苯系化合物在硝酸盐还原条件下的生物降解性能

Biodegradation of Benzene Series Compounds Under Nitrate Reducing Conditions

运用驯化的反硝化混合菌群进行了苯系化合物(BTEX)的厌氧降解试验.结果表明,混合菌群能够在反硝化条件下有效降解苯、甲苯、乙苯、邻二甲苯、间二甲苯和对二甲苯.BTEX的降解规律符合底物抑制的Monod模型,当初始浓度小于50mg.L-1时,6种受试基质的厌氧降解速率顺序为:甲苯>乙苯>间二甲苯>邻二甲苯>对二甲苯>苯.整个试验过程中NO-3的消耗与苯、甲苯、乙苯、邻二甲苯、间二甲苯及对二甲苯生物降解之间的摩尔比分别为:9.47,9.26,11.14,12.46,13.36,13.02.混合菌群厌氧降解BTEX时需要NO-3为电子受体进行起始反应,能够以NO-3或NO-2为电子受体进一步降解生成的中间产物.

A series of batch experiments were performed using mixed bacterial culture to investigate the biodegradability of benzene, toluene, ethylbenzene and the xylene isomers （BTEX） under denitrifying conditions, The results show that BTEX can be degraded effectively by the mixed bacterial culture. The biodegradation of BTEX could be modeled by the substrate inhibition Monod equation. When the concentrations of BTEX were less than 50 mg·L^-1, the anaerobic degradation rates decreased with toluene〉 ethylbenzene 〉 m-xylene 〉 o-xylene〉 p-xylene〉 benzene. The ratio between the amount of nitrate consumed and the amount of the benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylenedegraded was 9.47, 9.26, 11.14, 12.46, 13.36 and 13.02, respectively, The electron acceptor needed in the initial anaerobic degradation of BTEX was nitrate, and then both nitrate and nitrite could be served as the electron acceptors for the further degradation of the intermediates of BTEX.