苜蓿施用污泥效果的研究Ⅱ 对土壤理化性质及元素含量的影响

Studies on effects of application of sewage sludge on alfalfa Ⅱ. Effects on physical and chemical character, element accumulation of the soil

将兰州市七里河污水处理厂生活污泥施用于苜蓿人工草地 ,探讨其对土壤环境的影响。结果表明 ,施用污泥 ,改善了土壤理化性质 ,增加了土壤肥力 ,土壤中有机质、全 N和全 P的含量增加 ,土壤容重下降。污泥施用量与土壤有机质、全氮含量呈极显著正相关 (P<0 .0 1) ,与土壤容重呈极显著负相关 (P<0 .0 1)。当污泥施用量在 4 kg/ m2以上时 ,0～ 2 0 cm土层 Fe和 Ca的含量显著增加 ;施用量 8kg/ m2 时 ,Cu和 Zn的含量显著高于对照 ;而 K、Mn和重金属元素 Ni、Pb、As和 Hg的含量与对照无显著差异 ,且各元素都未向土壤下层迁移 ,没有对土壤环境造成污染。

Sewage sludge collected from Qilihe Sewage Treatment Factory, Lanzhou, China, was applied to artificial grassland sown with Medicago sativa L. cv. Xingjiang Daye, and effects of sewage sludge on the soil environment were investigated. The results showed that application of sewage sludge improved the physical and chemical characters of the soil--the contents of organic matter, total N and P were increased; unit weight was decreased. While the application dosage of sewage sludge was in the range of 4~8 kg/m2, the contents of Fe, Ca, Cu and Zn were increased significantly, and the contents of K, Mn and heavy metal element of Ni, Pb, As and Hg in soils of 0~20 cm depth were no significant difference compared with that of the control. Also, the above elements had not moved into the lower layer of the soil and the application of sewage sludge did not cause the pollution of the soil environment.