Study On Physical Quantification And Health Risk Assessment Of Soil Environmental Damage Identification In Legacy Contaminated Sites

In recent years,with the rapid development of social economy,the continuous expansion of city size,the increasingly perfect urban construction planning and layout,and the relocation and development of industrial parks,the pollution problem of the left over sites has become increasingly prominent,which not only damages the environment,but also endangers human health.The reasons for the environmental hazards caused by the historically left contaminated sites are complex,and the administrative supervision is not in place,and there is a lack of effective implementation means for the compensation for the environmental damage caused by the left sites,which leads to many residents and social disputes.In view of this,the state has introduced the ecological environmental damage compensation system to solve such problems.Among them,environmental damage identification and assessment is an important technical means and scientific basis for ecological damage compensation.It is particularly important to understand and master the technical method system of environmental damage identification and assessment,so as to adopt reasonable compensation means.To in the field of environmental damage appraisal,the appraisal of soil environmental legacy contaminated sites at the amount of damage,this paper combined with the legacy of contaminated sites in a chemical plant in shenyang,selection of hexavalent chromium as characteristics of pollutants,the category of industrial land hexavalent chromium screening value as a baseline environmental standard,quantitative site earthwork quantity scope of pollution,pollution and pollution.Furthermore,according to the future site planning and the impact on human health,the human health risk assessment was carried out on the repaired residual contaminated site,and the human health risk control values under different exposure paths were obtained.Finally,based on the human health risk control values,the recommended restoration scheme was proposed,and the main conclusions were as follows:(1)The pollution investigation results show that the pollutant hexavalent chromium is the pollutant with the largest number of points exceeding the standard,the largest concentration exceeding the standard,the largest pollution area and the deepest pollution depth in the research site.With hexavalent chromium as the background value,the maximum over-standard rate is 96.85%.The maximum over-standard rate of hexavalent chromium was 15.04% with control value as background value.(2)Kriging interpolation method was used to analyze the spatial distribution of hexavalent chromium in pollutants.The results show that the horizontal area of hexavalent chromium pollution decreases with the increase of sampling depth.In the vertical direction,the area of hexavalent chromium increases first and then decreases with the increase of depth,and the pollution volume presents a gourd-like distribution.(3)The results of health risk assessment of the contaminated site showed that the carcinogenic risk of hexavalent chromium was higher in the study site,and the human health risk control value of hexavalent chromium was finally obtained as 3.7mg/kg.(4)Formulate a restoration plan based on the risk control value of human health:adopt appropriate horizontal barrier technology in the risk control area to isolate the pollution source,and implement monitoring in the later stage;The area to be repaired was partitioned by reduction stabilization technology for in situ repair and ectopic repair.This paper analyzes the key links of damage quantification,health risk assessment and soil remediation in the identification and assessment technology of soil environmental damage of contaminated sites,so as to provide a technical method system for the practical application of soil environmental damage identification of contaminated sites.Provide technical support for the identification and assessment of soil environmental damage of the entire contaminated site;To provide a scientific basis and comprehensive management strategy for the reuse,redevelopment and value protection of the final contaminated site.