Polyacrylamide added as a nitrogen source stimulates methanogenesis in consortia from various wastewaters

• Published in: Water research (Oxford) 2005-09, Vol.39 (14), p.3333-3341
• Main Authors: Haveroen, Melissa E., MacKinnon, Michael D., Fedorak, Phillip M.
• Format: Article
• Language: English
• Subjects: Acetates - analysis; Acetates - metabolism; Acrylic Resins - pharmacology; Agriculture; Anaerobiosis; Anions; Applied sciences; Bacteria, Aerobic - drug effects; Bacteria, Aerobic - metabolism; Benzoates - analysis; Benzoates - metabolism; Biological and medical sciences; Biotechnology; Carbon - metabolism; Ecosystem; Environment and pollution; Exact sciences and technology; Fermentation; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Methane; Methane - analysis; Methane - metabolism; methane production; methanogens; microbial activity; mine spoil; Nitrogen; Nitrogen - metabolism; Other industrial wastes. Sewage sludge; Pollution; Polyacrylamide; Polymers - metabolism; Sewage - chemistry; Sewage - microbiology; Sewage sludge; Soil; Tailings; Time Factors; Waste Disposal, Fluid - methods; Wastes; Water Microbiology; water pollution; water treatment; Water treatment and pollution
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2005.05.042

Polyacrylamides are widely used as flocculants to enhance clarification of drinking waters and domestic wastewaters, for stabilization of agricultural soils, and to aid in managing mine tailings. The flocs produced with polyacrylamide may be deposited into retention areas that become anaerobic. Although it is unlikely that the carbon backbone of these polymers would be cleaved by microbial activity, the amide group could serve as a nitrogen source for microorganisms. Previous studies have shown that aerobic bacteria utilize the nitrogen from polyacrylamide. This study assessed whether methanogenesis was stimulated when an anionic polyacrylamide (Magnafloc ® LT27AG) was the sole fixed nitrogen source in serum-bottle microcosms. Microorganisms from two oil sands tailings sources, and a domestic anaerobic sewage sludge were used, with benzoate or acetate provided as carbon and energy sources. In each inoculum-substrate combination, the presence of polyacrylamide-enhanced methane production, indicating that polyacrylamide may stimulate microbial activities in anaerobic environments that are rich in fermentable carbon, but lack nitrogen sources.