低浓度辛基酚的好氧生物降解特性和群落多样性

利用摇瓶序批式试验研究了好氧菌群对低浓度辛基酚的生物降解特性和群落特征.结果表明,在辛基酚初始浓度水平为200、100、50μg·L-1的条件下,一级反应动力学常数分别为0.131、0.219和0.431d-1,辛基酚浓度升高显示出一定的代谢抑制作用.在pH值为5～9的范围内,弱碱性条件(pH=8)最有利于辛基酚的生物降解.甲醇、葡萄糖、苯酚、酵母浸出物等有机添加物普遍可以改善辛基酚的生物代谢,其中,苯酚和酵母浸出物的促进效果最明显,在200μg·L-1的初始浓度下,辛基酚降解半衰期从5.3d分别降至3.2d和2.3d.与较高浓度烷基酚类污染物试验结果不同,实验过程中发现的主要优势菌以γ-proteobacteria、β-proteobacteria和Firmicutes为主.

Aerobic biodegradation and biodiversity characteristics of low-concentration octylphenol

The biodegradation performance of octylphenol(OP) in low concentration by aerobic bacterial community and the involved microbial biodiversity were investigated in this study with batch tests.Experimental results showed that the first order kinetic constant at OP concentration of 200,100,50 μg · L-1 was 0.131,0.219 and 0.431 d-1 respectively,indicating that the microbial metabolism was depressed with high levels of OP.Alkaline condition of pH 8 was found to be most favorable for OP biodegration in the range of pH 5 to 9.Moreover,addition of organic compounds,such as methanol,glucose,phenol and yeast extract could improve the biodegradation of OP,with the most significant effect associated with phenol and yeast extract.The half-life of OP was shortened from 5.3 d to 3.2 d and 2.3 d,respectively,with initial OP concentration of 200 μg · L-1.The dominant bacterial species were found to be γ-proteobacteria,β-proteobacteria and firmicutes,which was different from the result obtained from alkylphenol ethoxylates biodegradation at high concentration.