Table 3. Summary of adsorption performance of various adsorbents for the removal of Marine toxins from different matrices, including removal efficiency, isotherm and kinetic models, optimal operating conditions, maximum adsorption capacity (qmax), contact time, and reusabilitya.
| Adsorbent | Adsorbate | Matrix | Removal efficiency% | Isotherms/kinetics | Fitting model method | R 2 | Reusability | Optimal conditions | q max (mg g−1) | Contact time (min) | Ref. | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dose G | C 0 (mg L−1) | pH | Temp. K | |||||||||||
| Graphene nanoplatelets (GnPs) | Saxitoxin (STX) | Aqueous solution/simulated field water | >90 | Langmuir/pseudo-second-order (physisorption chemisorption) | Non-linear | — | — | 0.0020 | — | 7 | 298 | 0.05124 | 60 | 81 |
| Hydroxyl-modified peptidoglycan (HM-A4α) | Tetrodotoxin (TTX) | Fish muscle extract | 99.8 | Not specified | Not specified | Not specified | — | 0.003 | 5 | — | 310 | 0.00148 | 60 | 154 |
| Polyaluminium chloride-modified clay | Brevetoxin 2 | Aqueous solution | 98 | Freundlich/pseudo-second-order | Linear | 0.87 | Good (reusable for 3 cycles with some loss in efficiency) | 0.10 | 0.01 | 7.24 | 293 | 6.41 | 120 | 155 |
| Carboxyl-functionalized covalent organic polymer (TpPa-COOH) | Saxitoxin (STX) | Natural freshwater | ∼99.7 | Langmuir/pseudo-second-order (physisorption & chemisorption) | Linear | 0.99 | Good (reusable for at least 3 cycles) | 0.00011 | — | 6–7 | 292 | 5.69 | 60 | 156 |
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 means; standard deviations (±) are omitted to maintain table uniformity across the vast range of cited literature where such data was largely unavailable.