摘要
采用氨氧化菌Nitrosomonas europaea降解17α-乙炔雌二醇(EE2),考察降解过程中氨氮的作用以及EE2的降解机制.结果表明,N.europaea降解EE2属于共代谢过程,氨氮是共代谢发生的必要条件.氨氧化过程产生的亚硝氮会在酸性条件下将EE2硝基化,反应符合一级动力学模型,降解速率常数与亚硝酸根、H^+及游离亚硝酸浓度成正相关.通过控制pH值大于7.5抑制硝基化反应,证实了N.europaea对EE2的生物降解作用,生物降解反应符合一级动力学模型且降解速率常数为0.0069h^-1.当N.europaea氨氧化反应导致pH值低于7.5时,EE2的去除存在生物降解和硝基化的协同作用,EE2去除符合一级动力学模型且降解速率常数为0.0093h^-1.同时还发现一种未曾报道过的EE2生物降解产物M613,对于其雌激素效应和毒性还需进一步探究.
In this study,Nitrosomonas europaea,one type of ammonia oxidizing bacteria,was used to remove 17 α-ethinylestradiol(EE2).The role of ammonia nitrogen in EE2 degradation by AOB and the degradation mechanism of EE2 were investigated.The results showed that degradation of EE2 by N.europaea was a co-metabolic process,and ammonia nitrogen was necessary for co-metabolism of EE2.The NO2--N produced during the ammonia oxidation process could nitrate EE2 under acidic condition.The nitration of EE2 obeyed first-order reaction kinetics and the degradation rate constants were positively correlated with the concentration of nitrite,H^+and FNA.The biodegradation of EE2 by N.europaea was proved by suppressing nitration of EE2 through controlling pH higher than 7.5.The co-metabolism reaction fitted first-order kinetic model with the degradation rate constant of 0.0069h^-1.Biodegradation and nitration of EE2 were synergistic for EE2 removal when pH was lower than 7.5 during ammonia oxidation process.And EE2 removal by synergistic function obeyed first-order reaction kinetics with the degradation rate constant of 0.0093h^-1.In addition,unreported EE2 biodegradation product M613 was found in this study.Its estrogen effect and toxicity need to be further investigated.
作者
王丽丽
姜晓满
李安婕
WANG Li-li;JIANG Xiao-man;Li An-jie(Key Laboratory of Water and Sand Science,Ministry of Education,State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University,Beijing 100875,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2020年第12期5246-5252,共7页
China Environmental Science
基金
国家自然科学基金资助项目(51778056)。
