田间条件下猪粪炭与黄磷渣配施对土壤镉污染的修复效果

Remediation effect of combined application of pig manure biochar and yellow phosphorus slag on cadmium contaminated paddy soil

为探究猪粪炭和黄磷渣配施对田间土壤镉(Cd)污染的修复效果,本研究以镉污染水稻田为研究对象,探讨两种钝化材料单施和配施对土壤理化性质、Cd有效态含量、Cd化学形态及水稻不同部位Cd含量的影响.结果表明猪粪炭与黄磷渣配施处理下土壤Cd有效态含量降低幅度最大,达90.49%,单施猪粪炭和单施黄磷渣处理下土壤Cd有效态含量分别降低了69.95%和15.77%.化学形态分析结果表明,相比对照,配施处理下土壤中易迁移的可交换态Cd比例降低了51.21%,而土壤中难迁移的铁锰氧化物结合态和有机结合态Cd比例分别增加了39.73%和38.15%.各处理对水稻生物量都没有负面影响,但水稻各部位Cd含量相比对照均显著降低.配施处理下水稻各部位中Cd含量均低于对照及单施处理,其中水稻籽粒中Cd含量降幅为78.31%,降低至0.05 mg·kg^(−1),远低于国家标准食品污染物限量标准值(<0.2 mg·kg^(−1)).生物炭与黄磷渣配施显著降低水稻土中Cd有效态含量和水稻籽粒中Cd的积累量,对Cd污染水稻田钝化修复效果优于单施处理,本研究结果可为土壤Cd污染的修复提供科学依据.

Field experiment was conducted to investigate the effects of single and combined application of pig manure biochar and yellow phosphorus slag on remediation of cadmium(Cd)polluted paddy soil,and the reduction of accumulation in rice.The available Cd and Tessier speciation of Cd in the soil,and the concentration of Cd in different parts of rice were determined.The reduction of available Cd in soil with combined application was 90.49%,which was lower than that with single application of pig manure biochar(69.95%)and yellow phosphorus slag(15.77%).Compared with the control,the ratio of exchangeable fraction of Cd in soil decreased by 51.21%,while the ratio of Fe-Mn oxides-bound and organic-bound fraction increased by 39.73%and 38.15%,respectively.All treatments significantly reduced the concentration of Cd in different parts of rice.The content of Cd in all parts of rice followed by the combined application was lower than that by single application,especially in grains,the Cd concentration decreased to 0.05 mg·kg^(−1),which was 78.31%lower than that of the control group,also far below the National standard for food safety-Limits of contaminants in foods(<0.2 mg·kg^(−1)).The combined application of pig manure biochar and yellow phosphorus slag could effectively reduce the content of available Cd in soil and the accumulation of Cd in rice,the immobilization effect was better than that of single application.The results of this study could provide scientific basis for the remediation of cadmium polluted soils.