南京城市土壤Pb的含量及其化学形态

The concentration and chemical speciation of Pb in Nanjing urban soils

研究了南京城市土壤Pb的含量及其化学形态分布 ,结果表明 :土壤全Pb平均含量为 10 7 3mg kg ,变幅为 36 3— 472 6mg kg ,土壤Pb污染严重 .表层土壤Pb以残渣态和铁锰氧化物结合态为主 ,各形态比例为残渣态 >铁锰氧化物结合态 碳酸盐结合态 >有机结合态 >可交换态 .与非城区土壤比较 ,城市土壤中Pb不仅含量高 ,而且活性大 。

The concentration and chemical speciation of Pb in Nanjing urban soils were studied. The results indicated that the mean Pb concentration in urban soils was 107 3?mg/kg, ranging from 36 3 to 472 6?mg/kg, and urban soils were seriously polluted with Pb. For urban topsoils, the Pb was dominated by residual and Fe Mn oxides fractions, and followed by the order of residual>Fe Mn oxidescarbonate>organic>exchangeable. Compared with Pb in non urban soils, Pb in urban soils had not only elevated concentration, but also higher activity and more serious threat to the environment.