Kinetics and isotherms of lead ions removal from wastewater using modified corncob nanocomposite

Abstract

A promising new eco-friendly sorbent from agricultural waste (silica/corncob nanocomposite) was successfully prepared and used for the removal of lead ions from the solution. The characterization and identification of the synthesized sorbents were investigated using different techniques. A comparative adsorption study between two sorbents was estimated to identify the best efficient sorbent. The potential of the best sorbent to remove lead ions (Pb2+) from an aqueous solution was investigated in batch experiments, where several parameters such as contact time, pH, sorbent dose, and initial concentration of Pb2+ ions were investigated. For deep information, Kinetic and isotherm models were applied for sorption. Furthermore, the column study was evaluated from silica/corncob nanocomposite for removal of Pb2+ ions and the potential ability of the synthetic nanocomposite to be regenerated and reuse was also studied. It is remarkable that with 0.3 g of silica/corncob nanocomposite, up to 95% of Pb2+ could be removed at pH = 5.5 after 60 min which is higher than corncob (77%). From the kinetics and isotherms data, the harmony of data was fitted with the pseudo-second-order kinetic model and the Langmuir isotherm model. From a single column results, it seems that silica/corncob nanocomposite has proven to be a promising material and economical for the removal of heavy metals. Moreover, the results showed that the removal efficiency for Pb2+ was more than 90% for the first two cycles, and then slightly decreased to 85%. So, the silica/corncob nanocomposite can be reused for the removal of heavy metals from wastewater for at least 3 cycles.