Biosorption of Copper (II) from Aqueous Solutions by Sclerotiogenic Aspergillus oryzae G15

This study aimed at investigating the biosorption of copper(II) from aqueous solutions by sclerotiogenic Aspergillus oryzae G15. Potentiometric titration analysis results indicated that carboxyl group was mainly responsible for Cu(II) adsorption. Sclerotia were a better biosorbent than mycelia, which could be ascribed to the higher amount of carboxyl sites exposed after differentiation. Langmuir isotherm model fitted well the absorption process of mycelia and sclerotia with the maximum theoretical sorption capacities of 35.34 and 73.53 mg/g, respectively. Scanning electron microscopy coupled with energy dispersive X-ray analysis confirmed that there was surface biosorption of Cu(II) on the adsorbents. Based on the fourier transform infrared spectroscopy analyses results, it could be proposed that the increased sorption capacity of sclerotia was due to increased functional groups related to the biosorption process. Cu(II)-loaded biosorbents could be regenerated and reused, which indicated that A. oryzae G15 could be considered as an alternative for removing Cu(II) from wastewater.