Risk Assessment And Remediation Program Discussion Of A Typical Fluoride Contaminated Site

In this paper, the relocation enterprise legacy site in the eastern lower reaches of the Yangtze river has carried on the detailed investigation.I mainly do the study to identify characteristics of pollutants, collect soil and groundwater environmental samples and analyze the content of heavy metals, organic compound and fluoride in different environmental mediums. According to the result of investigation and analysis, the health risk assessment method was used to evaluate the pollution, and the soil remediation of fluoride contaminated site was studied. Main conclusions are as follows:1、The investigation of the contaminated site①The surface soil in planning for sensitive land area of the site was contaminated by fluorideThe fluoride values in planning for non-sensitive land area of the site were lower than the appropriate screening value of 《 the ground soil screening value of environmental risk assessment》 (DB11/T811-2011)The surface soil in planning for sensitive land area of the site was contaminated by fluoride, with the exceeding rate of 0.07～2.34.② The content of water soluble fluoride is low.The survey to select four points of the upper soil, a total of eight soil sample, added to test the content of water soluble fluoride. The contents of 8 soil water soluble fluorine are in 1～7 mg/kg. The average of water soluble fluorine proportion of total fluorinetotal is 0.35%, lower than the tillage soil water soluble fluorine ratio of total fluoride, that have been reported in China (average 0.43%).③ The investigated site of the soil were not polluted by heavy metals and organic compounds④ The content of heavy metal and inorganic indicators in groundwater of investigated site achieves the 《groundwater quality evaluation standard》 (GB/T14848-93) class IV water quality standards. Groundwater is neutral and not detected by organic pollutants.2、The health risk assessmentResearch within the planning for residential land, land for primary and secondary school education and other sensitive way, focus on fluoride pollution. The risk of cancer is higher than the acceptable level of risk, the risk is not acceptable. It needs to protect soil remediation and risk control measures. In land for housing and education situation, exposed two ways of fluoride intake of soil and soil particles inhaled through the mouth, cumulative risk control value is 663.3 mg · kg-1.3、remediation program discussion of a typical fluoride contaminated siteThe ecological risk of fluorine pollution in the studied soil is smaller, soil fluoride could intake through the mouth of the toxicity of cancer and inhaling soil particles both exposure pathways, Combined with the human health risk assessment of. We recommended that taking risk reduction measures, namely to block exposed way to treatment and disposal excess fluoride soil. Including as a cushion layer under the road during the soil development and construction, or add a cover layer and cement hardening, then buried deep under the ground, to achieve the purpose of blocking contaminated soil exposed way.