Study on the effectiveness of spent waste sugarcane bagasse for adsorption of different petroleum hydrocarbons water pollutants: kinetic and equilibrium isotherm

This study investigates the capability of spent waste sugarcane bagasse (SWSB), obtained from bioethanol production process, for biosorption of diesel oil and kerosene, in an attempt to be applied for wastewater treatment with an enrichment of the SWSB for its use as a renewable solid biofuel. The chemical composition, microstructure, surface morphology, and reactive surface functionalities of the adsorbent were determined. Effect of different pH, salinity, initial pollutant concentrations, temperatures, and adsorbent dosages were also studied. The results showed that the sorption of petroleum products depends on the adsorbent material and the adsorbate type. The biosorption was favorable, where the SWSB removed 63-41% of diesel oil and 70-50% of kerosene in solutions containing 5-20%w/v of these contaminants. The kinetic equilibrium was reached after 6h and the biosorption follows the pseudo-second-order rate expression. The SWBS expressed good biosorption capacity 44-86 and 78-110mg/g over a wide range of pH and salinities. The biosorption potential increased with increase in the temperature and decreased with increase in the biosorbent dosage. The sorption may be partly due to absorption/partitioning of pollutants onto the SWBS and partly due to adsorption onto the surface of SWBS. The linear, Freundlich, and Temkin models could provide adequate fit for sorption onto the SWSB, while Langmuir model provided the best adequate fit at low temperature. The analysis of the obtained isotherm data proved the predominance of chemisorption and the endothermic nature of the biosorption process. The calorific value of the SWSB recorded approximate to 32.91 and 33.61MJ/kg for SWSB after biosorption of diesel oil and kerosene, respectively. The results recommend the applicability of the low cost, readily available, sustainable and environmentally friendly SWSB for wastewater treatment, and production of a renewable solid biofuel, which would have positive impact on economy, energy, and environment.