Pb和Cd赋存形态与土壤理化性质相关性研究

Correlation between Fractionation Content of Pb,Cd and Physico-chemical Properties of Contaminated Soils

选择我国14种具有代表性的重金属污染土壤，测定其主要理化性质（pH、阳离子交换量、有机质、粉粒和黏粒），采用改进的BCR顺序提取法对其中的Pb和Cd进行形态分析，运用SPSS 20.0软件进行Pearson相关性分析，建立逐步回归模型，研究重金属赋存形态与理化性质的相关性。结果表明，Pb和Cd的酸可溶态与pH值呈极显著负相关，相关性系数r分别为-0.80和-0.78，与阳离子交换量呈显著正相关，r分别为0.54和0.61，与有机质、粉粒和黏粒无相关性；Cd的可还原态与有机质呈显著正相关，r=0.56，与其它理化性质无相关性；可氧化态与有机质和黏粒呈显著正相关，与其它理化性质无相关性；残渣态与主要理化性质均无显著相关性。由逐步回归模型发现，酸可溶态、可还原态、可氧化态与理化性质回归效果均较好。

14 soil samples contaminated with heavy metal in China were collected. Physico-chemical properties （pH, CEC, OM, powder and clay） of the soil samples were determined. 4 fractionations percentage of Pb and Cd were also detected through improved BCR sequential extraction process. The correlation between the fractionation percentage of Pb, Cd and the physico-chemical properties of the soil samples and stepwise regression model were studied and built by SPSS 20.0. The results indicated that the acid-soluble fraction content of Pb and Cd were negatively correlated with pH, and correlation coefficient are -0.80 and -0.78. The acid-soluble fraction of Pb and Cd have a positive correlation with CEC, r=0.54 and 0.61; The acid-soluble fraction of Pb and Cd have no correlation with OM,powder and clay; The reducible fraction of Cd has a positive correlation with OM, r=0.56; There was also no significant correlation of reducible fraction of Cd with other properties; The oxidizable fraction of Pb and Cd has a positive correlation with OM and clay extremely, however has no correlation with other properties; No significant correlation of the residual fraction of Pb and Cd with pH, Eh, CEC, OM, powder content and clay content was identified. Good Stepwise regression results of acid-soluble fraction, reducible fraction, the oxidizable fraction and properties were discovered.