Coconut shell-derived green synthesised carbon nanotubes for clean-up of crude oil spills

Abstract The global economy has led to an increase in oil transportation and exploitation, posing a threat to aquatic and terrestrial ecosystems. Crude oil spilled water purification is a major challenge worldwide. Researchers are focusing on finding adsorbents that improve oil adsorption capability. In the present study the adsorption of crude oil using synthesized carbon nanotubes (CNTs) prepared from coconut shell was investigated by batch adsorption experiments under varying parameters (adsorbent dosage and contact time) after analytical techniques (UV–vis, FTIR and SEM) confirmed the formation of the CNTs. The morphological modification significantly increased the hydrophobicity of the adsorbent, thus creating a synthesized CNTs with a much better adsorption capacity for crude oil removal having a maximum adsorption capacity of 4855.8 mg/g. The experimental results showed that the percentage of crude oil removal increased with an increase in adsorbent dosage and the contact time respectively. According to the correlation coefficient (R 2 = 0.9801) value obtained from the adsorption isotherm investigations, the isotherms were found to fit the Freundlich isotherm somewhat better than the Langmuir isotherm model, which is consistent with the findings reported in the literature. These findings have made the synthesised CNTs an attractive, useful, and environmentally friendly adsorbent for controlling crude oil spill.