Chromium removal in constructed wetlands: A review

The distribution, mobility and availability of metals in the environment depend not only on their total concentration but also on their formations and bounds with the soil. Hexavalent chromium is a very toxic, metal compound, frequently found in polluted industrial wastewaters, and causes serious environmental problems. The potential application of constructed wetlands in the treatment of chromium bearing wastewaters has been reported recently. This paper reviews research on constructed wetlands treating chromium polluted wastewaters, and focuses on several design and operational parameters. The review highlights the effect of vegetation type, hydraulic residence time and porous media type on wetland performance. Constructed wetlands have been proved to be rather efficient at treating chromium containing wastewaters.