Comparative Study on Different Horizontal Subsurface Substrates in Flow Wetlands

A greenhouse experiment has been conducted to study the effect of using different wetland substrates that have been compiled on the basis of effluent treatment efficiency. wetland beds have been prepared with locally available plants, in particular (phragmites australis). the effectiveness of the treatment was evaluated on parameters such as biological oxygen demand (bod), chemical oxygen demand (cod), total kjeldahl nitrogen (tkn), total suspended solids (tss) and total phosphorus (tp). the results indicate that nutrient reduction corresponds to lower flow in wetland beds. at the lower flow rate of 2.34 m^3/day, the system with plastic supports showed the highest removal efficiencies of bod, cod, tkn, tss and tp in percentages of 74.42, 74.9 %, 63.28, 87.49 and 71.29 %, correspondingly.