钝化剂对土壤重金属镉含量及其在川麦冬中累积的影响

Effects of passivators on content of heavy metal cadmium in soil and its accumulation in Ophiopogon japonicus

目的通过盆栽实验,综合评价不同钝化材料对土壤镉的钝化以及对川麦冬Cd含量降解的影响。方法以一年生川麦冬为供试材料,采用土壤盆栽实验方法研究了钝化材料汉白玉(Ar)、秸秆生物炭(Br)、粉煤灰(Fh)、菌渣(Me)、硅藻土(Dm)对土壤总Cd、有效Cd和川麦冬各部Cd吸收累积的影响。结果2种Cd污染程度土壤,不同钝化材料处理下均能提高土壤pH值;土壤阳离子交换量均极显著高于对照组,与土壤pH值成正相关;土壤总Cd含量和土壤有效Cd、麦冬地上部和地下部Cd含量较对照均极显著降低。综合各项指标发现,Ar对重金属Cd的钝化效果最佳,Br和Fh效果其次。结论结合盆栽实验结果来看,Ar、Br、Fh、Me和Dm能够有效降低土壤总Cd含量、有效Cd含量和麦冬各部Cd含量,还能促进麦冬的稳收增产;综合分析,Ar、Fh和Br对重金属Cd钝化效果最好,可作为涪城麦冬种植区土壤钝化修复首选材料。

Objective A pot experiment was conducted to comprehensively evaluate the effects of different passivation materials on the passivation of cadmium in soil and the degradation of Cd content in Ophiopogon japonicus.Methods Using one-year-old O.japonicus as experimental material,the effects of passivation materials such as white marble(Ar),straw biochar(Br),fly ash(Fh),bacterial residue(Me),and diatomite(Dm)on the absorption and accumulation of soil total Cd,available Cd and Cd in different parts of O.japonicus were studied by soil pot experiment.Results In the two Cd contaminated soils,the soil pH value was increased under different passivation materials treatments,and the soil cation exchange capacity was significantly higher than that of the blank control group,which was positively correlated with the soil pH value,while the total soil Cd content and soil available Cd content,and the Cd content of the aboveground and underground parts of O.japonicus were significantly lower than those of the control.According to all the indexes,it was found that the passivation effect of Ar on heavy metal Cd was the best,followed by Br and Fh.Conclusion Combined with the results of pot experiment,Ar,Br,Fh,Me and Dm could effectively reduce the total Cd content,effective Cd content and Cd content of O.japonicus,and also promote the stable harvest and yield of O.japonicus.Comprehensive analysis,Ar,Fh and Br have the best passivation effect on heavy metal Cd and can be used as the preferred materials for soil passivation remediation in the planting area of O.japonicus in Santai.Conclusion Based on the results of pot experiments,Ar,Br,Fh,Me and Dm can effectively reduce the total Cd content,effective Cd content and Cd content of Ophiopogon japonicus in various parts of the soil,and can also promote the stable income and production of Ophiopogon japonicus;comprehensive analysis,Ar,Fh And Br has the best passivation effect on heavy metal Cd,and can be used as the first choice for soil passivation restoration in the Ophiopogon japonicus planting area in Fucheng.