石灰和泥炭处理对超积累植物东南景天清除土壤重金属的影响

Effect of Lime and Peat on the Heavy Metal Removal by a Zinc and Cadmium Hyperacumulator of Sedum alfredii

[目的]采用植物修复技术对广西崇左市某一铅锌矿区的重金属污染土壤进行治理。研究石灰和泥炭处理对东南景天和玉米的生长及积累重金属的影响。[方法]进行为期1年的大田试验,植物种植模式为单种玉米和玉米套种东南景天2种方式;土壤改良剂的处理为单施石灰和石灰+泥炭处理2种方式。[结果]大田试验证明,在土壤Zn和Cd分别达3 574 mg/kg和29 mg/kg的条件下,东南景天生长良好,其地上部Zn和Cd含量最高达21 982 mg/kg和1 013 mg/kg。施用石灰或泥炭均可促进东南景天和玉米的生长,提高2种植物对Zn的积累,抑制玉米对Cd的积累。[结论]在施用石灰+泥炭的基础上采用玉米套种东南景天的方式可以获得最大的Zn和Cd去除效果。

[Objective]To remediate a heavy metal polluted soil at Chongzuo City of Guangxi by phytoremediation technique and study the effect of lime and peat treatment on the growth and heavy metals accumulation of S.alfredii and maize.[Method]The planting models were the single cropping of maize and the intercropping of S.alfredii and maize.The soil was improved by the single treatment of lime and the combined treatment of lime and peat.[Result]After one year＇s field experiment,in the soil with 3 574 mg/kg Zn and 29 mg/kg Cd,S.alfredii grew well and accumulated 21 982 mg/kg Zn and 1 013 mg/kg Cd in shoots.The use of lime and peat improved the growth and the uptake of Zn in S.alfredii and maize,but restrained the accumulation of Cd in maize.[Conclusion]The highest amount of heavy metal removal was obtained under the intercropping of S.alfredii with maize growing in the soil amended with lime and peat.