References

1. F. Ge, M. Li, H. Ye, B. Zhao, Effective removal of heavy metal ions Cd²⁺, Zn²⁺, Pb²⁺, Cu²⁺ from aqueous solution by polymermodified magnetic nanoparticles, J. Hazard. Mater., 211–212 (2012) 366–372.
2. X. Zhang, S. Lin, X. Lu, Z. Chen, Removal of Pb(II) from water using synthesized kaolin supported nanoscale zero-valent iron, Chem. Eng. J., 163 (2010) 243–248.
3. R. Laus, V.T. De Fávere, Competitive adsorption of Cu(II) and Cd(II) ions by chitosan crosslinked with epichlorohydrintriphosphate, Bioresour. Technol., 102 (2011) 8769–8776.
4. L. Wang, L. Yang, Y. Li, Y. Zhang, X. Ma, Z. Ye, Study on adsorption mechanism of Pb (II) and Cu (II) in aqueous solution using PS-EDTA resin, Chem. Eng. J., 163 (2010) 364–372.
5. W. Yang, P. Ding, L. Zhou, J. Yu, X. Chen, F. Jiao, Preparation of diamine modified mesoporous silica on multi-walled carbon nanotubes for the adsorption of heavy metals in aqueous solution, Appl. Surf. Sci., 282 (2013) 38–45.
6. N.C. Dias, P.A. Steiner, M. Cristina, B. Braga, Characterization and modification of a clay mineral used in adsorption tests, J. Miner. Mater. Charact. Eng., 3 (2015) 277–288.
7. D. Mohan, K.P. Singh, Single- and multi-component adsorption of cadmium and zinc using activated carbon derived from bagasse - an agricultural waste, Water Res., 36 (2002) 2304–2318.
8. M.O. Ojemaye, O.O. Okoh, A.I. Okoh, Performance of NiFe₂O₄-SiO₂-TiO₂ magnetic photocatalyst for the effective photocatalytic reduction of Cr(VI) in aqueous solutions, J. Nanomater., 2017 (2017) 1–11.
9. H.S. El-Desoky, M.M. Ghoneim, R. El-Sheikh, N.M. Zidan, Oxidation of Levafix CA reactive azo-dyes in industrial wastewater of textile dyeing by electro-generated Fenton’s reagent, J. Hazard. Mater., 175 (2010) 858–865.
10. I.J. Vassilis, Ion exchange and adsorption fixed bed operations for wastewater treatment - Part I : modelling fundamentals and hydraulic analysis, J. Eng. Studies Res., 16 (2010) 29–41.
11. A.Y. Zahrim, N. Hilal, Treatment of highly concentrated dye solution by coagulation/flocculation-sand filtration and nanofiltration, Water Res. Ind., 3 (2013) 23–34.
12. M.A. Barakat, New trends in removing heavy metals from industrial wastewater, Arab. J. Chem., 4 (2011) 361–377.
13. M.O. Ojemaye, O.O. Okoh, A.I. Okoh, Adsorption of Cu²⁺ from aqueous solution by a novel material; azomethine functionalized magnetic nanoparticles, Sep. Purif. Technol., 183 (2017) 204–215.
14. I.A.A. Hamza, B.S. Martincigh, J.C. Ngila, V.O. Nyamori, Adsorption studies of aqueous Pb(II) onto a sugarcane bagasse/ multi-walled carbon nanotube composite, Phys. Chem. Earth, 66 (2013) 157–166.
15. L. Lin, X. Xu, C. Papelis, T.Y. Cath, P. Xu, Sorption of metals and metalloids from reverse osmosis concentrate on drinking water treatment solids, Sep. Purif. Technol., 134 (2014) 37–45.
16. L.G. Lv, G. Tsoi, X.S. Zhao, Uptake equilibria and mechanisms of heavy metal ions on microporous titanosilicate ETS-10, Ind. Eng. Chem. Res., 43 (2004) 7900–7906.
17. M. Abdel, G. Al-zhrani, S.A. Kosa, Simultaneous removal of copper (II), lead (II), zinc (II) and cadmium (II) from aqueous solutions by multi-walled carbon nanotubes, C. R. Chim., 15 (2012) 398–408.
18. O. Yayayuruk, A.E. Yayayuruk, C. Kocak, S. Kocak, Lead and copper removal using Kula volcanics from environmental waters, Sep. Sci. Technol., 52 (2017) 2777–2787.
19. S.B. Chen, Y.B. Ma, L. Chen, K. Xian, Adsorption of aqueous Cd²⁺, Pb²⁺, Cu²⁺ ions by nano-hydroxyapatite: single- and multimetal competitive adsorption study, Geochem. J., 44 (2010) 233–239.
20. D. Hillel, Environmental Soil Physics, 1st ed., Academic Press, San Diego, CA, 1998. Available at: https://dewagumay.files.wordpress.com/2011/12/environmental-soil-physics.pdf.
21. P. Srivastava, B. Singh, M. Angove, Competitive adsorption behavior of heavy metals on kaolinite, J. Colloid Interface Sci., 290 (2005) 28–38.
22. A. Sdiri, T. Higashi, R. Chaabouni, F. Jamoussi, Competitive removal of heavy metals from aqueous solutions by montmorillonitic and calcareous clays, Water Air Soil Pollut., 223 (2011) 1191–1204.
23. Y.H. Li, Z. Ding, Z. Luan, Y. Zhu, C. Xu, D. Wu, B. Wei, Competitive adsorption of Pb²⁺, Cu²⁺ and Cd²⁺ ions from aqueous solutions by multiwalled carbon nanotubes, Carbon, 41 (2003) 2787–2792.
24. R. Sitko, E. Turek, B. Zawisza, E. Malicka, E. Talik, J. Heimann, A. Gagor, B. Feist, R. Wrzalik, Adsorption of divalent metal ions from aqueous solutions using graphene oxide, Dalton Trans., 42 (2013) 5682–5689.
25. O. Oyetade, V. Nyamori, B. Sreekantha, B.S. Martincigh, Adsorption of Selected Pollutants from Aqueous Solutions onto Modified Carbon Nanotubes, University of KwaZulu-Natal, Durban, 2015.
26. M. Kavand, T. Kaghazchi, M. Soleimani, Optimization of parameters for competitive adsorption of heavy metal ions (Pb²⁺, Ni²⁺, Cd²⁺) onto activated carbon, Korean J. Chem. Eng., 31 (2014) 692–700.
27. K. Swayampakula, V.M. Boddu, S.K. Nadavala, K. Abburi, Competitive adsorption of Cu(II), Co(II) and Ni(II) from their binary and tertiary aqueous solutions using chitosan-coated perlite beads as biosorbent, J. Hazard. Mater., 170 (2009) 680–689.