| Coal,which plays an important role in promoting the development of energy,power and chemical industry,is an significant part of the global energy structure.In recent years,with the large-scale development and utilization of coal resources,a series of changes have taken place in the coal mining area and its surrounding ecological environment,especially the large area of land resources have been abandoned,which seriously affects the sustainable development of the coal mining area.Therefore,the problem of soil quality of wasteland in coal mining area has been widely concerned by local residents.This paper took Sudong mining area of Huaibei coalfield(Zhuxianzhuag coal mine and Luing coal mine)as the research area,through sampling and testing soil of farmland and wasteland,analyzed their soil physical,chemical properties and fertility level,discussed the changes of contents,sources and health risk of heavy metals,finally comprehensively evaluated the soil quality of farmland and wasteland by using the minimum data set(MDS)method,which can provide a scientific basis for the development and utilization of wasteland in the coal mine area.The main achievements are as follows:(1)The contents of soil moisture and CEC in 30-60 cm layer of wasteland were lower than those of farmland,while the contents of EC and salt in 0-30 cm and 30-60 cm layer of wasteland were higher than those of farmland.The soil of wasteland belonged to alkaline soil,the content of TK in 0-30 cm layer was higher than that in farmland,and the content of SOM in 0-30 cm and 30-60 cm layer was higher that in farmland.The content of AP in 0-30 cm layer was lower than that in farmland,while the content of AN in 30-60 cm layer was higher than that in farmland.The content of AK in 0-30 cm layer is wasteland<farmland,but the content in 30-60 cm layer is wasteland>farmland.The content of TN and TP were lower than farmland.In general,the level of soil fertility in wasteland is general,which is lower than that in farmland,meanwhile,SOM?TN and AP are the limiting factors of soil fertility of wasteland.(2)The contents of Cu,Zn,As and Cd in the surface of wasteland and farmland exceeded the background value of Anhui Province,and the contents of Cd exceeded the National class I standard.In the profile soil,the contents of Cu,Zn,As and Cd in wasteland and farmland were higher than the background values,among the exceeding degree of As and Cd were the most prominent.The results of pollution assessment showed that the pollution level of Cd in wasteland and farmland reached heavy pollution,As belonged to the level of medium pollution,and the other elements were warning to light pollution.The potential ecological risk index showed that the wasteland was slightly to strongly damaged,while the farmland was slightly damaged.(3)Five sources were identified in the soil of the wasteland,which were natural sources(34.22%),coal mining(22.66%),construction waste(18.14%),agricultural activities(13.02%)and traffic pollution(11.97%).Four factors were found in the farmland soil,which were coal mining(38.25%),natural sources(35.33%),traffic pollution(18.63%)and agricultural activities(7.8%).Moreover,the results of health risk assessment of different pollution sources showed that agricultural pollution and construction waste in the wasteland were the most contributors to the health risk of adults and children,and in farmland,coal mining made a major contribution to the non carcinogenic and carcinogenic risk of adults and children.(4)The SQI-TDS and SQI-MDS of wasteland and farmland were lower than 0.545 and 0.438,belonging to grade V.Figure[28]Table[23]Reference[166]... |
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