首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Biogeochemical Elimination of Chromium (VI) from Contaminated Water
Authors:Jennifer L Nyman  Frank Caccavo  Al B Cunningham  Robin Gerlach
Institution:1. Center for Biofilm Engineering, Montana State University-Bozeman, Bozeman, MT 59717;2. Department of Biology, Whitworth College, Spokane, WA 99251
Abstract:Ferrous iron Fe(II)] reductively transforms heavy metals in contaminated groundwater, and the bacterial reduction of indigenous ferric iron Fe(III)] to Fe(II) has been proposed as a means of establishing redox reactive barriers in the subsurface. The reduction of Fe(III) to Fe(II) can be accomplished by stimulation of indigenous dissimilatory metal-reducing bacteria (DMRB) or injection of DMRB into the subsurface. The microbially produced Fe(II) can chemically react with contaminants such as Cr(VI) to form insoluble Cr(III) precipitates. The DMRB Shewanella algae BrY reduced surface-associated Fe(III) to Fe(II), which in batch and column experiments chemically reduced highly soluble Cr(VI) to insoluble Cr(III). Once the chemical Cr(VI) reduction capacity of the Fe(II)/Fe(III) couple in the experimental systems was exhausted, the addition of S. algae BrY allowed for the repeated reduction of Fe(III) to Fe(II), which again reduced Cr(VI) to Cr(III). The research presented herein indicates that a biological process using DMRB allows the establishment of a biogeochemical cycle that facilitates chromium precipitation. Such a system could provide a means for establishing and maintaining remedial redox reactive zones in Fe(III)-bearing subsurface environments.
Keywords:metal reduction  chromium  bacteria  bioremediation  biobarrier  iron  permeable reactive barrier
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号