Analysis Of Heavy Metal Pollution In Soils Around A Coal Gangue Hill And Screening Of Remediation Plants

Heavy metal contaminated soil is one of the most concerned problems in environmental pollution.It threatens agricultural production and food safety and can be enriched into human body through food chain,causing serious harm to human beings and the environment.Phytoremediation of heavy metal contaminated soil has the advantages of no secondary pollution and beautifying the environment.This paper takes the soil polluted by heavy metals around a gangue hill in Fuxin mining area as the research object,expounds the pollution characteristics of heavy metals in the soil,evaluates the potential ecological risks of heavy metals pollution in the soil,and analyzes the pollution degree.Four herbaceous plants including ryegrass,pennisetum,Setaria viridis and plantain were selected for indoor pot experiments to analyze the remediation potential of the above four herbaceous plants on heavy metal contaminated soil,thus providing a certain data basis for engineering practice.The results of spatial distribution of heavy metals in soil in the study area show that the content of heavy metals in soil generally shows a downward trend with the increase of distance from coal gangue piles.Speciation analysis data of heavy metals show that the heavy metals in the soil are mainly in the inactive residue state,and the acid extractable state has the lowest content.The total potential ecological risk degree of heavy metals in the soil of the study area is slight,and the pollution degree is Ni> Cu> Pb> Zn from high to low,among which Ni is the most important potential ecological risk factor.Through the determination and research of various biological and chemical indexes of ryegrass,plantain,Setaria viridis and Pennisetum under different concentrations of metal stress and relevant data analysis,Pennisetum viridis can be used as a pioneer species for phytoremediation due to its large biomass.Ryegrass can be used as a phytoremediation species for heavy metal contaminated soil because of its good tolerance to various metal ions.