Graphene oxide/Fe₃O₄/SO₃H nanohybrid: a new adsorbent for adsorption and reduction of Cr(vi) from aqueous solutions

Abstract

A sulfonated magnetic graphene oxide (SMGO) hybrid was successfully synthesized via the nucleophilic substitution reaction and characterized. The removal of chromate by SMGO was investigated. The effects of contact time, initial pH of the solution, and initial chromate concentration on the removal efficiency were investigated. The optimal experimental conditions for enhanced chromate removal were found to be a contact time of 60 min at an initial solution pH of 3. The observed data were fitted with Lagergren pseudo-second-order kinetic model, indicating that chromate adsorption on SMGO was a chemical interaction in nature. The Langmuir model was also used to describe the adsorption processes and the adsorption capacity was found to be 222.22 mg g À1. Thermodynamic studies (DG < 0, DH > 0, DS > 0) revealed that the adsorption process was exothermic and spontaneous. SMGO has potential to be applied several times after desorption in wastewater treatment.

Upcycling of groundwater treatment sludge to magnetic Fe/Mn-bearing nanorod for chromate adsorption from wastewater treatment

“…Compared with the Freundlich model, the Langmuir model fitted well to the adsorption of chromate on MA-1 and MA-10, suggesting that MA-1 and MA-10 had an energetically homogeneous surface for chromate adsorption [28]. The maximum adsorption capacity (q m ) of MA-10 was 183.2 mg/g, which was lower than 222.2 mg/g on magnetic graphene oxide [29], but was higher than 51.8 mg/g on jacobsite/chitosan nanocomposites [30], 153.9 mg/g on magnetic chitosan particles [31], and 169.5 mg/g on polypyrrole/Fe 3 O 4 nanocomposite [32] ( Table 3). Magnetic graphene oxide was an expensive man-made carbon material, which should increase the cost of wastewater treatment.…”

Silica based inorganic–organic hybrid materials for the adsorptive removal of chromium

“…To evaluate the thermodynamic feasibility and spontaneous nature of the adsorption process, thermodynamic parameters including the entropy (DS ), enthalpy (DH ) and standard Gibbs free energy (DG ) were calculated. [78][79][80] The magnitude of DG was calculated from the following equation:…”

Sonochemical Formation of Copper/Iron‐Modified Graphene Oxide Nanocomposites for Ketorolac Delivery

“…is the principal cross‐linking agent . To date, this sonochemical pathway has been very successful in the encapsulation of antibiotic nanoparticles in GO that is immaculate or modified with Ag, Fe 3 O 4 , Au, and their bimetallic compounds . Currently, little is known about the sonochemical formation mechanism of hybrid copper/iron GO nanocomposites and much less about NSAID intercalation into their structures.…”