Comparative Study of the Adsorption of Crude Oil from Surface Water Using Esterified Rice Husk and Saw Dust

The comparative adsorption of crude oil from water surface using sawdust and rice husk absorbents was carried out. The sawdust and rice husk were carbonized and further modified with stearic acid. The prepared adsorbents were characterized using Scanning electron microscopy (SEM), Fourier Transform Infra-red (FTIR) Spectroscopy, proximate and physiochemical analysis. Batch experiments were carried out to investigate the effects of the initial oil concentration, the dosage of the adsorbents, temperature, pH and contact time on the adsorption capacities of the adsorbents and percentage sorption of the crude oil. The characterization results obtained showed that the surface modification through carbonization and stearic acid activation improved the physiochemical properties of sawdust and rice husk respectively. The FTIR results revealed that the biomass samples have numerous functional groups and the major functional groups present are O-H, N-H, N-CH3, C=C-C, C-Cl, Si-O-Si. The SEM results also showed that carbonization and stearic acid activation of the saw dust and rice husk were able to effect surface modification of the prepared adsorbents by the removal of volatile matters; improvement of porosity hence the improvement of their surface areas respectively. The process parameters investigated were found to influence the adsorption capacity of the absorbents respectively and subsequently the percentage sorption of the crude oil.

Meanwhile, the results of the percentage sorption of sawdust and rice husk samples, based on the average weight of oil adsorbed; show 96.577% and 67.327% as their respective adsorption efficiency. Hence, the comparative adsorption efficiency of the carbonized and esterified saw dust and rice husk absorbents, showed that esterified saw dust adsorbent performed better than the esterified rice husk adsorbent.