1. V. Geissen, H. Mol, E. Klumpp, G. Umlauf, M. Nadal, M. van der Ploeg, S.E.A.T.M. van de Zee, C.J. Ritsema, Emerging pollutants in the environment: a challenge for water resource management, Int. Soil Water Conserv. Res., 3 (2015) 57–65.
  2. B. Medjahed, M.A. Didi, B. Guezzen, Optimization study of adsorption of nickel(II) on bentonite, World Acad. Sci. Eng. Technol., Int. J. Chem. Mol. Eng., 12 (2018) 134–138.
  3. B. Das, N.K. Mondal, P. Roy, S. Chattaraj, Equilibrium, kinetic and thermodynamic study on chromium(VI) removal from aqueous solution using Pistia stratiotes biomass, Chem. Sci. Trans., 2 (2013) 85–104.
  4. P.R. Choudhury, P. Bhattacharya, S. Ghosh, S. Majumdar, S. Saha, G.C. Sahoo, Removal of Cr(VI) by synthesized titania embedded dead yeast nanocomposite: optimization and modeling by reponse surface methoology, J. Environ. Chem. Eng., 5 (2017) 214–221.
  5. N.R. Bourestan, A. Nematollahzadeh, A.P. Jadid, H. Basharnavaz, Chromium removal from water using granular ferric hydroxide adsorbents: an in-depth adsorption investigation and the optimization, Chem. Phys. Lett., 748 (2020) 137395, doi: 10.1016/j.cplett.2020.137395.
  6. Iarc Monograhs On The Evaluation Of Carcinogenic Risks To Humans, Chromium, Nickel and Welding, Vol. 49, International Agency for Research on Cancer 1990, World Health Organization, Lyon-France, ISBN 92 832 1249 5. ISSN 0250-9555.
  7. L. Escudero-Castejón, J. Taylor, S. Sánchez-Segado, A. Jha, A novel reductive alkali roasting of chromite ores for carcinogen-free Cr6+-ion extraction of chromium oxide (Cr2O3) – a clean route to chromium product manufacturing!, J. Hazard. Mater., 403 (2021) 123589, doi: 10.1016/j.jhazmat.2020. 123589.
  8. R.A. Kumbasar, Studies on extraction of chromium(VI) from acidic solutions containing various metal ions by emulsion liquid membrane using Alamine 336 as extractant, J. Membr. Sci., 325 (2008) 460–466.
  9. R.A. Kumbasar, Selective extraction of chromium(VI) from multicomponent acidic solutions by emulsion liquid membranes using tributhylphosphate as carrier, J. Hazard. Mater., 178 (2010) 875–882.
  10. M. Rajasimman, R. Sangeetha, P. Karthik, Statistical optimization of process parameters for the extraction of chromium(VI) from pharmaceutical wastewater by emulsion liquid membrane, Chem. Eng. J., 150 (2009) 275–279.
  11. S. Kalidhasan, N. Rajesh, Simple and selective extraction process for chromium(VI) in industrial wastewater, J. Hazard. Mater., 170 (2009) 1079–1085.
  12. P. Sun, K. Huang, X. Wang, N. Sui, J. Lin, W. Cao, H. Liu, Chin, Three-liquid-phase extraction and separation of V(V) and Cr(VI) from acidic leach solutions of high-chromium vanadium–titanium magnetite, J. Chem. Eng., 26 (2018) 1451–1457.
  13. A. Béni, D. Nagy, S. Kapitány, J. Posta, Separation/preconcentration of chromium species with continuous liquid-liquid extraction device and its determination by AAS, Microchem. J., 150 (2019) 104077, doi: 10.1016/j.microc.2019.104077.
  14. M. Sattari-Najafabadi, M. Nasr Esfahany, Hexavalent chromium extraction from aqueous solutions in a liquid-liquid slug flow microreactor, Chem. Eng. Process. Process Intensif., 157 (2020) 108156, doi: 10.1016/j.cep.2020.108156.
  15. N. Rajesh, B.G. Mishra, P.K. Pareek, Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on a mixed bed adsorbent (acid activated montmorillonite–silica gel) column, Spectrochim. Acta, Part A, 69 (2008) 612–618.
  16. N. Rajesh, R.K. Jalan, P. Hotwany, Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column, J. Hazard. Mater., 150 (2008) 723–727.
  17. N. Rajesh, B. Deepthi, A. Subramaniam, Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its ionassociation complex with cetyltrimethylammoniumbromide on an alumina column, J. Hazard. Mater., 144 (2007) 464–469.
  18. V.M. Nik, E. Konoz, A. Feizbakhsh, A. Abdullah, M. Sharif, Simultaneous extraction of chromium and cadmium from bean samples by SrFe12O19@CTAB magnetic nanoparticles and determination by ETAAS: an experimental design methodology, Microchem. J., 159 (2020) 105588, doi: 10.1016/j.microc.2020.105588.
  19. J. Noro, K. Maruyama, Y. Komatsu, Separation of chromium(III) and chromium(VI) by the combination of solvent and ion exchange methods, Anal. Sci., 17 (2001) 1333–1336.
  20. L. Gzara, M. Dhahbi, Removal of chromate anions by micellar-enhanced ultrafiltration using cationic surfactants, Desalination, 137 (2000) 241–250.
  21. A. Hafiane, D. Lemordant, M. Dhahbi, Removal of hexavalent chromium by nanofiltration, Desalination, 130 (2000) 305–312.
  22. A. Oussalah, A. Boukerroui, A. Aichour, B. Djellouli, Cationic and anionic dyes removal by low-cost hybrid alginate/natural bentonite composite beads: adsorption and reusability studies, Int. J. Biol. Macromol., 124 (2019) 854–862.
  23. M.A. Didi, B. Makhoukhi, A. Azzouz, D. Villemin, Colza oil bleaching through optimized acid activation of bentonite - a comparative study, Appl. Clay Sci., 42 (2009) 336–344.
  24. B. Makhoukhi, M.A. Didi, D. Villemin, A. Azzouz, Acid activation of bentonite for use as a vegetable oil bleaching agent, Grasas Y Aceites, 60 (2009) 343–349.
  25. B. Makhoukhi, M.A. Didi, H. Moulessehoul, A. Azzouz, D. Villemin, Diphosphonium ion-exchanged montmorillonite for telon dye removal from aqueous media, Appl. Clay Sci., 50 (2010) 354–361.
  26. B. Makhoukhi, M.A. Didi, H. Moulessehoul, A. Azzouz, Telon dye removal from Cu(II)–containing aqueous media using p-diphosphonium organo-montmorillonite, Med. J. Chem., 2 (2011) 44–55.
  27. M.S. Phadke, 2nd ed., Pearson, United Kingdom, 2009.
  28. A. Kundu, B.S. Gupta, M.A. Hashim, G. Redzwan, Taguchi optimisation approach for chromium removal in a rotating packed bed contractor, J. Taiwan Inst. Chem. Eng., 57 (2015) 91–97.
  29. B. Naik, A.C. Reddy, Optimization of tensile strength in TIG welding using the Taguchi method and analysis of variance (ANOVA), Therm. Sci., 8 (2018) 327–339.
  30. S. Rao, P. Samant, A. Kadampatta, R. Shenoy, An overview of Taguchi method: evolution, concept and interdisciplinary applications, Int. J. Sci. Eng. Res., 4 (2013) 621–626.
  31. S.R. Korake, P.D. Jadhao, Investigation of Taguchi optimization, equilibrium isotherms, and kinetic modeling for cadmium adsorption onto deposited silt, Heliyon, 7 (2021) e05755, doi: 10.1016/j.heliyon.2020.e05755.
  32. R.A. Kumbasar, Extraction of chromium(VI) from multicomponent acidic solutions by emulsion liquid membranes using TOPO as extractant, J. Hazard. Mater., 167 (2009) 1141–1147.
  33. I. Puigdomenech, “HYDRA (Hydrochemical Equilibrium Constant Database) and MEDUSA (Make Equilibrium Diagrams Using Sophisticated Algorithms) Programs,” Royal Institute of Technology, Sweden. Available at http://www.kemi.
  34. A. Mansri, K.I. Benabadji, J. Desbrières, J. François, Chromium removal using modified poly(4-vinylpyridinium) bentonite salts, Desalination, 245 (2009) 95–107.
  35. M.K. Dahri, M.R.R. Kooh, L.B.L. Lim, Application of Casuarina equisetifolia needle for the removal of methylene blue and malachite green dyes from aqueous solution, Alex. Eng. J., 54 (2015) 1253–1263.
  36. B.H. Hameed, M.I. El-Khaiary, Equilibrium, kinetics and mechanism of malachite green adsorption on activated carbon prepared from bamboo by K2CO3 activation and subsequent gasification with CO2, J. Hazard. Mater., 157 (2008) 344–351.
  37. S. Abera, D. Salari, M.R. Parsa, Employing the Taguchi method to obtain the optimum conditions of coagulation–flocculation process in tannery wastewater treatment, Chem. Eng. J., 162 (2010) 127–134.
  38. Z. Sefrou, N.E. Belkhouche, Cloud point extraction of La(III) by C13E10 non-ionic surfactant: statistical refinement of experimental optimization by L9 Taguchi’s design, Chem. Eng. Res. Des., 153 (2020) 819–828.