改良剂对锑矿区土壤锑形态和生物可利用性影响的研究

Study on the Effect of Amendment on Sb Form and Bioavailability in Antimony Mine Area

利用人工造林结合应用土壤改良剂的试验,研究了土壤改良剂对重金属锑的形态差异、分布特征和生物可利用性的影响,为锑矿区重金属污染土壤生态修复提供技术依据。结果表明:随着土壤改良剂施放量的增加,土壤的pH增加,当每株施放改良剂达300g时,土壤pH由酸性变为弱碱性。不同剂量的土壤改良剂对0～20cm、40～60cm土层Sb的碳酸盐结合态有显著影响,对20～40cm土层Sb的碳酸盐结合态有极显著影响;对40～60cm土层Sb的残渣态有极显著影响。锑矿区土壤0～20cm土层中Sb的形态以铁锰氧化态、有机物结合态、残渣态形式存在,20～40cm土层中Sb的形态以铁锰氧化态、有机物结合态、残渣态形式存在,40～60cm土层中Sb的形态主要以有机物结合态、铁锰氧化态形式存在。施用改良剂可增加Sb的生物可利用态18.92%～24.23%,降低Sb的生物潜在可利用态17.55%～18.92%,降低Sb的不可利用态0.95%～6.03%,显著增加了Sb的生物活性,增加了Sb的生物有效性,增加了重金属Sb的生态风险,此时Sb易于被植物吸收并进入植物体,对植物产生一定的毒害作用。

The author used artificial afforestation combined soil amendment experiment for studying influence of soil amendment to Sb heavy metal forms,distribution characteristics and bioavailability,and providing the technical basis for antimonymine area ecological restoration.The results showed that with the increase in discharging amount of soil amendment,soil pH values increased and as per plant use 300 g casting amendment,the soil pH value from acidic becomes alkaline.Different doses of soil amendment on the 0-20 cm and 40-60 cm soil Sb carbonate bound had significant effects and 20-40 cm soil had very significant effect.However,to 40-60 cm residual form had very significant effect.Sb forms had Fe-Mn oxidate state form,organic bound and residual form in 0-20 cm and 20-40 cm soil;but mainly form were organic bound and Fe-Mn oxidate state forms in 40-60 cm soil.Cast amendment increased Sb bioavailability 18.92%-24.23%,decreased Sb potential bioavailability 17.55%-18.92%,decreased Sb non-bioavailability 0.95%-6.03%.In addition,significantly increased the biological activity and the bioavailability of Sb,thus increased the ecological risk of heavy metal Sb,this moment Sb easily absorbed by plants and entered the plant to some extent on the toxic effects of plant.