Enhanced immobilization of mercury (II) from desulphurization wastewater by EDTA functionalized graphene oxide nanoparticles

• Published in: Environmental technology 2020-05, Vol.41 (11), p.1366-1379
• Main Authors: Sun, Jiaxing, Chen, Heng, Qi, Dongxu, Wu, Hao, Zhou, Changsong, Yang, Hongmin
• Format: Article
• Language: English
• Subjects: Acetic acid; Adsorbents; Adsorption; adsorption isotherm; Chemical composition; Chemical reactions; Desulfurization; Edetic Acid; EDTA; Endothermic reactions; Ethylenediaminetetraacetic acids; Flue gas; Flue gas desulfurization; Graphene; graphene oxide; Graphite; Heavy metals; Immobilization; Kinetics; Mercury; Mercury (metal); Mercury compounds; Metal industry wastewaters; Metal ions; Nanoparticles; Optimization; Oxides; pH effects; Photoelectron spectroscopy; Photoelectrons; regeneration; Scanning electron microscopy; Waste Water; Wastewater treatment; Water Pollutants, Chemical; X ray photoelectron spectroscopy
• ISSN: 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2018.1534893

Graphene oxide (GO) is a new promising nanometer material in a superconductor and wastewater heavy metal ions removal for its functionalized groups. Ethylenediaminetetraacetic acid functionalized graphene oxide complexes (EDTA-GO) was produced by a realizable silanization chemical reaction. Characteristics of Hg(II) removal in desulphurization wastewater was also under investigation. The chemical composition and microstructures of the EDTA-GO adsorbents were characterized by X-ray photoelectron spectroscopy (XPS), Transmission electron microscope (TEM), Scanning Electron Microscopy (SEM) analyses. To investigate the performance of EDTA-GO adsorbents on adsorption of Hg(II) in wastewater of wet flue gas desulphurization (WFGD), experiments were performed to optimize the main influence factors such as reaction temperatures (35-70°C), pH values(2-13), contact time (0-120 min), initial Hg(II) concentrations(800 ug/L) and adsorbent doses (20-50 mg/L). The maximum uptake removal efficiency (97.14%) was achieved under the optimal conditions at the pH of 7, the temperature of 70°C, the Hg(II) concentration of 1200 μg/L and the EDTA-GO dose of 40 mg/L. The kinetic data fitting results were well consistent with the pseudo-second-order model (R 2  = 0.99997) and a spontaneous and endothermic adsorption reaction was elaborated by thermodynamics studies (ΔG  0, ΔS > 0). The experiments of recycled adsorbents by HCl generation were carried out to obtain the performance of the reused EDTA-GO adsorbent, the fourth regenerative adsorption efficiency still maintained 80.4%, which indicated that excellent potential application in desulphurization wastewater treatment.