Soil Pollution Investigation And Assessment Of Abandoned Coal Chemical Plant Area

According to the results of the first soil pollution survey conducted in China from 2005 to 2013,the overall soil environment situation in China is not optimistic,and the soil pollution in some areas is relatively serious,and the soil pollution problem has been widely concerned with 16.1% of the total national soil overage rate.End of 2003 to August 2006.The state has carried out the "baode-jungel-fugu" black triangle renovation,forcing the closure of small earth coke ovens with serious pollution below the scale,actively guiding the comprehensive utilization of raw gas,focusing on the rectification of enterprises with excessive pollution,and shutting down a large number of small earth coke ovens with serious pollution.The pollution of organic compounds and some heavy metals in the soil left by such closed factories is worthy of attention.The site the original production enterprises in the process of development,project and organics,heavy metals in waste water and waste residue produced may leak through the staging point,leaching transfer infiltration into the soil,such as potential pollution include location and the surrounding,to form a larger harm to ecological environment and human health,so it is necessary to carry out factory of abandoned coal characteristic of soil pollution and human health risk assessment.Scholars at home and abroad have carried out extensive studies on soil pollution characteristics and human health risk assessment of coal production,transportation,storage,coal burning power plant and other surrounding areas.However,there are few reports on the investigation and assessment of soil pollution in abandoned coal-burning(coking)plants.Therefore,it is necessary to further study the soil pollution status of the abandoned coal gasification plant,so as to make better use of the site and provide reference for the land use management in the next step.Proven coal factory presence of organic matter in soil,heavy metal pollution and human health risk,based on the coal chemical industry factory as the research area,using the single factor pollution index method and comprehensive pollution index method to evaluate the characteristics of soil pollution,through field sampling,testing and system analysis characteristics and spatial distribution of soil pollution in the factory;According to the spatial distribution of soil pollutants and the distribution of different process units in the plant area,the source analysis of soil pollutants was carried out.Human health risk assessment of different pollutants and risk assessment of secondary building construction in the coal-gasification plant.The research results are as follows:(1)according to the data analysis,the potential pollution sources in the field are mainly distributed in the coal heap and washing area,production area and blue carbon stacking area,and the key indicators are: organic matter,heavy metal,total nitrogen,total phosphorus,phenol,total cyanide and sulfide.Through the analysis of the physical and chemical properties of the soil,it can be known that the soil in this area is relatively alkaline with medium content of organic matter and low content of total nitrogen and total phosphorus of soil nutrients,indicating that the soil nutrients in the field are poor and not suitable for farmland.(2)according to the experimental results,except for a small amount of total petroleum hydrocarbons,none of the organic pollutants were detected,and the total petroleum hydrocarbons were far less than the screening value of the second category of land indicators in the "soil environmental quality soil pollution risk control standard for construction land(trial)".Heavy metal pollutants in addition to hexavalent chromium,cadmium did not detect out,the other heavy metals were detected.According to single pollution index evaluation method,the detection of heavy metals were lower than the soil environmental quality risk of construction land soil pollution control standard(trial)"construction land soil pollution risk screening value of the second type of land use index,which suggests that coalification legacy site soil under this standard is not affected by organic pollutant and heavy metal pollution.It is important to note that in the soil have petroleum hydrocarbon detection,that the site affected by a certain degree of organic pollution,but the results is not more than the soil environmental quality risk of construction land soil pollution control standard(trial)"construction land soil pollution risk screening value of the second type of land use index,indicated that the organic pollution risk is acceptable.(3)the soil pollution investigation of such waste coking sites should focus on the process area,the waste water treatment area and the storage area of raw materials and products.The depth of investigation should be greater than the depth of pollution sources.The investigation factors should focus on organic pollutants and take into account the heavy metal pollution.