驯化活性污泥对邻苯二甲酸丁基苄酯的降解

Biodegradation of Butylbenzyl Phthalate by Acclimated Activated Sludge

活性污泥对邻苯二甲酸丁基苄酯(BBP)降解研究结果表明,活性污泥能在1d内降解90%以上的BBP,是一高效的邻苯二甲酸丁基苄酯降解菌群.活性污泥对邻苯二甲酸丁基苄酯降解符合一级动力学特征,在100、300和500mg·L-1浓度范围内的降解动力学方程分别为lnc=-0·0699x+5·6171、lnc=-0·0683x+8·4083、lnc=-0·0583x+7·2806,半衰期为9·92、10·15、11·89h,降解速率常数kb为0·0699、0·0683、0·0583d-1.其降解速率常数随着BBP浓度增加而降低,说明高浓度的邻苯二甲酸丁基苄酯对其生物降解有抑制作用.另外,采用HPLC-MSn方法从活性污泥对邻苯二甲酸丁基苄酯的降解物中鉴定出2种产物,分别为邻苯二甲酸丁酯和邻苯二甲酸苄酯,降解途径是邻苯二甲酸丁基苄酯先生成单酯,然后变成邻苯二甲酸,最终氧化成CO2和H2O.

The results of degradation of butyl benzyl phthalate(BBP) by activated sludge demonstrate that the activated sludge is a high efficiency flora for degrading BBP, which can degrade BBP quickly and more than 95% BBP is degraded in one day. The degradation of BBP can be described by the first-order dynamics model, the concentration in range of 100,300,500 mg·L~ -1, the dynamics equation of degradation respectively is lnc=-0.0699x+5.6171,lnc=-0.0683x+8.4083、and lnc= -0.0583x+7.2806, t_ 1/2 is 9.92,10.15,11.89 h, the constant of degrading rate k_b is 0.0699、0.0683 and 0.0583 d~ -1. The constant of degrading rate decreases as the concentration of BBP increases, which shows that BBP of high concentration inhibits its biodegradation. In addition, two degraded productions, monobutyl phthalate and methanoyal phthalate, are identified from the degradation of BBP with HPLC-MSn. The route of degradation is that BBP produces mono-ester firstly, and then the product turns into phthalic acid, finally it oxidizes into CO_2 and H_2O.