Removal of BOD5 in constructed wetlands with horizontal sub-surface flow: Czech experience

Constructed wetlands with horizontal sub-surface flow (HSF CWs) usually pro vide high removal of BOD5. Organic compounds are degraded by both aerobic a nd anaerobic bacteria in the rhizosphere of vegetated beds. The results fro m the Czech HSF CWs showed an average treatment efficiency of 86.6% with an average effluent BOD5 concentration of 13.2 mg l(-1). The BOD5 loading of vegetated beds of HSF CWs varied between 2.6 and 99.6 kg ha(-1) d(-1) with an average of 33.5 kg ha(-1) d(-1). The results also indicated that the rem oval of BOD5 is not temperature dependent and is steady throughout the year . (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rig hts reserved.