A Comparative Study for Batch Process of Phenol Biosorption onto Different Spent Waste Biomass: Kinetics and Equilibrium

Abstract

This work illustrates a comparative batch study for the application of spent waste biomass—yeast Saccharomyces cerevisiae SSCW from bioethanol production process and used tea leaves STW, which is one of the major organic wastes in Egypt—as low-cost biosorbents for removal of phenol from aqueous solution. Factors affecting the adsorption process—pH, initial phenol concentration, contact time, and operational temperature—were studied. SSCW and STW showed good affinity towards phenol, 17.96 and 13.98 mg/g, respectively. Kinetic studies showed that biosorption follows the pseudo-second-order rate expression. It was found that increasing pH results in lower phenol loading per unit weight of the biosorbent, while increasing temperature, increases the biosorption efficiency. The equilibrium concentration and adsorption capacity at equilibrium were determined using three different sorption models: Langmuir, Freundlich, and Temkin isotherms. The results were better described by Langmuir isotherm, indicating mono-layer coverage of phenol onto sorbents. The calculated heat of adsorption indicated that the biosorption process is taking place by chemical adsorption and has an endothermic nature.

Keywords:

• biosorption
• phenol
• spent Saccharomyces cerevisiae waste
• spent tea waste