碱渣对土壤中镉有效性的影响

Effect of Alkali Slag on Cadmium Bioavailability in the Contaminated Soil

用盆栽试验研究碱渣及其用量对小白菜（Brassica chinesis）产量、镉吸收量,土壤pH及有效态镉含量的影响,以期为碱渣的利用提供新的途径。结果表明：碱渣对小白菜生长有促进作用,用量3 g/kg时增产效果最佳,与对照相比,增加了48.1%,继续增加用量小白菜产量增加幅度降低;施用碱渣显著提高土壤pH,且pH与施用量呈显著正相关（R=0.792,P〈0.05）关系,但土壤有效态镉含量随着碱渣用量的增加呈递增趋势,与对照处理相比,用量为6 g/kg时增加22.0%,达显著水平;碱渣促进根系对镉吸收累积,与对照相比,碱渣处理根系镉含量增加了29.7%~61.0%,达显著水平,并有增加小白菜地上部镉含量的趋势。这说明碱渣能提高土壤镉有效性,促进植物对镉吸收,可用来强化镉污染土壤的植物修复。

Pot experiment was done to study the effects of alkali slag dosages on biomass and cadmium uptake of Brasscia chinensis,soil pH and DTPA-Cd in a Cd contaminated soil.Results indicated that application of alkali slag promoted the growth of Brassica chinensis.Biomass of Brassica chinensis increased by 48.1% compared with the control when addition of 3 g/kg,and then the rate of biomass increase reduced with the increase of dosage.Alkali slag increased soil pH significantly,and there was a positive correlation between the pH and dosage.But DTPA-Cd increased with the increase of alkali slag dosage,with addition of 6g/kg,DTPA-Cd significantly increased by 22.0% compared with the control.Alkali slag promoted the absorption and accumulation of Cd in Brassica chinensis root and had tended to increase the concentration of shoot,and the concentration of root increased by 29.7%~61.0% compared with the control.Alkali slag can be used as amendment which would enhance phytoremediation effective in heavy metal contaminated soil.