Insight into Decolorization Characteristics of a Green Biocomposite Sorbent System Prepared by Immobilization of Fungal Cells on Lignocellulosic Matrix: Box-Behnken Design

In this study, the biosorption performance of Thamnidium elegans (T. elegans) immobilized on Phragmites australis (P. australis), a new biocomposite (TEPA), was examined for decolorization of water using batch and column mode tests. Various affecting experimental parameters such as pH, biocomposite amount, and stirring speed were examined and optimized by an experimental design. Regression analysis indicated that the findings of the Box-Behnken experimental design (BBD) optimization experiment closely match a quadratic model. ANOVA findings revealed that pH and TEPA amount affected Reactive Blue 49 (RB49) biosorption yield. Optimum experimental RB49 decolorization was achieved with the biosorption yield of 96.51% at the conditions of pH: 1.68, TEPA mass: 53.4 mg, stirring speed: 204 rpm, and contact time: 45 min. RB49 sorption onto TEPA was explained using the Elovich and the pseudo-second-order kinetic and the Freundlich isotherm models. The maximum RB49 sorption capacity was 140.36 mg g⁻¹ at defined optimum conditions. Unloaded and dye-loaded biocomposite sorbents were characterized by SEM and FTIR analysis. The isoelectric point of TEPA was found as pH 1.7 by the zeta potential measurements. Furthermore, the newly developed biocomposite sorbent indicated the promise in terms of decolorizing real wastewater without losing dye sorption ability. Saturation biosorption capacities in column mode were 104.58 and 70.98 mg g⁻¹ in dye solution and real wastewater samples, respectively. TEPA can be considered cost-effective, ecofriendly, and promising alternative adsorbent for decolorization of reactive dye contaminated wastewater, as shown by all the findings.