Biosorption of aluminum ions onto Rhodococcus opacus from wastewaters

This fundamental work deals with the biosorption removal of Al (III) using a Rhodococcus opacus strain. Several variables that have an effect on the capacity of aluminum biosorption from water streams by R. opacus were studied, particularly the effects of solution pH, biosorbent concentration, metal concentration, contact time, ionic strength and temperature of biosorption. The most favorable biosorption pH value of Al (III) was determinate as around 5.0 and the maximum sorption capacity was found to be 41.59 mg g−1 at pH 5.0 (initial concentration of 50 mg L−1) and temperature 25 °C.The experimental data obtained have been analyzed using four two-parameter models (Langmuir, Freundlich, Temkin and Dubinin-Radushkevich) and two three-parameter models (Redlich–Peterson and Sips). In order to determine the best fit isotherm, three error analysis methods were used to evaluate the data: correlation coefficient, chi-square and residual root mean square error. Dynamics of sorption process were studied and the values of rate constant of biosorption were calculated. The uptake capacity is a function of pH solution, ionic strength and biosorbent concentration.