Oil palm empty fruit bunch-based nanocellulose as a super-adsorbent for water remediation

Oil palm empty fruit bunch (EFB)-based nanocellulose (NC) was successfully produced as a super-adsorbent for water remediation via sulfuric (NCS) and phosphoric (NCP) acid hydrolysis and functionalized with activated carbon (AC). The formation of sulfonic groups on the NCS surface could achieve higher remediation capabilities than that of EFB-NCP. In a very short period, 2 wt.% of the formulated EFB-NCS super-adsorbent showed a selective and remarkable metal adsorption capability to Pb2+ at 86% efficiency and 24.94 mg/g adsorption capacity, which were double compared to those of rice-straw NC, and maintained a similar adsorptive capacity after second reusability. Conversely, the insignificant improvement in the adsorption capacity of NCS/AC was attributed to the disturbed surface functionality of micron-size AC. The NCS/AC showed notable organic degradation capability for reducing the chemical oxygen demand (COD) to 93%. All super-adsorbents could maintain the pH, TDS, sulfate and phosphate contents within the government water quality specifications.