The Efficiency And Pathway Of PAEs Removal In Sewage Treatment Plant And Simulation By Fugacity Model

Endocrine disrupting compounds (EDCs) are chemicals leading humans andwildlife suffering from the disease by the potential to elicit negative effects on theendocrine systems, which become a hot research topic for environmentalists.Formunicipal wastewater is the significant resource of these chemical，the study on removaland the fate of EDCs in urban sewage treatment plant is important for keeping themfrom environment and urban drinking water system.Phthalate acid esters (PAEs) are used as important additives which impartflexibility in polyvinylchloride (PVC) resins.The combination of substances betweenPAEs and plastic is so week that PAEs can spread to the surrounding environment mediaeasily. PAEs emissions standards in each country have introduced a series of policies.Inthis paper, we collect sewage and sludge samples in Anaerobic-aerobic Process (A/O)and Biological Aerated Filter Process (BAF) sewage treatment plant in Harbin. Gettingthe level of PAEs by gaschromatographic mass spectrometry (GC/MS),and analysis theefficiency and pathway of PAEs removal in two sewage treatment plants.Simulating thepathway of PAEs removal in A/O process by the Sewage Treatment Plant FugacityModel.The study found that except DHP and DCHP,the remaining six kinds of PAEshave detected by different rates.Any units of the sewage treatment plant are able to remove the six kinds of PAEswith different rates.The removal efficiency of six kindes of PAEs in primary settlingtank is about50%,and the removal efficiency of long chain of PAEs presented betterthan the short chain of PAEs.Aerobic Unit has a better removal capacity than AnaerobicUnit for PAEs,as DMP is an exception.The removal efficiency of PAEs is about60%and44%respectively in inclined plate settling tank and biological aerated filtertank.Except DMP and DEP, the six PAEs have a better remove in inclined plate settlingtank than biological aerated filter unit.There is no big difference between A/O processand BAF process with the total six PAEs average removal rate of two season is87%and88%,respectively.Seasonal variation has an effect on the removal efficiency of sewagetreatment plant and it shows a higher performance for A/O process than BAF process. Ingeneral there is a higher efficiency in autumn than in winner.The study on pathway of removal PAEs in A/O process shows that the ratio ofsubstrate absorption、biodegradation to the influent is70%and18%,respectively,as it is79%and8%in BAF process.The main pathway of removal these six kinds of PAEs intwo sewage treatment plants is substrate absorption as biodegradation is the secondaryway.The rate of biodegradation in A/O process is higher than that in BAF process and the biodegrade capacity shows a positive relationship with the octanol-water partitioncoefficient (Kow) of PAEs.On the contrary, the substrate absorption capacity of BAFprocess is better than that of A/O process and it shows a negative relationship with theKow of PAEs.The application of sewage treatment plant fugacity for PAEs removal pathway inthe A/O process shows that the model has a certain uncertainty with the half-life of thepollutants in the different processing units.The simulation results has certain referencevalue,and can be used to evaluate the removal to the waterworks of pollutant chemicalswhich have a similar position with long-chain PAEs.