青葙修复镉污染土壤的田间试验研究

为探索氯化铵与柠檬酸和青葙(Celosia argentea L.)联合修复重金属Cd污染土壤的方法,通过田间试验,研究了氯化铵与柠檬酸对青葙生长和吸收富集Cd的影响、根际土与非根际土之间的差异,以及对土壤Cd含量和形态的影响。结果表明,种植青葙并施加氯化铵(C+AC)处理能显著促进青葙地上部干重的提高,比只种植青葙(C)处理增产53.03%;种植青葙并施加柠檬酸(C+CA)处理能提高青葙对Cd的吸收富集能力,地上部Cd含量比C处理提高16.64%;而C+AC处理对青葙地上部Cd积累量的促进效果最佳,比C处理提高69.49%;青葙的种植均显著降低根际土Cd的酸溶态含量,C、C+AC和C+CA处理的降低幅度分别为10.31%,15.00%和12.67%,显著大于非根际土;C+CA处理的土壤Cd含量降率最大,为5.33%,而不种植青葙,不施加药剂(CK)处理为1.43%,只有C+CA处理的26.83%。因此,青葙植物提取对Cd的降低仍起关键作用,且施加柠檬酸对表层土壤Cd的修复性能最好。

Field Experiment on Remediation of Cadmium Contaminated Soil by Celosia argentea L.

In order to explore the remediation method of heavy metal cadmium (Cd) contaminated soil by combining ammonium chloride with citric acid and Celosia argentea L., the effects of ammonium chloride and citric acid on the growth and absorption and enrichment of Cd of C. argentea L., the difference between rhizosphere soil and non-rhizosphere soil, and the effects of ammonium chloride and citric acid on soil Cd content and morphology were studied through field experiment. The results indicated that planting C. argentea L. and applying ammonium chloride treatment (C+AC) could significantly improve the dry weight of above-ground parts of C.argentea L., which increased the yield by 53.03% compared with only planting C. argentea L. (C) treatment. C+CA treatment could improve the ability of Cd absorption and enrichment of C. argentea L., and the Cd content in the above ground parts was 16.64% higher than that of C treatment. The C+AC treatment had the best effect on the accumulation of Cd in the above ground parts of C. argentea L., which was 69.49% higher than that of C treatment. The cultivation of C. argentea L. had significantly reduced the acid-soluble content of Cd in the rhizosphere soil, and the reductions of acid-soluble content of Cd in C, C+AC and C+CA treatments were 10.31%, 15.00% and 12.67%, respectively, which were significantly greater than that in non-rhizosphere soil. The soil Cd reduction rate of C+CA treatment was the highest, which was 5.33%, while that of the CK (without planting C. argentea L.or applying chemicals) was 1.43%, which was only 26.83% of the C+CA treatment. Therefore, the extraction of C.argentea L. still played a key role in Cd reduction, and the best remediation performance of citric acid on surface soil Cd pollution.