Polyacrylamide added as a nitrogen source stimulates methanogenesis in consortia from various wastewaters.
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.
Haveroen
Melissa E
ME
Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9.
MacKinnon
Michael D
MD
Fedorak
Phillip M
PM
D000085:Acetates / Q000032:analysis / Q000378:metabolism; D000180:Acrylic Resins / Q000494:pharmacology*; D000383:Agriculture; D000693:Anaerobiosis; D000838:Anions; D001420:Bacteria, Aerobic / Q000187:drug effects* / Q000378:metabolism; D001565:Benzoates / Q000032:analysis / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D017753:Ecosystem; D005285:Fermentation; D008697:Methane / Q000032:analysis / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D011108:Polymers / Q000378:metabolism; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D012987:Soil; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods; D014871:Water Microbiology; D000099166:Polyacrylamides
D000085:Acetates; D000180:Acrylic Resins; D000838:Anions; D001565:Benzoates; D002244:Carbon; D008697:Methane; D009584:Nitrogen; D011108:Polymers; D012722:Sewage; D012987:Soil; D000099166:Polyacrylamides