污泥对风沙土养分与重金属效应的淋溶模拟研究

[目的]探讨城市生活污泥在沙化林地利用的可行性。[方法]通过室内淋溶模拟试验,研究施用污泥对风沙土养分及重金属含量的影响。[结果]施加污泥模拟淋溶后,风沙土总氮、总磷、速效氮、速效磷在各土层含量显著增加,且0～20 cm土层增幅明显大于20～40、40～60 cm土层;各重金属(Cu、Cr、Pb、Zn)含量在0～20 cm土层增加显著,40～60 cm土层增幅较小。施用污泥淋溶后,风沙土内梅罗指数(0.67)虽低于国家林地土壤质量标准(0.70),短期内未对土壤造成严重污染,但若长期施用污泥,应注意各重金属特别是Cd的累积效应所带来的潜在危害。[结论]城市污泥在沙化林地的短期应用具有较好的可行性。

Simulated Leaching Research on the Effects of Sewage Sludge on Nutrients and Heavy Metals in Aeolian Sand Soil

[Objective] The study aims to discuss the feasibility of urban sewage sludge applied to desertification forestland.[Method] Through the simulated leaching test,the effects of sewage sludge on nutrients and heavy metals in aeolian sandy soil were analyzed.[Result] After the simulated leaching with sewage sludge,the contents of total nitrogen(TN),total phosphorus(TP),available nitrogen(AN) and available phosphorus(AP) in each layer of aeolian sandy soil increased significantly,and the increase in 0-20 cm soil was more significant than that in 20-40 and 40-60 cm soil.Meanwhile,the content of each heavy metal in 0-20 cm soil rose significantly,while the increase was small in 40-60 cm soil.In addition,after the application of sewage sludge,the Nemrow Index of aeolian sandy soil was 0.67,lower than the national soil quality standard of forest land(0.70),and the short-time application of sewage sludge to sandy soil did not cause serious pollution.However,if sewage sludge has been applied to aeolian sandy soil for a long term,the potential hazard of lone-term accumulated heavy metals(especially Cd) should be paid more attention to.