低浓度制药废水对AAO工艺污水厂的冲击影响及对策

The impact of low concentration pharmaceutical wastewater shock on AAO process WWTP and its countermeasures

针对某城市污水厂经常出现的低浓度制药废水冲击问题,在分析其进水水质和有机物分子质量分布的基础上,研究了低浓度制药废水冲击对于污水厂AAO工艺的污泥活性、出水水质和去除效果等方面的影响,并评估了所采取的工艺调控措施的效果。结果表明:低浓度制药废水含有芳香烃、长链烷烃和酰胺类大分子有机污染物,B/C为0.13,B/N为1.07,可生化性差,难降解且有生物毒性;低浓度制药废水冲击导致活性污泥中毒老化、性能变差,7 d左右污泥性能及出水水质显著变差;COD去除率从79.10%降至46.66%,氨氮、总氮去除率变化不大。常规工艺调控措施短期内对缓解COD去除效果不明显,对稳定氨氮、总氮的去除效果较好;采用应急投加活性炭、Fenton工艺等措施对于稳定COD去除的效果较好。研究结果可为应对低浓度制药废水冲击,制定相应工艺调控措施提供一定基础。

The impact of low concentration pharmaceutical wastewater shock on the sludge activity,effluent quality and removal effect of the AAO process in a municipal wastewater plant was investigated,based on the analysis of in⁃fluent quality and molecular weight distribution of organic matter,and the effect of control measures was evaluated.The results showed that the low concentration pharmaceutical wastewater contained aromatic hydrocarbons,longchain alkanes and amide macromolecular organic pollutants,with B/C of 0.13 and B/N of 1.07,which were poorly biochemical,difficult to degrade and biotoxic.The impact of low concentration pharmaceutical wastewater led to the aging of activated sludge performance,and the sludge performance and effluent quality deteriorated signifi⁃cantly around 7 d.The COD removal rate decreased from 79.10%to 46.66%,while the ammonia nitrogen and total nitrogen removal rates did not change much.The general process control measures had poor effect on COD removal in the short term,but were more effective on ammonia nitrogen and total nitrogen removal.Emergency dosing of acti⁃vated carbon and Fenton process were more effective for stabilising COD removal.The results of the study can pro⁃vide some basis for the development of corresponding process regulation measures in response to the impact of low concentration pharmaceutical wastewater.