USE OF MORINGA-DERIVED ACTIVATED CARBON TO REMOVE BORON FROM SYNTHETIC SEAWATER

Abstract

Boron has been identified as a contaminant in drinking water across different countries; this is a threat to sensitive plant species and human health. Therefore, regulatory standards require that boron concentrations be lowered to 0.3 mg/L for potable water and between 0.5 mg/L and 1 mg/L for irrigation water. Traditional methods for boron removal are frequently expensive or inefficient at low concentrations. In this study, the feasibility of using Moringa oleifera seed husk to produce activated carbon for the removal of boron from synthetic seawater was investigated. The main objective of this study was to determine the boron removal efficiency of various preparation methods of activated carbon produced from Moringa oleifera seed husk (chemical activation and physical activation) through a batch adsorption process with synthetic seawater. The process parameters (adsorbent dose, temperature, and initial boron concentration) of the best sorbent were optimized. The surface properties of the best sorbent were characterized through FTIR and SEM. Equilibrium isotherm and kinetics for the best sorbent based on the optimized parameters were determined. The result showed that chemically activated carbon was found to possess the best adsorption for the removal of boron from synthetic seawater with 88.02 % at neutral pH and room temperature (25°C±2°C). SEM showed that chemical treatment of Moringa oleifera seed husk improves the porosity and the extent of surface functionality of Moringa oleifera seed husk. FTIR analysis showed that hydroxyl (–OH), carboxyl (–COOH), and carbonyl (C=O) groups were present, which were involved in the adsorption of boron by chemically activated carbon. The highest removal efficiency of 89.72% was obtained at a temperature of 55°C, 0.9 g/L biosorbent dose, and an initial boron concentration of 1 mg/L, obtained using Response Surface Methodology (RSM). The equilibrium data of this study were fitted with the Langmuir isotherm with a regression value of R²= 0.9685, while the adsorption kinetics were adequately described by the sequential fitting of the pseudo-second -order models with a regression value of R²= 0.9942.