Chapter 8 - Dye Wastewater Treatment by Vertical-Flow Constructed Wetlands

Abstract

Two different azo dyes (Acid Blue 113 and Basic Red 46 (BR46)) have been fed as part of synthetic wastewater recipes to vertical-flow construction wetland set-up comprising wetlands with gravel media as controls and wetlands planted with Phragmites australis (common reed) for each dye. Two different concentrations were used for each dye at two hydraulic retention times. In case of low dye concentrations, the presence of plants for the long contact time scenario impacted significantly positive on the removal efficiencies of nutrients. For chemical oxygen demand (COD), the removal percentages were 50%, 59%, and 67% for the control and for the wetlands with short and long retention times, respectively. For the high concentration of BR46, the removal percentages for this dye and COD were 94% and 82%, and 89% and 74% for the long and short retention times, respectively.