Abstract
This work investigates the potentiality of application of spent waste biomass (yeast Saccharomyces cerevisiae, rice straw, and sugarcane bagasse) from bioethanol production process as low-cost biosorbents for removal of phenol from petroleum refinery wastewater. Batch adsorption studies were carried out under varying experimental conditions of contact time, initial phenol concentration, and operational temperature. Rice straw showed better affinity towards phenol than sugarcane bagasse, while S. cerevisiae did not express any biosorption capacity. The biosorption process on rice straw or sugarcane bagasse was fast and the time to reach equilibrium was found to be 150 min. Kinetic studies showed that biosorption follows the pseudo-second order rate expression. The results were better described by the Langmuir isotherm model than the Freundlich and Temkin isotherm models. The calculated heat of adsorption indicated that the biosorption process is taking place by chemical adsorption and has an endothermic nature.