Safety Study On The Purification Technology Of Drinking Water Combined Pollution Based On Magnetic Anion Exchange Resin Adsorption

Environmental monitoring data demonstrated that the main source water was subjected to different levels of pollution in China.Generally,more than 50%of the river water was unfit for the drinking water sources,and the number is 80%in city.However,conventional drinking water treatments can hardly remove the high-concentration and combined pollutants.The newly developed magnetic exchange resin(NDMP)by our team can efficiently remove natural organic pollutants and anionic pollutants,but limited researches focus on the pretreatment of NDMP resins,removal performance on different types of drinking water combined pollution and reduction of human health risks of real engineering.The main conclusions are listed below.(1)Generally,spatial and temporal variations of in pollution profiles were observed in drinking water of downstream areas of the Huaihe River,and pollution level in summer is higher than it's in winter,the concentrations of CODMn and ammonia nitrogen(NH3-N)in Yimusi river system were lower than them in Lixia river system.Moreover,the Tongyu River and Mangshe River system contained high levels of aluminum(Al),iron(Fe)and manganese(Mn)in summer which exceeds the drinking water standard.The risk of exceeding standard of fluorinion(F-)existed in Qiangwei and Xinyi River system,and high level of bromide(Br-)was also detected in source water of coastal area.Analyses of toxic organic pollutants indicated that polycyclic aromatic hydrocarbons(PAHs),polychlorinated biphenyl(PCBs),phthalic acid ester(PAEs),organochlorine pesticide(OCPs)and others were present in drinking water sources of downstream area of the Huaihe River.Similarly,the concentrations of organic pollutants were higher in the Lixia River system than them in the Yimusi River system,OCPs were the most frequently detected ones and PAEs were the highest among all the types of organic pollutants.Human health risk analysis demonstrated that the source water from the Taidong River and Tongyu River displayed potential carcinogenic effects in March,and the risks of potential carcinogenic effects were higher in July and August than it's in March.Additionally,no significant cytotoxicity of source water from the Yangtze River,Lake Tai,the Tongyu River,the Zhongshan River and the Mangshe River was observed to RT-WL cells.EROD results found all the tested source water samples had dioxin-like toxicity,the detected PAHs and PCBs accounted for no more than 6.05%of the toxicity source.Micronucleus test indicated that source water from the Tongyu River,the Zhongshan River and the Mangshe River showed significant genotoxicity,this may be caused by high concentrations of organic pollutants in these rivers.Except for source water from the Yangtze River,all other source water samples presented indirect mutagenicity;the detected PAHs and PCBs are all typical indirect mutagens.All the source water samples showed estrogenic effects but no androgenic effects according to the CALUX test,high level of PAEs in the source water of the Tongyu River may correlate with high level of estrogenic effects.(2)Effluents of raw resins contained numerous organic pollutants including aromatic compounds,PAEs,dodecanol and cyclohexanol,and turbidity also increased in effluent.Rinse can efficiently remove the organic pollutants in raw resins.For the NDMP-2 resin,the turbidity can drop to 0.2 NTU after cleaning by 500 BV distilled water,1500 BV distilled water was needed for the NDMP-3 resin.The performance of stimulated underground water for cleaning cannot reach the distilled water,1000 and 2000 BV of it were needed when achieving the same performance for NDMP-2 and NDMP-3 resins,respectively.Moreover,there was no risk of excess iron(Fe)when continuously using the NDMP resins.After rinse by 2000 BV stimulated underground water,no obvious organic pollutants were observed in the effluents.Nitrosamine DBPs was detected in the effluents of raw NDMP-3 resin when underwent chlorination,but after rinse by 2000 BV of stimulated underground water,no nitrosamine was detected.The effluents of both types of raw resins showed no mutagenicity,but a little bit of genotoxicity.No toxicity of both effluents and disinfected effluents were observed after effective rinse.After all,the raw NDMP resins should be sufficiently pretreated before use in drinking water treatment.(3)Fluorescence excitation-emission-matrix combined with parallel factor analysis identified four components in source water of different rivers or lake,and the abundance of each component differed greatly among the different samples.Extremely high levels of tryptophan-like and tyrosine-like proteins,which were present in Taihu Lake,were expected because the annual cyanobacterial bloom in Taihu Lake can contribute to the high concentrations of proteins.High levels of terrestrial humic-like substances in the Tongyu River,the Mangshe River and the Zhongshan River suggested serious pollution of the rivers.The Yangtze River only had low concentrations of tryptophan-like protein.Compared with the CT,the AT evidently reduced the concentrations of dissolved organic carbon,adsorbable organic halogens(AOX),bromide and disinfection by-products.Toxicological evaluation indicated that the AT completely eliminated the cytotoxicity,and greatly reduced the genotoxicity and oxidative stress of all raw water.However,the CT increased the cytotoxicity of Taihu Lake and the Zhongshan River water,genotoxicity of Taihu Lake and the Mangshe River water,as well as the levels of superoxide dismutase and malondialdehyde of the Mangshe River water.Correlation analysis indicated that the AOX of the treated samples was significantly correlated with the genotoxicity and glutathione concentration,but exhibited no correlation with either of them for all the samples.(4)The NDMP technology was found to effectively reduce TOC and ammonia nitrogen concentrations to reach the prescribed standards,but the conventional treatment seemed not effective in carbon and nitrogen removal.Cross-omics profiling and phenotypic analysis were conducted to comprehensively assess the toxicities of source of drinking water(SDW),effluent of conventional treatment(ECT)and effluent of advanced treatment(EAT)in a water treatment plant.SDW feeding increased body weight,and relative liver and kidney weights of mice.Hepatic histopathological damages and serum biochemical alterations were observed in the mice fed with SDW and ECT,but EAT feeding showed no obvious effects.Transcriptomic analysis demonstrated that exposure to water samples caused differential expression of hundreds of genes in livers.Cluster analysis of the differentially expressed genes which generated by both microarrays and digital gene expression showed similar grouping patterns.Proteomic and metabolomics analyses indicated that drinking SDW,ECT and EAT generated 59,145 and 41 significantly altered proteins in livers and 8,2 and 0 altered metabolites in serum,respectively.SDW was found to affect several metabolic pathways including metabolism of xenobiotics by cytochrome P450 and fatty acid metabolism.SDW and ECT might induce molecular toxicities to mice,but the advanced treatment process can reduce the potential health risk by effectively removing toxic chemicals in drinking water.