Reduction of Nitrate Content in Water by the Use of Banana Peels Biochar

Abstract

The intensification of agricultural, domestic and industrial activities leads to the increasing contamination of groundwater and surface water by nitrates. Indeed, agricultural runoff, septic tank effluents, landfill leachates or wastewater treatment plant effluents contribute to this nitrification, yet drinking water containing high nitrate content can cause health problems. The study examines the improvement of nitrate removal in synthetic water solution by adsorption on banana peel’s activated carbon (BPAC). Different effects of physicochemical parameters, such as the optimal contact time of BPAC in solution, the pH of the nitrate solution, the initial concentration of nitrate solution, the BPAC mass, and the temperature were evaluated. The study revealed that BPAC has a low nitrate adsorption capacity under normal laboratory conditions. However, this adsorption capacity of BPAC increases with increasing of temperature and initial content of nitrate, while it decreases with increasing BPAC mass. For a content of 100 mg/L nitrate solution, the maximum adsorption capacity was 0, 687 mg/g for an equilibrium time of 180 min. Nitrate adsorption is optimal in acidic media (pH=3). The application of kinetic models to the experimental data showed that the mechanism of nitrate adsorption on BPAC obeys pseudo-first order kinetics. The Freundlich isotherm perfectly describes the mechanism of nitrate adsorption on BPAC.