Isotherm and Kinetic Adsorption of Boron onto Limestone As a Low-cost Adsorbent

This study was performed to determine isotherm and kinetic adsorption of boron from synthetic wastewater using limestone as a low cost adsorbent. Boron adsorption was performed at optimum condition at pH range of 6-8, contact time of 90 min and limestone dosage of 240 g/L where the boron removal was achieved at 40%. Adsorption isotherm of boron on limestone was more representative by Freundlich model (R-2 = 0.91) rather than Langmuir model (R-2 = 78) indicated that multilayer adsorption was dominance. The kinetic study indicated that the adsorption of boron on limestone well obeyed pseudo-first order model (R-2 = 0.780), pseudo-second order (R-2 = 0.987), Elovich (R-2 = 0.931) and Intra-particle model (R-2 = 0.960). Chemically adsorption mechanisms were dominant in this study based on the highest R-2 for pseudo-second order model.