腐殖酸对贵州万山地区土壤中汞赋存形态的影响

Effect of humic acids on the mercury speciation in soils of Wanshan area in Guizhou Province

通过盆栽试验研究了不同浓度(1%C、1.5%C、2%C)腐殖酸(HAs)活性组分(富里酸FA,胡敏酸HA)对含汞土壤中汞赋存形态的影响。结果表明,HAs的添加可以显著降低土壤水溶态汞和交换态汞的含量,增加土壤碱溶态汞和有机结合态汞的含量,从而有效降低土壤汞的生物有效性,但不同腐殖酸浓度与组分对土壤汞形态转化的影响不一。与对照CK相比,不同浓度FA和HA作用下土壤水溶态汞和交换态汞在45 d内分别下降了6.28%~7.05%、13.25%~15.89%和7.32%~7.46%、14.26%~16.7%;而土壤碱溶态汞和有机结合态汞在45 d内分别上升了13.03%~16.24%、14.33%~17.27%和2.52%~8.67%、15.96%~19.16%。

A pot experiment was conducted to study the effects of different concentrations(1% C, 1.5% C, 2% C) of fulic acid(FA) and humic acid(HA) on the speciation of mercury in mercury-containing soils. The results showed that the addition of HAs significantly reduced the content of water-soluble mercury and exchangeable mercury in the soil and increased the content of alkali-soluble and organic-bound mercury in the soil, which could effectively reduce the bioavailability of soil mercury. However, the effects of different humic acid concentrations and components on the transformation of soil mercury were different. Compared to the control CK, under the action of different concentrations of FA and HA, water-soluble mercury and exchangeable mercury decreased by 6.28% to 7.05%, 13.25% to 15.89% and 7.32% to 7.46%, 14.26% to 16.7%, respectively, within 45 days;alkali-soluble mercury and organic-bound mercury increased by 13.03% to 16.24%, 14.33% to 17.27%, and 2.52% to 8.67%, 15.96% to 19.16%, respectively, within 45 days.