骨炭粉对Cd污染农田的修复效果与稳定性评价

为了探明骨炭粉对Cd污染土壤的修复效果及稳定性，以潮土与红壤Cd污染农田土壤为对象，基于土壤Cd有效态、作物降Cd率（DR，%）及降Cd失活率（IR，%）等指标，研究田间条件下施用3种浓度（0.25%、0.50%及1.0%）骨炭粉对Cd污染土壤的修复效果及120，360d后修复效果的稳定性.结果表明：骨炭粉处理均能有效促进潮土与红壤中作物生长，增加作物产量.施用骨炭粉能不同程度提高土壤中pH值、阳离子交换量（CEC）、全磷及有效磷含量；其中，0.5%和1.0%骨炭粉处理均显著（P<0.05）提高土壤pH值、土壤全磷及有效磷含量.与对照相比，不同骨炭粉处理120d后潮土和红壤中有效态Cd含量分别降低32.1%~48.4%、32.8%~56.2%，360d后土壤中有效态Cd仍然显著低于对照，降幅为26.9%~37.8%、25.8%~39.5%.对修复后三季作物Cd吸收测定结果表明，与对照相比，不同浓度（0.25%~1.0%）骨炭粉处理的第一季作物降Cd率（DR_-Cd）分别达36.0%~60.4%、33.9%~58.2%，作物降Cd率随骨炭粉施用量增加而增加.基于降Cd失活率（IR_-Cd）对骨炭粉修复效果的稳定性测定结果表明，潮土与红壤施用骨炭粉360d后，第三季作物降Cd失活率IR_-Cd为21.2%~34.7%和6.2%~21.6%，表明在酸性红壤中修复效果的稳定性大于潮土.综上骨炭粉对Cd污染土壤的修复效果及其稳定性结果表明，骨炭粉在Cd污染农田土壤修复中具有较大应用价值.

Remediation effect of bone charcoal on Cd polluted soil and its sustainability assessment under field condition

To investigate the remediation effect and its sustainability of bone charcoal on Cd polluted soil, this paper studied the remediation effect of bone charcoal application (0.25%, 0.50% and 1.0%) on Cd polluted soils, i.e. the fluvo-aquatic soil in Henan province and red earth in Hunan province, the phytoavailability of Cd in soil, the decreasing rate of Cd in crops (DR,%) and inactivation rate (IR,%) of Cd reducing defined as comparison with the first season crop, etc were used to evaluate the remediation efficiency and its sustainability after 120d and 360d application under field conditions. all bone charcoal applications could effectively promote the growth of crops and increase the yield of crops in tested soils. The application of bone charcoal improved the pH value, CEC, total P and available P content in soils to various degrees. Among the treatments, the bone charcoal application with 0.5% and 1.0% (w/w) significantly (P<0.05) improved the pH value, total P and available P content in soils when compared with the control groups. The content of available Cd as extracted with DPTA-CaCl₂-TEA in fluvo-aquatic soil and red earth decreased by 32.1%~48.4% and 32.8%~56.2% respectively after 120d of bone charcoal application treatments. The content of DPTA-CaCl₂-TEA-Cd in the soils was still significantly lower than that of the control groups after 360d, with a decrease of 26.9%~37.8% and 25.8%~39.5%, respectively. The uptake of Cd by three-season rotation crops showed that, as compared with the controls, the decreasing rate (DR,%) of Cd uptake by first season crop treated with different application levels (0.25%~1.0%) of bone charcoal ranged from 36.0% to 60.4% for fluvo-aquatic soil and 33.9% to 58.2% for red earth, respectively, the decreasing rate (DR,%) of Cd increased with the application level of bone charcoal. The inactivation rate (IR,%) of Cd was used to evaluate the sustainability of remediation efficiency in this study, the result indicated that the IRs of Cd for the third season crop ranged from 21.2%~34.7% in fluvo-aquatic soil and 6.2% to 21.6% in red earth, respectively, which indicated that the sustainability of remediation efficiency for acidic red earth was better than that in fluvo-aquatic soil. Taking into account all these factors of remediation effect and the sustainability of remediation efficiency, bone charcoal could be potentially used in the remediation of Cd polluted soil.