Purification capacity of a highly loaded laboratory scale tidal flow reed bed system with effluent recirculation.
The purification capacity of a laboratory scale tidal flow reed bed system with final effluent recirculation at a ratio of 1:1 was investigated in this study. In particular, the four-stage reed bed system was heavily loaded with strong agricultural wastewater. Under the hydraulic and organic loading rates of 0.43 m3/m2.d and 1055 gCOD/m2.d, respectively, the average removal efficiencies obtained for COD, BOD5, SS, NH4-N and P were 77%, 78%, 66%, 62% and 38%, respectively. Even with the high loading rates, approximately 30% of NH4-N was converted into NO2-N and NO3-N from the mid-stage of the system where nitrification took place. The results suggest that the multi-stage reed bed system could be employed to treat strong wastewater under high loading, especially for the substantive mass removal of solids, organic matter and ammoniacal-nitrogen. Tidal flow combined with effluent recirculation is a favourable operation strategy to achieve this objective.
Zhao
Y Q
YQ
School of Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, BT9 5AG, Northern Ireland, UK. y.zhao@qub.ac.uk
Sun
G
G
Allen
S J
SJ
D000383:Agriculture; D001673:Biodegradation, Environmental; D005374:Filtration; D009566:Nitrates / Q000302:isolation & purification*; D009584:Nitrogen / Q000302:isolation & purification*; D010758:Phosphorus / Q000302:isolation & purification*; D006109:Poaceae; D014865:Waste Disposal, Fluid / Q000379:methods*; D014872:Water Movements; D018508:Water Purification / Q000379:methods*
D009566:Nitrates; D010758:Phosphorus; D009584:Nitrogen