Removal of Chromium (VI) and Acid Orange 142 dye from Contaminated Wastewater using Bio-waste Mycelium of Aspergillus Ustus: Extraction, Isotherms and Kinetics Studies

This work reported the adsorption of Cr (VI) ions and acid orange 142 dye onto dead fungal biomass. The mycelium of Aspergillus ustus (MAU) was successfully cultured, grown, extracted and utilized as an efficient adsorbent. The extensive characterization studies of the as-prepared MAU sample were achieved with the Fourier Transform Infrared Spectrophotometer (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses. Process variables' effects were conducted in the following ranges: pH (3.0–6.0), contact time (0–120 min) and MAU dosage (0.5–5.0 g/L). The FTIR studies revealed that the amino, hydroxyl, and acetamide functional groups on the MAU provided veritable sites for Cr (VI) and AO142 binding. Optimum Cr (VI) uptake was however recorded at 80 min at pH 5.0, while that of AO142 dye was established at 120 min and pH 3.0. The Temkin and pseudo-second-order model aptly described the experimental isotherm and kinetic data. Hence, the MAU was efficient at adsorbing Cr (VI) and AO142 dye from an aqueous solution, but with a higher adsorption capacity for the AO142 molecules.