Table 2. Summary of adsorption performance of various adsorbents in aqueous matrix for the removal of dyes from different matrices, including removal efficiency, isotherm and kinetic models, optimal operating conditions, maximum adsorption capacity (qmax) and contact timea.
| Adsorbent | Adsorbate | Optimal condition for adsorbate | q max (mg g−1) | Contact time (min) | Removal efficiency (%) | Isotherms/kinetics | Model fitting method | R 2 (isotherm model) | Ref. | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dose G | C 0 (mg L−1) | pH | Temp. K | |||||||||
| Ziziphus spina-christi seeds AC | Methylene blue | 0.6 | 500 | — | — | 666.66 | 30 | 98.62 | Langmuir/pseudo-second order | Linear | 0.986 | 42 |
| Moringa stenopetale seed husk AC | Methylene blue | 0.055 | 316 | — | — | 436.68 | 19.3 | 99.4 | 0.954 | |||
| Burmese grape seeds AC | Methylene blue | — | 60 | — | — | 163.9 | 40 | Not specified | 0.983 | |||
| Commercial granular activated carbon (GAC) | Tartrazine | 2 | 5 | 2 | 296 | 10.20 | 60 | 99.81 | Langmuir/Pseudo-second-order | Linear | 0.993 | 43 |
| Rice husk (RH) | 4 | 5 | 2 | 296 | 6.87 | 120 | 90.45 | 0.983 | ||||
| Framework@calcium alginate aerogel composite sponge | Tartrazine | 0.02 | — | 4 | 328 | 710.75 | 100 | Up to 98.7 | Langmuir/pseudo-second-order | Non-linear | — | 63 |
| Spent coffee ground biochar (SCGB) | Remazol Brilliant Blue R (RBBR) | 0.20 | 74.7 | 2 | — | Not specified | 120 | 95.4 | Not specified | Not specified | Not specified | 67 |
| NiFe-layered double hydroxide supported metal–organic framework-embedded alginate bead composite | Tartrazine | 1.33 mg mL−1 | 8.02 | 3.74 | ∼298 | Not specified | 283 | 94.82 | Langmuir–Freundlich/pseudo-second-order | Non-linear | — | 110 |
| Orange peel powder (sulfuric acid activated) | Tartrazine | 0.2 | 40 | 3 | 298 | 122.25 | ∼20 | Not specified | Temkin/pseudo-second-order | Linear | 0.999 | 113 |
| Orange peel powder (thermally activated) | 121.74 | 0.999 | ||||||||||
| Orange peel powder (soda activated) | 116.35 | 0.999 | ||||||||||
| Surfactant-modified zeolite (SMZ-CPC) | 0.08 | 30 | 10 | 298 | 5.06 | 30 | > 94 | Sips/Elovich | Non-linear | — | 118 | |
| Magnetite@PEI (Fe3O4@PEI) | Ponceau 4R | 0.0026 | — | 5–10 | 298 | 204 | 5 | 95–99 | Langmuir/pseudo-second-order | Linear | 0.992 | 119 |
| Magnetite@chitosan (Fe3O4@CS) | Azorubine | 0.0029 | 5–8 | 298 | 142 | 10 | 95–99 | 0.996 | ||||
| Polyamide (PA) nanofibers | Sunset yellow | ∼20 | — | 3 | 298 | 39 | 30 | ∼95 | 0.999 | |||
| Magnetic chitosan composite (m-CS-c-PAM) | Sunset yellow | 1 | 20 | — | 298 | 359.71 | 60 | Not specified | Langmuir/pseudo-second order | Linear | Not specified | 120 |
| Chitosan-vermiculite beads | Brilliant blue | 5 g L−1 | 500 | 10.9 | 298 | 181.6 | 1440 | |||||
| Brewers' spent grains-activated carbon | Tartrazine | 2 | 10 | 3 | 308 | 32.15 | 60 | 100 | Langmuir/Elovich | Linear | Not specified | |
| Gelatin/montmorillonite nanocomposite | Malachite green | — | 350 | 9 | — | 950.5 | 45 | Not specified | Langmuir isotherm | Non-linear | — | 121 |
| Graphene/ZnO/hydroxyapatite nanocomposite | Azo dyes | — | — | — | — | 700 | 4 | 94.8–96.5 | Langmuir/chemisorption | Linear | 0.982 | 122 |
| Carbonized bamboo leaves powder (citric acid treated) | Methylene blue | 0.2 | 400 | 7.5 | 305 | 725 | 60 | Not specified | Langmuir | Linear | Not specified | 123 |
| Spent tea leaves | 0.7 | 65 | 9 | 303 | 300.05 | 120 | Not specified | Not specified | Not specified | |||
| Michelia figo leaves (MFL) | — | 200 | 11 | 298 | 238.10 | 180 | Langmuir/pseudo second order | Linear | Not specified | |||
| Cassava sievate biomass AC | Tartrazine | 0.1 | 150 | 1–2 | 303–313 | 20.83 | 90 | Not specified | Freundlich/pseudo-second-order | Linear | 0.999 | 124 |
| Sunset yellow | 0.091 | 0.926 | ||||||||||
| Zinc–aluminum layered double hydroxide (Zn–Al-LDH) | Tartrazine | 0.4 | 40 | 5.8 | 298 | 282.48 | 60 | 96.83 | Langmuir/pseudo-second-order | Linear | 0.990 | 125 |
| Polyamidoamine (PAMAM) dendrimer gel | 0.02 | 1500 | 7 | 293 | 689.7 | 60 | Not specified | Langmuir/pseudo-second-order | Linear | >0.980 | ||
| AF-CMS (amine-functionalized cellulose microGraphenes) | — | 500 | 4 | 318 | 618.65 | 30 | >0.990 | |||||
| Layered double hydroxide/Diatomite (LDH/DIA) | 0.01 | 20 | 8 | 293 | 555.6 | 60 | 0.990 | |||||
| Magnesium aluminum azelate layered double hydroxide | Tartrazine | 0.1 | — | ∼298 | 173.2 | 1440 (24 h) | 99.9 | Langmuir | Linear | 0.999 | 126 | |
| β-cyclodextrin/chitosan/PVA composite hydrogel film | Tartrazine | 0.005 | — | 20 mg L−1 | ∼298 | 1436.04 | 180 | 96.3 | Langmuir/pseudo-second-order | Non-linear | — | 127 |
| β-Cyclodextrin/chitosan/PVA composite hydrogel film | Congo red | 0.01 | 7 | ∼298 | 366.34 | 120 | 95.38 | — | ||||
| Activated carbon from bovine rumen waste | Tartrazine | 0.025 | — | 3 | 318.15 | 111.90 | 60 | 99.96 | Freundlich/pseudo-first-order | Non-linear | — | 128 |
| Silica xerogel modified with cetyltrimethylammonium bromide (SiO2-CTAB) | Tartrazine | 0.020 | — | 6.8 | 297 | 9.62 | 60 | Not specified | Langmuir/pseudo-second-order | Linear | 0.740 | 129 |
| Dialdehyde-functionalized nanocellulose fibrils/chitosan/aminated metal–organic framework aerogel (NDC) | Tartrazine | 0.5 g L−1 | 100 | 3 | 303 | 689.66 | 720 | 98.56 | Langmuir/Pseudo-second-order | Non-linear | — | 130 |
| EGDE-crosslinked chitosan film (0.32 mm thickness) | Tartrazine | 0.024–0.030 | — | 2.5 | 303 | 873.37 | 1500 | Not specified | Sips/pseudo-first-order | Non-linear | — | 131 |
| Manganese–iron layered double hydroxide modified polyvinylidene fluoride (PVDF) polymer membrane | Tartrazine | 0.015 | 16 | 5 | ∼298 | 20.97 | 15 | 94.74 | Langmuir/pseudo-first-order | Linear | 0.963 | 132 |
| Manganese–iron layered double hydroxide modified polyviylidene fluoride (PVDF) polymer membrane | Erythrosine B | 0.015 | 13 | 13 mgL−1 | ∼298 | 6.15 | 15 | 92.13 | 0.996 | |||
| Magnetic graphene oxide-semicarbazide (MGO-Se) | Tartrazine | 2 | 50 | 3.5 | 298 | 33.2 | 9 | 91.7 | Langmuir/pseudo-second-order | Linear | 0.998 | 133 |
| Magnetic graphene oxide-semicarbazide (MGO-Se) | Sunset yellow | 2 | 50 | 3.5 | 298 | 29.8 | 9 | 92.8 | 0.991 | |||
| Sweet potato residue-derived activated carbon (SPAC) | Carmine | 0.1 | 5–70 | 7 | 323 | 468.1 | 180 | Not specified | Sips/pseudo-second-order | Non-linear | — | 134 |
| Tartrazine | 5–250 | 323 | 267.4 | — | ||||||||
| Allura red AC | 5–70 | 323 | 252.6 | — | ||||||||
| Treated avocado seed (TAS) | Basic yellow 28 | 0.075 | — | 10 | 293–323 | 49.30 | 60 | 89.93 | Temkin/pseudo-second-order | Non-linear | — | 135 |
| Iron doped activated carbon from Delonix regia bark | Methylene blue | 1 | 50–250 | 6 | 298 | 357.14 | 90 | >99 | Langmuir/pseudo-second-order | Linear | 0.998 | 136 |
| Iron doped activated carbon from Delonix regia bark | Tartrazine | 1 | 50–250 | 3 | 298 | 147.06 | 60 | >98 | 0.999 | |||
| Cola nut shell AC (phosphoric acid activation) (potassium hydroxide activation) | Tartrazine | 0.5 | 5–30 | 2 | ∼298 | 24.57 | 5 | Not specified | Langmuir/pseudo-second-order | Linear | 0.981 | 137 |
| 0.5 | 5–30 | 2 | ∼298 | 21.60 | 10 | Not specified | 0.982 | |||||
| Doum palm seed shell activated carbon | Rhodamine B | 1 | — | 10 | 303 | 88.40 | 40 | Not specified | Freundlich/pseudo-second-order | Linear | 0.99 | 138 |
| Methylene blue | — | 12 | 333 | 81.81 | 30 | 0.98 | ||||||
| Methyl orange | — | 2 | 333 | 73.38 | 90 | 0.97 | ||||||
| Cobalt-impregnated clinoptilolite (15% co) | Lanaset green B | — | ∼7 | 298 | 152.51 | 60 | Langmuir/pseudo-second-order | Non-linear | Not specified (standard error) σ = 0.001–0.019 | |||
| Fly ash/polyacrylic acid/melamine (FA/PAA/M) composite | Sudan II | 1–30 | 2–8 | 296 | 142.3 | ∼70 | 95 (1st cycle) | Langmuir/pseudo-second-order | Non-linear | — | 139 | |
| ZnO–Al2O3-rGO/MWCNT (photocatalyst/Adsorbent) | Sudan III | 0.6 | — | 5.5 | 298 | 220 | ∼90 | >98% (calculated from qmax) | Langmuir/pseudo-second-order | Non-linear | — | 140 |
| Nelumbinis stamen activated carbon (NSAC) | Sudan red G | 0.4 | 5–15 | 3 | 323 | 36.19 | 16 | 92.13 | Langmuir/pseudo-second-order | Linear | 0.988 | 141 |
| Nelumbinis stamen activated carbon (NSAC) | Sudan I | 35.64 | 95.57 | 0.974 | ||||||||
| Nelumbinis stamen activated carbon (NSAC) | Sudan II | 34.60 | 90.06 | 0.961 | ||||||||
| Nelumbinis stamen activated carbon (NSAC) | Sudan red 7B | 38.97 | 91.75 | 0.994 | ||||||||
| Antimony-based ionic liquid (M–Sb) | Sudan II | 0.75 | 0.75 | — | — | 162.1 | 40 | >90 | Langmuir/pseudo-second-order | Non-linear | — | 142 |
| Bismuth-based ionic liquid (M–Bi) | — | — | 170.0 | — | ||||||||
| Pristine biochar from rice husk | Eriochrome Black T (EBT) | 1.5 | — | 2 | Not specified | 120 | 94 | Not specified | Not specified | Not specified | 143 | |
| Natural diatomite (ND) | Carmoisine | 1 | 50 | 2 | 290 | 12 | 30 | Not specified | Freundlich/pseudo-second-order | Linear | ∼0.99 | 144 |
| Graphene oxide-chitosan-Fe (GO-CS-Fe) nanocomposite | Sudan I | 1 | 350 | 4 | 310 | 360.6 | 90 | 99.1 | Langmuir/pseudo-second-order | Non-linear | — | 145 |
| Sudan II | 353.7 | 98.3 | — | |||||||||
| Sudan III | 351.0 | 97.7 | — | |||||||||
| Nanosized scoria | Carmoisine | 200 | 45 | 7 | 318 | 54.42 | 17 280 (12 days) | >95 | Not specified | Not specified | Not specified | 146 |
| Activated carbon from raphanus seeds solid residual (ACRS) | Methylene blue (MB) | 1 | 10 | 7 | 318 | 8.6 | 120 | ∼99 | Langmuir/pseudo-second-order | Linear | 0.968 | 147 |
| Graphene oxide-carboxymethyl cellulose-co-acrylamide (GO/P(CMC-Co-Am)) nanocomposite | Azure C (basic violet 3) | 1 | 50 | 5 | 290 | 9.14 | 120 | Not specified | No isotherm model applied/pseudo-second-order | Not specified | Not specified | 148 |
| Polyaniline/Bi2O3 (PANI/Bi2O3) nanocomposite | Alizarin red | 1 | 10 | 11.4 | 303 | 9.006 | 100 | 95 | Langmuir/pseudo-second-order | Non-linear | — | 149 |
| Forsterite nanoparticles | Evans blue | 1 | 10–99 | 3 | 42.3 | 10 | ∼100 | Langmuir/pseudo second-order | Linear | 0.996 | 150 | |
| Chrysotile | Methylene blue (MB) | 0.14 | 419 | 13 | 298 | 352.97 | 5.5 | ∼99 | Langmuir/pseudo-first-order | Non-linear | — | 151 |
| Lizardite | 0.1 | 449 | 254.85 | 15 | Freundlich/pseudo-first-order | — | ||||||
| Activated carbon from guava seeds | Tartrazine | 12 | 20 | 6.10 | 298 | 1.62 | 80 | 97.6 | Elovich/pseudo-second-order | Linear | 0.983 | 152 |
| Activated sawdust from pinus halepensis wood | 0.05 | — | 2 | 127.74 | 60 | 99.52 | Langmuir/pseudo-second-order | Non-linear | — | 153 | ||
a
All adsorption capacities are reported in mg g−1, and concentrations are expressed in mg L−1. Where necessary, units have been converted for consistency. ‘—’ indicates data not reported in the original study or R2 values omitted for non-linear entries to ensure comparability. Parameter estimation in the majority of cited literature is based on linear transformations; however, modern standards advocate for nonlinear fitting due to its higher reliability. As a comprehensive review, our primary goal is to compile and present the existing body of data as originally reported in the literature. To maintain data integrity while avoiding the mathematical inconsistency of comparing coefficients with different Y-axes, R2 values are listed only for linear isotherm studies. All cross-methodological evaluations of adsorbent performance are strictly based on absolute adsorption capacities(qmax). Values represent reported single values; standard deviations (±) are omitted to maintain table uniformity across the vast range of cited literature where such data was largely unavailable.