1. E. Repo, J.K. Warchol, T.A. Kurniawan, M.E. Sillanpää, Adsorption of Co(II) and Ni(II) by EDTA- and/or
    DTPA-modified chitosan: kinetic and equilibrium modeling, Chem. Eng. J., 161 (2010) 73–82.
  2. A.H. Shalla, Z. Yaseen, M.A. Bhat, T.A. Rangreez, M. Maswal, Recent review for removal of metal ions by hydrogels, Sep. Sci. Technol., 54 (2019) 89–100.
  3. H. Masoumi, A. Ghaemi, H.G. Gilani, Evaluation of hypercross-linked polymers performances in the removal of hazardous heavy metal ions: a review, Sep. Purif. Technol., 260 (2021) 118221, doi: 10.1016/j.seppur.2020.118221.
  4. M. Agarwal, K. Singh, Heavy metal removal from wastewater using various adsorbents: a review, J. Water Reuse Desal., 7 (2017) 387–419.
  5. A. Shafique, Removal of toxic pollutants from aqueous medium through adsorption: a review, Desal. Water Treat., 234 (2021) 38–57.
  6. S. Martini, S. Afroze, K.A. Roni, M. Setiawati, D. Kharismadewi, A review of fruit waste-derived sorbents for dyes and metals removal from contaminated water and wastewater, Desal. Water Treat., 235 (2021) 300–323.
  7. Z. Al-Qodah, M.A. Yahya, M. Al-Shannag, On the performance of bioadsorption processes for heavy metal ions removal by low-cost agricultural and natural by-products bioadsorbent: a review, Desal. Water Treat., 85 (2017) 339–357.
  8. M. Nasrollahzadeh, M. Sajjadi, S. Iravani, R.S. Varma, Starch, cellulose, pectin, gum, alginate, chitin and chitosan derived (nano) materials for sustainable water treatment: a review, Carbohydr. Polym., 251 (2021) 116986, doi: 10.1016/j.carbpol.2020.116986.
  9. J. Kaur, P. Sengupta, S. Mukhopadhyay, Critical review of bioadsorption on modified cellulose and removal of divalent heavy metals (Cd, Pb, and Cu), Ind. Eng. Chem. Res., 61 (2022) 1921–1954.
  10. Z.A. Sutirman, M.M. Sanagi, W.I.W. Aini, Alginate-based adsorbents for removal of metal ions and radionuclides from aqueous solutions: a review, Int. J. Biol. Macromol., 174 (2021) 216–228.
  11. H.B. Quesada, T.P. de Araújo, D.T. Vareschini, M.A.S.D. de Barros, R.G. Gomes, R. Bergamasco, Chitosan, alginate and other macromolecules as activated carbon immobilizing agents: a review on composite adsorbents for the removal of water contaminants, Int. J. Biol. Macromol., 164 (2020) 2535–2549.
  12. H. Musarurwa, N.T. Tavengwa, Application of carboxymethyl polysaccharides as bio-sorbents for the sequestration of heavy metals in aquatic environments, Carbohydr. Polym., 237 (2020) 116142, doi: 10.1016/j.carbpol.2020.116142.
  13. H. Javadian, M. Ruiz, T.A. Saleh, A.M. Sastre, Ca-alginate/carboxymethyl chitosan/Ni0.2Zn0.2Fe2.6O4 magnetic bionanocomposite: synthesis, characterization and application for single adsorption of Nd3+, Tb3+, and Dy3+ rare earth elements from aqueous media, J. Mol. Liq., 306 (2020) 112760, doi: 10.1016/j.molliq.2020.112760.
  14. Q. Song, J. Gao, Y. Lin, Z. Zhang, Y. Xiang, Synthesis of crosslinking chitosan-PVA composite hydrogel and adsorption of Cu(II) ions, Water Sci. Technol., 81 (2020) 1063–1070.
  15. X. Gao, C. Guo, J. Hao, Z. Zhao, H. Long, M. Li, Adsorption of heavy metal ions by sodium alginate-based adsorbent-a review and new perspectives, Int. J. Biol. Macromol., 164 (2020) 4423–4434.
  16. H. Wang, Y. Wang, C. Li, L. Jia, Fabrication of eco-friendly calcium cross-linked alginate electrospun nanofibres for rapid and efficient removal of Cu(II), Int. J. Biol. Macromol., 219 (2022) 1–10.
  17. Y. Na, J. Lee, S.H. Lee, P. Kumar, J.H. Kim, R. Patel, Removal of heavy metals by polysaccharide: a review, Polym. Plast. Technol. Mater., 59 (2020) 1770–1790.
  18. P.M. Pakdel, S.J. Peighambardoust, Review on recent progress in chitosan-based hydrogels for wastewater treatment application, Carbohydr. Polym., 201 (2018) 264–279.
  19. H. Shehzad, E. Ahmed, A. Sharif, Z.H. Farooqi, M.I. Din, R. Begum, I. Nawaz, Modified alginate-chitosan-TiO2 composites for adsorptive removal of Ni(II) ions from aqueous medium, Int. J. Biol. Macromol., 194 (2022) 117–127.
  20. S. Potiwiput, H. Tan, G. Yuan, S. Li, T. Zhou, J. Li, Y. Chen, Dual-cross-linked alginate/carboxymethyl chitosan hydrogel containing in situ synthesized calcium phosphate particles for drug delivery application, Mater. Chem. Phys., 241 (2020) 122354, doi: 10.1016/j.matchemphys.2019.122354.
  21. X.G. Chen, H.J. Park, Chemical characteristics of O-carboxymethyl chitosans related to the preparation conditions, Carbohydr. Polym., 53 (2003) 355–359.
  22. X. Wang, H. Zhang, Q. He, H. Xing, K. Feng, F. Guo, W. Wang, Core-shell alginate beads as green reactor to synthesize grafted composite beads to efficiently boost single/co-adsorption of dyes and Pb(II), Int. J. Biol. Macromol., 206 (2022) 10–20.
  23. R. Benaddi, F. Aziz, H.K. El, N. Ouazzani, Adsorption and desorption studies of phenolic compounds on hydroxyapatitesodium alginate composite, Desal. Water Treat., 220 (2021) 297–308.
  24. W. Luo, Z. Bai, Y. Zhu, Comparison of Co(II) adsorption by a cross-linked carboxymethyl chitosan hydrogel and resin: behaviour and mechanism, New J. Chem., 41 (2017) 3487–3497.
  25. C.X. Wang, Q.P. Song, Removal of Cu(II) ions from aqueous solutions using N-carboxymethyl chitosan, Water Sci. Technol., 66 (2012) 2027–2032.
  26. W. Wang, Q. Lu, Z. Zhuo, W. Zhang, H. Liu, J. Zhang, T. Guerrero, Synthesis and characterization of recyclable
    O-carboxymethyl chitosan Schiff base for the effective removal of Cd(II) from aqueous solution, Desal. Water Treat., 189 (2020) 264–275.
  27. Y. Song, N. Wang, L.Y. Yang, Y.G. Wang, D. Yu, X.K. Ouyang, Facile fabrication of ZIF-8/calcium alginate microparticles for highly efficient adsorption of Pb(II) from aqueous solutions, Ind. Eng. Chem. Res., 58 (2019) 6394–6401.
  28. M. Hassan, R. Naidu, J. Du, F. Qi, M.A. Ahsan, Y. Liu, Magnetic responsive mesoporous alginate/β-cyclodextrin polymer beads enhance selectivity and adsorption of heavy metal ions, Int. J. Biol. Macromol., 207 (2022) 826–840.
  29. Y. Zhang, S. Lin, J. Qiao, D. Kołodyńska, Y. Ju, M. Zhang, D.D. Dionysiou, Malic acid-enhanced chitosan hydrogel beads (mCHBs) for the removal of Cr(VI) and Cu(II) from aqueous solution, Chem. Eng. J., 353 (2018) 225–236.
  30. E.I. Ugwu, A. Othmani, C.C. Nnaji, A review on zeolites as cost-effective adsorbents for removal of heavy metals from aqueous environment, Int. J. Environ. Sci. Technol., 19 (2022) 8061–8084.
  31. R.J. Kongarapu, A.K. Nayak, M.U. Khobragade, A. Pal, Surfactant bilayer on chitosan bead surface for enhanced Ni(II) adsorption, Sustain. Mater. Technol., 18 (2018) e00077, doi: 10.1016/j.susmat.2018.e00077.
  32. P. Yu, H.Q. Wang, R.Y. Bao, Z. Liu, W. Yang, B.H. Xie, M.B. Yang, Self-assembled sponge-like chitosan/reduced graphene oxide/montmorillonite composite hydrogels without cross-linking of chitosan for effective Cr(VI) sorption, ACS Sustainable Chem. Eng., 5 (2017) 1557–1566.
  33. M.J. Ahmed, B.H. Hameed, Insights into the isotherm and kinetic models for the co-adsorption of pharmaceuticals in the absence and presence of metal ions: a review, J. Environ. Manage., 252 (2019) 109617, doi: 10.1016/j.jenvman.2019.109617.
  34. T. Hu, Q. Liu, T. Gao, K. Dong, G. Wei, J. Yao, Facile preparation of tannic acid–poly(vinyl alcohol)/sodium alginate hydrogel beads for methylene blue removal from simulated solution, ACS Omega, 3 (2018) 7523–7531.
  35. T. Huang, Y.W. Shao, Q. Zhang, Y.F. Deng, Z.X. Liang, F.Z. Guo, Y. Wang, Chitosan-cross-linked graphene oxide/carboxymethyl cellulose aerogel globules with high structure stability in liquid and extremely high adsorption ability, ACS Sustainable Chem. Eng., 7 (2019) 8775–8788.
  36. J. Yuan, C. Yi, H. Jiang, F. Liu, G.J. Cheng, Direct ink writing of hierarchically porous cellulose/alginate monolithic hydrogel as a highly effective adsorbent for environmental applications, ACS Appl. Polym. Mater., 3 (2021) 699–709.
  37. W. Luo, Z. Bai, Y. Zhu, Fast removal of Co(II) from aqueous solution using porous carboxymethyl chitosan beads and its adsorption mechanism, RSC Adv., 8 (2018) 13370–13387.
  38. P. Zhang, K. Zou, L. Yuan, J. Liu, B. Liu, T.P. Qing, B. Feng, A biomass resource strategy for alginate-polyvinyl alcohol double network hydrogels and their adsorption to heavy metals, Sep. Purif. Technol., 301 (2022) 122050, doi: 10.1016/j.seppur.2022.122050.
  39. H. Luo, Y. Liu, H. Lu, Q. Fang, H. Rong, Efficient adsorption of tetracycline from aqueous solutions by modified alginate beads after the removal of Cu(II) ions, ACS Omega, 6 (2021) 6240–6251.
  40. Q. Liao, H. Rong, M. Zhao, H. Luo, Z. Chu, R. Wang, Strong adsorption properties and mechanism of action with regard to tetracycline adsorption of double-network polyvinyl alcoholcopper alginate gel beads, J. Hazard. Mater., 4229 (2022) 126863, doi: 10.1016/j.jhazmat.2021.126863.