Removal of arsenate using graphene oxide-iron modified clinoptilolite-based composites: adsorption kinetic and column study

Abstract

In this study, graphene oxide (GO), iron modified clinoptilolite (FeZ), and composites of GO-FeZ (GOFeZA and GOFeZB) were synthesized and characterized using SEM, EDS, XRF, FTIR, and pHpzc. The arsenate uptake on composites of GOFeZA and GOFeZB was examined by both kinetic and column studies. The adsorption capacity increases with the increase of the initial arsenate concentration at equilibrium for both composites. At the initial arsenate concentration of 450 μg/L, the arsenate adsorption on GOFeZA and GOFeZB was 557.86 and 554.64 μg/g, respectively. Arsenate adsorption on both composites showed good compatibility with the pseudo second order kinetic model. The adsorption process was explained by the surface complexation or ion exchange and electrostatic attraction between GOFeZA or GOFeZB and arsenate ions in the aqueous solution due to the relatively low equilibrium time and fairly rapid adsorption of arsenate at the beginning of the process. The adsorption mechanism was confirmed by characterization studies performed after arsenate was loaded onto the composites. The fixed-bed column experiments showed that the increasing the flow rate of the arsenate solution through the column resulted in a decrease in empty bed contact time, breakthrough time, and volume of treated water. As a result of the continuous operation column study with regenerated GOFeZA, it was demonstrated that the regenerated GOFeZA has lower breakthrough time and volume of treated water compared to fresh GOFeZA.

Development of sustainable strontium ferrite graphene nanocomposite for highly effective catalysis and antimicrobial activity

“…This established that the particles were dispersed all over the GO giving collapsed nano stacks. Because of hydrogen bonding and Van der Waal forces, composites may have formed as GO and self-assembled 17 . EDS spectra for SF@GOC has been given in Fig.…”

Advances in the Applications of Clinoptilolite-Rich Tuffs

“…Because Fe-oxyhydroxides, which are available commercially, are usually used to remove toxic As from subterranean water, which is not cost-effective, upgrading ZT to Fe-ZT or Fe 3 O 4 -ZT makes it an economically viable adsorbent [ 40 , 41 , 42 , 43 , 44 , 45 ]. A straightforward two-step process has typically been employed.…”

“…Considering this, modified zeolite forms that employ non-compromising materials for modification are investigated. Fe-ZT was shown to be a suitable adsorbent for oxoanionic species [ 40 , 41 , 42 , 43 , 44 , 45 , 74 ].…”