Environmental geochemical characteristics of cadmium of soil and coal gangue in mining-induced subsidence area of Panji mine in Huainan

Taking the soil and coal gangue of Panji coal mining-induced subsidence area in Huainan as the research object, the content of Cd in the samples was determined by inductively coupled plasma mass spectrometry (ICP-MS), and the spatial distribution characteristics of trace elements were explored; the heavy metals in the samples were studied by Tessier's five-step morphology extraction method. The morphology of Cd and its bioavailability were analyzed. Finally, the method of geo-accumulation index was used to evaluate the degree of Cd pollution in soil and coal gangue in the subsidence area. The results showed that:the Cd content in the subsidence area of Panji coal mining area in Huainan was 4.17 times higher than the background value of the soil in Huainan, and the Cd content in coal gangue samples was 5.33 times higher than the background value of Huainan soil and coal background value; the residual Cd in coal gangue and soil accounted for the majority, the exchangeable Cd content was low, but the potential bioavailable state content was high; the results of the geo-accumulation index method indicate that the moderate Cd contamination in the soil and coal gangue in the subsidence area of Panji coal mining area in Huainan should be controlled by priority measures.