Dokuz Eylül Üniversitesi Mühendislik Fakültesi Fen ve Mühendislik Dergisi, vol.23, no.69, pp.1049-1056, 2021 (Peer-Reviewed Journal)
In this study, the effects of hydrochloric acid (HCl) and acetic acid (HAc) modification on the hexadecyltrimethyl ammonium bromide (HTAB) and K+ adsorption characteristics of a natural zeolite wereinvestigated. Electrokinetic evaluations showed that the zeta potential values of acid-modifiedsamples were considerably more negative compared to natural zeolite. Additionally, the pHregulation behavior of the acid-modified samples was found to differ from the natural zeolite sampleand it was in agreement with the results of zeta potential measurements. It was clear that the acidmodification processes positively affected the surface properties and improved the cation exchangecapacity (CEC) of natural zeolite. The results for the adsorption studies showed that the adsorptiondensity of zeolite increased at elevated HTAB and K+ concentrations. Moreover, following the zeta andpH profile results, a considerable difference in the adsorption ability between natural and acidmodified zeolite samples is present in terms of HTAB and K+ adsorption characteristics. It isconcluded that acid modification can be used in the enhancement of the adsorption ability of zeolites.