Effect of pH, Initial Concentration, Background Electrolyte, and Ionic Strength on Cadmium Adsorption by TiO2 and γ-Al2O3 Nanoparticles

Document Type : Original Research Paper


Soil Science Department, Faculty of Agriculture, Urmia University, P.O.Box 57159-44931, Urmia, Iran


The entrance of Cd (II) to aqueous environments causes a major problem to human health. The current article examines the efficiency of TiO2 and γ-Al2O3 nanoparticles in Cd (II) removal from aqueous medium as influenced by different chemical factors, such as pH, initial concentration, background electrolyte, and ionic strength, in accordance with standard experimental methods. It conducts Batch experiments, fitting various isotherm models (Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich) to the equilibrium data. Saturation indices (SI) of TiO2 and γ-Al2O3 nanosorbents indicate that adsorption is a predominant mechanism for Cd (II) removal from aqueous solution, giving maximum Cd (II) adsorption rates of 3348 and 1173 mg/kg for TiO2 and γ-Al2O3 nanoparticles, respectively, both obtained at the highest pH level (pH = 8) as well as the highest initial Cd (II) concentration (equal to 80 mg/ L). Cadmium removal efficiency with TiO2 and γ-Al2O3 nanoparticles has increased by raising pH from 6 to 8. The Freundlich adsorption isotherm model could fit the experimental equilibrium data well at different pH levels. Also, it has been revealed that cadmium adsorption drops as the ionic strength is increased. The maximum Cd (II) adsorption (1625 mg/kg) has been attained at 0.01 M ionic strength in the presence of NaCl. Thermodynamic calculations demonstrate the spontaneous nature of Cd (II) adsorption by TiO2 and γ-Al2O3 nanoparticles. The former (TiO2) have high adsorption capacities, suggesting they are probably effective metal sorbents, compared to the latter (γ-Al2O3).


Allison, J. D., Brown, D. S. and Novo-Gradac, K. J. (1991). MINTEQA2/PRODEFA2, a geochemical assessment model for environmental systems: version 3.0 user's manual. Environmental Research Laboratory, Office of Research and Development, US Environmental Protection Agency.
Bashir, S., Rizwan, M. S., Salam, A., Fu, Q., Zhu, J., Shaaban, M. and Hu, H. (2018). Cadmium immobilization potential of rice straw-derived biochar, zeolite and rock phosphate: extraction techniques and adsorption mechanism. J. Phys. Chem., 100(5); 727-732.
Bonilla-Petriciolet, A., Sellaoui, L., Mendoza-Castillo, D. I., Reynel-Avila, H. E. and Lamine, A. B. (2018). A new statistical physics model for the ternary adsorption of Cu2+, Cd2+ and Zn2+ ions on bone char: experimental investigation and simulations. J. Colloid Interface Sci., 21(2); 84-89.
Bhardwaj, A., Chand, P., Pakade, Y. B., Joshi, R. and Sharma, M. (2019). Kinetic and equilibrium studies on adsorption of cadmium from aqueous solution using Aesculus Indica seed shell. Geoderma., 40(1); 251-262.
Chen, K., He, J., Li, Y., Cai, X., Zhang, K., Liu, T. and Liu, J. (2017). Removal of cadmium and lead ions from water by sulfonated magnetic nanoparticle adsorbents. J. Colloid Interface Sci., 494 (1); 307-316.
Cheng, M., Zeng, G., Huang, D., Lai, C., Xu, P., Zhang, C. and Liu, Y. (2016). Hydroxyl radicals based advanced oxidation processes (AOPs) for remediation of soils contaminated with organic compounds: a review. Chem. Eng. Sci., 284 (1); 582-598.
Dubinin, M.M. (1960). Sorption and structure of active carbons. I. Adsorption of organic vapors, Zhurnal Fizicheskoi Khimii. 21 (1); 1351–1362.
El-Deen, S. E. A. and Zhang, F. S. (2016). Immobilisation of TiO2-nanoparticles on sewage sludge and their adsorption for cadmium removal from aqueous solutions. J. Exp. Nanosci., 11(4); 239-258.
Fan, H. L., Zhou, S. F., Jiao, W. Z., Qi, G. S. and Liu, Y. Z. (2017). Removal of heavy metal ions by magnetic chitosan nanoparticles prepared continuously via high-gravity reactive precipitation method. Carbohydr. Polymer., 174 (3); 1192-1200.
Folens, K., Huysman, S., Van Hulle, S. and Du Laing, G. (2017). Chemical and economic optimization of the coagulation-flocculation process for silver removal and recovery from industrial wastewater. Sep. Purif. Technol., 179 (2); 145-151.
Freundlich, H. M. F. (1906). Over the adsorption in solution. J. Phys. Chem., 57; 1100-1107.
Gatabi, M. P., Moghaddam, H. M. and Ghorbani, M. (2016). Efficient removal of cadmium using magnetic multiwalled carbon nanotube nanoadsorbents: equilibrium, kinetic, and thermodynamic study. J. Nanoparticle Res., 18(7); 189-195.
Haq, S., Rehman, W. and Waseem, M. (2019). Adsorption Efficiency of Anatase TiO2 Nanoparticles against Cadmium Ions. J. Inorg Organomet P., 29(3): 651-658.
Huang, Y., Fulton, A. N. and Keller, A. A. (2016). Simultaneous removal of PAHs and metal contaminants from water using magnetic nanoparticle adsorbents. Sci Total Environ., 571 (1); 1029-1036.
Kataria, N. and Garg, V. K. (2018). Green synthesis of Fe3O4 nanoparticles loaded sawdust carbon for cadmium (II) removal from water: Regeneration and mechanism. Chemosphere., 208(2); 818-828.
Koju, N. K., Song, X., Wang, Q., Hu, Z. and Colombo, C. (2018). Cadmium removal from simulated groundwater using alumina nanoparticles: behaviors and mechanisms. Environ Pollut., 240 (1); 255-266.
Kow, K. W., Kiew, P. L., Yusoff, R. and Abdullah, E. C. (2017). Preliminary evidence for enhanced adsorption of cadmium (II) ions using nano-magnetite aligned in silica gel matrix. Chem. Eng. Trans., 56 (2); 1231-1236.
Kim, K., Park, M. S., Na, Y., Choi, J., Jenekhe, S. A. and Kim, F. S. (2019). Preparation and application of polystyrene-grafted alumina core-shell nanoparticles for dielectric surface passivation in solution-processed polymer thin film transistors. Organic Electronics, 65 (1); 305-310.
Laidler, K. J. (1984). The development of the Arrhenius equation. J. Chem. Educ., 61(6); 494.
Lu, F. and Astruc, D. (2018). Nanomaterials for removal of toxic elements from water. Coordination Chemistry Reviews, 356 (1); 147-164.
Pollution, 6(2): 223-235, Spring 2020
Pollution is licensed under a "Creative Commons Attribution 4.0 International (CC-BY 4.0)"
Lin, J., Su, B., Sun, M., Chen, B. and Chen, Z. (2018). Biosynthesized iron oxide nanoparticles used for optimized removal of cadmium with response surface methodology. Sci Total Environ., 627 (1); 314-321.
Lajayer, B. A., Najafi, N., Moghiseh, E., Mosaferi, M. and Hadian, J. (2018). Removal of heavy metals (Cu2+ and Cd2+) from effluent using gamma irradiation, titanium dioxide nanoparticles and methanol. J. Nano Structure., 8(4); 483-496.
Li, Y., Yang, Z., Chen, Y. and Huang, L. (2019). Adsorption, recovery, and regeneration of Cd by magnetic phosphate nanoparticles. J. Phys. Chem., 24(2); 1-12.
Langmuir, I. (1916). The constitution and fundamental properties of solids and liquids. Part I. Solids. Chemosphere., 38(11); 2221-2295.
Islam, M. A., Morton, D. W., Johnson, B. B., Pramanik, B. K., Mainali, B. and Angove, M. J. (2018). Metal ion and contaminant sorption onto aluminium oxide-based materials: a review and future research. J. Environ. Chem. Eng., 25 (2); 35-42.
Musso, T. B., Parolo, M. E. and Pettinari, G. (2019). pH, Ionic Strength, and Ion Competition Effect on Cd (II) and Ni (II) Sorption by a Na-bentonite Used as Liner Material. Polish Journal of Environmental Studies, 28(4); 35-41.
Parvin, F., Rikta, S. and Tareq, S. M. (2019). Application of Nanomaterials for the Removal of Heavy Metal from Wastewater. J. Nanotech in Water and Wastewater Treat., 34(2); 137-157.
Rahmani, A., Zavvar Mosavi, H. and Fazli, M. (2010). Effect of nanostructure alumina on adsorption of heavy metals, Desalination, 253(2); 94–100.
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 E., 58 (2); 333-343.
Saleh, T. A. (2016). Nanocomposite of carbon nanotubes/silica nanoparticles and their use for adsorption of Pb (II): from surface properties to sorption mechanism. Desalin Water Treat., 57(23); 10730-10744.
Sza ył w z E and Skoczko, I. (2018). The use of activated alumina and magnetic field for the removal heavy metals from water. J. Eco Eng., 19(3); 53-62.
Sharma, M., Singh, J., Hazra, S. and Basu, S. (2019). Adsorption of heavy metal ions by mesoporous ZnO and TiO2: Adsorption and kinetic studies. Microchemical Journal., 14 (1); 105-112.
Sharififard, H., Ghorbanpour, M. and Hosseinirad, S. (2019). Cadmium removal from wastewater using nano-clay/TiO2 composite: kinetics, equilibrium and thermodynamic study. Chemosphere., 25(2); 163-169.
Tajali Rad, F., Kefayati, H. and Shariati, S. (2019). Synthesis of propyl aminopyridine modified magnetite nanoparticles for cadmium (II) adsorption in aqueous solutions. Sci Total Environ., 33(2); 32-40.
Temkin, M. J. and Pyzhev, V. (1940). Recent modifications to Langmuir isotherms.
Tabesh, S., Davar, F. and Loghman-Estarki, M. R. P pa a n γ-Al2O3 nanoparticles using modified sol-gel method and its use for the adsorption of lead and cadmium ions. J. Alloy Compd., 730 (2); 441-449.
Vilardi, G., Mpouras, T., Dermatas, D. Verdone, N., Polydera, A. and Di Palma, L. (2018). Nanomaterials application for heavy metals recovery from polluted water: The combination of nano zero-valent iron and carbon nanotubes. Competitive adsorption non-linear modeling. Chemosphere., 201 (2); 716-729.
Wang, F., Yang, W., Cheng, P. Zhang, S., Zhang, S. Jiao, W. and Sun, Y. (2019). Adsorption characteristics of cadmium onto microplastics from aqueous solutions. Chemosphere., 235 (1); 1073-1080.
Yu, Z., Hao, R., Zhang, L. and Zhu, Y. (2018). Effects of TiO2, SiO2, Ag and CdTe/CdS quantum dots nanoparticles on toxicity of cadmium towards Chlamydomonas reinhardtii. Ecotoxic and environ safety., 156 (1); 75-86.
Zadeh, B. S., Esmaeili, H. and Foroutan, R. (2018). Cadmium (II) Removal from Aqueous Solution Using Microporous Eggshell: Kinetic and Equilibrium Studies. Indonesian Chem., 18(2); 265-271.