Preparation and characterization of polymer coated partially esterified sugarcane bagasse for separation of oil from seawater.

Sugarcane bagasse (B), a low-cost agricultural waste, was modified via esterification and coating with polyacrylonitrile (PAN) and evaluated as a hydrophobic sorbent for diesel oil removal from artificial seawater. Esterification was carried out using stearic acid (SA) and CaO, the reaction conditions, including B:SA mass ratio, CaO concentration, reaction time and temperature were optimized. Additional hydrophobicity was achieved by coating the esterified bagasse (EB) with a hydrophobic polymer (PAN). The advantages of hydrophobicity were clearly expressed by decreased water absorption capacity and increased oil adsorption capacity. The presence of hydrophobic groups was evidenced through Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. FTIR spectroscopy showed some changes in the spectrum of B. XRD patterns indicated that the crystalline structure of B turned amorphous. SEM micrographs illustrated that the surface of EB roughened and PAN was unevenly deposited on it, which led to an increase in the surface area of both sorbents. Moreover, efficient desorption and resorption of diesel oil, paraffin oil, gasoline oil and vegetable oil were recorded in six cycles. Generally, the results are promising and the prepared sorbents can positively contribute to environmental remediation.