iAs) and arsine (AsH) were produced in R1, while the generated iAs in the effluent of R1 was almost completely oxidized to iAs in the aerobic reactor (R2). However, the concentration of ROX in the effluent of R2 was almost the same as that in the effluent of R1. After 85days operation, iAs and residual ROX as the main forms of As were observed after the A-O process. Furthermore, the mass balance of As at steady state revealed that around 0.08%, 3.91% and 96.01% of total As was transformed into gas (biogas), solid (excess sludge) and liquid (effluent). Additionally, the 16S rRNA analysis demonstrated that the existence of ROX in livestock wastewater may play a crucial role in the diversity of bacterial community in the A-O system.
为了评估罗沙胂（ROX）对牲畜废水处理的影响，采用缺氧-好氧（A-O）工艺的实验室规模中试研究了在不同时期添加不同浓度的 ROX。通过分析气、液、固相间砷的形态和迁移，建立了 A-O 系统中砷的质量平衡。结果表明，在缺氧反应器（R1）中，约 80%的总 ROX（初始浓度为 50mgROXL）被去除，其中至少约 11%的总 ROX 由于 ROX 中 C-As 键的直接断裂而转化为无机砷（iAs）。在 R1 中产生了无机砷（iAs）和胂（AsH3），而 R1 出水中生成的 iAs 在好氧反应器（R2）中几乎完全被氧化为 iAs。然而，R2 出水中的 ROX 浓度几乎与 R1 出水中的 ROX 浓度相同。经过 85 天的运行，A-O 工艺后观察到 iAs 和残余 ROX 是砷的主要存在形式。此外，在稳定状态下的砷质量平衡表明，总砷的约 0.08%、3.91%和 96.01%分别转化为气体（沼气）、固体（剩余污泥）和液体（出水）。此外，16S rRNA 分析表明，牲畜废水中 ROX 的存在可能在 A-O 系统中细菌群落的多样性中发挥关键作用。
