Kinetics and equilibrium studies on biosorption of nickel from aqueous solution by dead fungal biomass of Mucor hiemalis

The kinetics and equilibrium of the biosorption of nickel from aqueous solution were investigated using physico-chemically treated dead biomass of Mucor hiemalis in a batch system. The biosorption characteristics of Ni (II) ions were studied with respect to well-established effective parameters including pH, temperature, rotational speed, biosorbent dosage, initial metal ion concentration and contact time. The uptake of Ni (II) increased with an increase in pH, the Ni (II) concentration, temperature and rotational speed, whereas it decreased with increase in the biomass concentration. Biosorption equilibrium was established in about 150 min. The Ni (II) adsorption data were analyzed using the first and the second-order kinetic models as well as intra-particular rate expressions. The second-order equation was the most appropriate equation to predict the biosorption capacities of the fungal preparation. The sorption data obtained at pH 8.0 conformed well to both the Langmuir and the Freundlich isotherm models. The reusability of the biosorbent was tested in five consecutive adsorption–desorption cycles and the regeneration efficiency was above 80%. From the practical viewpoint, the abundant and inexpensive dead fungal biomass could be used as an effective, low cost and environmentally friendly biosorbent for the detoxification of Ni (II) from aqueous solution.

► M. hiemalis, a fermentation waste is an economic biosorbent for removal of Ni (II).
► Conditions were optimized for maximizing removal of Ni (II).
► M. hiemalis proved to be comparable to various biosorbents in its sorption capacity.
► The kinetics study contributed to the designing of full scale batch process.
► The stability and the potential reusability of the biosorbent was demonstrated.