采用SBR反应器驯化中度嗜盐菌为主的活性污泥,高效处理高盐邻氯苯酚(2-CP)废水。不同盐度的驯化结果表明,当NaCl质量浓度为10~80g/L时,2-CP和COD的去除率均达到91%。当NaCl质量浓度为80g/L,2-CP质量浓度在1 000 mg/L以上时,去除率可以维持在98%,反应器达到最佳处理效果。在此条件下,活性污泥胞外聚合物(EPS)的含量最高达到142.6mg/g。随着盐度升高,EPS中的多糖含量也随之增加。采用显微镜和扫描电镜(SEM)观察,发现在高盐条件下,活性污泥中大部分微生物呈现球状,且菌群有自发聚集的趋势。16SrRNA基因文库分析表明,产碱杆菌是污泥中的优势菌群,它属于变形菌门。PCR扩增和测序分析2-CP降解途径的关键酶基因,发现羟化酶、氯代邻苯二酚1,2-双加氧酶和氯代邻苯二酚2,3-双加氧酶同时存在于活性污泥系统中,表明该活性污泥可能具有多样的2-CP降解途径。
The activated sludge dominated by moderately halophilic bacteria were acclimated using SBR reactor,which used to remove the 2-chlorophenol(2-CP)efficiently from wastewater.When the mass concentration of NaCl was between 10g/L and 80g/L,the removal rates of both 2-CP and COD reached91%.When the mass concentration of NaCl was 80g/L and the 2-CP mass concentration was above 1 000mg/L,the removal rate of 2-CP could maintain at 98%,in which the SBR reactor achieved the best treatment effect.The concentration of extracellular polymers(EPS)of activated sludge reached the highest amount of 142.6mg/g at this operation condition.With the increase of salinity,the amount of polysaccharide in EPS increased.As observed by using microscope and scanning electron microscopy(SEM),most of the microorganisms appeared pellets and the microbial community had a tendency to gather spontaneously under the high salinity condition.16 SrRNA gene clone library analysis showed that the dominated bacterial population in the activated sludge was Alcaligenes faecalis which belonged to Proteobacteria.PCR and sequence analysis of the key enzyme gene in 2-CP degradation showed that hydroxylase,chlorinated catechol 1,2-dioxygenase and chlorinated catechol 2,3-dioxygenase co-existed inthe activated sludge system,which indicated the diverse 2-CP degradation pathway.