title: Volatile fatty acids production from anaerobic treatment of cassava waste water: effect of temperature and alkalinity.
abstract: The production of volatile fatty acids (VFAs), intermediates in the anaerobic degradation process of organic matter from waste water, was evaluated in this work. A batch reactor was used to investigate the effect of temperature, and alkalinity in the production of VFAs, from the fermentation of industrial cassava waste water. Peak production of total volatile fatty acids (TVFAs) was observed in the first two days of acidogenesis. A central composite design was performed, and the highest yield (3400 mg L(-1) of TVFA) was obtained with 30°C and 3 g L(-1) of sodium bicarbonate. The peak of VFA was in 45 h (pH 5.9) with a predominance of acetic (63%) and butyric acid (22%), followed by propionic acid (12%). Decreases in amounts of cyanide (12.9%) and chemical oxygen demand (21.6%) were observed, in addition to the production of biogas (0.53 cm(3) h(-1)). The process was validated experimentally and 3400 g L(-1) of TVFA were obtained with a low relative standard deviation.
authors.affiliation: a Center of Engineering and Exact Sciences , State University of Western of Paraná - Unioeste , Rua da Faculdade, 645, Toledo-PR 85903000 , Brazil.
authors.forename: Salah Din Mahmud
authors.initials: SD
authors.lastname: Hasan
authors.forename: Citieli
authors.initials: C
authors.lastname: Giongo
authors.forename: Mônica Lady
authors.initials: ML
authors.lastname: Fiorese
authors.forename: Simone Damasceno
authors.initials: SD
authors.lastname: Gomes
authors.forename: Tatiane Caroline
authors.initials: TC
authors.lastname: Ferrari
authors.forename: Tarcio Enrico
authors.initials: TE
authors.lastname: Savoldi
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors; D005232:Fatty Acids, Volatile / Q000032:analysis / Q000378:metabolism*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D002365:Manihot / Q000737:chemistry*; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D005232:Fatty Acids, Volatile; D062065:Wastewater
keywords: acidogenesis; cassava waste water treatment; fermentation; response surface methodology; volatile fatty acids