title: Disinhibition of excessive volatile fatty acids to improve the efficiency of autothermal thermophilic aerobic sludge digestion by chemical approach.
abstract: In this study, we explored a chemical approach to eliminate inhibition of excessive volatile fatty acids (VFAs) in autothermal thermophilic aerobic digestion (ATAD). Ferric nitrate, ferric chloride, potassium nitrate and potassium chloride were employed to demonstrate the combined action of ferric ion and nitrate ion. Supplementation of ferric nitrate in the sludge digestion system resulted in reducing the concentration of Total VFAs (TVFA) by round 5000mg/L and more than 2000mg/L of acetic acid at the end of digestion. Lower TVFA concentration contributed to faster sludge stabilization rate and the VS removal of ferric nitrate dosed digester achieved 38.18% after 12days digestion which was 9days in advance compared with the stabilization time of sludge in digester without chemicals addition. Lower concentrations of NH4(+)-N and SCOD in supernatant while higher content of TP in digestion sludge were obtained in digester with ferric nitrate added.
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Ningben
authors.initials: N
authors.lastname: Jin
authors.affiliation: School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia.
authors.forename: Bo
authors.initials: B
authors.lastname: Jin
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: nwzhu@sjtu.edu.cn.
authors.forename: Nanwen
authors.initials: N
authors.lastname: Zhu
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Haiping
authors.initials: H
authors.lastname: Yuan
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Ruan
mesh_terms: D000332:Aerobiosis; D019149:Bioreactors / Q000382:microbiology*; D002712:Chlorides; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D005290:Ferric Compounds; D006358:Hot Temperature; D009566:Nitrates; D017680:Potassium Compounds; D012722:Sewage / Q000382:microbiology*; D018505:Waste Management / Q000379:methods*
chemical_list: D002712:Chlorides; D005232:Fatty Acids, Volatile; D005290:Ferric Compounds; D009566:Nitrates; D017680:Potassium Compounds; D012722:Sewage; C025302:ferric nitrate; C023844:potassium nitrate; C024555:ferric chloride
keywords: Autothermal thermophilic aerobic digestion; Chemical approach; Ferric nitrate; Sludge stabilization; Volatile fatty acids disinhibition