title: Food waste decomposition in leachbed reactor: role of neutralizing solutions on the leachate quality.
abstract: The neutralization effects of 0.1M NaHCO(3), KPO(4)-buffer (pH 7.0) and sodium acetate (NaOAc) solutions (500 ml/kg food waste/day) on controlling the pH and leachate quality in an acidogenic reactor of food waste anaerobic digestion was investigated. pH of leachate from the reactor was low and ranged from 3.24 to 4.15. Although differences in chemical oxygen demand (COD) were observed, the cumulative COD yields were almost similar. Ammonia concentrations gradually decreased from 26 to 3mg/l after 15 days. Acetic acid was the major fraction and the total VFAs decreased gradually for a week and increased thereafter, with a sharp increase in NaOAc treatment. VFAs yield and acetate/propionate ratio were the highest in NaOAc treatment, followed by NaHCO(3) and KPO(4) treatments. Volatile solids reduction was the lowest in NaOAc treatment (47.5%) and highest in NaHCO(3) treatment (67.0%). With lower decomposition and higher yield of VFA and COD, NaOAc could be used as a neutralizing agent in acidogenic reactors to improve the efficiency of the acidogenesis process.
authors.affiliation: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong SAR.
authors.forename: Ammaiyappan
authors.initials: A
authors.lastname: Selvam
authors.forename: Su Yun
authors.initials: SY
authors.lastname: Xu
authors.forename: Xiang Yang
authors.initials: XY
authors.lastname: Gu
authors.forename: Jonathan W C
authors.initials: JW
authors.lastname: Wong
mesh_terms: D000085:Acetates / Q000737:chemistry; D019342:Acetic Acid / Q000737:chemistry; D000641:Ammonia / Q000737:chemistry; D019149:Bioreactors; D002021:Buffers; D004867:Equipment Design; D005232:Fatty Acids, Volatile / Q000737:chemistry; D005502:Food; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D011422:Propionates / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D019346:Sodium Acetate / Q000737:chemistry
chemical_list: D000085:Acetates; D002021:Buffers; D005232:Fatty Acids, Volatile; D011422:Propionates; D019346:Sodium Acetate; D000641:Ammonia; C029658:propionic acid; D009584:Nitrogen; D019342:Acetic Acid; D010100:Oxygen