Engineered ecosystem for sustainable on-site wastewater treatment.
A pilot-scale engineered ecosystem (PSEE) operated for over 2 years in sub-tropical conditions, produced an effluent with COD (median 38 mg/L) and TSS (median 3mg/L) levels comparable to that required by the AS/NZS 1547:2000 Onsite Domestic Wastewater Management standard. Only partial nitrification was achieved as dissimilatory nitrate reduction to ammonia occurred; however the level of NH(4)-N was reduced by 75% and total inorganic nitrogen by 53%. Phosphorus was not removed by the system due to the lack of regular sludge removal. Mass balances around the system showed that bacteria removed 36% of the influent nitrogen and 76% of the influent COD. Algae and plants were shown to remove 5% of the influent nitrogen, and 6% of the influent phosphorus. Challenges in developing a sustainable on-site wastewater treatment system were largely met by minimising chemical, energy and labour inputs, eliminating the need for frequent sludge handling, and creating an effluent quality suitable for re-use in non-potable applications. However, the sludge removal from the system needs to be adequately managed to avoid excessive accumulation as this can cause a range of negative impacts.
Kavanagh
Lydia J
LJ
Advanced Wastewater Management Centre, The University of Queensland, St. Lucia 4072, Australia. l.kavanagh@uq.edu.au
Keller
Jurg
J
D001419:Bacteria / Q000378:metabolism; D019149:Bioreactors; D017753:Ecosystem; D004738:Engineering; D056890:Eukaryota / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D010944:Plants / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*; D014873:Water Pollutants / Q000378:metabolism
D014873:Water Pollutants; D010758:Phosphorus; D009584:Nitrogen