Treatment of lead contaminated water using lupin straw: Adsorption mechanism, isotherms and kinetics studies
Desalination and Water Treatment
School of Engineering
Lupin straw has been studied for its efficiency as a low-cost natural adsorbent to remove dissolved Pb2+ ions from synthetic wastewater. Experiments were carried out within this study to understand the effect of various environmental conditions such as contact times, pHs, adsorbent dosages, and adsorbate concentrations. The surface characteristics of lupin straw were investigated utilizing energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy devices. The highest percentage removal of Pb(II) was found to be 98.4% at 5 mg/L initial metal concentration. The breakthrough curve and exhaustive capacity of the adsorbent were determined to be 10.98 and 20.16 mg/g, respectively. Experimental results were evaluated using different isotherm equations developed by Langmuir, Freundlich, Harkins–Jura, Redlich–Peterson, and Halsey. Among these, the Freundlich and Halsey isotherms had a higher correlation coefficient (r² > 0.998). The pseudo-first-order, pseudo-second-order, intra-particle diffusion, Elovich, and fractional power kinetic models were utilized to investigate the dynamic mechanism of lead adsorption over time.