Removal of crude oil from aqueous solution using lauric acid modified oil palm leaves adsorbent

摘要

Recently, the abundant and biodegradable biomass was reported to be convenient for oil spill clean–up due to its low-cost and environmental friendly. One of the agricultural wastes, namely oil palm leaves (OPL) were chemically modified by a fatty acid, lauric acid (LA) and employed as an adsorbent to remove crude oil from aqueous solution. The textural and surface properties of the lauric acid modified oil palm leaves (OPLLA) were characterized by FTIR, FESEM, and N2 adsorption. Thermal stability of the adsorbents was characterized by TGA. The effect of several parameters such as solution pH, loading of adsorbent, contact time, initial crude oil concentration, and adsorption temperature on crude oil adsorption were investigated. It was found that addition of LA created non-polar layer on oil palm leaves surface, thus endowing OPLLA with much better adsorption capacity for crude oil removal from aqueous solution. The adsorption was found to be dependent on all the studied parameters. The kinetic study revealed that adsorption process was rapid and obeyed pseudo second-order model. The equilibrium time was short and could be achieved within 20 minutes. Isotherm study indicated that the oil adsorption was fitted well by Freundlich model. The maximum adsorption capacity of OPLLA controlled by the solubilization mechanism was 1176.00 ± 12.92 mg g-1 with the removal percentage of 42.00 ± 0.46 % at 303 K. The potential of OPLLA to adsorb crude oil from crude oil contaminated seawater achieved 34.02 ± 0.45 % removal with the maximum adsorption capacity of 952.66 ± 11.31 mg g-1. These results demonstrated the potential of OPLLA as an alternative low-cost, biodegradable and effective adsorbent for oil spill clean-up.