Synthetic Zeolites Derived from Fly Ash as Effective Mineral Sorbents for Diesel Fuel Spill Remediation

Abstract

Development of an effective sorbent for diesel fuel spill remediation remains an important challenge in the field of synthesis due to the potential capacity of sorbents to efficiently purify contaminated sites. Fly ash, a coal combustion by-product, was used as a raw material to synthesize two inexpensive zeolites (SZ-1 and SZ-2) for oil spill remediation using an alkali fusion approach prior to hydrothermal treatment. The sorbents were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and N₂ adsorption/desorption. Diesel fuel sorption was used to examine the potential capacity of the synthetic zeolites to sorb oil and other petroleum products. Diesel fuel viscosity and density were determined at room temperature using a viscometer and a pycnometer, respectively. The synthetic zeolites exhibited a higher diesel fuel sorption capacity than fly ash. The SZ-1 zeolite sorbed approximately 1.43 g·g⁻¹ and SZ-2 sorbed approximately 1.9 g·g⁻¹. The sorption was mainly a physical process and mesopore filling seemed to play the dominant role. Sorbent textures were, therefore, vital for the sorption of petroleum products.