In this investigation the performance of three wetland systems, operated with UASB effluent was evaluated with respect to removal of nutrients, pathogens, as well as carbonaceous matter over a three years period. The efficiency of carbonaceous material removal varied from 70 to 86%; the produced effluent maintained an average value of 60mg.L-1. The removal of nitrogen and phosphorus during the first year of operation was considerable, 66 and 86% respectively. The wetland with vegetation produced effluent with a higher removal efficiency of thermo-tolerant Coliforms than units without vegetation, when both were operated with the same hydraulic load (23 mm d-1). However, variance analysis confirmed that there was no significant difference between the coliform removal efficiencies in the systems with and without vegetation.
Constructed wetland; macrophytes; post-treatment; domestic sewage
