Treatment of chromium-bearing wastewaters with constructed wetlands


Chromium can have detrimental effects on most organisms, including humans. The present study focused on the effect of treating chromium-bearing, organic-rich wastewater on constructed wetland performance. Eight laboratory-scale systems were used to study organic matter and chromium removals, with three features tested in duplicate: media with proven chromium sorption capacity, vegetation presence and intermittent influent loading. A set of two wetlands acted as the base design. Average BOD5 and chromium removal rates were 13.4g/m2day and 135mgCr/m2day, respectively. From an influent chromium concentration of 5mg/L, <0.5mg/L could be detected at the outlet during the study in all systems. Chromium removal efficiencies were statistically different for all systems (P<0.01), except when comparing the base design against the intermittent feed systems (P>0.05). Overall treatment performance of all systems was remarkably good in spite of significant chromium content and salinity. © 2010 The Authors. Water and Environment Journal © 2010 CIWEM.

Publication Title

Water and Environment Journal