Based On The Fugacity Model, The Environmental Behavior And Risk Of Typical POPs In Shenzhen Are Studied

Commonly,Persistent Organic Pollutants(POPs)are defined as a series of synthetic organic compounds which associates with bioaccumulation,persistence and highly toxic properties due to their steady physical and chemical properties.They have been existing in various environmental media on a global scale as a result of massive usage for many years.Monitoring concentration of POPs is considered as the most effective method to avoid the hazards of POPs in the early period.However,it is difficult to accomplish normal measurement of POPs concentration due to the limits of monitoring method,facility and funds.Donald Mackay has developed a model named fugacity model which is recognized an effective technique to study POPs in environmental media.Meanwhile,it can figure out POPs concentrations in every environmental media only depending on the environmental parameters of research area and physicochemical parameters of compound,which illustrates transfer and fate behavior of compound.In this research,a level III fugacity model is corresponding to actual environment that was built based on the fugacity method.Shenzhen was selected as the study area,which contains four environmental media: air,water,soil and sediment.This study simulated the concentrations,multimedia environmental behavior,long-range transport potential and ecological risk of perfluorooctane sulfonate(PFOS),perfluorooctanoic acid(PFOA)and PCDD/Fs in Shenzhen region,in order to serve as references of risk assessment and pollution treatment of typical POPs in Shenzhen.Concentrations of PFOS and PFOA in Shenzhen air was monitored to validate the model.The main results are summarized as follows:(1)This study simulated the concentrations and transfer fluxes of PFOS,PFOA and PCDD/Fs in air,water,soil and sediment in Shenzhen region,which is coincided relatively with the measured concentrations in the locality.The main source of PFOS and PFOA in Shenzhen area are upstream cities and rivers,and they exported with the(2)rivers.Moreover,PCDD/Fs mainly comes from local emissions and uptuyere area and export by advection of air.(3)The sensitivity analysis of model showed that three input parameters present the largest influence on the modeling results of POPs concentration,they are input rate of air,water advection and partition coefficient KOC.In addition,environment temperature,water solubility and rate of rainfall possess some impacts with POPs concentration.Rate of emission in air has a greater influence on PCDD/Fs concentration than PFOS and PFOA concentrations.Uncertainty analysis revealed that the variation coefficient of three POPs concentration is comparatively lower in fluid phase than solid phase.(4)The health risk assessment of this research demonstrated that PFOS and PFOA do not present immediate harm to human body.The long-range transport potential of three typical POPs were calculated by utilizing TaPL3 model in Shenzhen region.It can be conducted that the total persistent and characteristic travel distance of PCDD/Fs are relatively lower than PFOS and PFOA,whether air or water is the emission medium.Concentration of the PCDD/Fs was forecasted by changing the quantity of incinerated garbage,which resulted in the PCDD/Fs concentration in air would be higher than the limited value of Japan(600 fg I-TEQ·m-3).Meanwhile,it would cause threats to human health when the value of incinerated garbage reaches50000 tons per day.