A novel macrofungus for the biosorption of hazardous dye and its reuse potential: Experimental design approach using response surface methodology

In the present study, a novel biosorbent, namely Agaricus campestris, was used for the removal of Methylene Blue (MB) from an aqueous medium. The biosorbent was characterized using fourier-transform infrared spectrometer spectra, scanning electron microscopy-energy dispersive X-ray, and thermogravimetric analysis. The influence of important process parameters including pH (4–7), temperature (25°C–35°C), contact time (15–25 min), and biosorbent amount (40–80 mg) on the uptake of MB solution were also optimized, which significantly affected the removal efficiency of MB. A central composite design (CCD) combined with response surface modeling (RSM) was carried out to maximize MB removal by A. campestris for the adsorption process. A regression model was derived using RSM to predict the responses and analysis of variance (ANOVA), and to check model adequacy lack of fit test was used. The A. campestris adsorption capacity was determined as 24.2 mg g–1. The ANOVA showed a high coefficient of determination (R2 = 0.9987). This study clearly revealed that RSM was one of the most effective and appropriate method for the optimization of operating conditions. The possibility of reusing A. campestris was also investigated and, as a result, it was found quite possible and showed high performance in the recovery of MB.