title: Effect of pH on nickel biosorption by aerobic granular sludge.
abstract: The Ni2+ biosorption by aerobic granular sludge was studied at various initial pH values of 2-7. Results showed that the initial pH would play an important role in the Ni2+ removal by aerobic granules and affected the zeta potential of aerobic granules. A thermodynamic equilibrium isotherm previously developed can fit the experimental data very well at all studied pH values. The close relationship between the zeta potential and Ni2+ biosorption capacity of aerobic granules showed the electrostatic attraction between the aerobic granules and Ni2+ ions. It was also found that some light metals, such as K+, Mg2+ and Ca2+ would be released into the bulk solution during the Ni2+ uptake onto the aerobic granules, which in turn indicated that ion-exchange was one of the Ni2+ biosorption mechanisms.
authors.affiliation: Division of Environmental and Water Resource Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Joo-Hwa
authors.initials: JH
authors.lastname: Tay
mesh_terms: D000327:Adsorption; D001420:Bacteria, Aerobic; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D009532:Nickel / Q000737:chemistry* / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D055672:Static Electricity; D013816:Thermodynamics; D018505:Waste Management / Q000379:methods
chemical_list: D012722:Sewage; D009532:Nickel