title: Equilibrium, kinetic and thermodynamic studies on aluminum biosorption by a mycelial biomass (Streptomyces rimosus).
abstract: This work focused on kinetic, equilibrium and thermodynamic studies on aluminum biosorption by Streptomyces rimosus biomass. Infrared spectroscopy analysis shows that S. rimosus present some groups: hydroxyl, methyl, carboxyl, amine, thiol and phosphate. The maximum biosorption capacity of S. rimosus biomass was found to be 11.76 mg g(-1) for the following optimum conditions: particle size, [250-560] μm, pH 4-4.25, biomass content of 25 g L(-1), agitation of 250 rpm and temperature of 25 °C. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherms at free pH (pH(i) 4) and fixed pH (pH(f) 4). Langmuir model is the most adequate. With fixed pH, the maximum biosorption capacity is enhanced from 6.62 mg g(-1) to 11.76 mg g(-1). The thermodynamic parameters (ΔG°, ΔH° and ΔS°) showed the feasibility, endothermic and spontaneous nature of the biosorption at 10-80 °C. The activation energy (Ea) was determined as 52.18 kJ mol(-1) using the Arrhenius equation and the rate constant of pseudo-second-order model (the most adequate kinetic model). The mean free energy was calculated as 12.91 kJ mol(-1) using the D-R isotherm model. The mechanism of Al(III) biosorption on S. rimosus could be a chemical ion exchange and carboxyl groups are mainly involved in this mechanism.
authors.affiliation: Laboratory of Environmental Biotechnologies and Process Engineering, BIOGEP, Polytechnic National School of Algiers, Hacen Badi, El Harrach, Algiers, Algeria. aminatassist@yahoo.fr
authors.forename: Amina
authors.initials: A
authors.lastname: Tassist
authors.forename: Hakim
authors.initials: H
authors.lastname: Lounici
authors.forename: Nadia
authors.initials: N
authors.lastname: Abdi
authors.forename: Nabil
authors.initials: N
authors.lastname: Mameri
mesh_terms: D000327:Adsorption; D000535:Aluminum / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D018533:Biomass; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D055672:Static Electricity; D013302:Streptomyces / Q000378:metabolism*; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
chemical_list: D014874:Water Pollutants, Chemical; D000535:Aluminum