Removal of bisphenol S from drinking water by adsorption using activated carbon and the mechanisms involved

Abstract

Bisphenol S, an alternative chemical to bisphenol A, has a negative effect on living organisms and has frequently been detected in drinking water systems. A promising and cost-effective method for removing bisphenol S from tap water is adsorption by activated carbon. However, activated carbon significantly decreased the adsorption capacity of bisphenol S in tap water comparing with that in deionized water based on the experimental results. Dissolved organic matter in tap water was likely responsible for it. The adsorption kinetics can be described by a pseudo-second-order model. The Langmuir isotherm model can well describe the process, suggesting monolayer adsorption. The maximum adsorption capacity was calculated as 83.19 mg g −1 . Higher temperature and pH were unfavorable to the process. Changes in entropy, enthalpy, and Gibbs free energy were calculated and implied a spontaneous and exothermic adsorption process. Fourier transform infrared spectroscopic analysis found that hydroxyl and amino functional groups are the main groups involved. The research provides a substantial basis for understanding bisphenol S removal from drinking water by adsorption using activated carbon to limit direct exposure to bisphenol S in drinking water.

Removal of Bisphenol S (BPS) by Adsorption on Activated Carbons Commercialized in Brazil

“…The results obtained in the present study are consistent with recent studies concerning BPS adsorption on activated carbons [ 23 , 34 , 35 , 36 , 37 , 38 , 39 ], as the experimental data adequately fit the Langmuir model. Nevertheless, this study obtained more satisfactory results the studies above.…”

“…In recent studies involving BPS adsorption on activated carbons in ultrapure water matrices, the experimental data have appropriately fit the pseudo-second-order kinetic model as shown in Table 6 [ 23 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Nevertheless, none of the studies obtained better experimental data fits with the pseudo-first-order kinetic model.…”

“…The maximum BPS adsorption capacity, 27.89 mg/g, was lower than that found in the present study. Zhao et al (2022) achieved a maximum BPS adsorption capacity of 83.19 mg/g, applying 250 mg/L of commercial activated carbon in adsorption tests using ultrapure water; the initial concentration of BPS varied in the 20–50 mg/L range [ 39 ].…”

“…Since this kinetic model assumes that chemisorption predominates in the process [33], the surface interactions between the adsorbate and adsorbent likely involve electron sharing or exchange. In recent studies involving BPS adsorption on activated carbons in ultrapure water matrices, the experimental data have appropriately fit the pseudo-second-order kinetic model as shown in Table 6 [23,[34][35][36][37][38][39][40][41]. Nevertheless, none of the studies obtained better experimental data fits with the pseudo-first-order kinetic model.…”