Modification of kapok cotton fibres into porous cellulose triacetate beads for oil spill remediation

Abstract

Marine oil spills have been widely reported, and bioremediation is proposed to be an environmentally friendly approach to clean these spills. However, maintaining a high biomass of oil-degrading bacteria has proved challenging. Here, a carrier that enables simultaneous bacterial immobilisation and oil absorption is proposed as a solution. Porous cellulose triacetate beads (PCTBs) derived from cellulose triacetate powder were obtained through the acetylation of kapok fibres. This study revealed, that 12.5 and 16.67% w/v PCTBs precipitated in distilled water showed crude oil absorbency of 2.4850 ± 0.1326 and 1.9852 ± 0.2343 g/g, respectively. Reusability tests of PCTBs showed promising results with no reduction in oil absorption after five reabsorption cycles. Successful immobilisation of the oil-degrading bacteria Acinetobacter venetianus on PCTBs was achieved, and enumeration of bacteria showed no statistically significant differences compared with those on kapok fibres despite the raw fibres having a larger surface area. The scanning electron microscopy analysis revealed that A. venetianus adhered to the outer and inner walls of the beads through secreted exopolysaccharides. PCTBs with oil-degrading bacteria are potentially able to absorb and degrade oil simultaneously, thus highlighting the novelty of a working alternative for sustainable oil spill mitigation.