Treatment of faecal sludge from septic tanks using First Stage of French Vertical Flow Constructed Wetlands

Abstract

Mostly disposed into the environment without any treatment, faecal sludge from septic tanks remains a critical environmental issue in major developing countries. Despite being considered an efficient natural solution for sludge treatment, Vertical Flow Constructed Wetlands have uncommonly been applied to deal with this issue. In this study, we investigated the performance of the First Stage of French Vertical Flow Constructed Wetlands as a practicable alternative for septic tank sludge treatment in the Andean region. From the results obtained during the first six months of operation, satisfactory removal efficiencies of over 40 % for COD and TS were obtained in a pilot scale. Appearing important for organic matter mineralization, high aeration capacity was maintained as showed in the DO concentrations measured in the influent and effluent, i.e. 0.33 mg.L-1 and 2.8 mg.L-1, despite the sludge load.