Investigation of optimum conditions for efficient COD reduction in synthetic sulfamethazine solutions by Pleurotus eryngii var. ferulae using response surface methodology

This study aims to explore the optimum conditions for P. eryngii var. ferulae in adsorption of sulfamethazine (SM) from synthetic solutions via reduction of chemical oxygen demand (COD). The optimum conditions were optimized using the response surface methodology (RSM) developed by the application of the quadratic model associated with the central composite design. For this aim, RSM was employed to determine the effects of some parameters on this adsorption process by fungal biomass as an effective and available adsorbent. The investigated parameters were initial concentration of sulfamethazine (70–235 mg L−1), solution pH (3–7), adsorbent dosage (0.3–1.5 g), and contact time (5–25 min). The significant factors on each experimental design response were identified from the analysis of variance. The results of RSM analyzes revealed that optimum conditions of initial SM concentration, pH, adsorbent dosage, and contact time for maximum COD removal (82%) were achieved as 400 mg L−1, 11, 1.46 g, and 15.4 min, respectively. The results showed that dead biomass of P. eryngii var. ferulae were an appropriate adsorbent for the removal of COD in the SM medium from synthetic solutions.