Probing the Interaction between Fluoride and the Polysaccharides in Al(III)- and Zr (IV)-Modified Tea Waste by Using Diverse Analytical Characterization Techniques

Abstract

The objective of this study was to assess the efficacy of interaction between fluoride and a household tea waste (HTW) material modified using aluminium sulfate and zirconyl oxy chloride. Tea waste is an inexpensive source of biomass comprising lignin, cellulose and hemicelluloses, condensed tannins and proteins. The incorporation of Al (III) and Zr (IV) was accomplished by dilute nitric acid hydrolysis of the tea waste material. The polymeric aluminium and zirconium cations interact with tea waste through the surface hydroxyl, carbonyl, carboxylic functional groups and glycosidic linkages. Since, Al (III) and Zr (IV) ion are hard acids, they interact with the hard base fluoride effectively. The mechanism was supported through Thermogravimetric analysis (TGA), Fourier Transform Infra‐Red (FT‐IR) spectrometry, Fourier Transform Raman (FT‐Raman) spectrometry, Energy Dispersive X ray spectrometry (EDS), X‐ray Diffraction (XRD) and X‐ray Photo Electron Spectroscopy (XPS) techniques. Preliminary batch adsorption studies resulted in linear and nonlinear Langmuir adsorption capacities as 17.51 and 17.54 mg g−1 respectively at pH 7.0. The sustainable adsorbent shows prospective application for defluoridation of water.

Efficient Fluoride Wastewater Treatment Using Eco-Friendly Synthesized AlOOH

“…In the O 1s spectra, the peak at 532.0 eV, which corresponds to Al-OH, also showed a decreasing trend from 68.03 to 63.04% (Table 1) [3]. The decrease in Al-OH bonding in AlOOH-2 and the formation of Al-F bonding indicated that the hydroxyl ions on the surface serve as active sites for fluoride ion adsorption and facilitate the exchange between hydroxyl ions and fluoride ions (Equation ( 1) and Figure 7) [3,45,46]. Also, the involvement of hydroxyl ions in the fluoride ion adsorption process was confirmed via FT-IR analysis of the AlOOH-2 before and after fluoride ion removal (details are shown in the text of the Supplementary Materials and Figure S6).…”

“…The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/nano13212838/s1, Figure S1 S1: comparison of the costs of common Al salts and Al foil used as precursors for Al-based adsorbent synthesis; Table S2: atomic percent of Al and O of AlOOH on Al foil with different immersing times in boiling DI water via EDS analysis; Table S3: atomic percent of Al and O of AlOOH-0.5, AlOOH-1, AlOOH-2, and AlOOH-4 via spot EDS analysis from a cross-sectional view; Table S4: kinetic model parameters of AlOOH-2 for pseudo-first-order model obtained from sorption experiments with different initial fluoride ion concentrations; Table S5: calculated parameters for Langmuir isotherm models obtained from equilibrium sorption experiments; Table S6: adsorption capacities of various Al-based adsorbents for fluoride ions [3,22,45,46,[50][51][52][53][54][55][56][57][58][59]; Table S7: concentrations of dissolved Al in the simulated wastewater with different pH conditions measured using inductively coupled plasma optical emission spectroscopy (ICP-OES) after removal of fluoride ions. ; Table S8: Al 2p and O 1s peak parameters for the regenerated AlOOH-2.…”

Fluoride Removal from Water Sources by Adsorption on MOFs

“…According to the XPS and FTIR characterization techniques conducted in this study, it is assumed that the leading mechanisms responsible for the adsorption of fluoride by the TDC-MOF materials were the ligand exchange and the electrostatic attraction (Figure 17). In addition, the literature showed that various characterization techniques supported fluoride adsorption through electrostatic, ion-exchange and hydrogen-bonding mechanisms [74][75][76]. The effect of pH showed that the adsorption capacity of Al-TDC increased signif- The three TDC-MOFs synthesized by Huang et al [63], i.e., Al-TDC, Ce-TDC and Zr-TDC, displayed high chemical stability in a wide pH range (4-10) when used for the treatment of constant 5 mg/L initial fluoride concentration.…”

Covalent immobilization of β-galactosidase using a novel carrier alginate/tea waste: statistical optimization of beads modification and reusability

“…Black tea contains structural proteins (soluble and insoluble), polysaccharides that dissolve in hot water [ 4 ]. Essentially, tea contains a variety of biologically active ingredients including methylxanthines, alkaloids (caffeine, theophylline, and theobromine), polyphenols (catechins, flavonoids, and proanthocyanidins), pigments, terpenoids, vitamins, amino acids, and polysaccharides [ 5 – 7 ]. Tea waste frequently contains nearly identical amounts of components as regular tea [ 8 ].…”