The Concentration,Distribution Characteristics And Risk Assessment Of PPCPs In The Water And Sediment Of Luoma Lake

Luoma Lake is a water-carrying lake which is located in Subei Water Wetland Reserve,Jiangsu Province.It is an important part of South-North Water Diversion Project.The water quality of Luoma Lake has a significant impact on drinking water safety,aquatic ecology and economic development in Suqian and Xuzhou.Pharmaceuticals and Personal Care Products(PPCPs)is a new type of pollutant,which has been detected in many lakes at home and abroad.So far,there have been few studies on PPCPs in Luoma Lake.In this study,61 PPCPs were selected as target compounds to detect the water and sediment of Luoma Lake,analyze the temporal and spatial distribution characteristics of PPCPs,evaluate their ecological risk,and explore the pollution sources of PPCPs in the water,aiming to provide effective theoretical support and decision-making basis for water environmental protection of Luoma Lake.In addition,surface water samples from Nansi Lake and Hongze Lake,two other water-carrying lakes in the eastern route of the South-to-North Water Diversion Project,were collected to compare the composition and content characteristics of PPCPs in the surface water of the three lakes.The main conclusions are as follows:The mean values of DEET,thiamphenicol and florfenicol in the surface water of Luoma Lake were the highest in the dry season,while lincomycin,caffeine and DEET were the highest in the wet season.The detection rates of carbamazepine,DEET,sulpiride,caffeine and lincomycin were 100% in both seasons.The characteristics of spatial pollution were high in the north and low in the south,high in the east and low in the west.The PPCPs with high risk in surface water during dry season were carbamazepine and caffeine,and the PPCPs with medium and high risk were enrofloxacin,norfloxacin,sulfadiazine,roxithromycin and lincomycin.During wet season,caffeine,carbamazepine,lincomycin and sulfamethoxazole in surface water were at high risk,clarithromycin and clindamycin were at medium risk.14 and 48 PPCPs were detected in the surface sediments of Luoma Lake in dry and wet seasons,respectively.The contents of DEET,ketoprofen and caffeine were the highest in dry season,while those of sulfamethoxazole,ketoprofen and tylosin were the highest in wet season.The detection rate of DEET was 100% in both seasons.The spatial pollution was characterized by uniform distribution as a whole in dry season,and high in the north and low in the south in wet season.The risk assessment showed that caffeine,ofloxacin and sulfamethoxazole were at high risk during dry season.Caffeine,sulfamethoxazole,doxycycline,tetracycline,tylosin,ciprofloxacin,erythromycin,sulfadimidine,oxytetracycline had high risk in the wet season,while ofloxacin,lincomycin,chlortetracycline,sulfadimidine,chloramphenicol had medium risk.Five kinds of PPCPs were detected in feed 1 and seven were detected in feed 2 in Luoma Lake.The concentrations of monensin,flumequine and pefloxacin in feed 1were the highest,and the concentrations of sulfaquinoxaline in feed 2 were the highest,followed by enrofloxacin.Among them,DEET and caffeine were the only two compounds with high content detected in water and sediment in both seasons.The use of feed aggravated the DEET pollution in Luoma Lake,but it had little effect on the caffeine content.A total of 29 types of PPCPs were detected in three lakes,21 of which had duplicates.The overlap rate of Nansi Lake,Luoma Lake and Hongze Lake was 82.35%94.74%,and 81.82% respectively.Hongze Lake had the most kinds and the highest pollution level.The pollution of Nansi Lake was the same as Luoma Lake.It may be related to the same inflow from Hongze Lake and Nansi Lake,which was different from Hongze Lake.The clustering results of water and sediment in Luoma Lake were similar,and the pollution was significantly affected by water diversion in the dry season,but greatly affected by human activities in the wet season.The traceability results of the marker method showed that the canal received a large amount of water diversion during the dry season,and the pollution was relatively concentrated.It was the main collection area for the sewage of unknown origin in Luoma Lake.The Laoyi River and the Yi River in the wet season were the main input channels for sewage from unknown sources in the Luoma Lake.In addition,the pollution level in the wet season was significantly higher than that in the dry season.The pollution of Luoma Lake was mainly related to the consumption of beverages and snacks,upstream influx and the development of tourism.The west bank of Nansi Lake was significantly affected by the incoming water from the Yellow River,and point source pollution occurred.The main cause of Hongze Lake pollution was the inflow of water from the upstream Huaihe River and the developed tourism industry.