重金属镉胁迫下多种污染物的协同去除研究

Study on Simultaneous Removal of Multi-Pollutants Under Cadmium Stress

研究了MBR在重金属镉胁迫下对多种污染物的同步去除效果及微生物种群特征。结果表明,低含量的镉离子不利于自养脱氮,长期作用后导致自养脱氮微生物厌氧氨氧化菌相对丰度从16.2%降低到9.9%,但可以通过升高碱度提高pH并降低DO含量的方式使自养脱氮得到部分恢复。在长期镉胁迫下有机物去除有降低趋势,但随着反硝化的增强可恢复有机物去除性能。镉胁迫对MBR系统中的浊度去除效果没有影响,浊度去除率始终保持在98%以上。镉离子长期作用对微生物种群影响较大,反硝化菌相对丰度从0.21%增加到8.03%,2种耐镉菌群Pseudomonas和Pseudoxanthomonas分别从最初的0.23%和0.15%增加到了第60天的1.83%和2.07%。

The simultaneous removal of multi-pollutants by MBR under cadmium stress and microbial characteristics was investigated. Results showed that the low content of cadmium ion was adverse to autotrophic nitrogen removal, and the long-term effect led to the abundance decrease of anaerobic ammonia-oxidizing bacteria from 16.2% to 9.9%. Increased pH and lowered DO content could help recover the nitrogen removal performance. The organic removal under long-term cadmium stress was reduced lightly affected, but the removal performance could be recovered while the denitrifieation was enhanced. Turbidity removal efficiency was always higher than 98% in MBR system, both with or without cadmium ion addition. The long-term effect of cadmium ion resulted in the increase of denitrifying bacteria from 0.21% to 8.03%, and the two kinds bacteria of Pseudomonas and Pseudoxanthomonos both increased from initial 0.23% and 0. 15% to 1.83% and 2.07%, respectively.