Iron-trimesate impregnated moss composites for application in petroleum recovery and remediation of petroleum-contaminated water

Abstract

Crude oil spills are major environmental and economic concerns. The use of sorbents for removal of crude oil from water surfaces has remained a viable solution to crude oil spills. In this study, a novel composite material produced by impregnation of the metal-organic framework (MOF), iron-trimesate (Fe-tri), onto the moss species, Barbula indica, was investigated for its crude oil sorption capacity. Various moss/Fe-tri composition, including moss/Fe-tri 50:50, moss/Fe-tri 75:25, and moss/Fe-tri 25:75, were prepared and tested along with the pure substances for their capability to sorb crude oil. Infrared spectrometric analyses carried out for moss/Fe-tri 50:50, pure moss sample, and pristine unmodified Fe-tri (MOF) revealed characteristics bonds and functional groups such as -OH, -C=O, C-H and aromatic rings on the materials. The results obtained from the crude oil sorption tests showed relatively high sorption capacity values, which decreased in the order: moss/Fe-tri 75:25 (2.81 g/g) > pure moss sample  (2.39 g/g) > moss/Fe-tri 50:50 (2.32 g/g) >  moss/Fe-tri 25:75 (2.09 g/g) > Fe-tri (1.68 g/g), indicating that the impregnation of moss with Fe-tri enhanced crude oil retention capacity. Water sorption test results further demonstrated the suitability and efficiency of the materials as sorbents for removal of crude oil from water and also indicated that sorbent porosity and pore volume influenced sorption performance. The findings revealed that impregnating mosses with metal-organic frameworks could yield a composite with better crude oil retention property, and highly efficient for application in recovery of crude oil from water and remediation of water contaminated with same.