The Chemical Characteristics And Risk Assessment Of Typical Pollutants In Groundwater Of Shijiazhuang City

In this study,the groundwater of Shijiazhuang city was selected as the research area,and groundwater samples were collected in September 2020 and June 2021,respectively.The chemical characteristics and controlling factors of groundwater were analyzed by Gibbs chart,Piper chart,factor analysis,and cluster analysis.The spatio-temporal distribution characteristics of heavy metals in groundwater were analyzed by inductively coupled plasma mass spectrometer.The pollution sources and health risks of heavy metals were analyzed and assessed by APCS-MLR model and health risk model.The concentration characteristics of quinolones（QNs）antibiotics in groundwater were analyzed by ultra-high performance liquid chromatography tandem mass spectrometry（HPLC-MS）.The spatial and temporal distribution characteristics of quinolones（QNs）antibiotics were analyzed by Arc Gis software.The relationship between QNs concentration and typical environmental factors was established.The ecological/health risks of QNs antibiotics were evaluated by risk quotient method.APCS-MLR model was used to analyze the pollution sources of QNs antibiotics,too.The main research results were listed as following:1)The spatial variation of main chemical ions in groundwater in different areas was different.The chemical types of groundwater were HCO₃·SO₄-Ca、HCO₃-Ca and HCO₃-Na·Ca..The contribution rate of weathering dissolution of carbonate and sulfate minerals,dissolution of rock salts and ion exchange to groundwater chemistry was71.01%,and the contribution rate of human activity pollution to groundwater chemistry was 12.93%.The cluster analysis results showed that the central and eastern plain areas of Shijiazhuang City were polluted by human activities.2)The concentration of heavy metals in groundwater ranged from 47.30 to 2560μg·L^-1.According to single factor and Nemerow index,Pb,Fe and Cd were the main heavy metals influencing groundwater.Industrial and agricultura activities,traffic discharge,and geological background were the three main sources of heavy metals in the groundwater.Thereinto,industrial and agricultural activities showed the highest contributtion to the accumulation of heavy metals.Except for the potential threat of heavy metals from industrial and agricultural activities to adults,the non-carcinogenic risks of heavy metals from other sources to adults and children were acceptable level.Moreover,the carcinogenic risks from industrial and agricultural activities to adults and children were potential threats.Thereinto,the carcinogenic health risks of Cd and As were higher.3)The concentrations of QNs antibiotics in groundwater ranged from 3.02 to 98.5ng·L^-1,and the detection rates of ciprofloxacin,Enoxacin and flumequine were relatively high.The overall spatial distribution of QNs concentration in groundwater showed higher values in southeast areas,while showed lower values in northwest areas.The mean of main physicochemical parameters COD,NO₃^-,TDS and HCO₃^-in groundwater in Shijiazhuang city were belonged to ClassⅢquality standard of groundwater（GB/T14848-2017）,and the spatial distribution of these chemicals showed significantly different.The physicochemical factors in southern area were higher than those in other areas.The correlation analysis results showed that temperature,chemical oxygen demand,total dissolved solids,total bacterial colony,and p H were significantly correlated with QNs（P<0.01 or P<0.05）.The main sources of QNs antibiotics in groundwater were pharmaceutical wastewater and domestic sewage,aquaculture and livestock breeding,and sewage treatment plants.Thereinto,pharmaceutical wastewater and domestic sewage showed the highest contribution to the accumulation of heavy metals.The ecological risks of CIP were at medium-high risk level,while other QNs were at medium-low risk level.