淹水条件下不同有机物料对土壤外源铜有效性的影响

Effects of Different Organic Matters on Availability of Added Cu in Soils Under Submerged Condition

将4种有机物料加入模拟铜污染(200mg·kg-1)的黄壤和石灰土中,在淹水条件下进行室内恒温培养试验,测定培养前后的Eh值和pH值及培养后的有效铜含量,并对其结果进行多重比较,进而讨论了引起这种变化的原因。结果表明,玉米秸秆、葡萄糖/蛋白胨能够明显促进土壤还原作用,使土壤处于氧化还原平衡状态,使黄壤和石灰土的Eh值下降至数十毫伏、甚至负值,使其pH值接近7,并使有效铜含量明显降低;风化煤、泥炭则不能促进该两种土壤的还原作用,其Eh值仍在数百毫伏左右,pH值和有效铜含量的变化都不明显。

Submerged incubation experiments in laboratory were conducted with samples of yellow soil and calcareous soil, respectively, to which four kinds of organic matters and 200 mg·kg-1 Cu2+ (simulating copper pollution ) were added. The Eh, pH values of treatments were determined at both the beginning and the end of the incubation. The contents of available copper in the treatments were determined at the end of the incubation. The obtained data were treated with the method of multiple comparison. The results showed that soil reduction was promoted in the treatments with receiving corn straw or/and glucose/peptone, the Eh value became very low, the pH value moved to 7.0, the contents of available copper decreased obviously, in comparison with the treatments receiving weathering coal or/and peat. The causes of the changes were also discussed.