铁基生物炭对镉污染农田土壤的修复作用研究

Remediation Effect of Fe-based Biochar on Cadmium Contaminated Farmland Soil

为探究铁基改性生物炭在镉污染农田土壤中的修复作用,以水稻秸秆为原料制备生物炭,并用氯化铁溶液进行改性,探究改性生物炭和普通市购炭对镉(Cd)污染土壤的修复性和长效性。结果表明,在生物炭施加量均为1%条件下,铁基改性生物炭和市购炭处理后土壤有效Cd降低率分别为52.16%和41.19%;与市购炭相比,经铁基改性生物炭处理后水稻和小麦籽粒Cd含量分别降低了42.86%和14.29%。且随着铁基生物炭施加量由0.5%增加到1%,水稻、小麦籽粒Cd含量分别下降了47.54%和30.77%。此外,持续3年测定施用1%添加量的铁基改性生物炭的大田实验表明,土壤有效Cd降低率始终保持在45%以上,证明铁基改性生物炭对镉污染土壤具有长效修复性。

In order to study the repairing effect of Fe-based modified biochar in cadmium(Cd)-contaminated farmland soil,the biochar pyrolyzed by rice straw was prepared and modified with ferric chloride solution. The repairing and long-term effect of modified biochar and market available biochar were studied on Cd-contaminated soil. The results showed that under the condition of 1% application rate, the reduction rate of soil available Cd after the treatment of Fe-based modified biochar and the market available biochar were 52.16% and 41.19%, respectively. Compared with the market available biochar, after treatment with Fe-based modified biochar, the content of Cd in rice and wheat grains decreased by 42.86% and 14.29%,respectively. Besides, with the increase of biochar application rate from 0.5% to 1%, the Cd content of rice and wheat grains decreased by 47.54% and 30.77%, respectively. In addition, a field experiment that determined the effect of Fe-modified biochar with the application of 1% for 3 years showed that the available Cd reduction rate of the soil kept more than 45%. It was proved that Fe-based modified biochar had long-term remediation to cadmium-contaminated soil.