Two and three-parameter isothermal modeling for liquid-phase sorption of Procion Blue H-B by inactive mycelial biomass of Panus fulvus

Procion Blue H-B (PBHB) was used as a model reactive dye for biosorption studies onto inactive/dead mycelial biomass of Panus fulvus. Process parameters like pH, contact time and temperature were optimized. pH 2, 150 min of contact time and 35°C were found to be more favorable for maximum biosorption. Various two- and three-parameter isotherms were employed to understand the biosorption process. Among the various two-parameter isothermal models applied, the Langmuir isotherm showed the best fit and among the three-parameter isothermal models, the Khan, Redlich-Peterson, Sips and Toth isotherm models showed similar fits and only the Koble-Corrigan model showed a poor fit. In kinetic studies, pseudo-first-order model fitted better than pseudo-second-order model. Maximum desorption was observed in alkaline pH, which reveals the possibility of a chemisorption mechanism involved in the removal of PBHB. Among the various desorption media assessed, 70% (v/v) acetone showed complete desorption of the sorbate from the sorbent. Scanning electron microscopy images revealed the non-fibrous nature of the adsorbent. FT-IR studies showed the existence of amine groups in the sorbent which are the major adsorbent sites for reactive dyes.