Adeli, M., Yamini, Y., & Faraji, M. (2017). Removal of copper, nickel and zinc by sodium dodecyl sulphate coated magnetite nanoparticles from water and wastewater samples. Arabian Journal of Chemistry, 10, S514-S521. doi:10.1016/j.arabjc.2012.10.012

Ahangari, A., Raygan, S., & Ataie, A. (2019). Capabilities of nickel zinc ferrite and its nanocomposite with CNT for adsorption of arsenic (V) ions from wastewater. Journal of Environmental Chemical Engineering, 7(6) doi:10.1016/j.jece.2019.103493

Ahmad, A., Rafatullah, M., Sulaiman, O., Ibrahim, M. H., Chii, Y. Y., & Siddique, B. M. (2009). Removal of cu(II) and pb(II) ions from aqueous solutions by adsorption on sawdust of meranti wood. Desalination, 247(1-3), 636-646. doi:10.1016/j.desal.2009.01.007

Ahmad, M., Wang, J., Xu, J., Zhang, Q., & Zhang, B. (2020). Magnetic tubular carbon nanofibers as efficient cu(II) ion adsorbent from wastewater. Journal of Cleaner Production, 252 doi:10.1016/j.jclepro.2019.119825

Ahmadpour, A., Eftekhari, N., & Ayati, A. (2014). Performance of MWCNTs and a low-cost adsorbent for chromium(VI) ion removal. Journal of Nanostructure in Chemistry, 4(4), 171-178. doi:10.1007/s40097-014-0119-9

Ali, W. N. N. W., Sufian, S., & Abdullah, M. Z. (2016). Green functionalization: Comparison of different carbonaceous materials. Paper presented at the Procedia Engineering, , 148 795-805. doi:10.1016/j.proeng.2016.06.566 Retrieved from www.scopus.com

Almomani, F., Bhosale, R., Khraisheh, M., kumar, A., & Almomani, T. (2020). Heavy metal ions removal from industrial wastewater using magnetic nanoparticles (MNP). Applied Surface Science, 506 doi:10.1016/j.apsusc.2019.144924

Alves, D. C. S., Gonçalves, J. O., Coseglio, B. B., Burgo, T. A. L., Dotto, G. L., Pinto, L. A. A., & Cadaval, T. R. S., Jr. (2019). Adsorption of phenol onto chitosan hydrogel scaffold modified with carbon nanotubes. Journal of Environmental Chemical Engineering, 7(6) doi:10.1016/j.jece.2019.103460

Amen, R., Yaseen, M., Mukhtar, A., Klemeš, J. J., Saqib, S., Ullah, S., . . . Bokhari, A. (2020). Lead and cadmium removal from wastewater using eco-friendly biochar adsorbent derived from rice husk, wheat straw, and corncob. Cleaner Engineering and Technology, 1 doi:10.1016/j.clet.2020.100006

Arshadi, M., Amiri, M. J., & Mousavi, S. (2014). Kinetic, equilibrium and thermodynamic investigations of ni(II), cd(II), cu(II) and co(II) adsorption on barley straw ash. Water Resources and Industry, 6, 1-17. doi:10.1016/j.wri.2014.06.001

Balintova, M., Holub, M., & Singovszka, E. (2012). Study of iron, copper and zinc removal from acidic solutions by sorption. Chemical Engineering Transactions, 28, 175-180. doi:10.3303/CET1228030

Bartczak, P., Norman, M., Klapiszewski, Ł., Karwańska, N., Kawalec, M., Baczyńska, M., . . . Jesionowski, T. (2018). Removal of nickel(II) and lead(II) ions from aqueous solution using peat as a low-cost adsorbent: A kinetic and equilibrium study. Arabian Journal of Chemistry, 11(8), 1209-1222. doi:10.1016/j.arabjc.2015.07.018

Bayazit, T. S., & Kerkez, Ö. (2014). Hexavalent chromium adsorption on superparamagnetic multi-wall carbon nanotubes and activated carbon composites. Chemical Engineering Research and Design, 92(11), 2725-2733. doi:10.1016/j.cherd.2014.02.007

Bernard, E., & Jimoh, A. (2013). Adsorption of pb, fe, cu and zn from industrial electroplating wastewater by orange peel activated carbon. International Journal of Engineering and Applied Sciences, 4(2), 95-103. Retrieved from www.scopus.com

Bollen, P., Quievy, N., Detrembleur, C., Thomassin, J. M., Monnereau, L., Bailly, C., . . . Pardoen, T. (2016). Processing of a new class of multifunctional hybrid for electromagnetic absorption based on a foam filled honeycomb. Materials and Design, 89, 323-334. doi:10.1016/j.matdes.2015.09.129

Božić, D., Stanković, V., Gorgievski, M., Bogdanović, G., & Kovačević, R. (2009). Adsorption of heavy metal ions by sawdust of deciduous trees. Journal of Hazardous Materials, 171(1-3), 684-692. doi:10.1016/j.jhazmat.2009.06.055

Briffa, J., Sinagra, E., & Blundell, R. (2020). Heavy metal pollution in the environment and their toxicological effects on humans. Heliyon, 6(9) doi:10.1016/j.heliyon.2020.e04691

Chwastowski, J., Staroń, P., Kołoczek, H., & Banach, M. (2017). Adsorption of hexavalent chromium from aqueous solutions using canadian peat and coconut fiber. Journal of Molecular Liquids, 248, 981-989. doi:10.1016/j.molliq.2017.10.152

Das, R., Abd Hamid, S. B., Ali, M. E., Ismail, A. F., Annuar, M. S. M., & Ramakrishna, S. (2014). Multifunctional carbon nanotubes in water treatment: The present, past and future. Desalination, 354, 160-179. doi:10.1016/j.desal.2014.09.032

Duan, C., Ma, T., Wang, J., & Zhou, Y. (2020). Removal of heavy metals from aqueous solution using carbon-based adsorbents: A review. Journal of Water Process Engineering, 37 doi:10.1016/j.jwpe.2020.101339

Edwards, E. R., Antunes, E. F., Botelho, E. C., Baldan, M. R., & Corat, E. J. (2011). Evaluation of residual iron in carbon nanotubes purified by acid treatments. Applied Surface Science, 258(2), 641-648. doi:10.1016/j.apsusc.2011.07.032

Fernández-Luqueño, F., López-Valdez, F., Gamero-Melo, P., Luna-Suárez, S., Aguilera-González, E. N., Martínez, A. I., . . . Pérez-Velázquez, I. R. (2013). Heavy metal pollution in drinking water — a global risk for human health: A review. Afr.J.Environ.Sci.Technol., 7(7), 567-584. Retrieved from www.scopus.com

Foo, K. Y., & Hameed, B. H. (2010). Insights into the modeling of adsorption isotherm systems. Chemical Engineering Journal, 156(1), 2-10. doi:10.1016/j.cej.2009.09.013

Franus, M., & Bandura, L. (2014). Sorption of heavy metal ions from aqueous solution by glauconite. Fresenius Environmental Bulletin, 23(3 A), 825-839. Retrieved from www.scopus.com

Fu, D., Ma, Q., Zeng, X., Chen, J., Zhang, W., & Li, D. (2013). Synthesis and magnetic properties of aligned carbon nanotubes by microwave-assisted pyrolysis of acetylene. Physica E: Low-Dimensional Systems and Nanostructures, 54, 185-190. doi:10.1016/j.physe.2013.06.022

Gangupomu, R. H., Sattler, M. L., & Ramirez, D. (2016). Comparative study of carbon nanotubes and granular activated carbon: Physicochemical properties and adsorption capacities. Journal of Hazardous Materials, 302, 362-374. doi:10.1016/j.jhazmat.2015.09.002

Gao, A., Xie, K., Song, X., Zhang, K., & Hou, A. (2017). Removal of the heavy metal ions from aqueous solution using modified natural biomaterial membrane based on silk fibroin. Ecological Engineering, 99, 343-348. doi:10.1016/j.ecoleng.2016.11.008

Gupta, V. K., Agarwal, S., Bharti, A. K., & Sadegh, H. (2017). Adsorption mechanism of functionalized multi-walled carbon nanotubes for advanced cu (II) removal. Journal of Molecular Liquids, 230, 667-673. doi:10.1016/j.molliq.2017.01.083

Gupta, V. K., Mittal, A., & Gajbe, V. (2005). Adsorption and desorption studies of a water soluble dye, quinoline yellow, using waste materials. Journal of Colloid and Interface Science, 284(1), 89-98. doi:10.1016/j.jcis.2004.09.055

Hao, Y. -., Man, C., & Hu, Z. -. (2010). Effective removal of cu (II) ions from aqueous solution by amino-functionalized magnetic nanoparticles. Journal of Hazardous Materials, 184(1-3), 392-399. doi:10.1016/j.jhazmat.2010.08.048

Huang, Z. -., Wang, X. -., & Yang, D. -. (2015). Adsorption of cr(VI) in wastewater using magnetic multi-wall carbon nanotubes. Water Science and Engineering, 8(3), 226-232. doi:10.1016/j.wse.2015.01.009

Ihsanullah, Abbas, A., Al-Amer, A. M., Laoui, T., Al-Marri, M. J., Nasser, M. S., . . . Atieh, M. A. (2016). Heavy metal removal from aqueous solution by advanced carbon nanotubes: Critical review of adsorption applications. Separation and Purification Technology, 157, 141-161. doi:10.1016/j.seppur.2015.11.039

Kamari, A., & Ngah, W. S. (2010). Adsorption of cu(II) and cr(VI) onto treated shorea dasyphylla bark: Isotherm, kinetics, and thermodynamic studies. Separation Science and Technology, 45(4), 486-496. doi:10.1080/01496390903526717

Kamari, A., Yusoff, S. N. M., Abdullah, F., & Putra, W. P. (2014). Biosorptive removal of cu(II), ni(II) and pb(II) ions from aqueous solutions using coconut dregs residue: Adsorption and characterisation studies. Journal of Environmental Chemical Engineering, 2(4), 1912-1919. doi:10.1016/j.jece.2014.08.014

Karami, H. (2013). Heavy metal removal from water by magnetite nanorods. Chemical Engineering Journal, 219, 209-216. doi:10.1016/j.cej.2013.01.022

Khandanlou, R., Ahmad, M. B., Masoumi, H. R. F., Shameli, K., Basri, M., & Kalantari, K. (2015). Rapid adsorption of copper(II) and lead(II) by rice straw/Fe3O4 nanocomposite: Optimization, equilibrium isotherms, and adsorption kinetics study. PLoS ONE, 10(3) doi:10.1371/journal.pone.0120264

Kosa, S. A., Al-Zhrani, G., & Abdel Salam, M. (2012). Removal of heavy metals from aqueous solutions by multi-walled carbon nanotubes modified with 8-hydroxyquinoline. Chemical Engineering Journal, 181-182, 159-168. doi:10.1016/j.cej.2011.11.044

Li, H., Xiao, D. -., He, H., Lin, R., & Zuo, P. -. (2013). Adsorption behavior and adsorption mechanism of cu(II) ions on amino-functionalized magnetic nanoparticles. Transactions of Nonferrous Metals Society of China (English Edition), 23(9), 2657-2665. doi:10.1016/S1003-6326(13)62782-X

Li, Y. -., Ding, J., Luan, Z., Di, Z., Zhu, Y., Xu, C., . . . Wei, B. (2003). Competitive adsorption of Pb2+, Cu2+ and cd 2+ ions from aqueous solutions by multiwalled carbon nanotubes. Carbon, 41(14), 2787-2792. doi:10.1016/S0008-6223(03)00392-0

Liu, C., & Cheng, H. -. (2005). Carbon nanotubes for clean energy applications. Journal of Physics D: Applied Physics, 38(14), R231-R252. doi:10.1088/0022-3727/38/14/R01

Liu, J., Chen, Y., Han, T., Cheng, M., Zhang, W., Long, J., & Fu, X. (2019). A biomimetic SiO2@chitosan composite as highly-efficient adsorbent for removing heavy metal ions in drinking water. Chemosphere, 214, 738-742. doi:10.1016/j.chemosphere.2018.09.172

Liu, S., Shen, Q., Cao, Y., Gan, L., Wang, Z., Steigerwald, M. L., & Guo, X. (2010). Chemical functionalization of single-walled carbon nanotube field-effect transistors as switches and sensors. Coordination Chemistry Reviews, 254(9-10), 1101-1116. doi:10.1016/j.ccr.2009.11.007

Liu, X., Guan, J., Lai, G., Xu, Q., Bai, X., Wang, Z., & Cui, S. (2020). Stimuli-responsive adsorption behavior toward heavy metal ions based on comb polymer functionalized magnetic nanoparticles. Journal of Cleaner Production, 253 doi:10.1016/j.jclepro.2019.119915

Lu, C., Chung, Y. -., & Chang, K. -. (2006). Adsorption thermodynamic and kinetic studies of trihalomethanes on multiwalled carbon nanotubes. Journal of Hazardous Materials, 138(2), 304-310. doi:10.1016/j.jhazmat.2006.05.076

Lu, J., Drzal, L. T., Worden, R. M., & Lee, I. (2007). Simple fabrication of a highly sensitive glucose biosensor using enzymes immobilized in exfoliated graphite nanoplatelets nafion membrane. Chemistry of Materials, 19(25), 6240-6246. doi:10.1021/cm702133u

Luo, N., Li, X., Wang, X., Yan, H., Zhang, C., & Wang, H. (2010). Synthesis and characterization of carbon-encapsulated iron/iron carbide nanoparticles by a detonation method. Carbon, 48(13), 3858-3863. doi:10.1016/j.carbon.2010.06.051

Ma, J., Zhuang, Y., & Yu, F. (2015). Equilibrium, kinetic and thermodynamic adsorption studies of organic pollutants from aqueous solution onto CNT/C@Fe/chitosan composites. New Journal of Chemistry, 39(12), 9299-9305. doi:10.1039/c5nj01876e

Ma, X., Li, L., Yang, L., Su, C., Wang, K., Yuan, S., & Zhou, J. (2012). Adsorption of heavy metal ions using hierarchical CaCO 3-maltose meso/macroporous hybrid materials: Adsorption isotherms and kinetic studies. Journal of Hazardous Materials, 209-210, 467-477. doi:10.1016/j.jhazmat.2012.01.054

Machado, F. M., Fagan, S. B., da Silva, I. Z., & de Andrade, M. J. (2015). Carbon nanoadsorbents doi:10.1007/978-3-319-18875-1_2 Retrieved from www.scopus.com

Mahalingam, P., Maiyalagan, T., ManiKandan, E., Syed Shabudeen, P. S., & Karthikeyan, S. (2013). Dynamic and equilibrium studies on the sorption of basic dye (basic brown 4) onto multi-walled carbon nanotubes prepared from renewable carbon precursors. J Environ Nanotechnol, 2, 43. Retrieved from www.scopus.com

Malik, L. A., Bashir, A., Qureashi, A., & Pandith, A. H. (2019). Detection and removal of heavy metal ions: A review. Environmental Chemistry Letters, 17(4), 1495-1521. doi:10.1007/s10311-019-00891-z

Marković, R., Stevanović, J., Stevanović, Z., Bugarin, M., Nedeljković, D., Grajić, A., & Stajić-Trošić, J. (2011). Using the low-cost waste materials for heavy metals removal from the mine wastewater. Materials Transactions, 52(10), 1849-1852. doi:10.2320/matertrans.M2011191

Maryam, M., Suriani, A. B., Shamsudin, M. S., & Rusop, M. (2013). BET analysis on carbon nanotubes: Comparison between single and double stage thermal CVD method doi:10.4028/www.scientific.net/AMR.626.289 Retrieved from www.scopus.com

Miyamoto, J. -., Kanoh, H., & Kaneko, K. (2005). The addition of mesoporosity to activated carbon fibers by a simple reactivation process. Carbon, 43(4), 855-857. doi:10.1016/j.carbon.2004.10.049

Mubarak, N. M., Sahu, J. N., Abdullah, E. C., & Jayakumar, N. S. (2016). Rapid adsorption of toxic pb(II) ions from aqueous solution using multiwall carbon nanotubes synthesized by microwave chemical vapor deposition technique. Journal of Environmental Sciences (China), 45, 143-155. doi:10.1016/j.jes.2015.12.025

Mubarak, N. M., Sahu, J. N., Abdullah, E. C., Jayakumar, N. S., & Ganesan, P. (2015). Novel microwave-assisted multiwall carbon nanotubes enhancing cu (II) adsorption capacity in water. Journal of the Taiwan Institute of Chemical Engineers, 53, 140-152. doi:10.1016/j.jtice.2015.02.016

Nata, I. F., Wicakso, D. R., Mirwan, A., Irawan, C., Ramadhani, D., & Ursulla. (2020). Selective adsorption of pb(II) ion on amine-rich functionalized rice husk magnetic nanoparticle biocomposites in aqueous solution. Journal of Environmental Chemical Engineering, 8(5) doi:10.1016/j.jece.2020.104339

Oliveira, J. A., Cunha, F. A., & Ruotolo, L. A. M. (2019). Synthesis of zeolite from sugarcane bagasse fly ash and its application as a low-cost adsorbent to remove heavy metals. Journal of Cleaner Production, 229, 956-963. doi:10.1016/j.jclepro.2019.05.069

Palanivell, P., Ahmed, O. H., Latifah, O., & Majid, N. M. A. (2020). Adsorption and desorption of nitrogen, phosphorus, potassium, and soil buffering capacity following application of chicken litter biochar to an acid soil. Applied Sciences (Switzerland), 10(1) doi:10.3390/app10010295

Pavan Kumar, G. V. S. R., Malla, K. A., Yerra, B., & Srinivasa Rao, K. (2019). Removal of cu(II) using three low-cost adsorbents and prediction of adsorption using artificial neural networks. Applied Water Science, 9(3) doi:10.1007/s13201-019-0924-x

Peigney, A., Laurent, C., Flahaut, E., Bacsa, R. R., & Rousset, A. (2001). Specific surface area of carbon nanotubes and bundles of carbon nanotubes. Carbon, 39(4), 507-514. doi:10.1016/S0008-6223(00)00155-X

Pyrzyńska, K., & Bystrzejewski, M. (2010). Comparative study of heavy metal ions sorption onto activated carbon, carbon nanotubes, and carbon-encapsulated magnetic nanoparticles. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 362(1-3), 102-109. doi:10.1016/j.colsurfa.2010.03.047

Qu, S., Huang, F., Yu, S., Chen, G., & Kong, J. (2008). Magnetic removal of dyes from aqueous solution using multi-walled carbon nanotubes filled with Fe2O3 particles. Journal of Hazardous Materials, 160(2-3), 643-647. doi:10.1016/j.jhazmat.2008.03.037

Rafatullah, M., Sulaiman, O., Hashim, R., & Ahmad, A. (2009). Adsorption of copper (II), chromium (III), nickel (II) and lead (II) ions from aqueous solutions by meranti sawdust. Journal of Hazardous Materials, 170(2-3), 969-977. doi:10.1016/j.jhazmat.2009.05.066

Rahman, M. S., & Islam, M. R. (2009). Effects of pH on isotherms modeling for cu(II) ions adsorption using maple wood sawdust. Chemical Engineering Journal, 149(1-3), 273-280. doi:10.1016/j.cej.2008.11.029

Rao, G. P., Lu, C., & Su, F. (2007). Sorption of divalent metal ions from aqueous solution by carbon nanotubes: A review. Separation and Purification Technology, 58(1), 224-231. doi:10.1016/j.seppur.2006.12.006

Rao, M. M., Ramana, D. K., Seshaiah, K., Wang, M. C., & Chien, S. W. C. (2009). Removal of some metal ions by activated carbon prepared from phaseolus aureus hulls. Journal of Hazardous Materials, 166(2-3), 1006-1013. doi:10.1016/j.jhazmat.2008.12.002

Rodríguez, C., Briano, S., & Leiva, E. (2020). Increased adsorption of heavy metal ions in multi-walled carbon nanotubes with improved dispersion stability. Molecules, 25(14) doi:10.3390/molecules25143106

Sankhla, M. S., Kumari, M., Nandan, M., Kumar, R., & Agrawal, P. (2016). Heavy metals contamination in water and their hazardous effect on human health-a review. International Journal of Current Microbiology and Applied Sciences, 5(10), 759-766. Retrieved from www.scopus.com

Sengupta, J. (2018). Carbon nanotube fabrication at industrial scale: Opportunities and challenges. Handbook of nanomaterials for industrial applications (pp. 172-194) doi:10.1016/B978-0-12-813351-4.00010-9 Retrieved from www.scopus.com

Shamsudin, M. S., Achoi, M. F., Asiah, M. N., Ismail, L. N., Suriani, A. B., Abdullah, S., . . . Rusop, M. (2012). An investigation on the formation of carbon nanotubes by two-stage chemical vapor deposition. Journal of Nanomaterials, 2012 doi:10.1155/2012/972126

Shan, R., Shi, Y., Gu, J., Wang, Y., & Yuan, H. (2020). Single and competitive adsorption affinity of heavy metals toward peanut shell-derived biochar and its mechanisms in aqueous systems. Chinese Journal of Chemical Engineering, 28(5), 1375-1383. doi:10.1016/j.cjche.2020.02.012

Siddiqa, A., Shahid, A., & Gill, R. (2015). Silica decorated CNTs sponge for selective removal of toxic contaminants and oil spills from water. Journal of Environmental Chemical Engineering, 3(2), 892-897. doi:10.1016/j.jece.2015.02.026

Sočo, E., & Kalembkiewicz, J. (2015). Removal of copper(II) and zinc(II) ions from aqueous solution by chemical treatment of coal fly ash. Croatica Chemica Acta, 88(3), 267-279. doi:10.5562/cca2646

Sun, W. -., Xia, J., & Shan, Y. -. (2014). Comparison kinetics studies of cu(II) adsorption by multi-walled carbon nanotubes in homo and heterogeneous systems: Effect of nano-SiO2. Chemical Engineering Journal, 250, 119-127. doi:10.1016/j.cej.2014.03.094

Suriani, A. B., Alfarisa, S., Mohamed, A., Isa, I. M., Kamari, A., Hashim, N., . . . Rusop, M. (2015). Quasi-aligned carbon nanotubes synthesised from waste engine oil. Materials Letters, 139, 220-223. doi:10.1016/j.matlet.2014.10.046

Suriani, A. B., Azira, A. A., Nik, S. F., Md Nor, R., & Rusop, M. (2009). Synthesis of vertically aligned carbon nanotubes using natural palm oil as carbon precursor. Materials Letters, 63(30), 2704-2706. doi:10.1016/j.matlet.2009.09.048

Suriani, A. B., Dalila, A. R., Mohamed, A., Mamat, M. H., Salina, M., Rosmi, M. S., . . . Rusop, M. (2013). Vertically aligned carbon nanotubes synthesized from waste chicken fat. Materials Letters, 101, 61-64. doi:10.1016/j.matlet.2013.03.075

Suriani, A. B., Dalila, A. R., Mohamed, A., Soga, T., & Tanemura, M. (2015). Synthesis, structural, and field electron emission properties of quasi-aligned carbon nanotubes from gutter oil. Materials Chemistry and Physics, 165, 1-7. doi:10.1016/j.matchemphys.2015.09.002

Suriani, A. B., Md Nor, R., & Rusop, M. (2010). Vertically aligned carbon nanotubes synthesized from waste cooking palm oil. Journal of the Ceramic Society of Japan, 118(1382), 963-968. doi:10.2109/jcersj2.118.963