Investigating the removal of methyl tertiary butyl ether (MTBE) from water using raw and modified fly ash waste materials

Classical techniques for remediation of methyl tertiary butyl ether (MTBE) from contaminated water sources are characterized by inherent limitations due to its unique physical and chemical characteristics, making further remediation researches promising. Fly ash (FA), which is a waste material derived from the combustion of coal or heavy liquid fuel has been reported to show favorable adsorption results with selected metals, dyes, and some organics in aqueous solution. In this study, raw FA, acid-treated FA, and metal oxide (silver, iron, and aluminum) impregnated FA were assessed on a bench scale, for MTBE adsorption in contaminated water system and benchmarked against activated carbon (AC). Results showed that only silver oxide (Ag₂O) impregnated FA achieved ~24% removal of MTBE from aqueous solution, while the other tested adsorbent materials achieved <10%. MTBE optimum adsorption was attained after 120 min of contact, and 0.5 g/L dosage of adsorbent. Conversely, silver oxide impregnation of AC brought about a drop in its MTBE removal efficiency from an optimum efficiency of 71 to 53%. Also, the Langmuir isotherm model best represented the MTBE adsorption behavior of both the Ag₂O-impregnated FA and AC, having R² of 88.75–89.92%, respectively.