The adsorption capacity of magnetic chitosan and its derivatives for Pb(ii)a.
| Adsorbent | Ion concentration (mg L−1) | Adsorption capacity of Pb(ii) (mg g−1) | pH; temp. (°C) | Kinetic model | Isotherm model | Cycles | Advantages | Reference |
|---|---|---|---|---|---|---|---|---|
| MCS-Sch | 10 | 121.95 | 5; — | — | Freundlich | 7 | The simplicity and minimum usage of the toxic compounds | 113 |
| TEPA/CS/CoFe2O4 | 200 | 228.3 | 5; 30 | Pseudosecond-order | Langmuir | — | High magnetization, efficient adsorption performance | 114 |
| MCS-PAA | 100 | 204.89 | 6; — | Pseudosecond-order | Langmuir | 5 | Excellent acid resistance | 115 |
| (Fe3O4/CS-Se)2 | 100 | 100.3 | 6; — | — | — | 4 | Easy to separate, short extraction times and less adsorbent | 116 |
| HA-MG-CH | 150 | 144.41 | 5; 25 | Pseudosecond-order | Sips | 5 | Effective reduction of metal ions below allowable levels | 117 |
| Pb(ii)-IMB | 200 | 69.48 | 5; — | Pseudosecond-order | Langmuir | 5 | Efficient adsorption, good selectivity, and convenient magnetic separation | 118 |
| CH-MNP-CA | — | 192.308 | 6.1; — | Pseudosecond-order | Langmuir | 5 | No secondary waste production, high saturation magnetization | 119 |
| MGC | 25 | 60.60 | 7; 60 | Pseudosecond-order | Langmuir | — | Applied to two fields with good adsorption performance | 120 |
| P-MCS | 40 | 151.06 | 6; 45 | Pseudosecond-order | Langmuir | 5 | Excellent magnetic separation and regeneration performance, cost savings | 121 |
| FFO@Sil@Chi-DTPA | — | 322.58 | 6; — | Pseudosecond-order | Langmuir | — | Excellent selective adsorption of multiple pollutants | 122 |
| CHT/ALG/Fe3O4@SiO2 | 180 | 234.77 | 4.2; 20 | Elovich | Langmuir | Simple and innovative preparation, stable in acid water system | 123 | |
| MCF3DG | 16 | — | 8.5; — | — | — | 5 | Lightweight with good strength and weight resistance, good magnetic response, non-toxic properties | 124 |
Abbreviations: MCS-Sch: magnetic chitosan-(d-glucosamine methyl)benzaldehyde; MCS-PAA: polyacrylic acid grafted magnetic chitosan nanocomposite; (Fe3O4/CS-Se)2: diphenyl diselenide onto chitosan carrying magnetite (Fe3O4) nanoparticles; HA-MG-CH: grafted hydrazinyl amine magnetite-chitosan; Pb(ii)-IMB: lead-ion-imprinted magnetic biosorbent; CH-MNP-CA: chitosan-conjugated magnetite nanobiocomposite; MGC: magnetic nanobiocomposite based on activated chitosan-magnetic guanidinylated chitosan nanobiocomposite; P-MCS: phosphorylated magnetic chitosan composite; FFO@Sil@Chi-DTPA: DTPA-modified chitosan-coated magnetic silica nanoparticle; CHT/ALG/Fe3O4@SiO2: magnetic chitosan/alginate/Fe3O4@SiO2 hydrogel composites; MCF3DG: novel magnetic three-dimensional graphene/chitosan/nickel ferrite nanocomposite.