Table 1 Summary of bio-adsorbents used for removal of salinity-causing ions
From: Bioadsorbents for the removal of salt ions from saline water: a comprehensive review
Bio-adsorbent used | Mode of study | Variation in parameter | Conditions of equilibrium for maximum removal efficiency | Maximum removal efficiency (%) | Maximum adsorption capacity | Reference |
|---|---|---|---|---|---|---|
E. crassipes | Batch | Dose: 1 to 6 g/50 ml Initial concentration: 100 to 200 mg/L of Cl- ions pH: 2 to 14 Contact time: 1 to 6 h | Dose = 4 g/50 ml Initial concentration = 150 mg/L pH = 6–7 Contact time = 4 h | 45% | NA | [38] |
Phyllanthus Emblica and Cynodan Dactylon | Batch | Dose: 0.2 to 1 g/200 ml Contact time: 15 to 240 min | For Phyllanthus Emblica: Contact time = 240 min Adsorbent dose = 1 g/200 ml Cynodan Dactylon: Contact time = 240 min Adsorbent Dose = 1 g/200 ml | For Phyllanthus Emblica: 56% Cynodan Dactylon: 44% | NA | [48] |
Parthenium (congress grass) | Batch | pH: 3 to 11 Initial concentration: 100 to 1000 mg/Lof Cl- ions Contact time: 10 to 240 min Dose: 1 to 7 g/L | Optimum pH = 7 Initial concentration = 100 mg/L Adsorbent dose = 1 g/L Contact time = 5 min | 88% | 24.39 mg/g | [35] |
Umbu seed (Spondndias tuberosas Arruda Câmara) | Batch | Initial Concentration: 100–300 mg/lL of NaCl synthetic sample Real water sample EC concentration = 1321–2280 μS/cm Contact time: 10, 20, 30 min, and 1, 2, 3 h Dose variation: up to 1 g/100 ml | Adsorbent dose = 1 g/100 mL Initial concentration: EC = 2280 μS/cm Contact time = 10 min | 39% | 250 mg/g | [79] |
Sugarcane Bagasse and Beet Pulp | Batch | pH: For Bagasse and Beet Pulp: pH = 2–10 For Bagasse: Dose = 0.1–4 g/50 mL for Beet Pulp: Dose = 0.1–2 g/50 mL Contact time = 10, 30, 45, 60, 90, and 120 min | For Bagasse: pH = 6, Adsorbent dose = 4 g/50 mL, CT = 120 min For Beet Pulp: pH = 10, Adsorbent dose = 2 g/50 mL, CT = 90 min | For Bagasse: 97.5% For Beet Pulp: 98.9% | NA | [44] |
Phragmites australis reed | Batch and Continuous | pH = 2 to 10 Dose = 2 to 10 g/L Contact time = 30 to 210 min Agitation speed = 100, 150, 200, and 3000 rpm Initial concentration = 2000 to 10,000 mg/L of NaCl | Contact time = 150 min pH = 4 and Adsorbent dose = 10 g/L Agitation speed = 300 rpm | 90% | 117.68 mg/g | [51] |
Cynodon dactylon based activated carbon | Batch | pH = 6–7 Initial Concentration = 2, 4, 6, 8, and 10 mg/L Temperature variation = 303, 313, 323, and 333 K Dose = 0.25 to 2.25 g/100 ml Particulate size =  > 53, 53–106, 106–150, 150–225, and 225–303 µm Contact time = 15–195 min | Initial Concentration = 3 mg/L of F− ions Adsorbent dose = 1.25 g/100 ml pH = 6–7 Agitation speed = 250 rpm Particle size = 53 µm Contact time = 105 min | 83.77% | 4.702 mg/g | [31] |