Clinoptilolite—a sustainable material for the removal of Bisphenol A from water

Bisphenol A is a remarkable chemical compound as it has many applications, mainly
in the plastics industry, but it also has toxic effects on the environment and human health. This
article presents a comparative study regarding the adsorption of BPA on Active carbon and zeolitic
tuff, ZTC. In this paper, the characterization of the zeolitic tuff, adsorbent, was carried out from an
elemental and mineralogical point of view, and it noted the pore size and elemental distribution,
using SEM, EDAX, and XRD analysis. The pore size varies from 30 nm to 10 µm, the atomic
ratio is Si/Al ≥ 4, and 80% of the mineralogical composition represents Ca Clinoptilolite zeolites
and Ca Clinoptilolite zeolites ((Na1.32K1.28Ca1.72Mg0.52) (Al6.77Si29.23O72)(H2O)26.84). Moreover, a
comparative study of the adsorption capacity of bisphenol A, using synthetic solutions on an activated
carbon type—Norit GAC 830 W, GAC—as well as on Clinoptilolite-type zeolitic tuff—ZTC, was
carried out. The experiments were carried out at a temperature of 20 ◦C, a pH of 4.11, 6.98, and
8.12, and the ionic strength was assured using 0.01 M and 0.1 M of KCl. The adsorption capacities
of GAC and ZTC were 115 mg/g and 50 mg/g, respectively, at an 8.12 pH, and an ionic strength
of 0 M. The Langmuir mathematical model best describes the adsorption equilibrium of BPA. The
maximum adsorption capacity for both adsorbents increased with an increasing pH, and it decreased
with increasing ionic strength.