Adsorption of emerging contaminants by graphene related materials and their alginate composite hydrogels. Issue 2 (April 2023)

• Record Type: Journal Article
• Authors: Tunioli, Francesca; Khaliha, Sara; Mantovani, Sebastiano; Bianchi, Antonio; Kovtun, Alessandro; Xia, Zhenyuan; Bafqi, Mohammad Sajad Sorayani; Okan, Burcu Saner; Marforio, Tainah Dorina; Calvaresi, Matteo; Palermo, Vincenzo; Navacchia, Maria Luisa; Melucci, Manuela
• Is Part Of: Journal of environmental chemical engineering. Volume 11:Issue 2(2023)
• Publication Date: 2023-04
• Subjects: Graphene related materials -- Polymer-graphene composites -- Water purification -- Emerging contaminants -- Alginate; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2023.109566
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Graphene nanosheets and nanoplatelets -alginate composite hydrogels were prepared by ionic gelation and the resulting gel beads were exploited for the removal of a mixture of eight selected emerging contaminants (ECs) in tap water, including bisphenol A, ofloxacin and diclofenac. The role of graphene related materials (GRM) on the gel bead structure, adsorption selectivity, kinetic, mechanism, and efficiency was investigated. Combined Scanning Electron Microscopy (SEM) and confocal Raman microscopy mapping showed a porous structure with pore size in the range of 100–200 µm and a homogeneous distribution of graphene nanosheets or nanoplatelets at the pores surface. The adsorption kinetic of GRM was much faster than that of granular activated carbon (GAC), the industrial sorbent benchmark, with removal capacity of ofloxacin from 2.9 to 4.3 times higher. A maximum adsorption capacity of 178 mg/g for rhodamine B was estimated by adsorption isotherm studies for reduced graphene oxide-based beads (a value comparable to that of powered activated carbon). Regeneration test performed on saturated beads by washing with EtOH, and subsequent reiterated reuses, showed no loss of adsorption performance up to the fourth reuse cycle. Graphical Abstract: The adsorption of emerging contaminants from tap water is related to the nanocarbon material chemistry in Alginate-graphene composite hydrogels. ga1 Highlights: Emerging contaminants (ECs) deriving from daily used chemicals are increasingly found in drinking water. Graphene related nanomaterials outperforms activated carbon in the adsorption of several ECs. Alginate-graphene composites do retain the adsorption capability of graphene nanomaterials. The composites performances depends on the graphene nanosheets oxidation degree. Reusability of graphene composites after alcoholic washing