中文摘要：

采用实验室批次实验方法,研究了零价铁对Cr（Ⅵ）模拟污染底泥的修复作用.结果表明,添加2%（以底泥干重计）的还原铁粉在24h内可将150mg·kg-1的Cr（Ⅵ）去除94.7%,较未加还原铁粉的Cr处理提高23.7%,较S＋Cr＋Fe处理（灭菌加铁）高14.2%;这说明,零价铁修复有效地促进了底泥中Cr（Ⅵ）的去除,底泥中的土著微生物也具有一定的去除Cr（Ⅵ）的作用.采用变性梯度凝胶电泳（Denatured Gradient Gel Electrophoresis,DGGE）和磷脂脂肪酸（Phospholipid Fatty Acid,PLFA）分析技术研究了零价铁修复对底泥微生物群落结构的影响.基于DGGE图谱的差异条带DNA序列分析和多样性指数分析表明：零价铁修复可使底泥中Cr（Ⅵ）耐受菌群减少,敏感菌群重新出现,并且可使底泥微生物的Shannon多样性指数恢复至未污染对照水平.PLFA指纹图谱分析结果表明：零价铁修复可使代表细菌生物量的磷脂脂肪酸17∶0的量以及Cr（Ⅵ）对底泥微生物的胁迫恢复至未污染对照水平.

英文摘要：

Laboratory batch experiments were carried out to determine the effectiveness of zero-valent iron （ZVI） on the rcmediation of Cr（ Ⅵ ）- contaminated sediments. This study showed that the removal rate of Cr（Ⅵ） was 94.7% with ZVI in 24 hours. This was 23.7% higher than the treatment without ZVI, and 14.2% higher than treatment with both sterilization and ZVL These results indicated that ZVI alone can efficiently remove Cr（ Ⅵ ）, and the indigenous microorganisms in sediments also can contribute to the removal. Microbial community structures were monitored by 16S rDNA PCR- Denaturing Gradient Gel Electrophoresis （ DGGE ） and Phospholipids Fatty Acid （PLFA.） analysis to identify the microbial community shift after the remediation of Cr（ Ⅵ ） using ZVI. DGGE analysis showed that species sensitive to Cr（ Ⅵ ） increased after remediation by ZVI, and species resistant to Cr （Ⅵ） decreased. Shannon＇ s index of diversity of the sediment microbial community, which was calculated from 16S rDNA PCR-DGGE data, was also restored to the control level. The results of PLFA analysis demonstrated that the content of the 17：0, as the biomarker associated with bacteria biomass, and the Cr（ Ⅵ ） stress on the microbes were both restored to the control level by using ZVI.