中文摘要：

磷矿粉被广泛用于固定污染土壤中的重金属,然而施用草酸活化磷矿粉后对土壤中铅形态的研究非常有限。该文采用Tessier连续提取法分析砖红壤中施加未活化和经草酸活化的磷矿粉后,砖红壤中外源铅形态的变化。结果表明：随着磷矿粉施加量的增加,各处理中交换态铅质量分数比对照（64.1mg/kg）显著下降,未活化磷矿粉处理（PR）的交换态铅质量分数为0.1mg/kg,而草酸活化磷矿粉处理（APR）中未检出;醋酸盐提取态铅质量分数除草酸活化磷矿粉2000mg/kg处理为24.5mg/kg（APR3）减少外,其他处理均高于对照（27.2mg/kg）,在未活化磷矿粉500mg/kg（PR2）处理时达到最大值41.8mg/kg;铁锰氧化物结合态除未活化磷矿粉50mg/kg（PR1）处理为69.5mg/kg低于对照（74.2mg/kg）外,其余均高于对照,在APR3处理时达最大值117.2mg/kg;有机物结合态铅质量分数除PR1处理为20.7mg/kg,其余均高于对照处理（21.8mg/kg）,在APR3处理时达到最大值46.5mg/kg;PR处理残渣态铅与对照相比（44.2mg/kg）显著增加至60.6mg/kg,对APR处理其变化范围为42.7～43.5mg/kg,各处理稍低于对照,但差异不显著（p〈0.05）。显然,磷矿粉的施加可有效降低砖红壤中交换态铅质量分数,增加稳定态铅质量分数,且草酸活化磷矿粉的效果更佳。同时,草酸活化后磷矿粉的释磷能力增加,除草酸活化磷矿粉最高施磷量处理外（5000mg/kg）,施入磷矿粉和草酸活化磷矿粉后释放的磷对环境构成风险可能性极小。X-射线衍射光谱（X-ray diffraction,XRD）和扫描电镜（scaning electron microscope,SEM）结果分析也表明草酸活化磷矿粉的释磷能力增加,更有利于固定土壤中的铅。该研究可为草酸活化磷矿粉固定土壤中的铅提供参考依据。

英文摘要：

Phosphate rock has been widely and successfully used in immobilization of lead in contaminated soils. However, limited investigations are obtained on the lead form in the contaminated soils particularly immobilized by oxalic acid-activated phosphate rock. This study focused on the changes of exogenous lead （Pb） added into latosol with the application of phosphate rock （PR） and oxalic acid-activated phosphate rock （APR） by Tessier＇s sequential extraction procedure. The results indicated that the content of exchangeable Pb in latosol was decreased obviously with the increase of PR and APR application compared with CK （64.1 mg/kg）, and that reduce to 0.1 mg/kg for PR treatment and less than the detection limit in APR treatments. The contents of NaAc extractable Pb in all treatments were higher than CK （27.2 mg/kg） except for APR3 treatment which was 24.5 mg/kg and reached the maximum in PR2 treatment （41.8 mg/kg）. The Fe-Mn oxide-bound Pb contents in all treatments were higher than CK except for PR1 treatment （69.5 mg/kg）, and reached the maximum 117.2 mg/kg in APR3 treatment. Organic compound-bound Pb contents with the addition of PR and APR were higher than CK （21.8 mg/kg） except for PR1 treatment （20.7 mg/kg）, also reached the maximum 46.5 mg/kg in APR3 treatment. The residue fraction was increased to 60.6 mg/kg compared with CK treatment （44.2 mg/kg）, and changed from 42.7 to 43.5 mg/kg for APR treatments which were not obviously lower than CK treatment （p〈0.05）. To sum up, with the addition of PR in the soil, the contents of exogenous exchangeable Pb were decreased obviously and the residual Pb contents augmented conversely in most treatments, showing that Pb was effectively immobilized and better fixation effect was obtained in APR. Meanwhile, the results of phosphorus fraction indicated that the released P ability was increased more for APR than that for PR. Although exogenous phosphorus was added into latosol, the released phosphorus is unlikely to pose a risk