Figure 1.
Schematic illustration about the synthesis of zeolite NaX-UP.
Table 1.
Elemental compositions determined by XRF method.
| S. No. | Composition | XRF [% weight] |
|---|---|---|
| 1 | SiO2 | 32.05 |
| 2 | TiO2 | 0.04 |
| 3 | Al2O3 | 27.07 |
| 4 | Fe2O3 | 0.40 |
| 5 | MnO | 0.08 |
| 6 | MgO | 1.16 |
| 7 | CaO | 5.32 |
| 8 | K2O | 0.52 |
| 9 | Na2O | 8.81 |
| 10 | P2O5 | 0.07 |
| 11 | SO3 | 0.10 |
| 12 | LOI | 24.19 |
| Σ | 99.81 |
Figure 2.
As shown in (A) PEI-zeolite NSs alginate bead (dusky and colorless), (B) the bare Fe3O4 NPs were decorated on their surface of PEI-zeolite NSs alginate bead (magnetic alginate bead, black color).
Figure 3.
Schematic illustration for preparation of magnetic alginate bead (adsorbent).
Figure 4.
(A) BET adsorption isotherms of NaX-UP zeolites, (B) Pore size distribution of zeolites.
Table 2.
Surface area, pore volume and pore diameter of NaX-UP zeolites.
| S. No. | SBET (m2 g-1) | Vtot0.99 (cm3 g-1) | VmikDR (cm3 g-1) | VmezBJH (cm3 g-1) |
|---|---|---|---|---|
| 1 | 472.0 | 0.222 | 0.176 | 0.13 |
Figure 5.
(A, B, C and D) Powder XRD spectra for (A) NaX-UP zeolite, black line (B) PEI-modified NaX-UP zeolite NSs, brown line; (C) bare Fe3O4 NPs, navy blue line, (D) Fe3O4 NPs decorated PEI-modified NaX-UP zeolite, green line.
Figure 6.
HR-SEM images and EDS spectra of (A) the bare Fe3O4 NPs were decorated on their surface of PEI-zeolite NSs alginate bead adsorbent, (B and C) after sorption of As(V) & V(V). From (A, B, C) denoted as HR-SEM images, (D, E, F) EDS spectra.
Figure 7.
Alginate beads mediated sorption of As(V) and V(V), (A, B) adsorption isotherms modeling of PEI modified NaX-UP zeolite beads, PEI modified Fe3O4 NPs beads, and Fe3O4 NPs decorated PEI modified NaX-UP zeolite beads for (A) As(V) and (B) V(V); adsorption isotherms modeling fitting with the Freundlich model (A: navy blue line; B: dark green line) and Langmuir model (A: cyan line; B: sky blue line). (C, D) Kinetic sorption curves of the PEI modified NaX-UP zeolite beads, PEI modified Fe3O4 NPs beads, and Fe3O4 NPs decorated PEI modified NaX-UP zeolite beads for (C) As(V) and (D) V(V), modeling of kinetics sorption curves with the pseudo-first-order kinetics (C: sky blue line; D: dark yellow line) and pseudo-second-order kinetic (C: dark brown line; D: dark green line). (A, B) Beads-mediated sorption of As (V) and V(V), (C, D) Kinetic sorption curves of As (V) and V(V), PEI-zeolite NSs modified alginate beads, bare Fe3O4 NPs modified alginate beads, and bare Fe3O4NPs decorated on their surface of PEI-zeolite NSs modified alginate beads (1.0 g) were incubated with various concentration of As(V) and V(V) at pH 4.5 for isotherm studies (A, B) and (C, D) the alginate beads were incubated with 50 mg mL-1 of As(V) and V(V) various time interval from 0-240 min at 298 K.
Table 3.
Adsorption isotherm parameters for uptake of Arsenic(V) and Vanadium(V).
| Sl. No. | Adsorbent | Isotherm | Characteristic values | Uptake of As(V) | Uptake of V(V) |
|---|---|---|---|---|---|
| 1 | PEI-modified zeolite beads | Langmuir | qm (mg g-1) | 35.4 | 38.9 |
| b (L mg-1) | 0.014 | 0.014 | |||
| RL | 0.69 | 0.69 | |||
| Adj. R2 | 0.96 | 0.96 | |||
| 2 | PEI-modified zeolite beads | Freundlich | KF (mg 1-1/n g-1 L 1/n) | 0.40 | 0.44 |
| n | 1.08 | 1.08 | |||
| Adj R2 | 0.98 | 0.98 | |||
| 3 | PEI-modified Fe3O4 beads | Freundlich | KF (mg1-1/ng-1L1/n) | 1.008 | 0.68 |
| n | 1.08 | 1.02 | |||
| Adj R2 | 0.98 | 0.98 | |||
| 4 | PEI-modified Fe3O4 beads | Langmuir | qm (mg g-1) | 88.4 | 53.1 |
| b (L mg-1) | 0.01 | 0.02 | |||
| RL | 0.57 | 0.30 | |||
| Adj. R2 | 0.96 | 0.96 | |||
| 5 | Fe3O4 decorated PEI-modified zeolite beads | Langmuir | qm (mg g-1) | 163.9 | 151.5 |
| b (L mg-1) | 0.02 | 0.02 | |||
| RL | 0.25 | 0.25 | |||
| Adj. R2 | 0.96 | 0.96 | |||
| 6 | Fe3O4 decorated PEI-modified zeolite beads | Freundlich | KF (mg1-1/ng-1L1/n) | 2.09 | 1.93 |
| n | 1.08 | 1.08 | |||
| Adj R2 | 0.98 | 0.98 |
Table 4.
Arsenic (V) adsorption capacity of various adsorbents reported in the literature.
| Adsorption material | pH | qm (mg g-1) | Reference |
|---|---|---|---|
| Alginate@Iron-zirconium@Zeolite W | 2.0 | 42.3 | Abdellaoui et al. 2021 |
| Chitosan-coated Na–X zeolite | 2.0 | 63.2 | Han et al. 2019 |
| Zeolite@nanoscale zero-valent iron | 3.0 | 38.2 | Suazo-Hernandez et al. 2019 |
| Na-X zeolite derived from cola fly ash | 2.14 | 27.7 | Yang et al. 2019 |
| Nanozero valent iron (NZVI) loaded on zeolite 5A | 4-12 | 72.0 | Yang et al. 2022. |
| β-cyclodextrin modified graphene oxide @ Fe3O4 NPs | 4-7.2 | 99.5 | Santhana Krishna Kumar et al. 2017 |
| Iron oxide (hydr) modified zeolite | 3.5 | 1.69 | Nekhunguni et al. 2017 |
| Ferric hydroxide microcapsule-loaded alginate beads | - | 3.80 | Sarkar et al. 2010 |
| Calcium alginate beads@methionine magnetic NPs | 7-7.5 | 6.6 | Lilhare et al. 2021 |
| Aluminum(III) exchange synthetic zeolite | 3-10 | 10.5 | Xu et al. 2002 |
| Fe-treated synthetic zeolite | - | 22.5 | Dousova et al. 2006 |
| Cerium(III) exchange synthetic zeolite | - | 23.4 | Haron et al. 2008 |
| Synthetic zeolites | 3.2 | 35.8 | Chutia et al. 2009 |
| PEI-modified zeolite beads | 5-7.5 | 35.4 | This study |
| PEI-modified Fe3O4 beads | 5-7.5 | 88.4 | This study |
| Fe3O4 decorated PEI-modified zeolite beads | 5-7.5 | 163.9 | This study |
Table 5.
Vanadium adsorption capacity of various adsorbents reported in the literature.
| Adsorption material | pH | qm (mg g-1) | Reference |
|---|---|---|---|
| LDH supported nanoscale zero valent iron | 3.0 | 93.7 | Kong et al. 2020 |
| Magnetic zeolite–polypyrrole composite | 4-5 | 74.9 | Mthombeni et al. 2016 |
| Syrian natural zeolite | 6.0 | 40.0 | Salman et al. 2017 |
| Goethite | 4-8 | 8.2 | Zhu et al. 2020 |
| Clinoptilolite modified polypyrrole and iron oxide NPs | 4.5 | 12.0 | Mthombeni et al. 2018 |
| Synthesised zero-valent iron modified kaloin | 5.0 | 15.0 | Bello et al. 2019 |
| Octylamine functionalized magnetite NPs | 3.2 | 25.7 | Parijaee et al. 2014 |
| Zeolite A | 4.5 | 30.0 | Mahmood et al. 2019 |
| PGTFS-NH3+Cl- | 6.0 | 45.9 | Anirudhan et al. 2010 |
| Biochar stabilized nano zero-valent iron | 2-10 | 48.5 | Fan et al. 2020 |
| Metal (hydr)oxide adsorbents | 3-4 | 111.1 | Naeem et al. 2007 |
| PEI-modified zeolite beads | 5-7.5 | 38.9 | This study |
| PEI-modified Fe3O4 beads | 5-7.5 | 53.1 | This study |
| Fe3O4 decorated PEI-modified zeolite beads | 5-7.5 | 151.5 | This study |
Table 6.
Arsenic (V) equilibrium kinetics sorption, adsorption capacity of various adsorbents reported in the literature.
| Adsorption material | Equilibrium kinetics (Time in min) | qm (mg g-1) | Reference |
|---|---|---|---|
| Chitosan-coated Na–X zeolite | 720 min | 63.2 | Han et al. 2019 |
| Na-X zeolite derived from cola fly ash | 120 min | 27.7 | Yang et al. 2019 |
| Iron oxide (hydr) modified zeolite | 90 min | 1.69 | Nekhunguni et al. 2017 |
| Calcium alginate beads@Methionine magnetic NPs | 110 min | 6.6 | Lilhare et al. 2021 |
| Aluminum(III) exchange synthetic zeolite | 960 min | 10.5 | Xu et al. 2002 |
| Synthetic zeolites | 100 min | 35.8 | Chutia et al. 2009 |
| PEI-modified zeolite beads | 100 min | 35.4 | This study |
| PEI-modified Fe3O4 beads | 100 min | 88.4 | This study |
| Fe3O4 decorated PEI-modified zeolite beads | 100 min | 163.9 | This study |
Table 7.
Vanadium equilibrium kinetics sorption, adsorption capacity of various adsorbents reported in the literature.
| Adsorption material | Equilibrium kinetics (Time in hours) | qm (mg g-1) | Ref |
|---|---|---|---|
| Magnetic zeolite–polypyrrole composite | 4 hours | 74.9 | Mthombeni et al. 2016 |
| Goethite | 12 hours | 8.2 | Zhu et al. 2020 |
| Clinoptilolite modified polypyrrole and iron NPs | 14 hours | 12.0 | Mthombeni et al. 2018 |
| Synthesised zero-valent iron modified kaloin | 2 hours | 15.0 | Bello et al. 2019 |
| PGTFS-NH3+Cl- | 4 hours | 45.9 | Anirudhan et al. 2010 |
| PEI-modified zeolite beads | 1.5 hours | 38.9 | This study |
| PEI-modified Fe3O4 beads | 1.5 hours | 53.1 | This study |
| Fe3O4 decorated PEI-modified zeolite beads | 1.5 hours | 151.5 | This study |
Table 8.
Adsorption kinetics for uptake of Arsenic(V) and Vanadium(V)
| Sl. No | Adsorbent | Order of kinetics | Characteristic values | Uptake of As(V) | Uptake of Vanadium(V) |
|---|---|---|---|---|---|
| 1 | PEI-modified zeolite beads | Pseudo first order | qe (mg g-1) | 1.36 | 1.28 |
| k1 | 0.007 | 0.018 | |||
| Adj. R2 | 0.92 | 0.94 | |||
| 2 | PEI-modified zeolite beads | Pseudo second order | qe (mg g-1) | 28.4 | 23.2 |
| k2 | 0.0005 | 0.0008 | |||
| Adj R2 | 0.98 | 0.98 | |||
| 3 | PEI-modified Fe3O4 beads | Pseudo second order | qe (mg g-1) | 67.1 | 46.5 |
| k2 | 0.0002 | 0.0004 | |||
| Adj R2 | 0.98 | 0.98 | |||
| 4 | PEI-modified Fe3O4 beads | Pseudo first order | qe (mg g-1) | 1.66 | 1.58 |
| k1 | 0.016 | 0.019 | |||
| Adj. R2 | 0.96 | 0.94 | |||
| 5 | Fe3O4 decorated PEI-modified | Pseudo first order | qe (mg g-1) | 1.86 | 1.72 |
| zeolite beads | k1 | 0.014 | 0.02 | ||
| Adj. R2 | 0.94 | 0.94 | |||
| 6 | Fe3O4 decorated PEI-modified | Pseudo second order | qe (mg g-1) | 99.0 | 77.5 |
| zeolite beads | k2 | 0.0001 | 0.0002 | ||
| Adj R2 | 0.98 | 0.98 |
Figure 8.
(A, B, C) Van’t Hoff plot for the adsorption of As (V) and V (V) on the (A) PEI-zeolite NSs modified alginate beads, (B) Fe3O4 NPs modified alginate beads, and (C) Fe3O4 NPs decorated PEI modified zeolite NSs alginate beads. (A-C) The beads-related nanomaterials (1.0 g) were incubated with 50 mg mL-1 of As (V) and V (V) at 298, 308, 318, and 328 K for 0-240 min under pH 7.0 conditions.
Table 9.
Adsorption of thermodynamics for uptake of As(V) and V(V).
| S. No. | Adsorbent | Uptake of metals | ΔS0 J mol-1 | ΔH0 KJ mol-1 | ΔG0 KJ mol-1 | |||
|---|---|---|---|---|---|---|---|---|
| 298K | 308K | 318K | 328K | |||||
| 1 | PEI-Zeolite NSs | As(V) | 145.7 | 42.5 | −2.1245 | −3.9625 | −5.2465 | −6.8752 |
| beads | V(V) | 124.8 | 39.1 | −1.4523 | −2.2754 | −3.1465 | −4.1254 | |
| 2 | PEI-Fe3O4 NPs | As(V) | −121.3 | −37.2 | −6.8875 | −5.2354 | 4.26548 | −2.1256 |
| beads | V(V) | −91.3 | −26.7 | −4.2810 | −3.8965 | −2.23689 | −1.4689 | |
| 3 | PEI-Zeolite NSs@ | As(V) | −163.1 | −54.8 | −8.3567 | −7.3658 | −5.2136 | −2.8969 |
| Fe3O4 NPs beads | V(V) | −126.4 | −50.3 | −5.1209 | −3.6875 | −1.4232 | −2.0256 | |