Ammonia removal from anaerobic digestion effluent of livestock waste using green alga Scenedesmus sp

• Published in: Bioresource technology 2010-11, Vol.101 (22), p.8649-8657
• Main Authors: Park, Jongmin, Jin, Hai-Feng, Lim, Byung-Ran, Park, Ki-Young, Lee, Kisay
• Format: Article
• Language: English
• Subjects: Agriculture - methods; Agronomy. Soil science and plant productions; Alkalinity; Ammonia; Ammonia - isolation & purification; Ammonia - metabolism; Ammonia removal; Anaerobic digestion; Anaerobic digestion effluent; Anaerobiosis - physiology; Animals; Biodegradation, Environmental; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biotechnology; Carbon; Consumption; Environment and pollution; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Industrial applications and implications. Economical aspects; Industrial Waste - prevention & control; Inhibitors; Livestock; Magnesium; Microalgae; Scenedesmus - metabolism; Semi-continuous operation; Use of agricultural and forest wastes. Biomass use, bioconversion
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2010.06.142

The green alga Scenedesmus was investigated for its ability to remove nitrogen from anaerobic digestion effluent possessing high ammonium content and alkalinity in addition to its growth characteristics. Nitrate and ammonium were indistinguishable as a nitrogen source when the ammonium concentration was at normal cultivation levels. Ammonium up to 100 ppm NH 4–N did not inhibit cell growth, but did decrease final cell density by up to 70% at a concentration of 200–500 ppm NH 4–N. Inorganic carbon of alkalinity in the form of bicarbonate was consumed rapidly, in turn causing the attenuation of cell growth. Therefore, maintaining a certain level of inorganic carbon is necessary in order to prolong ammonia removal. A moderate degree of aeration was beneficial to ammonia removal, not only due to the stripping of ammonium to ammonia gas but also due to the stripping of oxygen, which is an inhibitor of regular photosynthesis. Magnesium is easily consumed compared to other metallic components and therefore requires periodic supplementation. Maintaining appropriate levels of alkalinity, Mg, aeration along with optimal an initial NH 4 +/cell ratio were all necessary for long-term semi-continuous ammonium removal and cell growth.