Synergetic effect on the adsorption of cationic and anionic emerging contaminants on polymeric membranes containing Modified-Graphene Oxide: Study of mechanism in binary systems

The growing need to explore the adsorption potential of new materials in real water samples triggered the evolution from single to multicomponent systems in the area of adsorption. In this study, PAN membranes containing graphene oxide functionalized with safranin dye (hPAN@GO-SF) were applied in the adsorption of complex dyes, pharmaceuticals and surfactants from water and real samples, in single and binary systems, to evaluate the competitive or cooperative effects of adsorbate mixture on the adsorption mechanism. This is the first time that polymeric membranes containing GO have been used as adsorbent in multicomponent systems. The results obtained in single systems indicated that electrostatic interactions and H-bonding are the main mechanism, but chemisorption is also present. For the multicomponent systems, the adsorption potential of the membrane increased due to cooperative effects, reaching a percentage increase of 141% for DB22, a more than 3X increase for BB7 and exponential increase for SIL and PRO. Suggestion of mechanisms based on adsorbent/ adsorbate and adsorbate/adsorbate interactions supported by ion exchange, pi-pi, H-bonding and electrostatic interactions. Comparing the adsorption capacity of hPAN@GO-SF for contaminants in binary system with other materials in the literature used in single systems, this indicate that membrane is a potential adsorbent for wastewater treatment.