Modeling The Removal Of PPCPs In Wastewater Reclamation Processes And Their Ecological Risk

With the development of pharmaceutical industry,nursing industry,animal husbandry and aquaculture,the increasing load of pharmaceutical and personal care products?PPCPs?on the environment has become the research focus.Wastewater treatment and reclamation processes,as PPCPs'main sources,have also gained attention in terms of risk management.However,the traditional wastewater secondary treatment process contributes little on PPCPs removal.Therefore,the effect of wastewater reclamation processes on the removal of PPCPs has become an important research topic.Based on the field data of Qinghe Wastewater Reclamation Plant?QWRP?in Beijing,this paper developed a kinetic model for ozonation and chlorination processes,which can well simulate the concentrations of 14 PPCPs,TOC,NH₃-N and residual chlorine along the two process.In order to further break the limitations of the observed data,this study established a QSAR?Quantitative Structure Activity Relationship?model describing the quantitative relationship between the removal of PPCPs and their physical and chemical properties.Based on the above,this study examined the effluent concentrations of different types of PPCPs using Monte Carlo simulation.Further,this study took Carbamazepine?CAR?as an example to evaluate the ecological risk of QWRP effluent with species sensitivity distribution?SSD?models based on the local species of Beijing.The identified parameter values for the kinetic model are highly consistent with literature,and the sensitivity of the parameters can be well explained with reaction mechanisms.Therefore,the model is reliable for simulating the concentrations of PPCPs in QWRP.As for QSAR models,the regression coefficients can be reasonably explained according to reaction mechanism,and external validation results show that the model can predict the secondary rate constants of other PPCPs during ozonation and chlorination.The results for ecological risk accessment show that there exists ecological risk.Regional sensitivity analysis was used to identify the key control indexes,and then the risk management strategy was developed considering CAR concentration in the influent as well as ozone and chlorine dosage.