Abstract: In order to explore the effects of low molecular organic acids (citric acid and malic acid) on the form distribution of Cr in different chromium polluted soils,the reclaimed soil around the coal gangue hill of Panyi Mine in Huainan City was taken as the research object. By simulating the soil polluted by different concentrations of Cr,the influence mechanism of citric acid (CA) and malic acid (MA) on the occurrence form of Cr in soil was analyzed. The results showed that:① With the increase of exogenous Cr concentration,the activity of Cr in soil increased effectively. ② The addition of citric acid and malic acid increased the content of exchangeable Cr in soil,that is,the effectiveness of Cr increased. With the increase of citric acid and malic acid concentration,the activation effect of citric acid on Cr in soil continued to increase,and the activation effect of citric acid was better than malic acid. ③ With the extension of aging time,the activation effect of organic acids on Cr will weaken,and the weakly bound Cr will gradually transform into strongly bound Cr. Therefore,in the remediation of soil heavy metal Cr pollution,citric acid with good activation effect could be considered as a remediation assistant to improve the efficiency of soil remediation.

Key words: chromium pollution,citric acid,malic acid,occurrence state,pollution remediation