References

1. F.N. Acar, Z. Eren, Removal of Cu(II) ions by activated poplar sawdust (Samsun Clone) from aqueous solutions, J. Hazard. Mater., 137 (2006) 909–914.
2. A.M. Choi, J. Alam, Heme oxygenase-1: function, regulation, and implication of a novel stress-inducible protein in oxidant-induced lung injury, Am. J. Respir. Cell. Mol. Biol., 15 (1996) 9–19.
3. L.R. Bravo-Sánchez, B.S.V. de la Riva, J.M. Costa-Fernández, R. Pereiro, A. Sanz-Medel, Determination of lead and mercury in sea water by preconcentration in a flow injection system followed by atomic absorption spectrometry detection, Talanta, 55 (2001) 1071–1078.
4. M.M. Saeed, M. Ahmed, Retention, kinetics and thermodynamics profile of cadmium adsorption from iodide medium onto polyurethane foam and its separation from zinc bulk, Anal. Chim. Acta., 525 (2004) 289–297.
5. J.L. Gong, B. Wang, G.M. Zeng, C.P. Yang, C.G. Niu, Q.Y. Niu, Y. Liang, Removal of cationic dyes from aqueous solution using magnetic multi-wall carbon nanotube nanocomposite as adsorbent, J. Hazard. Mater., 164 (2009) 1517–1522.
6. M.M. Matlock, B.S. Howerton, D.A. Atwood, Chemical precipitation of heavy metals from acid mine drainage, Water Res., 36 (2002) 4757–4764.
7. C.H. Liu, J.S. Wu, H.C. Chiu, S.Y. Suen, K.H. Chu, Removal of anionic reactive dyes from water using anion exchange membranes as adsorbers, Water Res., 41 (2007) 1491–1500.
8. G. Capar, U. Yetis, L. Yilmaz, Membrane based strategies for the pre-treatment of acid dye bath wastewaters, J. Hazard. Mater., 135 (2006) 423–430.
9. R. De Lisi, G. Lazzara, S. Milioto, N. Muratore, Adsorption of a dye on clay and sand. Use of cyclodextrins as solubility-enhancement agents, Chemosphere., 69 (2007) 1703–1712.
10. K. Kadirvelu, K. Thamaraiselvi, C. Namasivayam, Removal of heavy metals from industrial wastewaters by adsorption onto activated carbon prepared from an agricultural solid waste, Bioresour. Technol., 76 (2001) 63–65.
11. D. Sud, G. Mahajan, M.P. Kaur, Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions – a review, Bioresour. Technol., 99 (2008) 6017–6027.
12. T. Panczyk, M. Drach, P. Szabelski, A. Jagusiak, Magnetic anisotropy effects on the behavior of a carbon nanotube functionalized by magnetic nanoparticles under external magnetic fields, J. Phys. Chem. C., 116 (2012) 26091–26101.
13. R.H. Baughman, A.A. Zakhidov, W.A. de Heer, Carbon nanotubes – the route toward applications, Science., 297 (2002) 787–792.
14. O. Moradi, K. Zare, M. Monajjemi, M. Yari, H. Aghaie, The studies of equilibrium and thermodynamic adsorption of Pb(II), Cd(II) and Cu(II) ions from aqueous solution onto SWCNTs and SWCNT-COOH surfaces, Fuller. Nanotub. Car. N., 18 (2010) 285–302.
15. G.-P. Rao, C. Lu, F. Su, Sorption of divalent metal ions from aqueous solution by carbon nanotubes: a review, Sep. Purif. Technol., 58 (2007) 224–231.
16. Z. Gao, T.J. Bandosz, Z. Zhao, M. Han, C. Liang, J. Qiu, Investigation of the role of surface chemistry and accessibility of cadmium adsorption sites on open-surface carbonaceous materials, Langmuir., 24 (2008) 11701–11710.
17. G.D. Vuković, A.D. Marinković, S.D. Škapin, M.D. Ristić, R. Aleksić, A.A. Perić-Grujić, P.S. Uskoković, Removal of lead from water by amino modified multi-walled carbon nanotubes, Chem. Eng. J., 173 (2011) 855–865.
18. G.D. Vuković, A.D. Marinković, M. Čolić, M.D. Ristić, R. Aleksić, A.A. Perić-Grujić, P.S. Uskoković, Removal of cadmium from aqueous solutions by oxidized and ethylenediamine-functionalized multi-walled carbon nanotubes, Chem. Eng. J., 157 (2010) 238–248.
19. J.P. Hu, J.H. Shi, S.P. Li, Y.J. Qin, Z.X. Guo, Y.L. Song, D.B. Zhu, Efficient method to functionalize carbon nanotubes with thiol groups and fabricate gold nanocomposites, Chem. Phys. Lett., 401 (2005) 352–356.
20. Z.F. Liu, Z.Y. Shen, T. Zhu, S.F. Hou, L.Z. Ying, Z.J. Shi, Z.N. Gu, Organizing single-walled carbon nanotubes on gold using a wet chemical self-assembling technique, Langmuir., 16 (2000) 3569–3573.
21. M. Hadavifar, N. Bahramifar, H. Younesi, Q. Li, Adsorption of mercury ions from synthetic and real wastewater aqueous solution by functionalized multi-walled carbon nanotube with both amino and thiolated groups, Chem. Eng. J., 237 (2014) 217–228.
22. N.M. Bandaru, N. Reta, H. Dalal, A.V. Ellis, J. Shapter, N.H. Voelcker, Enhanced adsorption of mercury ions on thiol derivatized single wall carbon nanotubes, J. Hazard. Mater., 261 (2013) 534–541.
23. C. Zhang, J. Sui, J. Li, Y. Tang, W. Cai, Efficient removal of heavy metal ions by thiol-functionalized superparamagnetic carbon nanotubes, Chem. Eng. J., 210 (2012) 45–52.
24. Q. Li, J.G. Yu, F. Zhou, X.Y. Jiang, Synthesis and characterization of dithiocarbamate carbon nanotubes for the removal of heavy metal ions from aqueous solutions, Colloid. Surface A., 482 (2015) 306–314.
25. M.H. Hsu, H. Chuang, F.Y. Cheng, Y.P. Huang, C.C. Han, K.C. Pao, D.S. Wu, Simple and highly efficient direct thiolation of the surface of carbon nanotubes, RSC. Adv., 4 (2014) 14777–14780.
26. B. Šljukic, C.E. Banks, R.G. Compton, Iron oxide particles are the active sites for hydrogen peroxide sensing at multiwalled carbon nanotube modified electrodes, Nano. Lett., 6 (2006) 1556–1558.
27. J. Xu, P. Yao, X. Li, F. He, Synthesis and characterization of water-soluble and conducting sulfonated polyaniline/ para-phenylenediamine-functionalized multi-walled carbon nanotubes nano-composite, Mater. Sci. Eng. B-Adv., 151 (2008) 210–219.
28. J. Hu, J. Shi, S. Li, Y. Qin, Z.X. Guo, Y. Song, D. Zhu, Efficient method to functionalize carbon nanotubes with thiol groups and fabricate gold nanocomposites, Chem. Phys. Lett., 401 (2005) 325–356.
29. Y.Z. You, C.Y. Hong, C.Y. Pan, Functionalization of carbon nanotubes with well-defined functional polymers via thiol-coupling reaction, Macromol. Rapid. Comm., 27 (2006) 2001–2006.
30. Y.S. Kim, J.H. Cho, S.G. Ansari, H.I. Kim, M.A. Dar, H.K. Seo, H.S. Shin, Immobilization of avidin on the functionalized carbon nanotubes, Synth. Met., 156 (2006) 938–943.
31. Y. Wang, Z. Iqbal, S.V. Malhotra, Functionalization of carbon nanotubes with amines and enzymes, Chem. Phys. Lett., 402 (2005) 96–101.
32. B. Xiao, K.M. Thomas, Adsorption of aqueous metal ions on oxygen and nitrogen fictionalized nanoporous activated carbons, Langmuir., 21 (2005) 3892–3902.
33. Y. Xie, D. Qian, D. Wu, X. Ma, Magnetic halloysite nanotubes/ iron oxide composites for the adsorption of dyes, Chem. Eng. J., 168 (2011) 959–963.
34. F. He, J. Fan, D. Ma, L. Zhang, C. Leung, H.L. Chan, The attachment of Fe3O4 nanoparticles to graphene oxide by covalent bonding, Carbon, 48 (2010) 3139–3144.
35. S. Azizian, Kinetic models of sorption: a theoretical analysis, J. Colloid Interf. Sci., 276 (2004) 47–52.
36. A.A. Farghali, M. Bahgat, W.M. ElRouby, M.H. Khedr, Decoration of multi-walled carbon nanotubes (MWCNTs) with different ferrite nanoparticles and its use as an adsorbent, J. Nanostruct. Chem., 3 (2013) 1–12.
37. G.P. Rao, C. Lu, F. Su, Sorption of divalent metal ions from aqueous solution by carbon nanotubes: a review, Sep. Purif. Technol., 58 (2007) 224–231.
38. G.D. Vukovic, A.D. Marinkovic, S.D. Skapin, Removal of lead from water by amino modified multi-walled carbon nanotubes, Chem. Eng. J., 173 (2011) 855–865.
39. E. Nieboer, D.H.S. Richardson, The replacement of the nondescript term ‘heavy metals’ by a biologically and chemically significant classification of metal ions, Environ. Pollu. Series B, Chem. and Phys., 1 (1980) 3–26.
40. S. Yang, J. Hu, C. Chen, Mutual effects of Pb (II) and humic acid adsorption on multiwalled carbon nanotubes/polyacrylamide composites from aqueous solutions, Environ. Sci. & Technol., 45 (2011) 3621–3627.