Biosorption of Azo dyes by spent Rhizopus arrhizus biomass

Neeta A Salvi,S Chattopadhyay

doi:10.1007/s13201-016-0417-0

Abstract

In the present study, spent Rhizopus arrhizus biomass was used for the removal of six azo dyes from aqueous solutions. The dye removal capacity of the biomass was evaluated by conducting batch tests as a function of contact time, biomass dosage, pH and initial dye concentrations. The pseudo-second-order kinetic model fitted well with the experimental data with correlation coefficients greater than 0.999, suggesting that chemisorptions might be the rate limiting step. The equilibrium sorption data showed good fit to the Langmuir isotherm model. Among the six dyes tested, the maximum monolayer adsorption capacity for fast red A and metanil yellow was found to be 108.8 and 128.5 mg/g, respectively. These encouraging results suggest that dead Rhizopus arrhizus biomass could be a potential biomaterial for the removal of azo dyes from aqueous dye solution.

Highlights

In the present study, spent Rhizopus arrhizus biomass was used for the removal of six azo dyes from aqueous solutions
Among the six dyes tested, the maximum monolayer adsorption capacity for fast red A and metanil yellow was found to be 108.8 and 128.5 mg/g, respectively. These encouraging results suggest that dead Rhizopus arrhizus biomass could be a potential biomaterial for the removal of azo dyes from aqueous dye solution
The spent R. arrhizus biomass used in our study was obtained virtually free of cost from biotransformation studies done for the asymmetric synthesis of chiral carbinols using fungus R. arrhizus (Salvi and Chattopadhyay 2011, 2008)

Summary

Introduction

Spent Rhizopus arrhizus biomass was used for the removal of six azo dyes from aqueous solutions. The spent R. arrhizus biomass used in our study was obtained virtually free of cost from biotransformation studies done for the asymmetric synthesis of chiral carbinols using fungus R. arrhizus (Salvi and Chattopadhyay 2011, 2008) This material was found to be an effective bio-material for the removal of trivalent actinides and fission products from low-level waste streams generated in the PUREX process (Dhami et al 1998a, b, 2002; Tripathi et al 2011). Its potential towards wastewater treatment was studied In this regard, the biosorption of six azo dyes viz., amaranth, fast red A, congo red, tartrazine, metanil yellow and sunset yellow FCF were investigated by spent R. arrhizus biomass under varying operating parameters, such as contact time, biomass amount, pH and initial dye concentrations.

Methods

Discussion

Conclusion