The role of nanoadsorbents and nanocomposite adsorbents in the removal of heavy metals from wastewater: A review and prospect

Document Type: Review Paper


Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, Jalan Gombak, 53100 Kuala Lumpur, Malaysia.


Significant attention has been given to nanotechnology as an emerging approach in water/wastewater treatment for heavy metals removal. Numerous research works on synthesizing, fabrication and upgrading nanoparticles have reported as an efficient adsorbent in removal of wide range of heavy metals from wastewater. This review intends to provide researchers with understanding and knowledge regarding the efficient nanoadsorbents, their adsorption mechanism towards selected heavy metals and fundamental principles of nanoadsorbent materials synthesis. In addition, further attention on the modification of nanoadsorbent and development of nanocomposites are highlighted in this paper as value added products to increase the adsorption capacity and enhance the heavy metals removal. Possible challenges and direction on utilization of nanocomposites for heavy metal removal in real wastewater effluent are discussed in view of their removal capability and cost efficiency. Future research works on developing a cost-effective way of nanocomposite production and toxicity testing of nanomaterials in wastewater applications are recommended. Further studies on the efficiency of the nanoadsorbents in pilot or industrial scale are highly needed to test the practicality of the nanoadsorbents for selected heavy metals removal from real wastewater.


Abd El fatah, M. and Ossman, M. E. (2014). Removal of heavy metal by nickel oxide nano powder. Int. J. Environ. Res., 8(3), 741–750.
Ahmad, R. and Hasan, I. (2017). Efficient Remediation of an Aquatic Environment Contaminated by Cr(VI) and 2,4-Dinitrophenol by XG-g-Polyaniline@ZnO Nanocomposite. J. Chem. Eng. Data, 62(5), 1594–1607.
Ahmaruzzaman, M. (2019). Nano-materials: Novel and Promising Adsorbents for Water Treatment. Asian J. Water, Environ. Pollut., 16(3), 43–53.
Ain, Q. U., Farooq, M. U. and Jalees, M. I. (2020). Application of Magnetic Graphene Oxide for Water Purification: Heavy Metals Removal and Disinfection. J. Water Process. Eng., 33, 101044, 1-12.
Alam, J., Shukla, A. K., Alhoshan, M., Arockiasamy Dass, L., Muthumareeswaran, M. R., Khan, A. and Ahmed Ali, F. A. (2018). Graphene oxide, an effective nanoadditive for a development of hollow fiber nanocomposite membrane with antifouling properties. Adv. Polym. Technol., 2017, 1–12.
Ali, M. E., Hoque, M. E., Safdar Hossain, S. K. and Biswas, M. C. (2020). Nanoadsorbents for wastewater treatment: next generation biotechnological solution. In Int. J. Environ. Sci. Technol. (Issue 0123456789). Springer Berlin Heidelberg.
Alimohammadi, M., Saeedi, Z., Akbarpour, B., Rasoulzadeh, H., Yetilmezsoy, K., Al-Ghouti, M. A., Khraisheh, M. and McKay, G. (2017). Adsorptive Removal of Arsenic and Mercury from Aqueous Solutions by Eucalyptus Leaves. Water Air Soil Pollut., 228(11), 1-27.
Auwal, A. and Hossen, J. (2018). Removal of Phenol From Aqueous Solution Using Tamarind Seed Powder As Adsorbent. IOSR J. Environ. Sci. Toxic. Food Technol. vf 12(3), 41–48.
Ayawei, N., Ebelegi, A. N. and Wankasi, D. (2017). Modelling and Interpretation of Adsorption Isotherms. J. Chem., 2017(3039817), 1-11.
Azizi, S., Shahri, M. M. and Mohamad, R. (2017). Green synthesis of zinc oxide nanoparticles for enhanced adsorption of lead Ions from aqueous solutions: Equilibrium, kinetic and thermodynamic studies. Molecules., 22(6), 1-14.
Azizian, S., Eris, S. and Wilson, L. D. (2018). Re-evaluation of the century-old Langmuir isotherm for modeling adsorption phenomena in solution. Chem. Phys., 513, 99–104.
Baalousha, M. (2009). Aggregation and disaggregation of iron oxide nanoparticles: Influence of particle concentration, pH and natural organic matter. Sci. Total Environ., 407(6), 2093–2101.
Bankole, M. T., Abdulkareem, A. S., Mohammed, I. A., Ochigbo, S. S., Tijani, J. O., Abubakre, O. K. and Roos, W. D. (2019). Selected Heavy Metals Removal From Electroplating Wastewater by Purified and Polyhydroxylbutyrate Functionalized Carbon Nanotubes Adsorbents. Sci. Rep, 9(1), 1–19.
Barak, A., Gangwar, V. D. and Shukla, S. K. (2018). Development and characterization of polyvinyl chloride-graphite membrane. Indian J. Chem. Technol., 25(2), 196–200.
Nik-Abdul-Ghani, N. R., et al.
Baruah, A., Chaudhary, V., Malik, R. and Tomer, V. K. (2019). 17 -Nanotechnology Based Solutions for Wastewater Treatment. In Nanotechnology in Water and Wastewater Treatment: Theory and Applications. Elsevier Inc.
Batool, F., Akbar, J., Iqbal, S., Noreen, S. and Bukhari, S. N. A. (2018). Study of Isothermal, Kinetic, and Thermodynamic Parameters for Adsorption of Cadmium: An Overview of Linear and Nonlinear Approach and Error Analysis. Bioinorg. Chem. Appl., 2018(3463724), 1-11.
Boretti, A. and Rosa, L. (2019). Reassessing the projections of the World Water Development Report. NPJ Clean Water., 2(1), 1-15.
Burakov, A. E., Galunin, E. V., Burakova, I. V., Kucherova, A. E., Agarwal, S., Tkachev, A. G. and Gupta, V. K. (2018). Adsorption of heavy metals on conventional and nanostructured materials for wastewater treatment purposes: A review. Ecotoxicol. Environ. Saf., 148, 702–712.
Cao, W., Ma, Y., Zhou, W. and Guo, L. (2015). One-pot hydrothermal synthesis of rGO-Fe3O4 hybrid nanocomposite for removal of Pb(II) via magnetic separation. Chem. Res. Chin. Univ., 31(4), 508–513.
Chen, X. (2015). Modeling of experimental adsorption isotherm data. Information (Switzerland), 6(1), 14–22.
Cheng, T. W., Lee, M. L., Ko, M. S., Ueng, T. H. and Yang, S. F. (2012). The heavy metal adsorption characteristics on metakaolin-based geopolymer. Appl. Clay Sci., 56, 90–96.
Dave, P. N. and Chopda, L. V. (2014). Application of iron oxide nanomaterials for the removal of heavy metals. J. Nanotechnol., 2014(98569,),1-14.
Dreyer, D. R., Park, S., Bielawski, C. W. and Ruoff, R. S. (2010). The chemistry of graphene oxide. Chem. Soc. Rev., 39(1), 228–240.
Dubey, R., Bajpai, J. and Bajpai, A. K. (2016). Chitosan-alginate nanoparticles (CANPs) as potential nanosorbent for removal of Hg (II) ions. Environ. Nanotechnol. Monit. Manag., 6(Ii), 32–44.
El-Khaiary, M. I. (2008). Least-squares regression of adsorption equilibrium data: Comparing the options. J. Hazard. Mater., 158(1), 73–87.
El-sayed, M. E. A. (2020). Nanoadsorbents for water and wastewater remediation. Sci. Total Environ., 739(139903), 1-12.
Elsehly, E. M., Chechenin, N. G., Makunin, A. V., Motaweh, H. A., Vorobyeva, E. A., Bukunov, K. A., Leksina, E. G. and Priselkova, A. B. (2016). Characterization of functionalized multiwalled carbon nanotubes and application as an effective filter for heavy metal removal from aqueous solutions. Chin. J. Chem. Eng., 24(12), 1695–1702.
Farooq, U., Kozinski, J. A., Khan, M. A. and Athar, M. (2010). Biosorption of heavy metal ions using wheat based biosorbents - A review of the recent literature. Bioresour. Technol., 101(14), 5043–5053.
Fu, D., He, Z., Su, S., Xu, B., Liu, Y. and Zhao, Y. (2017). Fabrication of a -FeOOH decorated graphene oxide-carbon nanotubes aerogel and its application in adsorption of arsenic species. J. Colloid Interface Sci., 505, 105–114.
Fu, F. and Wang, Q. (2011). Removal of heavy metal ions from wastewaters: A review. J. Environ. Manage., 92(3), 407–418.
Ge, F., Li, M. M., Ye, H. and Zhao, B. X. (2012). Effective removal of heavy metal ions Cd 2+, Zn 2+, Pb 2+, Cu 2+ from aqueous solution by polymer-modified magnetic nanoparticles. J. Hazard. Mater., 211–212, 366–372.
Gebru, K. A. and Das, C. (2017). Removal of Pb (II) and Cu (II) ions from wastewater using composite electrospun cellulose acetate/titanium oxide (TiO2) adsorbent. J. Water Process. Eng., 16, 1–13.
Ghiloufi, I., Ghoul, J. El, Modwi, A. and Mir, L. El. (2016). Ga-doped ZnO for adsorption of heavy metals from aqueous solution. Mater. Sci. Semicond. Process., 42, 102–106.
González, A. G., Pokrovsky, O. S., Santana-Casiano, J. M. and González-Dávila, M. (2017). Bioadsorption of heavy metals. In Prospects and Challenges in Algal Biotechnology, 4(1), 233–255, Springer Nature Switzerland AG.
Gupta, V. K., Agarwal, S., Bharti, A. K. and Sadegh, H. (2017). Adsorption mechanism of functionalized multi-walled carbon nanotubes for advanced Cu (II) removal. J. Mol. Liq., 230(Ii), 667–673.
Hadi Najafabadi, H., Irani, M., Roshanfekr Rad, L., Heydari Haratameh, A. and Haririan, I. (2015). Removal of Cu2+, Pb2+ and Cr6+ from aqueous solutions using a chitosan/graphene oxide composite nanofibrous adsorbent. RSC Adv., 5(21), 16532–16539.
Hallaji, H., Keshtkar, A. R. and Moosavian, M. A. (2015). A novel electrospun PVA/ZnO nanofiber adsorbent for U(VI), Cu(II) and Ni(II) removal from aqueous solution. J. Taiwan Inst. Chem. Eng., 46, 109–118.
Hasanzadeh, R., Najafi Moghadam, P. and Samadi, N. (2012). Synthesis and application of modified
Pollution, 7(1): 153-179, Winter 2021
poly (styrene-alt-maleic anhydride) networks as a nano chelating resin for uptake of heavy metal ions. Polym. Adv. Technol., 24(1), 34–41.
Hasbullah, H., Sabri, N. S. M., Said, N., Rosid, S. M., Roslan, M. I., Ismail, A. F., Jye, L. W. and Yusof, N. (2018). 16 -Nanoengineered Materials for Water and Wastewater Treatments. In Nanotechnology in Water and Wastewater Treatment: Theory and Applications. Elsevier Inc.
Hassan, K. H., Jarullah, A. A. and Saadi, S. K. (2017). Synthesis of Copper Oxide Nanoparticle as an Adsorbent for Removal of Cd (II) and Ni (II) Ions from Binary System. Int. J. Appl. Environ. Sci., 12(11), 1841–1861.
He, M., Wang, L., Lv, Y., Wang, X., Zhu, J., Zhang, Y. and Liu, T. (2020). Novel polydopamine/metal organic framework thin film nanocomposite forward osmosis membrane for salt rejection and heavy metal removal. Chem. Eng. J., 389(13), 124452, 1-14.
Hua, M., Zhang, S., Pan, B., Zhang, W., Lv, L. and Zhang, Q. (2012). Heavy metal removal from water/wastewater by nanosized metal oxides: A review. J. Hazard. Mater., 211–212, 317–331.
Huang, S., Ma, C., Liao, Y., Min, C., Du, P. and Jiang, Y. (2016). Removal of Mercury(II) from Aqueous Solutions by Adsorption on Poly(1-amino-5-chloroanthraquinone) Nanofibrils: Equilibrium, Kinetics, and Mechanism Studies. J. Nanomater., 2016(7245829), 1-11.
Ihsanullah, Abbas, A., Al-Amer, A. M., Laoui, T., Al-Marri, M. J., Nasser, M. S., Khraisheh, M. and Atieh, M. A. (2016). Heavy metal removal from aqueous solution by advanced carbon nanotubes: Critical review of adsorption applications. In Sep. Purif. Technol., 157, 141-161, Elsevier Inc..
İnce, M. and Kaplan İnce, O. (2017). An Overview of Adsorption Technique for Heavy Metal Removal from Water/Wastewater: A Critical Review. Int. J. Pure Appl. Sci. Technol., 2018, 10–19.
Indrasis Das, Sovik Das, I. C. and M. M. G. (2019). Bio-refractory pollutant removal using microbial electrochemical technologies: A short review. J. Indian Chem. Soc, 96(April), 493–497.
Jamshaid, A., Hamid, A., Muhammad, N., Naseer, A., Ghauri, M., Iqbal, J., Rafiq, S. and Shah, N. S. (2017). Cellulose-based Materials for the Removal of Heavy Metals from Wastewater - An Overview. Chem. Bio. Eng. Reviews., 4(4), 240–256.
Jayakaran, P., Nirmala, G. S. and Govindarajan, L. (2019). Qualitative and Quantitative Analysis of Graphene-Based Adsorbents in Wastewater Treatment. Int. J. Chem. Eng., 2019(9872502), 1-17.
Kacan, E. (2016). Optimum BET surface areas for activated carbon produced from textile sewage sludges and its application as dye removal. J. Environ. Manage., 166, 116–123.
Karnib, M., Kabbani, A., Holail, H. and Olama, Z. (2014). Heavy metals removal using activated carbon, silica and silica activated carbon composite. Energy Procedia, 50, 113–120.
Kecili, R. and Hussain, C. M. (2018). Mechanism of adsorption on nanomaterials. In Nanomaterials in Chromatography: Current Trends in Chromatographic Research Technology and Techniques. Elsevier Inc.
Khaled Habiba, Vladimir I. Makarov, Brad R. Weiner and, and Gerardo Morell. (2014). Fabrication of Nanomaterials by Pulsed Laser Synthesis . In Manufacturing Nanostructures (OCN). One Central Press.
Khan, I., Saeed, K. and Khan, I. (2019). Nanoparticles: Properties, applications and toxicities. Arabian J. Chem., 12(7), 908–931.
Khulbe, K. C. and Matsuura, T. (2018). Removal of heavy metals and pollutants by membrane adsorption techniques. Appl. Water Sci., 8(19), 1-30.
Krause, A., Zimmermann, K. F. and Chowdhury, S. (2015). Arsenic Contamination of Drinking Water and Mental Health, IZA DP No. 9400.
Kumar, A. and Jena, H. M. (2016). Preparation and characterization of high surface area activated carbon from Fox nut (Euryale ferox) shell by chemical activation with H3PO4. Results Phys., 6, 651–658.
Kumar, M., Chung, J. S. and Hur, S. H. (2019). Graphene composites for lead ions removal from aqueous solutions. Appl. Sci. (Switzerland), 9(14), 1-30.
Kumar, S., Nair, R. R., Pillai, P. B., Gupta, S. N., Iyengar, M. A. R. and Sood, A. K. (2014). Graphene Oxide − MnFe2O4 Magnetic Nanohybrids for E ffi cient Removal of Lead and Arsenic from Water. ACS Appl. Mater. Interfaces., 6, 20, 17426–17436
Kumara, N. T. R. N., Hamdan, N., Petra, M. I., Tennakoon, K. U. and Ekanayake, P. (2014). Equilibrium isotherm studies of adsorption of pigments extracted from Kuduk-kuduk (Melastoma malabathricum L.) pulp onto TiO2 nanoparticles. J. Chem., 2014(468975), 1-6.
Nik-Abdul-Ghani, N. R., et al.
Kyzas, G. Z., Deliyanni, E. A. and Matis, K. A. (2014). Graphene oxide and its application as an adsorbent for wastewater treatment. J. Chem. Technol. Biotechnol., 89(2), 196–205.
Kyzas, G. Z. and Matis, K. A. (2015). Nanoadsorbents for pollutants removal: A review. J. Mol. Liq., 203, 159–168.
Le, A. T., Pung, S. Y., Sreekantan, S., Matsuda, A. and Huynh, D. P. (2019). Mechanisms of removal of heavy metal ions by ZnO particles. Heliyon, 5(4), e01440, 1-27.
Li, L., Duan, H., Wang, X. and Luo, C. (2014). Adsorption property of Cr(vi) on magnetic mesoporous titanium dioxide-graphene oxide core-shell microspheres. New J. Chem., 38(12), 6008–6016.
Li, Y. H., Di, Z., Ding, J., Wu, D., Luan, Z. and Zhu, Y. (2005). Adsorption thermodynamic, kinetic and desorption studies of Pb2+ on carbon nanotubes. Water Res., 39(4), 605–609.
Lin, Y. F. and Chen, J. L. (2014). Magnetic mesoporous Fe/carbon aerogel structures with enhanced arsenic removal efficiency. J. Colloid Interface Sci., 420, 74–79.
Liu, D., Zhu, Y., Li, Z., Tian, D., Chen, L. and Chen, P. (2013). Chitin nanofibrils for rapid and efficient removal of metal ions from water system. Carbohydr. Polym., 98(1), 483–489.
Lofrano, G., Carotenuto, M., Libralato, G., Domingos, R. F., Markus, A., Dini, L., Gautam, R. K., Baldantoni, D., Rossi, M., Sharma, S. K., Chattopadhyaya, M. C., Giugni, M. and Meric, S. (2016). Polymer functionalized nanocomposites for metals removal from water and wastewater: An overview. Water Res., 92, 22–37.
Lu, H., Wang, J., Stoller, M., Wang, T., Bao, Y. and Hao, H. (2016). An Overview of Nanomaterials for Water and Wastewater Treatment. Adv. Mater. Sci. Eng., 2016(4964828), 1-10.
Lu, Y., He, J., Wu, L. and Luo, G. (2016). Relationship between breakthrough curve and adsorption isotherm of Ca(II) imprinted chitosan microspheres for metal adsorption. Chin. J. Chem. Eng., 24(2), 323–329.
Lyubchik, S., Lyubchik, A., Lygina, O., Lyubchik, S. and Fonsec, I. (2011). Comparison of the Thermodynamic Parameters Estimation for the Adsorption Process of the Metals from Liquid Phase on Activated Carbons. Thermodynamics - Interaction Studies - Solids, Liquids and Gases. doi:10.5772/19514, IntechOpen.
Madadrang, C. J., Kim, H. Y., Gao, G., Wang, N., Zhu, J., Feng, H., Gorring, M., Kasner, M. L. and Hou, S. (2012). Adsorption behavior of EDTA-graphene oxide for Pb (II) removal. ACS Appl. Mater. Interfaces., 4(3), 1186–1193.
Mahmoud, A. M., Ibrahim, F. A., Shaban, S. A. and Youssef, N. A. (2015). Adsorption of heavy metal ion from aqueous solution by nickel oxide nano catalyst prepared by different methods. Egypt. J. Pet., 24(1), 27–35.
Mahmoudi, E., Ng, L. Y., Ang, W. L., Chung, Y. T., Rohani, R. and Mohammad, A. W. (2019). Enhancing Morphology and Separation Performance of Polyamide 6,6 Membranes By Minimal Incorporation of Silver Decorated Graphene Oxide Nanoparticles. Sci. Rep., 9(1), 1–16.
Mahmud, H. N. M. E., Huq, A. K. O. and Yahya, R. (2017). Polymer-based adsorbent for heavy metals removal from aqueous solution. IOP Conference Series: Mater. Sci. Eng., 206(1), 1-8.
Mallakpour, S. and Khadem, E. (2018). Carbon nanotubes for heavy metals removal. In Composite Nanoadsorbents. Elsevier Inc.
Maryam, M., Suriani, A. B., Shamsudin, M. S. and Rusop, M. (2013). BET analysis on carbon nanotubes: Comparison between single and double stage thermal CVD method. Adv. Mat. Res., 626, 289–293.
Masindi, V. and Muedi, K. L. (2018). Environmental Contamination by Heavy Metals. Heavy Metals. Hosam El-Din M. Saleh and Refaat F. Aglan, IntechOpen.
Mautner, A., Maples, H. A., Kobkeatthawin, T., Kokol, V., Karim, Z., Li, K. and Bismarck, A. (2016). Phosphorylated nanocellulose papers for copper adsorption from aqueous solutions. Int. J. Environ. Sci. Technol., 13(8), 1861–1872.
Mehdinia, A., Heydari, S. and Jabbari, A. (2020). Synthesis and characterization of reduced graphene oxide-Fe3O4@polydopamine and application for adsorption of lead ions: Isotherm and kinetic studies. Mater. Chem. Phys., 239(121964), 1-10.
Mercado-Borrayo, B. M., Schouwenaars, R., Litter, M. I., Montoya-Bautista, C. V. and Ramírez-Zamora, R. M. (2014). Metallurgical Slag as an Efficient and Economical Adsorbent of Arsenic. In Water Reclamation and Sustainability. Elsevier Inc.
Milewska-Duda, J., Duda, J., Nodzeñski, A., & Lakatos, J. (2000). Absorption and Adsorption of Methane and Carbon Dioxide in Hard Coal and Active Carbon. Langmuir, 16(12), 5458–5466.
Pollution, 7(1): 153-179, Winter 2021
Mkhoyan, K. A., Contryman, A. W., Silcox, J., Derek, A., Eda, G., Mattevi, C., Miller, S., Chhowalla, M., Mkhoyan, K. A., Contryman, A. W., Silcox, J., Stewart, D. A., Eda, G., Mattevi, C. and Miller, S. (2009). Atomic and Electronic Structure of Graphene-Oxide. Nano Lett., 9(3), 1058-1063.
Mohan, S., Kumar, V., Singh, D. K. and Hasan, S. H. (2017). Effective removal of lead ions using graphene oxide-MgO nanohybrid from aqueous solution: Isotherm, kinetic and thermodynamic modeling of adsorption. J. Environ. Chem. Eng., 5(3), 2259–2273.
Mohd Amil Usmani; Imran Khan; Bhat, A.H.; Pillai, R.S.; Mohamad Hafiz, M.K.; Mohammad Oves. (2017). Current trend in the application of nanoparticles for wastewater treatment and purification, a review.Curr. Org. Synth., 14, 1-21.
Morillo Martín, D., Faccini, M., García, M. A. and Amantia, D. (2018). Highly efficient removal of heavy metal ions from polluted water using ion-selective polyacrylonitrile nanofibers. J. Environ. Chem. Eng., 6(1), 236–245.
Mqehe-Nedzivhe, K. C., Makhado, K., Olorundare, O. F., Arotiba, O. A., Makhatha, E., Nomngongo, P. N. and Mabuba, N. (2018). Bio-adsorbents for the Removal of Heavy Metals from Water. In Arsenic - Analytical and Toxicological Studies, 26-37, IntechOpen.
Nair, R. R., Wu, H. A., Jayaram, P. N., Grigorieva, I. V. and Geim, A. K. (2012). Unimpeded permeation of water through helium-leak-tight graphene-based membranes. Science, 335(6067), 442–444.
Nasir, A. M., Goh, P. S., Abdullah, M. S., Ng, B. C., Ismail, A. F., He, M., Wang, L., Lv, Y., Wang, X., Zhu, J., Zhang, Y., Liu, T., Zarei, F., Marjani, A. and Soltani, R. (2019). Adsorptive nanocomposite membranes for heavy metal remediation: Recent progresses and challenges. Chem. Eng. J., 389(13), 96–112.
Nizamuddin, S., Siddiqui, M. T. H., Mubarak, N. M., Baloch, H. A., Abdullah, E. C., Mazari, S. A., Griffin, G. J., Srinivasan, M. P. and Tanksale, A. (2019). Iron Oxide Nanomaterials for the Removal of Heavy Metals and Dyes From Wastewater. In Nanoscale Materials in Water Purification. Elsevier Inc.
Pacheco, S., Tapia, J., Medina, M. and Rodriguez, R. (2006). Cadmium ions adsorption in simulated wastewater using structured alumina-silica nanoparticles. J. Non Cryst. Solids, 352(52–54), 5475–5481.
Panji, A., Simha, L. U. and Nagabhushana, B. M. (2016). Heavy Metals Removal by Nickel-Oxide Nanoparticles Synthesised by Lemon Juice Extract. Int. J. Eng. Manag. Res., 4(4), 287–291.
Peng, W., Li, H., Liu, Y. and Song, S. (2017). A review on heavy metal ions adsorption from water by graphene oxide and its composites. J. Mol. Liq., 230, 496–504.
Pérez-Ramírez, E. F., Luz-Asunción, M. de la, Martínez-Hernández, A. L. and Velasco-Santos, C. (2016). Graphene Materials to Remove Organic Pollutants and Heavy Metals from Water: Photocatalysis and Adsorption. Semiconductor Photocatalysis - Materials, Mechanisms and Applications., Wenbin Cao, IntechOpen.
Piri, S., Zanjani, Z. A., Piri, F., Zamani, A., Yaftian, M. and Davari, M. (2016). Potential of polyaniline modified clay nanocomposite as a selective decontamination adsorbent for Pb(II) ions from contaminated waters; kinetics and thermodynamic study. J. Environ. Health Sci. Eng., 14(1), 1–10.
Pramanik, B. K., Pramanik, S. K. and Suja, F. (2016). Removal of arsenic and iron removal from drinking water using coagulation and biological treatment. J. Water Health., 14(1), 90–96.
Qu, X., Alvarez, P. J. J. and Li, Q. (2013). Applications of nanotechnology in water and wastewater treatment. Water Res., 47(12), 3931–3946.
Ray, P. Z. and Shipley, H. J. (2015). Inorganic nano-adsorbents for the removal of heavy metals and arsenic: A review. RSC Adv., 5(38), 29885–29907.
Razzaz, A., Ghorban, S., Hosayni, L., Irani, M. and Aliabadi, M. (2016). Chitosan nanofibers functionalized by TiO2 nanoparticles for the removal of heavy metal ions. J. Taiwan Inst. Chem. Eng., 58, 333–343.
Robati, D. (2013). Pseudo-second-order kinetic equations for modeling adsorption systems for removal of lead ions using multi-walled carbon nanotube. J. Nanostructure Chem., 3(1), 3–8.
Rodríguez, C. and Leiva, E. (2019). Enhanced heavy metal removal from acid mine drainagewastewater using double-oxidized multiwalled carbon nanotubes. Molecules, 25(1), 1-22.
Saha, D. and Grappe, H. A. (2017). Adsorption properties of activated carbon fibers. In Activated Carbon Fiber and Textiles (Issue i). Elsevier Ltd.
Saleem, J., Shahid, U. Bin, Hijab, M., Mackey, H. and McKay, G. (2019). Production and applications of activated carbons as adsorbents from olive stones. Biomass Convers. Biorefin., 9(4), 775–802.
Nik-Abdul-Ghani, N. R., et al.
Samiey, B., Cheng, C. H. and Wu, J. (2014). Organic-inorganic hybrid polymers as adsorbents for removal of heavy metal ions from solutions: A review. Materials, 7(2), 673–726.
Shirzadeh, M., Sepehr, E., Rasouli Sadaghiani, M. H. and Ahmadi, F. (2020). Effect of pH, initial concentration, background electrolyte, and ionic strength on cadmium adsorption by TiO2 and γ-Al2O3 nanoparticles. Pollution, 6(2), 223–235.
Siddiqui, S. I. and Chaudhry, S. A. (2017). Arsenic : Toxic Effects and Remediation. Advanced Materials for Wastewater Treatment, 1-28, Scrivener Publishing LLC.
Singh, A. K. (2016). Nanoparticle Ecotoxicology. In Engineered Nanoparticles. Amsterdam ; Boston : Elsevier Ltd.
Singh, J., Dutta, T., Kim, K. H., Rawat, M., Samddar, P. and Kumar, P. (2018). “Green” synthesis of metals and their oxide nanoparticles: Applications for environmental remediation. J. Nanobiotechnology., 16(1), 1–24.
Sitko, R., Turek, E., Zawisza, B., Malicka, E., Talik, E., Heimann, J., Gagor, A., Feist, B. and Wrzalik, R. (2013). Adsorption of divalent metal ions from aqueous solutions using graphene oxide. Dalton Trans., 42(16), 5682–5689.
Šolic, M., Maletic, S., Isakovski, M. K., Nikic, J., Watson, M., Kónya, Z. and Trickovic, J. (2020). Comparing the adsorption performance of multiwalled carbon nanotubes oxidized by varying degrees for removal of low levels of copper, nickel and chromium(VI) from aqueous solutions. Water (Switzerland), 12(3), 1–18.
Soni, M., Mehta, P., Soni, A. and Goswami, G. K. (2018). Green Nanoparticles : Synthesis and Applications Green Nanoparticles : Synthesis and Applications Manish Soni , Priya Mehta , Anjali Soni And Girish K . Goswami. IOSR J. Biotechnol. Biochem., 4(3), 78–83.
Stafiej, A. and Pyrzynska, K. (2007). Adsorption of heavy metal ions with carbon nanotubes. Sep. Purif. Technol., 58(1), 49–52.
Tabatabaei, F. S., Izanloo, H., Heidari, H., Vaezi, N., Zamanzadeh, M., Nadali, A., Aali, R. and Asadi-Ghalhari, M. (2020). Modeling and optimization of arsenic (III) removal from aqueous solutions by GFO using response surface methodology. Pollution, 6(3), 543–553.
Taman, R. (2015). Metal Oxide Nano-particles as an Adsorbent for Removal of Heavy Metals. J. Adv. Chem. Eng., 5(3), 1-8.
Tan, K. L. and Hameed, B. H. (2017). Insight into the adsorption kinetics models for the removal of contaminants from aqueous solutions. J. Taiwan Inst. Chem. Eng., 74, 25–48.
Tchounwou, P. B., Yedjou, C. G., Patlolla, A. K. and Sutton, D. J. (2012). Molecular, clinical and environmental toxicicology Volume 3: Environmental Toxicology. In Molecular, Clinical and Environmental Toxicology, 101.
Teklehaimanot, G. Z., Kamika, I., Coetzee, M. A. A. and Momba, M. N. B. (2015). Population Growth and Its Impact on the Design Capacity and Performance of the Wastewater Treatment Plants in Sedibeng and Soshanguve, South Africa. Environ. Manage., 56(4), 984–997.
Thekkudan, V. N., Vaidyanathan, V. K., Ponnusamy, S. K., Charles, C., Sundar, S. L., Vishnu, D., Anbalagan, S., Vaithyanathan, V. K. and Subramanian, S. (2017). Review on nanoadsorbents: A solution for heavy metal removal from wastewater. IET Nanobiotechnol., 11(3), 213–224.
Torrik, E., Soleimani, M. and Ravanchi, M. T. (2019). Application of Kinetic Models for Heavy Metal Adsorption in the Single and Multicomponent Adsorption System. Int. J. Environ. Res., 13(5), 813–828.
UN-Water. (2020). World Water Development Report 2020 – Water and Climate Change.
Vélez, E., Campillo, G. E., Morales, G., Hincapié, C., Osorio, J., Arnache, O., Uribe, J. I. and Jaramillo, F. (2016). Mercury removal in wastewater by iron oxide nanoparticles. J. Phys. Conf. Ser., 687(1).
Vunain, E., Mishra, A. K. and Mamba, B. B. (2016). Dendrimers, mesoporous silicas and chitosan-based nanosorbents for the removal of heavy-metal ions: A review.Int. J. Biol. Macromol., 86, 570–586.
Wadhawan, S., Jain, A., Nayyar, J. and Mehta, S. K. (2020). Role of nanomaterials as adsorbents in heavy metal ion removal from waste water: A review. J. Water Process. Eng., 33(101038), 1-17.
Wan, S., He, F., Wu, J., Wan, W., Gu, Y. and Gao, B. (2016). Rapid and highly selective removal of lead from water using graphene oxide-hydrated manganese oxide nanocomposites. J. Hazard. Mater., 314, 32–40.
Wang, L., Shi, C., Pan, L., Zhang, X. and Zou, J. J. (2020). Rational design, synthesis, adsorption principles and applications of metal oxide adsorbents: A review. Nanoscale, 12(8), 4790–4815.
Wang, X. (2012). Nanomaterials as Sorbents to Remove Heavy Metal Ions in Wastewater Treatment. J. Anal. Toxicol., 2(7), 1-7.
White, R. L., White, C. M., Turgut, H., Massoud, A. and Tian, Z. R. (2018). Comparative studies on copper adsorption by graphene oxide and functionalized graphene oxide nanoparticles. J. Taiwan Inst. Chem. Eng., 0, 1–11.
WHO (2017). Drinking water quality guidelines. World Health Organization.
William Kajjumba, G., Emik, S., Öngen, A., Kurtulus Özcan, H. and Aydın, S. (2018). Modelling of Adsorption Kinetic Processes—Errors, Theory and Application. Advanced Sorption Process Applications, 1–19. IntechOpen.
Wu, F. C., Liu, B. L., Wu, K. T. and Tseng, R. L. (2010). A new linear form analysis of Redlich-Peterson isotherm equation for the adsorptions of dyes. Chem. Eng. J., 162(1), 21–27.
Xu, J., Cao, Z., Zhang, Y., Yuan, Z., Lou, Z., Xu, X. and Wang, X. (2018). A review of functionalized carbon nanotubes and graphene for heavy metal adsorption from water: Preparation, application, and mechanism. In Chemosphere,195, 351–364. Elsevier Ltd.
Yang, J., Hou, B., Wang, J., Tian, B., Bi, J., Wang, N., Li, X. and Huang, X. (2019). Nanomaterials for the removal of heavy metals from wastewater. Nanomaterials, 9(3), 1-39.
Yildiz, S. (2018). Artificial neural network approach for modeling of Ni(II) adsorption from aqueous solution by peanut shell. Ecol. Chem. Eng. S, 25(4), 581–604.
Yoon, Y., Kyu, W., Hwang, T., Ho, D., Seok, W. and Kang, J. (2016). Comparative evaluation of magnetite – graphene oxide and magnetite-reduced graphene oxide composite for As ( III ) and As ( V ) removal. J. Hazard. Mater., 304, 196–204.
Yousef, R. I., El-Eswed, B. and Al-Muhtaseb, A. H. (2011). Adsorption characteristics of natural zeolites as solid adsorbents for phenol removal from aqueous solutions: Kinetics, mechanism, and thermodynamics studies. Chem. Eng. J., 171(3), 1143–1149.
Youssef, A. M. and Malhat, F. M. (2014). Selective removal of heavy metals from drinking water using titanium dioxide nanowire. Macromol. Symp., 337(1), 96–101.
Yu, L., Ma, Y., Ong, C. N., Xie, J. and Liu, Y. (2015). Rapid adsorption removal of arsenate by hydrous cerium oxide-graphene composite. RSC Adv., 5(80), 64983–64990.
Yu, W., Sisi, L., Haiyan, Y. and Jie, L. (2020). Progress in the functional modification of graphene/graphene oxide: A review. RSC Adv., 10(26), 15328–15345.
Zare, E. N., Motahari, A. and Sillanpää, M. (2018). Nanoadsorbents based on conducting polymer nanocomposites with main focus on polyaniline and its derivatives for removal of heavy metal ions/dyes: A review. Environ. Res., 162, 173–195.
Zarei, F., Marjani, A. and Soltani, R. (2019). Novel and green nanocomposite-based adsorbents from functionalised mesoporous KCC-1 and chitosan-oleic acid for adsorption of Pb(II). Eur. Polym. J., 119, 400–409.
Zhang, M., Gao, B., Varnoosfaderani, S., Hebard, A., Yao, Y. and Inyang, M. (2013). Preparation and characterization of a novel magnetic biochar for arsenic removal. Bioresour. Technol., 130, 457–462.
Zhang, S., Shi, Q., Christodoulatos, C., Korfiatis, G. and Meng, X. (2019). Adsorptive filtration of lead by electrospun PVA/PAA nanofiber membranes in a fixed-bed column. Chem. Eng. J., 370, 1262–1273.
Zhao, G., Huang, X., Tang, Z., Huang, Q., Niu, F. and Wang, X. (2018). Polymer-based nanocomposites for heavy metal ions removal from aqueous solution: A review. Polym. Chem., 9(26), 3562–3582.