Pure zeolite LTJ synthesis from kaolinite under hydrothermal conditions and its ammonium removal efficiency

Abstract

Linde type J zeolite was synthesized out of kaolinite raw material through hydrothermal reactions, once potassium hydroxide was used as an activator. The physicochemical characteristics of the synthesized zeolite were surveyed by using XRD, SEM/EDX, and FT-IR analytical methods. Moreover, the capability of Linde Type J zeolite for ammonium ion removal from aqueous solutions was evaluated in the present study through batch adsorption experiments. Further, the ammonium ion concentration in the remnant leachates was measured making use of the photometry analysis. Subsequently, Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms were applied to describe the data obtained from the adsorption studies. The findings verified the highest R2 values of Freundlich isotherm model assuming an adsorption on the heterogeneous surface. Furthermore, the kinetic studies indicated the adsorption process follows pseudo-second-order model denoting the adsorption rate controlled by the chemical sorption. In a nut shell, Linde Type J zeolite, which was synthesized from raw kaolinite, demonstrated its brilliant performance in the process of ammonium ion sorption from aqueous solutions. This can guarantee the probable potential of LTJ zeolite in purification applications.