Akter, F., Das, S. S., Khan, M. M. R., Sultana, F. and Rahman, S. M., “Analysis on the physical and chemical properties and means of quality control of the tannery wastewater effluent in Dhaka city”, AJIRSET, 1 (8), 7 (2016).
 Al-Essa, K. and Khalili, F., “Heavy metals adsorption from aqueous solutions onto unmodified and modified Jordanian kaolinite clay: Batch and column techniques”, American Journal of Applied Chemistry, 6 (1), 25 (2018).
 Alidokht, L., Khataee, A., Reyhanitabar, A. and Oustan, S., “Reductive removal of Cr (VI) by starch-stabilized FeO nanoparticles in aqueous solution”, Desalination, 270 (1-3), 105 (2011).
 Anah, L. and Astrini, N., “Influence of pH on Cr (VI) ions removal from aqueous solutions using carboxymethyl cellulose-based hydrogel as adsorbent”, IOP Conference Series: Earth and Environmental Science, 60 (1), 012010 (2017).
 Annadurai, G., Ling, L. Y. and Lee, J. -F., “Adsorption of reactive dye from an aqueous solution by chitosan: Isotherm, kinetic and thermodynamic analysis”, Journal of Hazardous Materials, 152 (1), 337 (2008).
 Azom, M., Mahmud, K., Yahya, S. M., Sontu, A. and Himon, S., “Environmental impact assessment of tanneries: A case study of Hazaribag in Bangladesh”, International Journal of Environmental Science and Development, 3 (2), 152 (2012).
 Baocheng, Q., Jiti, Z., Xiang, X., Zheng, C., Hongxia, Z. and Xiaobai, Z., “Adsorption behavior of Azo Dye CI Acid Red 14 in aqueous solution on surface soils”, Journal of Environmental Sciences, 20 (6), 704 (2008).
 Bhattacharyya, K. G. and Gupta, S. S., “Adsorption of a few heavy metals on natural and modified kaolinite and montmorillonite: A review”, Advances in Colloid and Interface Science, 140 (2), 114 (2008).
 Biswas, S., Rashid, T. U., Mallik, A. K., Islam, M., Khan, M. N., Haque, P., Khan, M. and Rahman, M. M., “Facile preparation of biocomposite from prawn shell derived chitosan and kaolinite-rich locally available clay”, International Journal of Polymer Science, 2017, 1 (2017).
 Chatterjee, S., Lee, D. S., Lee, M. W. and Woo, S. H., “Nitrate removal from aqueous solutions by cross-linked chitosan beads conditioned with sodium bisulfate”, Journal of Hazardous Materials, 166 (1), 508 (2009).
 Chen, X., “Modeling of experimental adsorption isotherm data”, Information, 6 (1), 14 (2015).
 Dada, A. O., Olalekan, A. P., Olatunya, A. M. and Dada, O., “Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms studies of equilibrium sorption of Zn2+ unto phosphoric acid modified rice husk”, IOSR Journal of Applied Chemistry, 3 (1), 38 (2012).
 dos Santos Moyses, F., Bertoldi, K., Elsner, V. R., Cechinel, L. R., Basso, C., Stulp, S., Rodrigues, M. A. S. and Siqueira, I. R., “Effect of tannery effluent on oxidative status of brain structures and liver of rodents”, Environmental Science and Pollution Research, 24 (18), 15689 (2017).
 Febrianto, J., Kosasih, A. N., Sunarso, J., Ju, Y. -H., Indraswati, N. and Ismadji, S., “Equilibrium and kinetic studies in adsorption of heavy metals using biosorbent: A summary of recent studies”, Journal of Hazardous Materials, 162 (2), 616 (2009).
 Ghnimi, S. M. and Frini-Srasra, N., “A comparison of single and mixed pillared clays for zinc and chromium cations removal”, Applied Clay Science, 158, 150 (2018).
 Gong, X., Li, W., Wang, K. and Hu, J., “Study of the adsorption of Cr (VI) by tannic acid immobilised powdered activated carbon from micro-polluted water in the presence of dissolved humic acid”, Bioresource Technology, 141, 145 (2013).
 Greluk, M. and Hubicki, Z., “Kinetics, isotherm and thermodynamic studies of Reactive Black 5 removal by acid acrylic resins”, Chemical Engineering Journal, 162 (3), 919 (2010).
 Gupta, S. and Babu, B. V., “Removal of toxic metal Cr (VI) from aqueous solutions using sawdust as adsorbent: Equilibrium, kinetics and regeneration studies”, Chemical Engineering Journal, 150 (2), 352 (2009).
 Huang, J., Cao, Y., Shao, Q., Peng, X. and Guo, Z., “Magnetic nanocarbon adsorbents with enhanced hexavalent chromium removal: Morphology dependence of fibrillar vs particulate structures”, Industrial & Engineering Chemistry Research, 56 (38), 10689 (2017a).
 Huang, S., Xia, W., Li, Y., Zhang, B., Zhou, A., Zheng, T., Qian, Z., Huang, Z., Lu, S. and Chen, Z., “Association between maternal urinary chromium and premature rupture of membranes in the Healthy Baby Cohort study in China”, Environmental Pollution, 230, 53 (2017b).
 Jain, M., Garg, V. K. and Kadirvelu, K., “Chromium (VI) removal from aqueous system using Helianthus annuus (sunflower) stem waste”, Journal of Hazardous Materials, 162 (1), 365 (2009).
 Kandile, N. G. and Nasr, A. S., “Environment friendly modified chitosan hydrogels as a matrix for adsorption of metal ions, synthesis and characterization”, Carbohydrate Polymers, 78 (4), 753 (2009).
 Karthik, R. and Meenakshi, S., "Facile synthesis of cross linked-chitosan-grafted-polyaniline composite and its Cr (VI) uptake studies”, International Journal of Biological Macromolecules, 67, 210 (2014).
 Kumar, A. and Jena, H. M., “Adsorption of Cr (VI) from aqueous phase by high surface area activated carbon prepared by chemical activation with ZnCl2”, Process Safety and Environmental Protection, 109, 63 (2017).
 Leonel, E. C., Faria, E. H. d., Pimentel, R. C., Nassar, E. J., Ciuffi, K. J., Reis, M. J. D. and Calefi, P. S., “Utilization of glycerin from biodiesel production to obtaining kaolinite hybrid for Cr3+ adsorption”, Química Nova, 35 (7), 1407 (2012).
 Li, Y., Jin, Z., Li, T. and Li, S., “Removal of hexavalent chromium in soil and groundwater by supported nano zero-valent iron on silica fume”, Water Science and Technology, 63 (12), 2781 (2011).
 Liu, B. and Huang, Y., “Polyethyleneimine modified eggshell membrane as a novel biosorbent for adsorption and detoxification of Cr (VI) from water”, Journal of Materials Chemistry, 21 (43), 17413 (2011).
 Liu, X., Qian, X., Shen, J., Zhou, W. and An, X., “An integrated approach for Cr (VI)-detoxification with polyaniline/cellulose fiber composite prepared using hydrogen peroxide as oxidant”, Bioresource Technology, 124, 516 (2012).
 Mousharraf, A., Hossain, M. S. and Islam, M. F., “Potential of locally available clay as raw material for traditional-ceramic manufacturing industries”, Journal of Chemical Engineering, 26 (1), 34 (2012).
 Nair, V., Panigrahy, A. and Vinu, R., “Development of novel chitosan–lignin composites for adsorption of dyes and metal ions from wastewater”, Chemical Engineering Journal, 254, 491 (2014).
 Ozdemir, O., Armagan, B., Turan, M. and Çelik, M. S., “Comparison of the adsorption characteristics of azo-reactive dyes on mezoporous minerals”, Dyes and Pigments, 62 (1), 49 (2004).
 Pandey, S. and Mishra, S. B., “Organic-inorganic hybrid of chitosan/organoclay bionanocomposites for hexavalent chromium uptake”, Journal of Colloid and Interface Science, 361 (2), 509 (2011).
 Qiu, J., Wang, Z., Li, H., Xu, L., Peng, J., Zhai, M., Yang, C., Li, J. and Wei, G., “Adsorption of Cr (VI) using silica-based adsorbent prepared by radiation-induced grafting”, Journal of Hazardous Materials, 166 (1), 270 (2009).
 Rahman, M. M., Kabir, S., Rashid, T. U., Nesa, B., Nasrin, R., Haque, P. and Khan, M. A., “Effect of Î³-irradiation on the thermomechanical and morphological properties of chitosan obtained from prawn shell: Evaluation of potential for irradiated chitosan as plant growth stimulator for Malabar spinach”, Radiation Physics and Chemistry, 82, 112 (2013).
 Rahman, M. M., Kabir, S., Rashid, T. U., Nesa, B., Nasrin, R., Haque, P. and Khan, M. A., “Effect of ϒ-irradiation on the thermomechanical and morphological properties of chitosan obtained from prawn shell: Evaluation of potential for irradiated chitosan as plant growth stimulator for Malabar spinach”, Radiation Physics and Chemistry, 82, 112 (2013).
 Rashid, T. U., Rahman, M. M., Kabir, S., Shamsuddin, S. M. and Khan, M. A., “A new approach for the preparation of chitosan from Î³-irradiation of prawn shell: Effects of radiation on the characteristics of chitosan”, Polymer International, 61 (8), 1302 (2012).
 Schmuhl, R., Krieg, H. M. and Keizer, K., “Adsorption of Cu (II) and Cr (VI) ions by chitosan: Kinetics and equilibrium studies”, Water Sa., 27 (1), 1 (2001).
 Singh, R., Dong, H., Zeng, Q., Zhang, L. and Rengasamy, K., “Hexavalent chromium removal by chitosan modified-bioreduced nontronite”, Geochimica et Cosmochimica Acta, 210, 25 (2017).
 Song, Z., Williams, C. and Edyvean, R., “Sedimentation of tannery wastewater”, Water Research, 34 (7), 2171 (2000).
 Su, M., Fang, Y., Li, B., Yin, W., Gu, J., Liang, H., Li, P. and Wu, J., “Enhanced hexavalent chromium removal by activated carbon modified with micro-sized goethite using a facile impregnation method”, Science of The Total Environment, 647, 47 (2018).
 Tianwei, T., Xiaojing, H. and Weixia, D., “Adsorption behaviour of metal ions on imprinted chitosan resin”, Journal of Chemical Technology and Biotechnology, 76 (2), 191 (2001).
 Tirtom, V. N., Dincer, A., Becerik, S., Aydemir, T. and Celik, A., “Comparative adsorption of Ni (II) and Cd (II) ions on epichlorohydrin crosslinked chitosan-clay composite beads in aqueous solution”, Chemical Engineering Journal, 197, 379 (2012).
 Wang, S. F., Shen, L., Tong, Y. J., Chen, L., Phang, I. Y., Lim, P. Q. and Liu, T. X., “Biopolymer chitosan/montmorillonite nanocomposites: Preparation and characterization”, Polymer Degradation and Stability, 90 (1), 123 (2005).
 Wang, X. S., Chen, L. F., Li, F. Y., Chen, K. L., Wan, W. Y. and Tang, Y. J., “Removal of Cr (VI) with wheat-residue derived black carbon: Reaction mechanism and adsorption performance”, Journal of Hazardous Materials, 175 (1), 816 (2010).
 Wang, X. S., Chen, L. F., Li, F. Y., Chen, K. L., Wan, W. Y. and Tang, Y. J., “Removal of Cr (VI) with wheat-residue derived black carbon: reaction mechanism and adsorption performance”, Journal of Hazardous Materials, 175 (1-3), 816 (2010).
 Yano, K., Usuki, A., Okada, A., Kurauchi, T. and Kamigaito, O., “Synthesis and properties of polyimide-clay hybrid”, Journal of Polymer Science, Part A: Polymer Chemistry, 31 (10), 2493 (1993).
 Zhang, L., Zeng, Y. and Cheng, Z., “Removal of heavy metal ions using chitosan and modified chitosan: A review”, Journal of Molecular Liquids, 214, 175 (2016).
 Zhou, L., Li, R., Zhang, G., Wang, D., Cai, D. and Wu, Z., “Zero-valent iron nanoparticles supported by functionalized waste rock wool for efficient removal of hexavalent chromium”, Chemical Engineering Journal, 339, 85 (2018).