Evaluation And Treatment Of Groundwater Pollution In Informal Landfill Site In Zhongshan County,Guangxi

Landfill site does different degrees of harm to the water environment,atmospheric environment,soil environment and ecological environment near the site from many aspects,which seriously threatens the health of local residents.Among them,the leachate from informal landfill site pollutes groundwater most seriously.In view of the importance of groundwater,it is of great significance to carry out the environmental investigation of groundwater pollution in the area polluted by informal landfill site,which is crucial to human health risk assessment and remediation of groundwater pollution.The paper mainly includes the following three parts: First,hydrogeological engineering geological survey of Liyutang informal landfill site and its surrounding environment in Zhongshan County,Guangxi;Second,environmental impact assessment and groundwater pollution health risk assessment on the groundwater environment concerning the landfill site;Third,putting forward economic and reasonable plan for the remediation and treatment of the groundwater environment.Through this study,the following conclusions are obtained:(1)The leachate of Liyutang informal landfill site has caused serious pollution to the underlying soil layer of vadose zone and the surrounding groundwater environment.The monitoring results showed that Mercury in soil exceeded the standard.Also,ammonia nitrogen,volatile phenol,mercury,iron and total escherichia coli in groundwater exceeded the set standard.According to the analytical method,it takes about 50 years or more to remove the mercury in landfill to the abandoned old well W08 in Liyutang East.(2)Seven major pollutants of groundwater environment in the study area were selected for health risk assessment of groundwater pollution.According to the health risk assessment analysis,in general,the carcinogenic risk value and non carcinogenic hazard quotient of chromium,arsenic,cadmium and mercury in the study area are higher than those of volatile phenol.Chromium,arsenic,cadmium and mercury were selected to calculate the risk control values of groundwater pollution,and the calculated risk control values were 50μg/L,10μg/L,5μg/L and 0.9944μg/L,respectively.The carcinogenic risk value and non carcinogenic hazard quotient of pollutants in the study area basically exceeded the acceptable risk level,and the risk of human health through drinking water was higher.However,if groundwater is not used as drinking water source,the risk of groundwater pollution to human health in the study area is small.However,residents exposed to such environment for a long time will suffer from adverse effects.The relevant departments should strengthen the site management and monitoring to prevent residents from being threatened by health risks.(3)Based on the conclusion that the risk of groundwater pollution to human health is "small",it is suggested that the groundwater environment of the site should be treated at the source,and the specific scheme is "chemical oxidation degradation technology + recovery and utilization technology + site restoration".During the construction period of rehabilitation and treatment,daily monitoring should be carried out,and the operation of construction equipment should be kept a close watch on to prevent secondary pollution of groundwater caused by construction.