Frontiers of Environmental Science and Engineering   2016 年 10 卷 6 期

2016.12.01

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, ROX) has been widely used for decades as an organoarsenic feed additive to control intestinal parasites and improve feed efficiency in animal production. However, most of the ROX is excreted into the manure, causing arsenic contamination in wastewater. The arsenic compounds are toxic to microorganisms, but the influence of continuous ROX loading on upflow anaerobic sludge blanket (UASB) reactor is still unknown. In this study, the impact of ROX and its degradation products on the performance of the UASB reactor and the degradation and speciation of ROX in the reactor were investigated. The UASB reactor (hydraulic retention time: 1.75 d) was operated using synthetic wastewater supplemented with ROX for a period of 260 days. With continuous ROX addition at 25.0 mg?·L