Dynamic evolution and analysis of carbon tetrachloride pollution in karst groundwater in a city

Based on the monitoring data of carbon tetrachloride pollution occurring at the groundwater source zone of a southern suburb area of a city in 2000,the dynamic characteristics of a contaminant plume were analyzed.It is pointed out that the concentration of carbon tetrachloride(CT) in the well of a pesticide manufacturer was the highest in the study area,which was the pollution center in the south.The CT concentration in the well of a north orchard was much higher than in the wells in the middle,which was another pollution center.Therefore,the contamination plume is shaped like a dumbbell.The CT concentration in all the wells was reduced through pollution regulation,and the pollution nearly disappeared in April of 2005.The control factors that influenced the variation of CT concentration with space and time were analyzed in the study area.It was demonstrated that the dynamic variation of CT concentration was mainly influenced by contaminant input,rainfall,and groundwater exploitation.