基于信息扩散理论的广东大宝山地区土壤重金属污染评价

采用完全组合试验设计，比较了果壳有机肥（NM）、猪粪有机肥（PM）、污泥有机肥（SM）、腐殖土有机肥（HM）和蚯蚓土有机肥（EM）在不同用量下对不同污染程度土壤外源添加（CH₃COOH）₂Pb溶液]中有效Pb的影响，并探讨了土壤有效Pb变化与Pb形态转化的联系。结果表明，施用有机肥能降低轻度、中度和重度污染土壤中有效Pb的含量，且随着有机肥用量增加降幅增大，其中在中度和重度污染程度土壤中尤为显著。各有机肥中以SM、PM处理的效果最为突出，其土壤有效Pb含量较对照分别降低24.22%~36.10%和19.33%~35.48%。5种有机肥处理土壤有效Pb含量都随时间呈现先上升后下降的变化趋势，在培养至10 d达到峰值，此后逐步降低并在60 d后趋于稳定，其变化动态与Pb各形态转化动态具有一致性。经有机肥处理后，轻度污染土壤中，碳酸盐结合态铅（Carb-Pb）含量降低5.36%~12.91%，有机结合态铅（OM-Pb）含量稍有上升，残渣态铅（Res-Pb）含量增加18.92%~45.47%；在中度污染土壤中，Carb-Pb含量稍有下降，Res-Pb含量显著增加24.30%~38.04%；在重度污染土壤中，Carb-Pb含量无显著变化，OMPb和Res-Pb含量都有大幅增加，其增幅分别为14.46%~41.06%和29.02%~56.29%。土壤中Carb-Pb对有效Pb具有显著正向贡献，而OM-Pb和Res-Pb表现为显著的负向贡献。研究表明，有机肥主要通过降低Carb-Pb含量而大幅增加OM-Pb和Res-Pb含量，使得土壤Pb的有效性显著降低。

Evaluation of heavy metal pollution of soil in the Dabaoshan mining area based on the information diffusion theory

A complete combination experimental design was conducted to compare the effect of five organic manures under different dosages, including nutshell manure(NM), pig manure(PM), sludge manure(SM), humus manure(HM) and earthworm manure(EM), on the availability of lead(Pb) in soils with different levels of Pb(adjusted by addition of exogenous Pb as(CH₃COOH) ₂Pb solution), and the relationships between Pb availability and its chemical speciation in soils were also discussed. The results showed that the addition of organic manures reduced the contents of available Pb in soils with mild, moderate, and severe pollution of Pb, and the decline degree increased with increase of amount of organic manures which was particularly obvious in soil with moderate and severe contaminated Pb. SM and PM treatment showed the most prominent effects among the five organic fertilizer where the available Pb contents in soils were respectively decreased by 24.22%~36.10% and 19.33%~35.48% as compared with the control group. After adding organic manures, the change trends of contents of available Pb in soils with time showed increase firstly and then decrease until a peak value achieved in 10 days, following with gradual decline and finally approaching the stability in 60 days. The dynamics of Pb availability variation were consistent with the dynamics of Pb chemical speciation. After the treatment of organic manures, the contents of carbonates bond Pb(Carb-Pb) decreased by 5.36%~12.91% while those bounded by organic matter(OM-Pb) increased slightly, and those of residual Pb(Res-Pb) increased significantly by 18.92%~45.47%, for mild contaminated soil; For moderate contaminated soil, the contents of Carb-Pb slightly decreased while those of ResPb substantially increased by 24.30%~38.04%; For severe contaminated soil, the contents of Carb-Pb did not change significantly, and those of OM-Pb and Res-Pb increased apparently, raised by 14.46%~41.06% and 29.02%~56.29% respectively. The Carb-Pb had a significant positive contribution to available Pb in soil, while OM-Pb and Res-Pb demonstrated obvious negative contributions. The organic manures reduced significantly the availability of Pb in soil mainly by decreasing the contents of Carb-Pb and increasing those of OM-Pb and Res-Pb.