几种氯代苯甲酸的生物可降解性及其动力学

The Biodegradability of Chlorobenzoic Acids and Their Degrading Kinetics

2 ,4-二氯苯甲酸、4-氯苯甲酸、3-氯苯甲酸、2 -氯苯甲酸经过污泥的驯化作用可以达到降解 ,但是不同的接种污泥对相同的底物达到同样的降解效果所需的驯化时间不同 ,经 9d驯化的膜生物反应器中的污泥即具有经 2 8d驯化的一般活性污泥相当的降解活性 ,但 4种氯代苯甲酸的生物可降解性次序是一定的 :2 ,4-二氯苯甲酸 >4-氯苯甲酸 >3-氯苯甲酸 >2 -氯苯甲酸 ,不随污泥的驯化期及接种污泥而改变 .降解动力学研究表明 ,这 4种氯代苯甲酸在不同的污泥驯化期其降解动力学模式不同 ,在驯化初期底物的降解符合零级反应 ,在驯化后期符合一级反应 .

dichlorobenzoic acid(2,4DBA),4chlorobenzoic acid(4CBA),3chlorobenzoic acid(3CBA) and 2chlorobenzoic acid(2CBA) can be degraded by acclimated sludge.The acclimation time to reach the same degradation level is quite different between the sludge from the ordinary activated sludge reactor and that from the membrane bioreactor, the sludge from the membrane bioreactor is much easier to be acclimated.The four substances biodegradability follows the order:2,4DBA>4CBA>3CBA>2CBA,irrespective of the different inoculated sludge and their acclimation time.The studies of degradation kinetics showed that at the beginning of the sludge acclimation the four substances were degraded according to zero order reaction,whereas at the end of the sludge acclimation they were degraded according to first order reaction.