富里酸促进印度芥菜-棉花轮作对汞污染农田土壤修复的研究

Study on the Promotion of Fulvic Acid on the Remediation of Mercury Contaminated Farmland Soil by Brassica juncea- Cotton Rotation

[目的]提高汞污染农田土壤的修复效率。[方法]在汞污染农田土壤中投加富里酸(投加量为0、0.075、0.150、0.225 kg/m^(2)),并在试验结束后分析植物生物量和组织内汞含量及土壤总汞、有效汞含量,研究富里酸促进印度芥菜-棉花轮作对土壤汞的修复效果。[结果]投加富里酸可促进印度芥菜、棉花植株生长,但差异不显著,投加富里酸能提高印度芥菜、棉花中总汞的含量,促进印度芥菜、棉花根部汞向地上部分转运以及土壤总汞和有效汞的降低。每个种植季都投加富里酸,且富里酸投加量为0.075 kg/m^(2)促进效果最好,修复后,土壤总汞含量由(0.56±0.05)mg/kg降低至(0.32±0.04)mg/kg,土壤有效汞含量由(2.13±0.04)μg/kg降低至(0.48±0.05)μg/kg。[结论]投加富里酸可作为促进印度芥菜-棉花轮作修复汞污染农田土壤的潜在修复技术。

[Objective]In order to improve the remediation efficiency of mercury contaminated farmland soil.[Method]Fulvic acid(dosage:0,0.075,0.150,0.225 kg/m^(2))was added to the mercury contaminated farmland soil.After the experiment,the plant biomass,the mercury content in the tissue,the total mercury and the effective mercury content in the soil were analyzed,and the enrichment of mercury in Brassica juncea-cotton rotation were studied.[Result]The addition of fulvic acid had no significant effect on the biomass of Brassica juncea and cotton plants,but could increase the content of total mercury in plants,promote the transport of mercury from plant roots to aboveground parts and reduce the total and effective mercury in soil.When the fulvic acid dosage was 0.075 kg/m^(2),and each planting season was added with fulvic acid,the promotion effect was the best.After restoration,the total mercury content of soil decreased from(0.56±0.05)mg/kg to(0.32±0.04)mg/kg,and the effective mercury content of soil decreased from(2.13±0.04)μg/kg to(0.48±0.05)μg/kg.[Conclusion]The addition of fulvic acid can be used as a potential remediation technology to promote the remediation of mercury contaminated farmland soil by Brassica juncea-cotton rotation.