A study on lead adsorption by Mucor rouxii biomass

Removal of lead from its aqueous solutions by adsorption on different biomasses was studied. Mucor rouxii biomass (MRB) had been found to be the most efficient in this respect and removed more than 90% of lead from its aqueous solution. Adsorption of lead by the biomass was dependent on pH and temperature. Maximum sorption was noted at the pH range of 5.0–6.0 and an increase in temperature above 30 °C resulted in the decrease in adsorption indicating the exothermic nature of the process. The adsorption process was very fast initially, and around 70% of the total adsorption was completed within the first 10 min. The process is found to follow the pseudo second order rate kinetics throughout the period. Langmuir isotherm model fitted well to describe the isotherm data. Scanning electron micrographs showed homogeneous accumulation of lead ions on the surface of the biomass. From the FTIR study, involvement of various functional groups like amine, carboxyl, phosphate, etc. for the binding of lead ions was evident. Blocking of these functional groups indicated major involvement of phosphate group for metal ions binding. Lead ions could be desorbed from the loaded biomass with elution with 0.1 M hydrochloric acid.