RESUMEN
In order to explore the characteristics and sources of heavy metal pollution in cultivated soil around a red mud yard in Chongqingï¼ the content and spatial distribution characteristics of eight heavy metal elements ï¼Cdï¼ Crï¼ Hgï¼ Niï¼ Pbï¼ Asï¼ Cuï¼ and Znï¼ in the soil were analyzedï¼ and the single factor pollution index method and Nemerow comprehensive pollution index method were used to evaluate the characteristics of heavy metal pollution in soil. On the basis of correlation analysisï¼ the APCS-MLR and PMF models were used to quantitatively analyze the sources of heavy metals. The results showed that the average contents of the other seven heavy metal elements were higher than the background values of Chongqing soilï¼ except for that of Cr. The heavy metals Cdï¼ Hgï¼ and As were moderately pollutedï¼ and Pbï¼ Cuï¼ Niï¼ and Zn were mildly polluted. The spatial distribution pattern of Crï¼ Niï¼ Pbï¼ Cuï¼ and Zn in the soil was similarï¼ and there was a very significant positive correlation between them ï¼P < 0.01ï¼. The spatial distribution characteristics of Cdï¼ Hgï¼ and As were significantly differentï¼ and there was no significant correlation between them ï¼P > 0.05ï¼. The source apportionment showed that the sources of heavy metals in the soil in the study area were relatively complexï¼ and the APCS-MLR and PMF models could identify the same four pollution sourcesï¼ namely red mud yard percolation emission and natural sourcesï¼ thermal power generation emission sourcesï¼ agricultural activities and natural sourcesï¼ and non-ferrous metal smelting emission sources. There was little difference in the results of source apportionment between the two models. The contribution rates of the four pollution sources in the APCS-MLR model were 51.8%ï¼ 18.0%ï¼ 15.9%ï¼ and 14.3%ï¼ respectivelyï¼ whereas those in the PMF model were 45.9%ï¼ 12.8%ï¼ 21.5%ï¼ and 19.8%ï¼ respectively.