Biosorptive removal of eriochrome black-T using agaricus campestris: Parameters optimization with response surface methodology

In this study, Eriochrome Black T (EBT) removal from aqueous media by Agaricus campestris (AC) which is an eco-friendly biosorbent was investigated using a central composite design (CCD) combined with response surface methodology. The CCD was chosen as the statistical prediction method to reduce the number of experiments which, in turn, will directly save time and chemicals. To opti-mize the process, various experimental independent variables such as the pH of the solution, contact time, adsorbent dosage and temperature were selected. The optimal experimental conditions were obtained as 6.5, 30°C, 20 min and 20 mg, for solution pH, temperature, contact time and adsorbent dosage, respectively. Under these optimized conditions, maximum EBT (100 mg L–1 initial concentra-tion) removal efficiency was calculated as 64.2 mg g–1. The independent variables and their interaction significance were checked using analysis of variance and it was found that the EBT biosorption on AC was highly significant (p < 0.001). The results were justified by the relatively high correlation coefficients (R2 = 0.9967) of the statistical prediction. The EBT biosorption was confirmed by fourier transform infrared spectroscopy (FTIR) analysis monitoring the functional groups during EBT biosorption on AC. This was the first report on the parameter optimization of EBT biosorp-tion using AC in an experimental design. The used biosorbent was characterized by FTIR, scanning electron microscope coupled with energy dispersive spectrometer and thermogravimetric analysis. The proposed biosorption process efficiently removed EBT, present in various aqueous mediums and can be used in industrial processes.