Evaluating the Biosorption Properties of Three Bacillus Strains for Cu2+ Uptake From Wastewater

Document Type : Original Article


1 Graduate Faculty of Environment, University of Tehran, Tehran, Iran

2 Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran

3 Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran


Introduction: Toxic metal ion contamination is one of the most important environmental issues in the world. Wastewater of mines and certain industries are known sources of environmental heavy metal contaminations. Also, Copper (Cu) contamination is a common issue. Using biological tools particularly bacterial-derived compounds could be appropriate for bioremediation. 
Materials and Methods: In this study, the Cu2+ uptake from Chah Musa mine wastewater by three different Bacillus species was assessed using the batch equilibrium isotherm. The impact of pH, exposure time, temperature, and the bioabsorbent dose on the adsorption of Cu2+ ions was assessed. Also, the kinetics and isotherm models of Cu2+ ions adsorption were studied for three different Bacillus species.    
Results: The results showed that the maximum removal Cu2+ ions (99%) was obtained for Bacillus thuringiensis biomas. The correlation coefficient value (R2) of Freundlich isotherm was higher than Langmuir isotherm indicating better metal uptake based on the Freundlich model. The rates of adsorption for all bioadsorbant were attained to be conforming to the pseudo-second-order.
Conclusions: According to the current study, all three dead Gram-positive Bacillus spp. are favorable and effective candidates for the removal of Cu2+ from aqueous solutions and industrial wastewaters.