Synthesis of EDTA-functionalized graphene oxide-chitosan nanocomposite for simultaneous removal of inorganic and organic pollutants from complex wastewater

Monu Verma; Ingyu Lee; Joosung Oh; Vinod Kumar; Hyunook Kim

doi:10.1016/j.chemosphere.2021.132385

Synthesis of EDTA-functionalized graphene oxide-chitosan nanocomposite for simultaneous removal of inorganic and organic pollutants from complex wastewater

Chemosphere. 2022 Jan;287(Pt 4):132385. doi: 10.1016/j.chemosphere.2021.132385. Epub 2021 Sep 28.

Authors

Monu Verma¹, Ingyu Lee¹, Joosung Oh¹, Vinod Kumar², Hyunook Kim³

Affiliations

¹ Water-Energy Nexus Laboratory, Department of Environmental Engineering, University of Seoul, Seoul, 02504, Republic of Korea.
² Department of Life Sciences, Graphic Era (Deemed to Be University), Dehradun, Uttarakhand, 248002, India; Peoples' Friendship University of Russia (RUDN University), Moscow, 117198, Russia.
³ Water-Energy Nexus Laboratory, Department of Environmental Engineering, University of Seoul, Seoul, 02504, Republic of Korea. Electronic address: h_kim@uos.ac.kr.

PMID: 34597635
DOI: 10.1016/j.chemosphere.2021.132385

Abstract

Discharging of inorganic and organic pollutants creates a serious threat to the human health and the environment. In the current work, we have synthesized Ethylenediaminetetraacetic acid (EDTA) functionalized graphene oxide-chitosan nanocomposite (GO-EDTA-CS) for simultaneous removal of inorganic (i.e., mercury (Hg(II) and copper (Cu(II)) and organic pollutants (i.e., methylene blue (MB) and crystal violet (CV)) from wastewater via adsorption process. The structural, functional, morphological, elemental compositions, surface area and thermal properties of the synthesized nanocomposite were identified using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), Brunauer-Emmett-Teller (BET), and thermogravimetric analyzer (TGA), respectively. Different batch adsorption experiments such as pH effect, contact time, initial pollutants concentration, reusability etc. were studied in monocomponent system to optimize the results. The adsorption process apparently followed pseudo-second-order (PSO) kinetics for both pollutants, however the adsorption kinetics was also explained by the intra-particle diffusion model. The isotherm data for both metals ions and dyes were well fit by the Langmuir isotherm model. The maximum adsorption capacities of the adsorbent were determined 324 ± 3.30 130 ± 2.80, 141 ± 6.60, and 121 ± 3.50 mg g^-1 for Hg(II), Cu(II), MB, and CV, respectively. The excellent adsorption capacity was attributed to the availability of various active functional groups (e.g., -COOH, -OH, -NH₂, etc.) on the adsorbent. The EDS, elemental mapping and FTIR analysis performed before and after the adsorption of heavy metals and dyes by GO-EDTA-CS confirmed the simultaneous adsorption of the pollutants. Moreover, GO-EDTA-CS could maintain its adsorption capacity for both inorganic and organic pollutants even after seven cycles of adsorption-desorption, indicating itself a promising adsorbent for practical wastewater treatment containing both inorganic and organic toxic pollutants.

Keywords: Kinetics; Monolayer adsorption; Multiple pollutants; Reproducibility; Wastewater.

MeSH terms

Adsorption
Chitosan*
Edetic Acid
Environmental Pollutants*
Graphite
Humans
Kinetics
Nanocomposites*
Spectroscopy, Fourier Transform Infrared
Wastewater
Water Pollutants, Chemical* / analysis

Substances

Environmental Pollutants
Waste Water
Water Pollutants, Chemical
graphene oxide
Graphite
Chitosan
Edetic Acid