1. D. Mohan, K.P. Singh, V.K. Singh, Trivalent chromium removal from wastewater using low cost activated carbon derived from agricultural waste material and activated carbon fabric cloth, J. Hazard. Mater., 135 (2006) 280–295.
  2. X. Guan, H. Dong, J. Ma, I. Lo, Simultaneous removal of chromium and arsenate from contaminated groundwater by ferrous sulfate: batch uptake behavior, J. Environ. Sci., 23 (2011) 372–380.
  3. M. Owlad, M.K. Aroua, W.A. Daud, S. Baroutian, Removal of hexavalent chromium-contaminated water and wastewater: a review, Water Air Soil Pollut., 200 (2008) 59–77.
  4. S. Kalidhasan, N. Rajesh, Simple and selective extraction process for chromium (VI) in industrial wastewater, J. Hazard. Mater., 170 (2009) 1079–1085.
  5. S. Sugashini, K.M Meera Sheriffa Begum, Optimization using central composite design (CCD) for the biosorption of Cr(VI) ions by cross linked chitosan carbonized rice husk (CCACR), Clean Technol., Environ Policy, 15 (2013) 293–302.
  6. M. Bansal, U. Garg, D. Singha, V.K. Garg, Removal of Cr(VI) from aqueous solutions using pre-consumer processing agricultural waste: a case study of rice husk, J. Hazard. Mater., 162 (2009) 312–320.
  7. S. Kumar, B.C. Meikap, Removal of Chromium(VI) from waste water by using adsorbent prepared from green coconut shell, Desal. Wat. Treat., 52 (2014) 3122–3132.
  8. T. Karthikeyan, S. Rajgopal, L.R. Miranda, Chromium(VI) adsorption from aqueous solution by Hevea Brasilinesis sawdust activated carbon, J. Hazard. Mater., 124 (2005) 192–199.
  9. G. Moussavi, B. Barikbin, Biosorption of chromium(VI) from industrial wastewater onto pistachio hull waste biomass, Chem. Eng. J., 162 (2010) 893–900.
  10. Z. Xie, F. Ji, X. Qiu, H. Huang, Adsorption performance of orange residue adsorbent to hexavalent chromium. J. Chongqing Univ., 32 (2009) 192–196.
  11. Z. Sfaksi, N. Azzouz, A. Abdelwahab, Removal of Cr (VI) from water by cork waste, Arab. J. Chem., 7 (2014) 37–42.
  12. H. Singh, V.K. Rattan, Comparison of hexavalent chromium adsorption from aqueous solutions by various biowastes and granulated activated carbon, Indian Chem. Eng., 56 (2014) 12–28.
  13. S. Mittal, U. Vaid, N.G. Nabi, Removal of hexavalent chromium from aqueous solution: a comparative study of cone biomass of “Picea smithiana” and activated charcoal. Desal. Wat. Treat., 57 (2016) 11081–11095.
  14. M. Ossman, M. Mansour, M. Fattah, Peanuts shell and talc powder for removal of hexavalent chromium from aqueous solutions. Bulgarian Chem. Commun., 3 (2014) 629–639.
  15. S. Rangabhashiyam, N. Selvaraju, Evaluation of the biosorption potential of a novel Caryota urens inflorescence waste biomass for the removal of hexavalent chromium from aqueous solutions. J. Taiwan Inst. Chem. Eng., 47 (2015) 59–70.
  16. A. Patnaik, M. Mvubu, S. Muniyasamy, A. Botha, R.D. Anandjiwala, Thermal and sound insulation materials from waste wool and recycled polyester fibers and their biodegradation studies. Eng. Build., 92 (2015) 161–169.
  17. Z. Yin, M. Chen, S. Hu, H. Cheng, Carboxylate functionalized wool fibers for removal of Cu(II) and Pb(II) from aqueous solution, Desal. Wat. Treat., 57 (2016) 17367–17376. doi: 10.1080/19443994.2015.1084484
  18. Z. Yin, J. Xiong, M. Chen, S. Hu, H. Cheng, Recovery of uranium (VI) from aqueous solution by amidoxime functionalized wool fibers, J. Radioanal. Nucl. Chem., 307 (2016) 1471–1479.
  19. Z. Yin, B. Chen, M. Chen, S. Hu, H. Cheng, Recovery of chromium (III) ions from aqueous solution by carboxylate functionalized wool fibres, J. Soc. Leather Technol. Chem., 99 (2015) 101–106.
  20. C. Ki, E. Gang, I. Um, Y. Park, Nanofibrous membrane of wool keratose/silk fibroin blend for heavy metal ion adsorption, J. Membr. Sci., 302 (2007) 20–26.
  21. M. Monier, N. Nawar, D.A. Abdel-Latif, Preparation and characterization of chelating fibers based on natural wool for removal of Hg(II), Cu(II) and Co(II) metal ions from aqueous solutions, J. Hazard. Mater., 184 (2010) 118–125.
  22. Y.S. Ho, Review of second-order models for adsorption systems, J. Hazard. Mater., 136 (2006) 681–689.
  23. I. Langmuir, The adsorption of gases on plane surfaces of glass, mica and platinum, J. Am. Chem. Soc., 40 (1918) 1361–1403.
  24. B. Gao, Y. Gao, Y. Li, Preparation and chelation adsorption property of composite chelating material poly(amidoxime)/SiO2 towards heavy metal ions, Chem. Eng. J., 158 (2010) 542–549.
  25. J. Chang, Q. Dong, Principle and Analysis of Spectrum, Science Press: Beijing, 2012, pp. 53–97.
  26. B. Singha, S.K. Das, Biosorption of Cr(VI) ions from aqueous solutions: kinetics, equilibrium, thermodynamics and desorption studies, Colloid. Surf. B: Biointerfaces, 84 (2011) 221–232.
  27. J. Huang, M. Liu, Adsorption of Cr(e) on a novel cellulose chelation adsorbent. J. Cell. Sci. Technol., 18 (2010) 7–11.
  28. D.S. Bolotin1, N.A. Bokach1, V.Y. Kukushkin, Coordination chemistry and metal-involving reactions of amidoximes: relevance to the chemistry of oximes and oxime ligands. Coordin. Chem. Rev., 313 (2016) 62–93.
  29. N. Horzum, T. Shahwan, O. Parlak, M.M. Demir, Synthesis of amidoximated polyacrylonitrile fibers and its application for sorption of aqueous uranyl ions under continuous flow, Chem. Eng. J., 213 (2012) 41–49.
  30. N.K. Hamadi, X.D. Chen, M.M. Farid, M.G. Lu, Adsorption kinetics for the removal of chromium(VI) from aqueous solution by adsorbents derived from used tyres and sawdust. Chem. Eng. J., 84 (2001) 95–105.
  31. K. Muthukumaran, S. Beulah, Removal of chromium (VI) from wastewater using chemically activated syzygium jambolanum nut carbon by batch studies. Proc. Environ. Sci., 4 (2011) 266–280.
  32. Y. Lu, J. He, G. Luo, An improved synthesis of chitosan bead for Pb(II) adsorption, Chem. Eng. J., 226 (2013) 271–278.
  33. K. Mukherjee, Nandi, R. Nandi, D. Saha, B. Saha, Surfactant-assisted bioremediation of hexavalent chromium from contaminated water, Desal. Wat. Treat., 53 (2015) 746–751.
  34. R. Karthik, S. Meenakshi, Removal of hexavalent chromium ions from aqueous solution using chitosan/polypyrrole composite, Desal. Wat. Treat., 56 (2015) 1587–1600.
  35. S. Rengaraj, Y. Kim, C.K. Joo, J. Yi, Removal of copper from aqueous solution by aminated and protonated mesoporous aluminas: kinetics and equilibrium, J. Colloid. Interface Sci., 273 (2004) 14–21.
  36. D. Robati, Pseudo-second-order kinetic equations for modeling adsorption systems for removal of lead ions using multi-walled carbon nanotube, J. Nanostruct. Chem., 3 (2013) 55–60.
  37. K. Hall, L. Eagleton, A. Acrivos, T. Vermeulen, Pore-and solid-diffusion kineticsin fixed-bed adsorption under constant-pattern conditions, Ind. Eng. Chem. Fundam., 5 (1996) 212–223.