污泥重金属镉(Cd)钝化及在设施蔬菜上的应用效果

Passivation of Heavy Metals Cd in Municipal Sludge and Effects on Greenhouse Vegetable and Soil

以生活污泥、钝化剂和"绿冠F1"小油菜为试材,采用盆栽培养试验法,研究6种钝化剂对生活污泥重金属Cd钝化特征,以及污泥不同施用量和是否配施钝化剂对油菜生长和土壤环境质量的影响,以期为生活污泥在设施蔬菜上的应用提供参考依据。结果表明:粉煤灰能显著降低城市生活污泥中有效态Cd含量。施用污泥能够显著增加蔬菜产量、提高土壤含水量、pH和有机质含量,降低土壤硝态氮含量,同时也增加了土壤和植株Cd浓度,提高了污染风险;但是污泥和粉煤灰的配施可有效降低土壤中有效态Cd和植株可食用部分Cd含量。综合分析,添加粉煤灰的4.0%污泥处理对于增加蔬菜产量和品质、降低土壤中有效态Cd含量以及蔬菜可食用部分Cd含量效果最佳。

Taking municipal sludge, passivator and rape as test materials, the effects of six passivators on the passivation characteristics of heavy metal Cd in municipal sludge, as well as the effects of different application amounts of sludge and whether passivator was applied or not on rape growth and soil environmental quality were studied through pot culture experiment, in order to provide reference basis for the application of municipal sludge in protected vegetables.The results showed that flyash could significantly reduce the content of available Cd in municipal sewage sludge fertilizer.Application of sludge fertilizer could significantly increased vegetable yield, improved soil water content, pH and organic matter content, and reduced soil nitrate nitrogen content, but rised Cd concentration in soil and plants.Significantly, the combined application of sludge fertilizer and flyash passivator could effectively reduce the content of available Cd in soil and edible part of plant, especially with the combined application of 4.0% sludge fertilizer and flyash, which had the best effects on increasing vegetable yield and quality, reducing the risk of Cd pollution in soil and vegetables.