Table 5:
Natural gums and fibers for environmental bioremediation (heavy metals, organic dyes, radioactive materials and NPs)
| Gum-based Adsorbents (nanocomposite, hydrogels /NPs/fibers and membranes) |
Type of contaminants |
Adsorption capacity (mg/g), kinetic and adsorption models |
Adsorption/removal mechanisms |
References |
|---|---|---|---|---|
| GA/Fe3O4 | Cu2+ | 38.5; Langmuir isotherm and pseudo-2nd order kinetics | Complexation | (Banerjee and Chen, 2007a) |
| GK/PVA NF | Ag, Au and Pt NPs | 119 (Ag); 196 (Au) and 236 (Pt) | Functional group interactions | (Padil et al., 2015c) |
| GT/graphene oxide composite | Pd2+, Cd2+ and Ag+ | 142.50 (Pb2+), 112.50 (Cd2+) and 132.12(Ag+) pseudo-1st order kinetics, and Langmuir model. | Chemical reaction and mass transfer | (Sahraei and Ghaemy, 2017) |
| GT/Polyamidoxime nanohydrogel | Co2+, Zn2+, Cd2+ and Cr3+ | 100.0 (Co2+), 76.92 (Zn2+), 71.42 (Cr3+) and 66.67 (Cd2+); Temkin isotherm and pseudo-2nd order kinetics. | Metal- amidoxime/ GT chelating | (Masoumi and Ghaemy, 2014) |
| GT/ Fe3O4/poly(methyl methacrylate) NP | Cr 6+ | 7.64; Langmuir isotherm and pseudo-2nd order kinetics | Chemisorption | (Sadeghi et al., 2014) |
| GK | Hg 2+ | 62.5; Langmuir model and pseudo-2nd order kinetics | Micro-precipitation and ion-exchange process | (Vinod et al., 2011b) |
| GK/PAA/SiC NPs | Malachite green and rhodamine B | 757.57 (MG) and 497.51(RhB); Langmuir model and pseudo 2nd order kinetics | Physical adsorption controlled by diffusion | (Mittal et al., 2016) |
| GK/PAA-acrylamide/ SiO2 nanocomposite | Methylene blue | 1408.67; pseudo-2nd order kinetics, and Langmuir model | Physical adsorption plus electrostatic interactions | (Hemant Mittal et al., 2015a) |
| GK/PVA NF | Ag, Au, Pt, CuO and Fe3O4 NPs | 25.5 (Ag); 45.8 (Au); 51.5 (Pt); 7.5 (CuO); 5.2 (Fe3O4) |
Physisorption, interactions, complexation, | (Padil and Černík, 2015) |
| GK/PVA NF (plasma treated) |
Au, Ag, Pt, CuO and Fe3O4 NPs | 116 (Ag), 261.1 (Au), 289.8 (Pt), 66.3 (CuO) and 49.9 (Fe3O4); Langmuir model and pseudo-2nd order kinetics | Physisorption, interactions, complexation | (Padil and Černík, 2015) |
| KG | Pb2+, Cd2+, Ni2+, Cr3+, Cr6+, Fe2+, Co2+, Cu2+, Zn2+, As2+, Se2+, Hg2+ | Langmuir isotherm model and pseudo-2nd order kinetics | Physisorption, micro-precipitation and ion-exchange processes | ( Vinod et al., 2010a, 2010b; Vinod et al., 2009) |
| KG-nanocomposite | U6+ | 487; Langmuir isotherm model and pseudo-2nd order kinetics | Precipitation, ion exchange, complexation | (Sashidhar et al., 2015) |
| KG/Fe3O4 nanocomposite | Cd2+, Cu2+, Pb2+, Ni2+, Zn 2+, Hg 2+ | 106.8 (Cd2+), 56.6 (Pb2+), 85.9 (Cu2+), 49 (Ni2+), 37 (Zn2+) and 35 (Hg2+), Langmuir models | Interaction, physisorption | (Saravanan et al., 2012) |
| KG/PVA NF | Ag, Au and Pt NPs | 143.4 (Ag); 173.5 (Au) and 270.4 9 (Pt); Pseudo-2nd order kinetics | Functional group interaction | |
| GK- ZVI NPs | Cr3+ , Cr6+ and volatile organic compounds (cis-1,2-dichloroethene, perchloroethene and trichloroethene) | Complete degradation of Cr (Con. 10 ppm) and VOCs Pseudo-2nd order kinetics |
Functional group interaction | (Farooq et al., 2017) |
| GG/Pd NPs | G-250, methylene blue, methyl orange, and 4-nitrophenol | 150 μM (G-250), 62.5 μM (methylene blue), 30 μM (methyl orange) and 100 μM (4-nitrophenol) | Catalytic reduction | (Kora and Rastogi, 2015) |
| GG/PAA-co-acryl- amide /Fe3O4 NPs | Rhodamine B | 654.87; Langmuir model and pseudo-2nd order kinetics | Electrostatic attraction, and binding sites | (Mittal and Mishra, 2014) |