School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
J Hazard Mater. 2014 Jan 15;264:278-85. doi: 10.1016/j.jhazmat.2013.10.002. Epub 2013 Oct 9.
The organic toxicity of sludge in land applications is a critical issue; however, minimal attention has been given to the mechanism of toxicity formation during high-strength wastewater treatment. To investigate the relevant factors that contribute to sludge toxicity, synthetic wastewater with N,N-dimethylformamide (DMF) was treated in a sequential aerobic activated sludge reactor. The acute toxicity of sludge, which is characterised by the inhibition rate of luminous bacteria T3, is the focus of this study. Using an operational time of 28 days and a hydraulic retention time of 12h, the study demonstrated a positive relationship between the acute toxicity of sludge and the influent DMF concentration; the toxicity centralised in the intracellular and inner sections of extracellular polymeric substances (EPS) in sludge flocs. Due to increased concentrations of DMF, which ranged from 40 to 200mgL(-1), the sludge toxicity increased from 25 to 45%. The organic toxicity in sludge flocs was primarily contributed by the biodegradation of DMF rather than adsorption of DMF. Additional investigation revealed a significant correlation between the properties of the bacterial community and sludge toxicity.
污泥的土地应用中的有机毒性是一个关键问题；然而，在高强度废水处理过程中，毒性形成的机制很少受到关注。为了研究导致污泥毒性的相关因素，采用序批式好氧活性污泥反应器处理含有 N，N-二甲基甲酰胺（DMF）的合成废水。本研究的重点是污泥的急性毒性，其特征是发光菌 T3 的抑制率。在 28 天的运行时间和 12 小时的水力停留时间下，研究表明污泥的急性毒性与进水 DMF 浓度呈正相关；毒性集中在污泥絮体的细胞内和细胞外聚合物（EPS）的内层。由于 DMF 的浓度从 40 到 200mgL(-1)增加，污泥毒性从 25 增加到 45%。污泥絮体中的有机毒性主要是由 DMF 的生物降解引起的，而不是 DMF 的吸附。进一步的研究表明，细菌群落的性质与污泥毒性之间存在显著的相关性。
