Osama Mohamad, Gehong Wei
Northwest A&F University

The mining industry generates huge amounts of wastewater, containing toxic heavy metal. Treatment to remove heavy metals is necessary and recently work has have been focused on finding more environmentally-friendly materials of removing heavy metals from wastewater. Biosorption can be an effective process for heavy metal removal from aqueous solutions. Our objectives were to investigate the removal of copper (Ⅱ) from aqueous solutions by live and dead cells of Mesorhizobium amorphae CCNWGS0123 under differing levels of pH, agitation speed, temperature, initial copper concentration, biosorbent dose and contact time using flame atomic absorption spectroscopy for metal estimation.  Maximum copper was removed at pH 5.0, agitation speed 150 rpm, temperature 28 0C, initial Cu (Ⅱ) concentration of 100 mg L-1, dosage 0.5 g L-1 and equilibrium time was attained within 30 min. Experiment data were fitted by Langmuir and Freundlish isotherms equation with correlation coefficients 0.958, 0.934 respectively. FTINR analysis indicated that more functional groups were involved in the interaction between CCNWGS0123 and Cu. Scanning Electron Microscope results showed deformation, aggregation, and cell surface damage due to precipitation of copper on the cell surface. We concluded that live and dead cells of CCNWGS0123 were an efficient biosorbent for removal of Cu2+ from aqueous solution.