A Biosorption Isotherm Model for the Removal of Reactive Azo Dyes by Inactivated Mycelia of Cunninghamella elegans UCP542

Abstract

The biosorption of three reactive azo dyes (red, black and orange II) found in textile effluents by inactive mycelium of Cunninghamella elegans has been investigated. It was found that after 120 hours of contact the adsorption led to 70%, 85%, 93% and 88% removal of reactive orange II, reactive black, reactive red and a mixture of them, respectively. The mycelium surface was found to be selective towards the azo dyes in the following order: reactive red > reactive black > orange II. Dye removal from a mixture solution resulted in 48.4 mg/g retention by mycelium and indicated a competition amongst the dyes for the cellular surface. A Freundlich adsorption isotherm model exhibited a better fit, thus suggesting the presence of heterogeneous binding sites. Electrondense deposits observed on the mycelium ultrastructure suggest that the dyes are mainly retained under the cellular surface of the inactive biomass of C. elegans.

Fungal decolouration and degradation of azo dyes: A review

“…Decolouration can be accomplished by adsorption or enzymatic degradation. Inactivated mycelia of Cunninghamella elegans (Ambrosio et al, 2012), T. versicolor lyophilized biomass (Erden et al, 2011), T. versicolor (Baccar et al, 2011) or Fusarium solani non-viable cells (Abedin, 2008) are more efficient than materials such as activated carbon or amberlite. Adsorption is enhanced at pH 2e3 (Erden et al, 2011;Renganathan et al, 2006;Bakshi et al, 2006;Iqbal and Saeed, 2007;Pajot et al, 2011;Maurya et al, 2006), which is probably due to electrostatic attractions between charged dye molecules and the charged cell surface (Erden et al, 2011;Kaushik and Malik, 2009).…”

Removal of Zn2+ and Pb2+ using new isolates of Bacillus spp. PPS03 and Bacillus subtilis PPS04 from Paper mill effluents using indigenously designed Bench-top Bioreactor

“…Amera et al (2012) Table 2). Ambrósio et al (2012) reported that Freundlich isotherm yielded a better linear fit (R 2 >0.99) than the Langmuir model (R 2 >0.95) suggesting that the adsorption surface presents heterogeneity. The mycelial surface of Cunninghamella elegans was observed to be more selective towards the red dye followed by reactive black and orange II.…”

Statistical optimization of biosorption of Reactive Orange 13 by dead biomass of Rhizopus arrhizus NCIM 997 using response surface methodology

“…Application of dead fungal biomass obtained from R. arrhizus to remove textile dyes from industrial waste water is attractive due to its cheap and constant supply from industrial fermentation processes, high removal rates, easy storage and regenerative potential [11]. Some researchers have demonstrated the high dye binding capacity of R. arrhizus which exceeds that of some commercial ion exchange resins or activated carbon [19][20][21].…”

“…Hence, low-cost biosorbents with high adsorption capacities such as waste materials from large-scale industrial operations, natural materials derived from agriculture, microbial biosorbents such as Corynebacterium glutamicum, Escherichia coli, Pseudomonas luteola and Rhizopus arrhizus have gained attention [9,10]. A major advantage of biosorption is that it can be used in situ and integrated with many systems in the most eco-friendly manner [11].…”