三氯乙烯对厌氧水解酸化菌的抑制作用及去除特性

Inhibition and removal characteristics of trichloroethylene on anaerobic hydrolysis acidifying bacteria

三氯乙烯(TCE)是石化废水中典型的有机污染物,对微生物具有极强的毒性。通过对挥发性脂肪酸批次试验进行生物测定,探讨TCE对厌氧水解酸化菌的产酸抑制作用,在TCE作用下水解酸化菌的胞外聚合物(EPS)和污泥zeta电位的变化以及TCE的去除特性。结果表明:TCE浓度为75 mg/L(半抑制浓度,EC_(50))时,对水解酸化菌的产酸量有抑制作用;随着TCE浓度升高,水解酸化菌的EPS中蛋白质浓度先增大后减少,其中TCE浓度为_(50) mg/L时EPS中蛋白质浓度达到最大值,为(33.94±0.25)mg/L;zeta电位的结果显示,污泥的凝聚性能随TCE浓度增大(0~100 mg/L)而增大;厌氧水解酸化菌对TCE的脱氯能力随TCE浓度的升高而降低,水解酸化菌转化TCE的脱氯率由TCE浓度为10 mg/L时的77.83%降为200 mg/L时的6.67%。TCE对水解酸化菌具有强烈的抑制作用,TCE主要是通过抑制细胞的蛋白质合成来抑制微生物活性,进而限制水解酸化菌降解TCE的能力。

Trichloroethylene(TCE)is a typical organic pollutant in petrochemical wastewater,which is highly toxic to microorganisms.Batch bioassays of volatile fatty acid were carried out to explore the inhibitory effect of TCE on acid production of anaerobic hydrolysis acidifying bacteria,the variation of extracellular polymeric substances(EPS)and mud zeta potential of hydrolysis acidifying bacteria under TCE shock,and the removal characteristics of TCE.The results showed that TCE at a concentration of 75 mg/L(semi-inhibitory concentration,EC_(50))had an inhibitory effect on the acid production of hydrolysis acidifying bacteria.With the increase of TCE concentration,the protein concentration in EPS of hydrolsis acidifying bacteria first increased and then decreased.The maximum value of protein concentration in EPS was(33.94±0.25)mg/L when TCE concentration was _(50) mg/L.The results of zeta potential showed that the coagulation performance of sludge increased with the increase of TCE concentration(0-100 mg/L).The dechlorination ability of anaerobic hydrolysis acidifying bacteria to TCE decreased with the increase of TCE concentration,and the dechlorination rate of TCE converted by hydrolysis acidifying bacteria was 77.83%when the concentration of TCE was 10 mg/L.It decreased to 6.67%at 200 mg/L.TCE had a strong inhibitory effect on hydrolysis acidifying bacteria.TCE mainly inhibited microbial activity by inhibiting the protein synthesis of cells,thereby limiting the ability of hydrolysis acidifying bacteria to degrade TCE.