对氯苯酚废水处理引起的活性污泥有机毒性

Organic toxicity of sludge caused by treating p-chlorophenol wastewater

以处理难降解有机污染物对氯苯酚(4-CP)模拟废水的序批式好氧活性污泥系统为研究对象,探讨活性污泥在降解4-CP的过程中污泥有机毒性的形成与空间分布规律,以及污泥有机毒性随时间的变化趋势。处理组污泥用10 mg/L的4-CP模拟废水进行驯化。控制SBR系统的水力停留时间(HRT)和污泥停留时间(SRT)分别为12 h和20 d。结果表明,随着驯化时间的延长,处理组污泥毒性先升高后降低,最终达到稳定状态。在整个运行过程中,处理组污泥毒性始终高于对照组。4-CP的吸附与降解实验表明,污泥外层胞外聚集物(EPS)主要起吸附4-CP且向内层传递的作用,污泥有机毒性主要是由4-CP的降解过程引起,少部分由污染物吸附所致。

The formation of sludge organic toxicity and its spatial distribution were investigated via an aerobic activated sludge system treating synthetic wastewater containing toxic and refractory p-chlorophenol（ 4-CP）.Control sludge was acclimated using 10 mg / L 4-CP. The hydraulic retention time（ HRT） and sludge retention time（ SRT） were controlled at 12 h and 20 d,respectively,in a sequencing batch reactor（ SBR）. The results showed that the sludge toxicity of the control group first increased and then decreased to a steady state with operation time. The sludge toxicity of the control group was always higher than the blank group. The 4-CP adsorption and biodegradation tests showed that outer extracellular polymeric substances（ EPS） absorbed 4-CP,which was transferred inside,and the sludge toxicity mainly resulted in the process of 4-CP biodegradation.