Treatment of wastewater by constructed wetland in small settlements

The constructed wetland is a low-cost technology to control environmental p ollution. The system is especially suitable for small settlements. An innov ative constructed wetland technology is described in this paper. A pilot pl ant was used to assess the performance of the system. The experimental syst em consists of two serial connected tanks that settled up with fillers and Cyperus as treatment media. Wastewater is recycled periodically upward and downward between the two tanks. The treatment performance was monitored in different loading conditions in a one-year period. The average COD removal efficiency of 90% was observed at 122 g COD/m(2).day average loading condit ions. Other average removal values in the same conditions are as follows: s uspended solid 95%, TKN 77%, total nitrogen 61%, PO4-P 39%. The land requir ement for this system will be 0.82 m(2) per capita when applying as full-sc ale system.