An Assessment of Cadmium Removal from Simulated Waste Water Using Leftover Biomass of Water Hyacinth Immobilized via Emericella nidulans

Abstract

Aims: To study Cadmium removal from simulated waste water using water hyacinth biomass immobilized with Emericella nidulans. Place and Duration of Study: Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar. June 2012 and July 2013. Methodology: The spent biomass left after enzyme production was immobilized with Emericella nidulans and dried at 50°C. Furthermore, the dried biomass was utilized for the removal of heavy metals i.e. cadmium, chromium, copper and nickel. Response surface methodology (RSM) was applied for screening and optimization of process parameters for heavy metal removal. Results: Previously, production of enzyme from cellulosic biomass was done with the help of fungus Emericella nidulans using solid state fermentation method. In the present study, the leftover water hyacinth biomass was further assessed to be used as biosorbent for the removal of heavy metals. To accomplish the same, four heavy metals viz. cadmium (Cd), nickel (Ni), chromium (Cr) and copper (Cu) were screened out. It was revealed that the removal efficiency was maximum for Cd, followed by Cu, Ni and Cr, respectively. Percent removal was 97.2, 96.3, 95 and 94.6 for Cd, Cu, Ni and Cr, respectively. Furthermore, different process parameters were optimized using one factor at a time and box behnken design (BBD) of RSM. From the optimization studies it was concluded that removal efficiency was maximum at 40°C and pH 6. Optimum values of initial metal concentration, adsorbent dose and contact time were found to be 118 mg/L, 1% and 142 min. Conclusion: The spent biomass immobilized with Emericella nidulans left after enzyme production effectively removes cadmium from simulated waste water.