可降解螯合剂强化籽粒苋修复镉污染耕地的研究

Effects of Amaranthus hypochondriacus Enhanced by Biodegradable Chelating Agent on the Remediation of Cadmium Contaminated Farmland

评估籽粒苋对重金属镉的修复效果,为镉污染耕地修复提供理论依据和技术支撑,通过田间小区试验,探究籽粒苋种植方式、螯合剂类型、螯合剂添加量和螯合剂添加时间等因素对籽粒苋修复镉污染耕地的影响。从籽粒苋对镉的提取效率、种植管理人力成本、潜在环境风险等角度分析可知,条播种植方式优于直播和育苗插播,NTA优于EDDS和柠檬酸。在籽粒苋种植后85天,按450 kg/hm^(2)的标准施用可降解螯合剂NTA时,修复效果最佳,籽粒苋地上部分和地下部分的提取效率分别为5.4%和1.2%,单茬提取效率为6.6%,相对提高率为40.5%,总提取效率可达13.2%。因此,施用可降解螯合剂NTA可有效提高籽粒苋修复镉污染耕地的效率,可降解螯合剂强化高富集植物籽粒苋修复技术是一种绿色、经济、高效、环保的镉污染耕地修复方法,具有广阔的应用前景。

To provide a theoretical basis and technical support for the remediation of Cd contaminated farmland,the effects of Amaranthus hypochondriacus on the remediation of Cd contaminated farmland were evaluated.The effects of the planting modes of Amaranthus hypochondriacus,as well as the effects of the type,filling amount and filling time of chelating agents on the remediation of Cd contaminated farmland were investigated through field trials.The results showed that based on the analysis of Cd extraction efficiency,the labor cost of planting management,and potential environmental risks of Amaranthus hypochondriacus,the strip sowing mode was better than the direct seeding mode and transplanting mode,and NTA was better than EDDS and citric acid.85 days after planting Amaranthus hypochondriacus,the remediation efficiency was the best under the application of 450 kg/hm^(2) NTA.The extraction efficiency of Cd in the aboveground part and underground part of Amaranthus hypochondriacus was 5.4%and 1.2%,respectively.The extraction efficiency of Cd was 6.6%under single-cropping,the relative improvement rate was 40.5%,and the total extraction efficiency was 13.2%.Therefore,the application of biodegradable chelating agent of NTA could effectively improve the remediation efficiency of Cd contaminated farmland by Amaranthus hypochondriacus,and the technology of Amaranthus hypochondriacus enhanced by NTA is a green,economical,efficient and environmental-friendly remediation method for Cd contaminated farmland,which has a broad application prospect.