外源微生物对植物根系修复十溴联苯醚污染底泥的强化作用

Remediation of Decabromodiphenyl Ether Contaminated Sediment Through Plant Roots Enhanced by Exogenous Microbes

十溴联苯醚(BDE-209)作为溴系阻燃剂的主要代表之一,所造成的沉积物环境污染问题日益引起人们的重视.本研究利用河边常见植物再力花(Thalia dealbata)作为修复植物,引入外源微生物短短芽孢杆菌(Brevibacillus brevis)和铅黄肠球菌(Enterococcus casselifavus)以强化修复效果,通过盆栽试验模拟沉积物环境,考察了外源菌对植物根际修复沉积物中BDE-209的强化作用效果,以及不同处理组,沉积物中微生物数量、有机酸含量和微生物碳源利用能力的变化.结果发现,外源菌处理组中BDE-209的去除率高于相应的对照组,其中以加入B.brevis根际处理组BDE-209的去除率最好(66%),大于非根际处理组和无植物处理的对照组(37.93%和39.27%).植物的根际作用可以提高底泥中BDE-209的去除率、微生物的数量、有机酸含量和碳源利用能力.

Decabromodiphenyl ether （ BDE- 209）, a main ingredient of brominated flame retardants, has drawn more and more attention because of the pollution it caused in sediment. A pot experiment was conducted in a greenhouse to investigate the impact of Breυibacillus breυis and Enterococcus casselifaυus on the enhancement of phytoremediation by Thalia dealbata, which is common in the river bank and was found to be an effective plant for BDE- 209 removal. The concentration of organic acids, the amount of microorganisms and the ability of carbon utilization of soil microorganisms in different experimental groups were analyzed. The results showed that the removal rate of BDE- 209 in the exogenous microbes containing groups were higher than that of the control. And B. breυis presented the highest enhancement of phytoremediation with the removal rate rising highest to 66% compared with the control （non-rhizosphere group 37. 93% and no plant group 39. 27% ） after 60 days. The removal of BDE- 209 in sediment, quantity of microorganism, concentration of organic acids and the ability of carbon utilization of soil microorganisms in rhizosphere sediment were higher than those in non-rhizosphere sediment.