塔宾曲霉胞外聚合物协同膨润土钝化处理铅污染土壤

钝化修复技术因投入低、见效快、操作简单等特点，对中低浓度土壤污染的修复具有优越性。微生物胞外聚合物（EPS）具有优异的重金属吸附能力，用EPS溶液协同膨润土钝化处理铅污染土壤，考察了EPS用量、酸雨处理、钝化处理时间对钝化效果的影响。结果表明:EPS对铅（Ⅱ）吸附容量为241 mg/g。在钝化实验中随着EPS用量增加，钝化效果先增强后减弱，加入膨润土后能与EPS产生协同钝化效果，最多能增加59%的残渣态铅，酸雨处理和延长处理时间均能增加钝化效果。针对不同污染途径进行的多种评估结果表明，EPS与膨润土能有效降低土壤中可提取态铅的比例。

EXTRACELLULAR POLYMERIC SUBSTANCES OF ASPERGILLUS TUBINGENSIS AND BENTONITE PASSIVATION SOIL LEAD

Passivation remediation technology has good advantages in remediation of low-concentration soil pollution due to its low investment, quick effect, and simple operation. The microbial extracellular polymeric substances (EPS) have excellent heavy metal adsorption capacity. The EPS solution was used to synergize bentonite to passivate the lead-contaminated soil. The effects of EPS dosage, acid rain treatment, and passivation treatment time on the passivation effect were investigated. The results showed that the adsorption capacity of EPS for lead (Ⅱ) was 241 mg/g. In the passivation experiment, as the amount of EPS increased, the passivation effect was firstly enhanced and then weakened. After adding bentonite, it could produce a synergistic passivation effect with EPS, which could increase the residue lead content by up to 59%. Both acid rain treatment and extended treatment time could increase the passivation effect. Various evaluation results for different pollution pathways showed that EPS and bentonite could effectively reduce the proportion of extractable lead in the soil.