PAHs代谢物对PAHs生物降解的影响作用

Effects of natural metabolic mixtures of PAHs on its biodegradation

分别研究了芽胞杆菌CN2降解蒽产生的代谢物对蒽生物降解的影响和菲产生的代谢物对菲生物降解的影响．试验结果表明：（1）外加蒽（或菲）代谢物，对蒽（或菲）的降解均表现出促进作用．葸156h累计去除率可提高3．07％～6．10％，菲60h累计去除率可提高13．14％～30．35％．（2）在芽胞杆菌CN2作用下，蒽（或菲）生物降解过程能够用一级动力学方程式较准确地描述，外加代谢物可以增大降解反应表观速率常数k值；从不同时段内蒽（或菲）的降解速率看，反应初期0～2h内，外加代谢物对蒽（或菲）的降解速率提高最为明显，对蒽可提高0．281～1．20mg／L·h，对菲可提高0．570～1．13mg／L·h．（3）外加代谢物对蒽（或菲）降解液的pH值有缓冲作用，使降解液的pH值随降解时间下降趋势减缓．

The effects of metabolites of anthracene or phenanthrene on the biodegradation of anthracene or phenanthrene have been studied. The results showed that the natural state of metabolic mixtures of anthracene or phenanthrene exhibited promoting effects on biodegradation of anthracene or phenanthrene, the removing rates of anthracene were increased by 3.07%-6.10% within 156 h, find those of phenanthrene were 13.14%-30.35% within 60h. The biodegradation processes of anthracene or phenanthrene by Bacillus sp. CN2 could be described as first-order kinetics, and the only difference was that the values of k （the rate constant in the kinetic equation） for control groups were less than that of the degradation systems with addition of metabolic mixtures. The results also indicated that adding metabolic mixtures could enhance the biodegradation rate of anthracene and phenanthrene more obvious during earlier degradation stages than later stages, and for anthracene, the degradation rate increased by 0. 281%1.20 mg/L . h within 2 h,and for phenanthrene, it was 0. 570-1.13 mg/L. h. The metabolic mixtures could function as pH value buffer actions for the degradation fluids, so the pH values decreased slower than control groups.