Fungal biomass from Rhizomucor pusillus as adsorbent of chromophores from a bleach plant effluent

Abstract

Biomass of the mucoralean fungus Rhizomucor pusillus was examined as adsorbent of colour from a bleach plant effluent. Strong colour adsorption was observed in the first few hours of effluent treatment: 43 and 48% of colour being removed after 2 and 8 h, respectively. It appeared that the effluent contained a fraction of coloured compounds (approximately 50% of total) which was resistant to biosoption. R. pusillus could grow and tolerate temperatures of up to 55°C and retain 85% of its decolouring abilities at 55°C as compared to 30°C. For comparative purposes, activated carbon, a strong anion exchanger, a strong cation exchanger, chitin and chitosan were investigated as decolouring agents of bleach plant effluent. The possibility of complete regeneration of biomass and reuse on effluent was demonstrated. Only partial restoration of the decolouring activities of the commercial physico-chemical adsorbents was obtained, suggesting chemisorption of coloured compounds onto the sorbent material. Under the conditions used in this study, the following descending order of colour removal from bleach plant effluent was established: biomass (51%)>strong anion exchanger (48%)>activated carbon (37%)>chitosan (34%)>chitin (7%)>strong cation exchanger (4%).