title: Influence of deflocculation on microwave disintegration and anaerobic biodegradability of waste activated sludge.
abstract: In the present study, the potential benefits of deflocculation on microwave pretreatment of waste activated sludge were investigated. Deflocculation in the absence of cell lysis was achieved through the removal of extra polymeric substances (EPS) by sodium citrate (0.1g sodium citrate/g suspended solids), and DNA was used as a marker for monitoring cell lysis. Subsequent microwave pretreatment yielded a chemical oxygen demand (COD) solubilisation of 31% and 21%, suspended solids (SS) reduction of 37% and 22%, for deflocculated and flocculated sludge, respectively, with energy input of 14,000kJ/kg TS. When microwave pretreated sludge was subjected to anaerobic fermentation, greater accumulation of volatile fatty acid (860mg/L) was noticed in deflocculated sludge, indicating better hydrolysis. Among the samples subjected to BMP (Biochemical methane potential test), deflocculated microwave pretreated sludge showed better amenability towards anaerobic digestion with high methane production potential of 0.615L (gVS)(-1).
authors.affiliation: Department of Civil Engineering, Regional Centre of Anna University, Tirunelveli, India.
authors.forename: A Vimala
authors.initials: AV
authors.lastname: Ebenezer
authors.affiliation: Department of Civil Engineering, Thiagarajar College of Engineering, Thiruparankundram, Madurai, India.
authors.forename: S
authors.initials: S
authors.lastname: Kaliappan
authors.affiliation: Department of Civil Engineering, Regional Centre of Anna University, Tirunelveli, India.
authors.forename: S
authors.initials: S
authors.lastname: Adish Kumar
authors.affiliation: Department of Civil and Environmental Engineering, Sungkyunkwan University, South Korea.
authors.forename: Ick-Tae
authors.initials: IT
authors.lastname: Yeom
authors.affiliation: Department of Civil Engineering, Regional Centre of Anna University, Tirunelveli, India. Electronic address: rajeshces@gmail.com.
authors.forename: J Rajesh
authors.initials: JR
authors.lastname: Banu
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D002412:Cations; D002951:Citrates / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D005285:Fermentation; D005427:Flocculation; D006868:Hydrolysis; D008697:Methane / Q000737:chemistry; D008872:Microwaves; D012722:Sewage; D000077559:Sodium Citrate; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D002412:Cations; D002951:Citrates; D005227:Fatty Acids; D012722:Sewage; D000077559:Sodium Citrate; D004247:DNA; D008697:Methane
keywords: Anaerobic biodegradability; Deflocculation; Microwave irradiation; Pretreatment; Waste activated sludge