Absorption is one of the effective, simple and economical methods to remove oil from oily wastewater. The most widely used approach is to utilize lignocellulosic biomass as oil absorbent. However, the hygroscopic of cellulose have limited the oil-water separation capability of lignocellulosic fibers. In this study, the surface functionality of oil palm empty fruit bunch (EFB) fibers was slightly altered by grafting reduced graphene oxide (rGO). The modified EFB fibers show a distinct morphological and chemical characteristics changes as the surface of fibers has been coated with rGO. This was supported by FTIR analysis with the diminishing peak of hydroxyl group region of EFB fibers. While the surface modification on EFB fibers shows a diminution of a hydrophilic characteristic of 131.6% water absorption in comparison with 268.9% of untreated EFB fibers. Moreover, modified fibers demonstrated an oil-water separation increment as well, as it shows 89% of oil uptake and improved similar to 17 times of oil selectivity in oil-water emulsion than untreated EFB fibers.

Binderless electrodes of activated carbon monoliths (ACMs) and its composites with graphene are prepared by carbonization and activation of green monoliths consisting of self-adhesive carbon grains and 0-10 wt% KOH-treated graphene. Compared with ACMs, the optimized composite containing 6 wt% graphene exhibits more ordered micro-structures with increased crystallite height, and graphitic sp(2) carbons (I (D) /I (G) = 0.49 vs. 0.91) along with enhanced porosity; as revealed by X-ray diffraction, Raman, and N-2 adsorption-desorption studies. These modifications lead to increased electrical conductivity (13 vs. 9 S cm(-1)) through improved interconnections of carbon particles by graphene, and surface area similar to (800 vs. 456 m(2) g(-1)) due to increased inter-particle spacing. Further, contrary to ACMs, the composite electrodes can offer faster delivery of energy in almost 50% less response time (5 vs. 8 s) due to reduced equivalent series resistance (1.67 vs. 2.65 Omega) and charge transfer resistance (0.55 vs. 1.33 Omega).