## 3 Adsorption of Model Compounds by Eggshell Biocomposite Adsorbents
### Temperature Effects and Thermodynamic Parameters
& [64] \\ \hline Methyl red dye (MR) & ESP & pH 2; 180 min; 208 g/300 mL; 20 mg/L dye solution; 208-328 K & 1.66 & Langmuir and PSO & \(\Delta\text{H}^{\text{S}}\) = +, AS\({}^{\text{S}}\) = +, \\ \hline Remazol red & Eggshell & pH 1; 180 min, 208 dye matrix of alginate and poly vinyl alcohol & 46.9 & Freundlich and PSO & \(\Delta\text{H}^{\text{S}}\) = -, AS\({}^{\text{S}}\) = -, [7] ** \\ \hline  & & pH 6; 700 rpm; 293 K; 20 mg/L dye level; 1.5 g/100 mL solution & 9.94 & Langmuir and PSO & Photocatalytic degradation with P25 [53] \\ \hline Reactive yellow 145 (RY 145), & ESP & pH 2, RY145, 150 mg/L; 150 mg/L; 80 min; 101.5 for Cu & 88.45 for RY145 101.5 for Cu & Freundlich, Sips, Redlich-Peterson, D-R, and PSO & \(\Delta\text{H}^{\text{S}}\) = +, AS\({}^{\text{S}}\) = -, [50] \\ \hline Malathion & CES & 0.6 g, 100 mL, 300 ppm, pH 6, 2 h & 318.5 & Langmuir and PSO & Above 90\% desorption was achieved at 500 \({}^{\circ}\)C until after the third cycle & [21] \\ \hline  & & pH 7, 20 ppm, 50 mg, 50 mg, 15 min for MB & 17.35 MB, 1622 TB & PSO & 83\% degradation efficiency obtained at the 5 th cycle with acetone. Photodegradation was employed; Chitosan-ESP showed reduced & [59] \\ \hline Phenol & ESP & 3.5 g, pH 9, 25 \({}^{\circ}\)C, 15 mg/L & 0.45 & Freundlich and PSO & \(\Delta\text{H}^{\text{S}}\) = -, AS\({}^{\text{S}}\) = +, [52] \\ \hline
2,4- & & 5 mg, 30 mL, 100 mg/L, 24-DCP\({}_{2}\) (RhB); 120 min, 30 mg/L & 540, 600, 420, 510 & & \\ ciprofloxacin & CES & 100 mg/L, 24-DCP\({}_{2}\) (ClP); tetracycline & 120 min, 30 mg/L & and 570 was obtained for & 70\% removal with ethanol and could increase to 80\% after recalculation at & [69] \\ HCl (TCH); & & persulphate & 2.4-DCP, RhB, CIP, TCH and Ph, 24-DCP, RhB, CIP, TCH and Ph, 24-DCP, RhB, CIP, TCH and Ph, respectively & & 500 \({}^{\circ}\)C for 2 h \\ \hline Phenol & CES without & & & & \\  & membrane & 500 mg, 50 mL, 300  
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**Pollutants** & **Adsorbents** & **Adsorption** & **\(q_{e}\)** & **Equilibriumand** & **Remarks** & **Ref. ** \\  & & **Parameters** & **(mg/g)** & **Kinetic Models** & **Ref. ** \\ \hline \multirow{4}{*}{Pb\({}^{2+}\), Cu\({}^{2+}\)} & ESP, banana peel powder (BPP) & pH 7, 0.1 g, 90 min, 100 mL, 5 ppm, 100 rpm & Not reported (NR) & NR & Pb\({}^{2+}\) had higher adsorption than Cu\({}^{2+}\) & [72] \\  & Pumpkin powder & 5 ppm, 100 rpm & (NR) & NR & Cu\({}^{2+}\) & \\ \hline \multirow{4}{*}{Al\({}^{3+}\), Fe\({}^{2+}\), and Zn\({}^{2+}\)} & ESP, membrane biological reactor (MBR) & 12 ppm Zn\({}^{2+}\), 6 ppm Al\({}^{3+}\) and 6 ppm Fe\({}^{2+}\), 2 h, 5 ppm 25 \({}^{\circ}\)C & & & \\  & & & & & \\  & & & & & \\ \hline \multirow{4}{*}{Pb\({}^{2+}\), Cu\({}^{2+}\), Zn\({}^{2+}\), Cd\({}^{2+}\), & Chitosan (Ch), sugar beet factory & 0.01 Cd\({}^{2+}\), 8.1 Cu\({}^{2+}\), 2.2 Zn\({}^{2+}\), Pb\({}^{2+}\)} & Freundlich and PSO & Cd\({}^{2+}\) removal was higher in HK and Ch & [107] \\  & potassium (HK) & & was not detected & Ch & \\ \hline \multirow{4}{*}{Fe\({}^{3+}\), Cu\({}^{2+}\), Zn\({}^{2+}\), Ca\({}^{2+}\), & Calciened & & 6.25 Cu\({}^{2+}\), 5.29 Zn\({}^{  
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The bulk of the literature examined in this review focused solely on single component adsorbate systems. In environmental and industrial wastewater, the role of multicomponent species can affect the adsorption efficiency of other ions due to competitive adsorption. For example, the presence of chloride ions in the solution, especially at higher concentration, negatively affected the removal of nitrate ions due to the competitive effects for similar active sites on the adsorbent surface [42]. [PERSON] et al. [113] reported that chloride ions are able to adsorb quickly onto the available sorption sites, thereby increasing the electrostatic repulsion forces between nitrate and the sorbent. Competitive ions in solution drastically reduced the distribution coefficient (Kd) of the metal ions when compared to single component metal ion systems.