可溶性有机质对污染土壤中铊迁移行为的影响

Effect of Dissolved Organic Matter on Transfer Behavior of Thallium in Polluted Soils

目的为了查明可溶性有机质(DOM)对土壤中污染元素铊赋存形态的影响,方法采用形态分级提取方法,将土壤中的铊重金属分成酸可交换态、铁锰氧化物结合态、有机质结合态和残留态4组分,并采用Elan 6100型ICP-MS质谱仪测定各组分中铊的质量浓度。结果 DOM可降低酸可交换态的Tl,增加铁锰氧化物结合态和有机质结合态Tl的百分含量,但对残留态Tl的百分含量没有明显影响。因此,DOM可降低铊在土壤中的活动性,从而改变了铊在土壤中的迁移行为。结论可溶性有机质(DOM)自身的络合(螯合)能力及其吸附特性是改变重金属铊形态分布的主要因素。

Objective For ascertain that how to Dissolved organic matter impact form distribution of pollution - element thallium in soils. Methods A method of form grading extraction was used to divide heavy- metal thallium into four components that exchangeable -T1, Fe -Mn oxides fraction, organic form thallium and residual thallium, and ICP - MS of Elan 6100 was sued to measure the percentage composition of T1. Results The results showed that DOM can reduce the percentage composition of exchangeable - T1 and increase the percentage of Fe - Mn oxides fraction and organic form thallium. However, percentage composition of residual thallium appeared no variations after the addition of DOM. So, DOM can reduce the mobility and transfer behavior of thallium in soils. Conclusion The major factor that change species distribution of thallium is the complexing and chelation of DOM.