改性生物炭-凹凸棒石复合材料对镉污染土壤的修复效果研究OACHSSCD

This study investigated the effects of Fe-modified and Mg-modified biochar/attapulgite composite materials on soil pH,organic matter content,and available Cd through field experiments.It also analyzed the transformation of Cd chemical forms in the soil and the accumulation of Cd in different parts of rice at various growth stages to clarify the reme-diation effects and mechanisms of the modified composites on soil Cd pollution.The results indicate that Mg-modified bio-char/attapulgite composites(Mg-modified materials)effectively increased soil organic matter and pH,thereby improving basic soil properties.At a dosage of 7 500 kg·hm-2,Mg-modified materials reduced acid-soluble Cd proportion in the soil to 22.15%and increased residual Cd proportion to 37.16%,lowering the content of available Cd and decreasing Cd accumulation in various rice tissues.The Cd content in different rice tissues followed the order:root>stem>leaf>husk>grain.At the 7 500 kg·hm-2 application rate,both Fe-and Mg-modified materials effectively inhibited Cd accu-mulation in all rice tissues with the Cd content in mature rice grains was 0.85 and 0.80 mg·kg-1,respectively represen-ting reductions of 44.81%and 48.05%compared with the control,and 27.97%and 32.20%compared with the unmodi-fied composite material,respectively.This study provides theoretical and data support for the promotion and application of modified biochar/attapulgite composites in agricultural fields.