活性污泥中氧氟沙星降解菌的筛选及其去除性能研究

Study on screening of ofloxacin degrading bacteria from activated sludge and its removal performance

为了研究氧氟沙星(OFL)的有效去除,从城市污水厂剩余活性污泥中筛选得到一株去除OFL的优势菌株(OF01),鉴定为Alcaligenes(产碱杆菌属).对细菌接种量、初始OFL浓度、温度、pH、碳源、盐浓度进行单因素优化,并在优化基础上进行正交试验,结果表明该菌株接种3~6天生长速率快,去除OFL的能力强,到第10天其生物量和OFL去除率达到最大值;在细菌接种量10%(v/v)、初始OFL浓度15 mg/L、培养温度30℃、pH=7、投加乙酸钠为碳源、盐浓度5 g/L的优化条件下OF01对OFL的去除率最大为65.16%.OF01菌株有着合格的去除OFL的能力,降解过程生成三种降解产物,降解途径为哌嗪环裂解和羟基化反应实现对OFL的降解.

A dominant strain,OF01,was isolated from the residual activated sludge of a municipal wastewater treatment plant and identified as Alcaligenes to study the efficient removal of Ofloxacin(OFL).Based on single-factor optimization,an orthogonal experiment was conducted for the inoculating amount of bacteria,initial OFL concentration,temperature,pH,carbon source,and salt concentration.The results demonstrated that the strain had a rapid growth rate and a strong ability to remove OFL within 3~6 days after inoculation.Its biomass and OFL removal rate reached its maximum on the tenth day.Under optimal conditions of 10%(V/V)OFL inoculation,an initial concentration of 15 mg/L,a culture temperature of 30℃,a pH of 7,the addition of sodium acetate as a carbon source,and a salt concentration of 5 g/L,the maximum OF01 removal rate of OFL was 65.16%.OF01 can remove OFL efficiently and the degradation process produces three degradation products,which are the degradation of the piperazine ring and the degradation of OFL by hydroxylation.