污水再生处理工艺中卡马西平的去除过程模拟及其生态风险评价

卡马西平在污水和水环境中广泛存在,且对水生生态系统安全构成风险,因此成为目前研究较多的药品之一。以北京清河再生水厂为例,研究"超滤—臭氧氧化—氯消毒"处理工艺中卡马西平的去除特性,并针对臭氧氧化和氯消毒工艺建立模拟卡马西平去除过程的机理模型。同时,利用美国环境保护署ECOTOX数据库,获取卡马西平对北京市水生生物物种的毒性数据,并基于毒性数据建立物种敏感度分布(species sensitivity distribution,SSD)模型,评价再生水厂出水补给地表水体时卡马西平产生的生态风险。臭氧氧化和氯消毒模型对卡马西平、总有机碳、氨氮等指标的模拟误差总体低于20%,模型的灵敏参数均可以被较好地识别,且其不确定性显著下降。对比7种SSD模型发现,对数正态分布和对数Logistic分布模型较好地拟合了北京市6个物种的卡马西平毒性数据,二者预测得到的总体生态风险期望值分别为7.4%和8.5%。

Modeling the Removal of Carbamazepine in Wastewater Reclamation Processes and Its Ecological Risk

Carbamazepine has become one of the most intensively studied pharmaceuticals due to its frequent oc-currence in wastewater and the aquatic environment as well as its adverse impact on aquatic ecosystems.The Qing-he Wastewater Reclamation Plant(QWRP)in Beijing was investigated as a case study to characterize the removal of carbamazepine by the"ultrafiltration-ozonation-chlorination"process. A kinetic model was developed for the ozonation and chlorination processes, respectively, and model parameters were identified with the Hornberger-Spear-Young algorithm based on Latin Hypercube Sampling. The toxicity data of carbamazepine on the native a-quatic species of Beijing were obtained from the ECOTOX database developed by the U.S.Environmental Protec-tion Agency,and used to develop the species sensitivity distribution(SSD)models.The SSD models,together with the simulated carbamazepine concentration in the QWRP effluent,were finally applied to assess the expected total risk(ETR)of aquatic ecosystems which were augmented by the effluent. The ozonation and chlorination models could simulate the concentrations of carbamazepine,total organic carbon,and ammonia nitrogen quite well,with a relative error generally below 20%. All the sensitive model parameters could be well identified with their uncer-tainty significantly reduced.Among the 7 tested SSD models, log-normal distribution and log-logistic distribution models gave better performance in fitting the toxicity data of carbamazepine on the 6 native aquatic species of Bei-jing,and they estimated the ETR of aquatic ecosystems replenished by the QWRP effluent to be 7.4% and 8.5%, respectively.