Optimization of Toluidine Blue Biosorption in Aqueous Solutions Using Polyporus Squamosus Fungi as Absorbent by Response Surface Methodology

Textile wastewater including a large number of dyes and heavy metals can have adverse impacts on human health and surface water. In this work, biosorption Toluidine Blue from aqueous media onto natural Polypourus squamosus fungi as a low-cost biosorbent was investigated. Central Composite Design (CCD) in Response Surface Methodology (RSM) was successfully applied to optimize the biosorption condition. Medium parameters affected the biosorption of Toluidine Blue were determined to be initial pH, initial Toluidine Blue (Tb) concentration, temperature, and absorbent dosage. All experiments were carried out in a batch system using 250 mL flasks containing 100 mL of Toluidine Blue solution with a temperature-controlled magnetic stirrer. The Tb concentrations remaining in filtration solutions after biosorption were analyzed using UV-Spectro. With the obtained quadratic model, the optimal conditions for maximum biosorbed Toluidine blue were calculated to be 7, 27.5 mg/L, 35°C and 0.05 g for pH, C°, T (°C) and adsorbent dosage, respectively. Furthermore, most known isotherm models such as Langmuir and Freundlich were computed to find the best-fitted model.