有机肥结构特征对污染土壤Cd形态的影响

研究了以污泥和鸡粪为主要来源的两种不同有机肥主要组分和结构特征差异,结合吸附和土壤平衡试验,探讨了各组分对Cd吸附反应特征和土壤Cd形态分布的影响。结果表明:供试污泥有机肥含有较多的羧基,其最大络合量大于鸡厩肥;同时能更有效降低NH4NO3提取态Cd,但因为结合形态相对不稳定,因此导致EDTA提取态Cd有明显增加。而鸡厩有机肥含有更多π键,芳香化和腐熟化程度较高,与Cd吸附更稳定,在降低NH4NO3提取态Cd的同时也能降低EDTA提取态Cd。研究表明有机肥腐殖化、芳香化程度是影响其对重金属污染土壤修复与改良效果的主要因素。

The Effects of the Structural Characteristics of Organic Manure on Cd Morphology in Contaminated Soil

This study explored the main compositions and structural characteristics differences between two different sources of organic manure： sludge manure and chicken manure. Combined with adsorption test and soil balance test, this study discussed the effects of different manure compositions on Cd adsorption and Cd morphology in the soil. The resuhs showed that the sludge manure contained more carboxyl and had larger maximum metal binding capacity than chicken manure, and could be more effective to reduce the NH4 NO3-extractable Cd. However, on account of the unstable combination, the EDTA-extractable Cd had increased. The chicken manure contained more w bond, more aromatic and higher degree of maturity, thus the Cd adsorption was more stable, and could also reduce the EDTA-extractable Cd. This study showed that organic manure humification, degree of aromatization were the main influencing factors on remediation and improvement effect of heavy metal contaminated soil.