Adsorption of ammonia in wastewater using zeolite synthesized from coal fly ash

Abstract

Class F fly ash from Duyen Hai thermal power plant in Vietnam was used to synthesize zeolite A for the adsorption of ammonium in wastewater. Well-ordered cubic zeolite A was first synthesized using fly ash as source material by hydro-thermal method assisted by ultrasound. This material was characterized by XRD, SEM to study the morphology and crystallinity. The adsorption properties of ammonium ions (NH₄⁺) from aqueous medium onto zeolite A were investigated as a function of parameters such as equilibrium time, initial NH₄⁺ concentration, amount of zeolite used. The synthesized zeolite A displayed a fast adsorption rate and high adsorption capacity, indicating that this is a potential material for the treatment of NH₄⁺ from wastewater, especially in advanced ammonium treatment stages. The study shows that the adsorption process follows the Langmuir and Freundlich adsorption isotherms simultaneously.