两种景天修复Cd/Zn污染土壤效果的比较

Phytoremediation Effects and Contrast of Sedum alfredii and Sedum plumbizincicola on Cd/Zn Contaminated Soil

为对比研究重金属超富集植物东南景天与伴矿景天对酸性Cd/Zn污染土壤的提取修复效果,利用盆栽及田间试验同时种植两种景天。结果表明,(1)盆栽试验为期两年,种植东南景天的土壤Cd质量分数从3.51 mg·kg^(-1)降到0.46 mg·kg^(-1),土壤Zn质量分数从865 mg·kg^(-1)降为516 mg·kg^(-1);种植伴矿景天的土壤Cd质量分数从3.44 mg·kg^(-1)降到0.55 mg·kg^(-1),土壤Zn质量分数从852 mg·kg^(-1)降为577 mg·kg^(-1)。(2)田间试验为期一年,韶关种植东南景天的土壤Cd质量分数从1.38 mg·kg^(-1)降为1.07 mg·kg^(-1),土壤Zn质量分数从501 mg·kg^(-1)降为462 mg·kg^(-1);种植伴矿景天的土壤Cd质量分数从1.71 mg·kg^(-1)降为0.93 mg·kg^(-1),土壤Zn质量分数从585 mg·kg^(-1)降为505 mg·kg^(-1)。(3)在室内盆栽条件下,每年秋季种植的东南景天产量显著高于伴矿景天;东莞和韶关的伴矿景天在野外环境下均比东南景天具有更好的适应性及生长能力,生物产量远高于东南景天。(4)在盆栽试验条件下,东南景天重金属Cd、Zn修复能力与效果优于伴矿景天;而在野外田间试验条件下,伴矿景天对Cd、Zn的提取修复效果优于东南景天。综上,东南景天与伴矿景天对酸性Cd/Zn复合污染土壤均具有很好的提取修复效果。本研究对酸性Cd/Zn污染土壤的植物提取修复技术具有一定的参考意义。

In order to study the phytoremediation of hyperaccumulators Sedum alfredii and Sedum plumbizincicola on Cd/Zn contaminated soil and contrast the effects,pot and field experiments were conducted.Results showed that:(1)After two years of pot experiment,the mass fraction of Cd in Sedum alfredii planted soil decreased from 3.51 mg·kg^-1 to 0.46 mg·kg^-1 and the mass fraction of Zn in soil decreased from 865 mg·kg^-1 to 516 mg·kg^-1.Meanwhile,the mass fraction of Cd in Sedum plumbizincicola planted soil decreased from 3.44 mg·kg^-1 to 0.55 mg·kg^-1 and the mass fraction of Zn in soil decreased from 852 mg·kg^-1 to 577 mg·kg^-1.(2)After one year of field experiment in Shaoguan,the mass fraction of Cd in Sedum alfredii planted soil decreased from 1.38 mg·kg^-1 to 1.07 mg·kg-1 and the mass fraction of Zn in soil decreased from 501 mg·kg^-1 to 462 mg·kg^-1.Meanwhile,the mass fraction of Cd in Sedum plumbizincicola planted soil decreased from 1.71 mg·kg^-1 to 0.93 mg·kg^-1 and the mass fraction of Zn in soil decreased from 585 mg·kg^-1 to 505 mg·kg^-1.(3)The biomass production of Sedum alfredii was significantly higher than that of Sedum plumbizincicola(shoots)every autumn in pot experiment.However,the result was opposite in field experiment,because Sedum plumbizincicola had better adaptability and growth ability than Sedum alfredii in Shaoguan and Dongguan field.And(4)remediation efficiency of Sedum alfredii was better than Sedum plumbizincicola in the pot experiment,but the result was opposite in field.Summing up,both Sedum alfredii and Sedum plumbizincicola had good phytoremediation effects on Cd/Zn contaminated soil.This study has reference significance for phytoremediation technology of acidic Cd/Zn contaminated soil.