| In recent years,the massive use and even abuse of various emerging pollutants has made great contributions to a large number of residues in the sewage and the environment.Most of the existing processes in wastewater treatment plants cannot effectively remove the residual emerging contaminants in wastewater,making the tailwater of wastewater treatment plants an indirect source of pollution of emerging contaminants in the environment.Changzhou Xinlong Ecological Forest Wetland Park invokes the recycled water of riverside sewage plant as the source of landscape water,constructing five artificial wetlands:water forest,vertical flow wetland,surface flow wetland,stream wetland and river wetland,for further processing the treatment of recycled water,which can effectively control the conventional pollutants such as nitrogen,phosphorus and COD,but it is necessary to study and prove the distribution characteristics and potential ecological risks of emerging pollutants,so as to provide a practical basis for the landscape utilization of recycled water.The study developed an online-SPE tandem TSQ MS method to detect six typical acidic drugs in tailwater and an online-SPE-LC tandem QE~+Orbitrap HRMS screening method to detect the fugacity of ECs in the tailwater of wastewater plants and their wetland reclaimed landscape water,and investigated the degradation of typical ECs by UV/Cl advanced oxidation process.The study investigated the degradation efficiency and degradation characteristics of the emerging pollutant naproxen,analyzed and elucidated the degradation mechanism,assessed the ecological risks in the degradation process,and provided a theoretical basis and technical reference for the selection and application of UV advanced oxidation control processes for ECs.The specific research results are as follows.An on-line solid-phase extraction-liquid chromatography tandem mass spectrometry method was established for the determination of three types of six typical acidic drugs in the tailwater of wastewater plants with large volume injection.The results showed that the linear correlation was good in the range of 0.1-200 ng/L(r≥0.9964),the limits of detection were 0.01-0.16 ng/L,the limits of quantification were 0.02-0.52 ng/L,the spiked recoveries were 94.3%-102%,and the relative standard deviations were 0.01-0.16 ng/L.The relative standard deviations were 0.49%-10.1%.Carbamazepine 0.78 ng/L and diclofenac sodium 0.63 ng/L were detected in the tailwater,while benzofibrate,indomethacin,ibuprofen and ketoprofen were not found;all six substances were not found in the wetland park.The detection method based on Online-SPE/HRMS Orbitrap LCMS was established for the tailwater of the wastewater plant,and a broad-spectrum screening and quantitative analysis method was developed for the emerging pollutants in environmental water,which realized the broad-spectrum screening of 302 emerging organic pollutants in 7 categories in water,and combined with the standard addition method to achieve The results showed that the 302 target pollutants in the tailwater were identified and quantified.The results showed that 41 of the 302 target emerging contaminants were found in the tailwater,and sulfamethoxazole,sulfapyridine,methomyl,glyburide,perfluorocaproic acid,oxamyl and tri-n-butyl phosphate were detected at high concentrations in all locations.In addition,the concentrations of target emerging pollutants showed spatial correlation with the distribution of artificial wetland structures,indicating that artificial wetlands can reduce the content of emerging pollutants to a certain extent,but it is difficult to complete remove them.Taking NAP as a typical emerging pollutant,we studied the effect of UV/chlorine advanced oxidation degradation process to control NAP in depth,analyzing the kinetics of NAP UV/chlorine advanced oxidation degradation reaction,identifying and characterizing the intermediate products of UV advanced oxidation degradation.We Calculatied using quantum chemistry theory analyzed the molecular structure characteristics of NAP.ECOSAR simulations were conducted to assess the ecological risk of NAP and intermediates.It was found that the UV/chlorine advanced oxidation process can remove NAP efficiently,but the ecotoxicity of the products is enhanced. |
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