Clinoptilolite—A Sustainable Material for Removal of Bisphenol A from Water

Abstract

Bisphenol A is a remarkable chemical compound for its many applications mainly in the plastics industry, but also for its toxic effects on the environment and human health. BPA (4,4-isopropylidenediphenol) is an anthropogenic compound, moderately soluble in water (120 – 300 mg/l) at room temperature, and highly soluble in alkaline solutions, ethanol and acetone. BPA can bioconcentrate, bioaccumulate and biomagnify through food webs until it reaches humans. To prevent this, effective strategies are sought to allow its removal from the environment, through physico-chemical or enzymatic methods, advanced oxidation, adsorption and biodegradation, ultrasonic degradation. This article shows a comparative study regarding adsorption of BPA on Active carbon and zeolitic tuff, ZTC. In this paper, the characterization of the zeolitic tuff Rupea adsorbent, was carried out from an elemental and mineralogical point of view, pore size and elemental distribution, using SEM, EDAX, and XRD analysis. The pore size varies from 30 nm to 10 µm, atomic ratio Si/Al≥4, and the 80 % of mineralogical composition represent Ca Clinoptilolite zeolites Ca Clinoptilolite zeolite ((Na1.32K1.28Ca1.72Mg0.52)(Al6.77Si29.23O72)(H2O)26.84). 
 Also, a comparative study of the adsorbtion capacity of bisphenol A from synthetic solutions on activated carbon type - Norit GAC 830 W, GAC, as well as on Clinoptilolite-type zeolitic tuff, ZTC, Rupea, was carried out. The experiments were carried out at a temperature of 20 ºC, a pH of 4.11; 6.98 and 8.12, and ionic strength being assured using KCl of 0.01 M, and 0.1 M. The adsorption capacities of GAC and ZTC tend to 115 mg/g and 50 mg/g respectively, at 8.12 pH and ionic strength of 0 M. The Langmuir mathematical model most faithfully describes the adsorption equilibrium of BPA. The maximum adsorption capacity for both adsorbents increases with increasing pH, and decreases with increasing ionic strength.

Occurrence, persistence, and ecological risk of bisphenol A in surface water receiving raw leachate from a municipal solid waste open dump in Kerawalapitiya, Sri Lanka

“…BPA is moderately soluble in water (Corrales et al, 2015;Dura et al, 2023). Generally, when BPA is released into water, its moderate solubility guarantees that more than 96% will remain in water (CEPA, 2018).…”