title: Formation of aerobic granules in the presence of a synthetic chelating agent.
abstract: This paper examines the development of aerobic granular sludge in the presence of a synthetic chelating agent, nitrilotriacetic acid (NTA), in sequencing batch reactors (SBR). The growth of seed sludge at 0.26 mM, 0.52 mM and 1.05 mM of NTA was found to be significantly lower as compared to that in the absence of NTA. Aerobic granulation was significantly enhanced in the three SBRs (R2, R3 and R4), which were fed with 0.26 mM, 0.52 mM and 1.05 mM of NTA as a co-substrate, in comparison to the acetate-alone fed SBR (R1). After 2 months of operation, the mean diameter of the biomass stabilized at 0.35 mm in R1 (acetate alone), as compared to 2.18 mm in R4 (1.05 mM NTA+acetate). NTA degradation was established in SBRs, with almost complete removal during the SBR cycle. Batch experiments also showed efficient degradation of NTA by the aerobic granules.
authors.affiliation: Water and Steam Chemistry Division, Chemistry Group, Bhabha Atomic Research Centre, BARC Facilities, Kalpakkam, India. yvn@igcar.ernet.in
authors.forename: Yarlagadda V
authors.initials: YV
authors.lastname: Nancharaiah
authors.forename: Hiren M
authors.initials: HM
authors.lastname: Joshi
authors.forename: Tulsi V
authors.initials: TV
authors.lastname: Krishna Mohan
authors.forename: Vayalam P
authors.initials: VP
authors.lastname: Venugopalan
authors.forename: Sevilimedu V
authors.initials: SV
authors.lastname: Narasimhan
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002614:Chelating Agents / Q000737:chemistry*; D005427:Flocculation; D009571:Nitrilotriacetic Acid / Q000737:chemistry*; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods
chemical_list: D002614:Chelating Agents; D012722:Sewage; D009571:Nitrilotriacetic Acid