Coco peat powder as a source of magnetic sorbent for selective oil–water separation

Abstract

Coco peat powder (CPD), the main by-product of the coconut palm, is an excellent source of environmentally friendly magnetic sorbent with potential application in oil-spill cleanup. In order to develop the best resource for the agricultural crop and alleviate environmental stress caused by disposal of natural CPD, Fe3O4 nanoparticles were immobilized on coco peat powder (CPD) with the aid of mussel-inspired polydopamine (PDA) and then chemically modified by low-surface-energy octadecylamine (ODA) to fabricate a novel magnetic coco peat powder (MCPD) for selective oil–water separation. The obtained MCPD, which had high hydrophobicity (water contact angle: 135±3°) and saturation magnetization of 27.6 emu/g, exhibited remarkable sorption efficiency for convenient removal of oils from water and displayed excellent separating performance under an auxiliary magnetic field. The results indicated that the highest amount of oil sorption on MCPD reached 8.57 times of its own weight, and the oil could be desorbed from the oil-loaded MCPD and easily recycled for at least 11 cycles. The oil-loaded MCPD also exhibited high recyclability, with a loss of less than 15.32% in oil-sorption capacity after 11 cycles, which suggests that the MCPD prepared through the proposed synthesis process has high potential for application in large-scale removal of spilled oils from water. This work also provides a universal strategy for developing an oil-pollution treatment using natural resources from the waste stream.