Application of mesoporous zeolite Socony Mobil-5 (ZSM-5) as an adsorbent material for the removal of naphthenic acid present in oil-produced water

Abstract

The porous structure of ZSM-5 zeolite strongly affects the adsorption, especially when resistant compounds are present in the water, such as naphthenic acid in oil-produced water. In this sense, ME-ZSM-5 zeolite was synthesized by adding sodium alginate for later use as an adsorbent to remove naphthenic acid from synthetic water and real oil-produced water. Firstly, the results showed that the structural characteristics of the modified zeolite were improved by using sodium alginate (surface area of 235.58 m2 g−1 and total pore volume of 0.125 cm3 g−1). Besides, the adsorption of naphthenic acid from synthetic water was optimal using an adsorbent dosage of 3 g L−1 and pH 4, being the adsorption capacity of 195 mg g−1. Still, in synthetic solutions, the enthalpy of adsorption confirmed an exothermic process, and kinetic studies showed that the system reached equilibrium within the first 50 min. Finally, ME-ZSM-5 was applied to remove naphthenic acid from a real sample of oil-produced water and removed 92%. Therefore, ME-ZSM-5 zeolite was successfully synthesized and could be used as adsorbent material to uptake naphthenic acid from oil-produced water.