High-throughput Screening Of Emerging Organic Contaminants In Water Environments

The problem of water pollution is considered to be one of Chinese top ten environmental problems.As industrial production levels increase,more and more organic compounds are registered.The entry of various organic compounds into water environment by various ways during production,transportation and use leads to an increase in the frequency of detection of emerging organic contaminants(EOCs)including pesticide and disinfection by-products(DBPs)and pharmaceutical and personal care products(PPCPs),etc.These contaminants are considered to be toxic,persistent,and bioaccumulative that have detrimental effect on human health.Traditional target methods can accurately quantify based on prior information of some high concern substances,but there is nothing to do with the identification of emerging and unknown compounds in the environment.To this end,Researching on emerging organic contaminants in water environments established suspect screening and non-targeted screening strategy.A large number of organic contaminants can be identified by one injection,greatly improving the identification ability and efficiency of emerging organic contaminants.High-throughput screening methods based on different water environment characteristics are of great significance for the identification,distribution and fate of emerging organic contaminants in water environments.Among the emerging contaminants in water environments,per-and polyfluoroalkyl substances(PFASs)have received extensive attention due to their high toxicity,persistence and bioaccumulation.Although PFASs have been a key issue in the global water environmental,there are still a large number of undiscovered PFASs in the environment due to the development of new PFASs alternatives by manufacturers.We selected typical EOCs such as PFASs to establish LC-QTOF-MS high-throughput analysis for surface water and LC-QExactive Orbitrap-MS high-throughput analysis methods for groundwater including PFASs suspect screening and non-target screening based on migration process in water cycle and its concentration and distribution characteristics in different water environments.In addition,suspect screening strategy for some other emerging organic substances inclued pharmaceutical and pesticides was established,and the new types of contaminants were simply identified in surface water and groundwater.Wastewater treatment plants(WWTPs)are important sources for releasing emerging PFASs into the environment.PFASs suspect screening and non-targeted stragety using LC-QTOF-MS to discover PFASs in wastewater from certain fluorochemical industrial park in China.A total of 90 high-confidence PFASs were identified from 334 potential PFASs homologues,including 12 traditional PFASs(2 classes),41 previously reported PFASs(7 classes)and 37 newly discovered PFASs(6 classes).Only one class of PFASs was removed by the removal process.Instead,four PFAS classes were increased through treatment processes,which could be the transformation.products of PFAS precusors.These results implied that most discovered PFASs were not effectively removed in the WWTP.Eighteen of these PFASs were also detected in the nearby Yangtze River and chlorine substituted perfluoroalkyl.carboxylates(Cl-PFCAs)as the main component of wastewater were detected only in downstream,which means that downstream Cl-PFCAs may come from the WWTP.A large amount of PFASs in the treated sewage are still not effectively removed and enter the surface water.High-throughput screening of PFASs was done in the main river of Taihu Lake.There are 221 kinds of potential PFASs,of which 14 kinds have high confidence(Level 3 and above),and PFHxS contributes more than 50%in all points,followed by PFOS and PFOA.A total of 54 compounds were identified in the suspect screening of emerging contaminants.Including 17 kinds of drugs,15 kinds of PFASs,9 kinds of fungicides,7 kinds of insecticides,6 kinds of herbicides,the detection frequency and abundance of organic contaminants in Taihu Lake Basin have a great influence on the flow direction.It can be seen that the differential distribution of PFASs in water is the main cause of the difference between upstream and downstream.Under the interaction of water,organic contaminants migrated between surface water and groundwater.However,the concentration of EOCs in groundwater is usually lower than that of surface water.Constructing high-throughput screening method for EOCs in groundwater screened samples collected in BeiJing,NanJing,NanNing,Golmud,etc.135 kinds of potential PFASs were screened in groundwater,including 16 kinds of Level 3 and above.These 16 kinds of PFASs were all detected in sewage and Taihu surface water.The amount of PFASs detected was correlated with the level of regional economic development.In general,there are many PFASs detected in BeiJing groundwater,while Golmud and NanNing are less.Brief analysis of the source and correlation of PFASs in surface water and groundwater using the method of perfluorinated compound ratio.The results show that NanJing groundwater is affected by sewage and atmospheric deposition,while Geermu is mainly affected by atmospheric deposition.Based on groundwater samples from Beijing,there are significant differences in the types of EOCs screened in different layers of groundwater.37 EOCs were detected in shallow groundwater and 5 EOCs were detected in deep groundwater,and three of them were detected for the first time.