Adsorption of Pb(II) from Aqueous Solutions onto Humic Acid Modified by Urea-Formaldehyde: Effect of pH, Ionic Strength, Contact Time, and Initial Concentration

Meidita Kemala Sari(1), Rahmat Basuki(2), Bambang Rusdiarso(3*)

(1) Master Programs, Department of Chemistry, Faculty Mathematics and Natural Science, Universitas Gadjah Mada, Sekip Utara, PO BOX BLS 21, Yogyakarta 55281, Indonesia
(2) Doctoral Programs, Department of Chemistry, Faculty Mathematics and Natural Science, Universitas Gadjah Mada, Sekip Utara, PO BOX BLS 21, Yogyakarta 55281, Indonesia Department of Chemistry, Faculty of Military Mathematics and Natural Sciences, Universitas Pertahanan RI, Bogor 16810, Indonesia
(3) Department of Chemistry, Faculty Mathematics and Natural Science, Universitas Gadjah Mada, Sekip Utara, PO BOX BLS 21, Yogyakarta 55281, Indonesia
(*) Corresponding Author


Humic acid (HA) and urea-formaldehyde (UF) have been frequently reported as heavy metal adsorbents. However, the literature has never written HA modification by UF to improve the adsorbent’s performance. In this study, a new adsorbent of humic acid-urea formaldehyde (HA-UF) was synthesized. The reaction of the conducted the formation of HA-UF –COOH group of HA with the –NH2 group of UF was evidenced by decreasing total acidity from 549.26 cmol/kg (in HA) to 349.30 cmol/kg (in HA-UF). The success of HA-UF formation was characterized by attenuated total reflection-infrared (ATR-IR), energy dispersive X-Ray (EDX), and X-ray diffraction (XRD). The high stability of HA-UF was shown by 96.8% remaining in solid form at pH 12.4. Adsorption behavior of Pb(II) onto HA-UF was influenced by the ionic strength and pH, which were mainly driven by the ion exchange mechanism (EDR = 9.75 kJ/mol). The higher ionic strength will affect decreasing adsorbed Pb(II) at the optimum pH of 5.5. The effect of initial Pb(II) concentration (isotherm) shows that the data fitted well with the Langmuir-b isotherm model indicated the monolayer adsorption of Pb(II) onto homogenous surfaces of the HA-UF with the adsorption capacity of 2.26 × 10–4 mol/g (which is higher than its original HA of 1.12 × 10–4 mol/g). The Ho (pseudo-second-order) kinetics model represented the effect of contact time (kinetics) was represented by the Ho kinetics model. The synthesized adsorbent is also reusable, with 88.59% of adsorption capacity remaining in the fifth recycle run. Therefore, the adsorbent of HA-UF is suggested to be a promising candidate for adsorption applications.


humic acid-urea formaldehyde (HA-UF); Pb(II) adsorption; pH and ionic strength; isotherm; kinetics studies

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[1] Dehghani, M.H., Heibati, B., Asadi, A., Tyagi, I., Agarwal, S., and Gupta, V.K., 2015, Reduction of noxious Cr (VI) ion to Cr (III) ion in aqueous solutions using H2O2 and UV/ H2O2 systems, J. Ind. Eng. Chem., 33, 10–13.

[2] Siyal, A.A., Shamsuddin, M.R., Rabat, N.E., Zulfiqar, M., Man, Z., and Low, A., 2019, Fly ash based geopolymer for the adsorption of anionic surfactant from aqueous solution, J. Cleaner Prod., 229, 232–243.

[3] Heidarinejad, Z., Dehghani, M.H., Heidari, M., Javedan, G., Ali, I., and Sillanpää, M., 2020, Methods for preparation and activation of activated carbon: A review, Environ. Chem. Lett., 18 (2), 393–415.

[4] Santosa, S.J., Kunarti, E.S., Aprilita, N.H., Wulandari, B., and Bawani, D.N., 2019, Sorption mechanism and performance of peat soil humin for methylene blue and p-nitrophenol, Indones. J. Chem., 19 (1), 198–210.

[5] Dehghani, M.H., Yetilmezsoy, K., Salari, M., Heidarinejad, Z., Yousefi, M., and Sillanpää, M., 2020, Adsorptive removal of cobalt(II) from aqueous solutions using multi-walled carbon nanotubes and γ-alumina as novel adsorbents: Modelling and optimization based on response surface methodology and artificial neural network, J. Mol. Liq., 299, 112154.

[6] Rasoulzadeh, H., Dehghani, M.H., Mohammadi, A.S., Karri, R.R., Nabizadeh, R., Nazmara, S., Kim, K.H., and Sahu, J.N., 2020, Parametric modelling of Pb(II) adsorption onto chitosan-coated Fe3O4 particles through RSM and DE hybrid evolutionary optimization framework, J. Mol. Liq., 297, 111893.

[7] Shams, M., Nodehi, R.N., Dehghani, M.H., Younesian, M., and Mahvi, A.H., 2010, Efficiency of granular ferric hydroxide (GFH) for removal of fluoride from water, Fluoride, 43 (1), 61–66.

[8] Dehghani, M.H., Tajik, S., Panahi, A., Khezri, M., Zarei, A., Heidarinejad, Z., and Yousefi, M., 2018, Adsorptive removal of noxious cadmium from aqueous solutions using poly urea-formaldehyde: A novel polymer adsorbent, MethodsX, 5, 1148–1155.

[9] Rusdiarso, B., and Basuki, R., 2020, Stability improvement of humic acid as sorbent through magnetite and chitin modification, J. Kim. Sains Apl., 23 (5), 152–159.

[10] Basuki, R., Rusdiarso, B., Santosa, S.J., and Siswanta, D., 2021, Magnetite-functionalized horse dung humic acid (HDHA) for the uptake of toxic lead(II) from artificial wastewater, Adsorpt. Sci. Technol., 2021, 5523513.

[11] Chen, Q., Yin, D., Zhu, S., and Hu, X., 2012, Adsorption of cadmium(II) on humic acid coated titanium dioxide, J. Colloid Interface Sci., 367 (1), 241–248.

[12] Wu, P., Zhang, Q., Dai, Y., Zhu, N., Dang, Z., Li, P., Wu, J., and Wang, X., 2011, Adsorption of Cu(II), Cd(II) and Cr(III) ions from aqueous solutions on humic acid modified Ca-montmorillonite, Geoderma, 164 (3), 215–219.

[13] Zhang, X., Lei, Q., Wang, X., Liang, J., Chen, C., Luo, H., Mou, H., Deng, Q., Zhang, T., and Jiang, J., 2019, Removal of Cr(III) using humic acid-modified attapulgite, J. Environ. Eng., 145 (6), 04019028.

[14] Chen, R., Zhang, Y., Shen, L., Wang, X., Chen, J., Ma, A., and Jiang, W., 2015, Lead(II) and methylene blue removal using a fully biodegradable hydrogel based on starch immobilized humic acid, Chem. Eng. J., 268, 348–355.

[15] Lu, S., Liu, W., Wang, Y., Zhang, Y., Li, P., Jiang, D., Fang, C., and Li, Y., 2019, An adsorbent based on humic acid and carboxymethyl cellulose for efficient dye removal from aqueous solution, Int. J. Biol. Macromol., 135, 790–797.

[16] Tiwari, D., Bhunia, H., and Bajpai, P.K., 2016, Urea-formaldehyde derived porous carbons for adsorption of CO2, RSC Adv., 6 (113), 111842–111855.

[17] Chen, S., Lu, X., Pan, F., Wang, T., and Zhang, Z., 2017, Preparation and characterization of urea-formaldehyde resin/reactive montmorillonite composites, J. Wuhan Univ. Technol., Mater. Sci. Ed., 32 (4), 783–790.

[18] Liu, M., Wang, Y., Wu, Y., and Wan, H., 2018, Hydrolysis and recycling of urea formaldehyde resin residues, J. Hazard. Mater., 355, 96–103.

[19] Wibowo, E.S., and Park, B.D., 2020, Determination of crystallinity of thermosetting urea-formaldehyde resins using deconvolution method, Macromol. Res., 28 (6), 615–624.

[20] Nadeem, R., Manzoor, Q., Iqbal, M., and Nisar, J., 2016, Biosorption of Pb(II) onto immobilized and native Mangifera indica waste biomass, J. Ind. Eng. Chem., 35, 185–194.

[21] Foo, K.Y., and Hameed, B.H., 2010, Insights into the modeling of adsorption isotherm systems, Chem. Eng. J., 156 (1), 2–10.

[22] Arshad, M.A., Maaroufi, A., Pinto, G., El-Barkany, S., and Elidrissi, A., 2016, Morphology, thermal stability and thermal degradation kinetics of cellulose-modified urea-formaldehyde resin, Bull. Mater. Sci., 39 (6), 1609–1618.

[23] Nandiyanto, A.B.D., Oktiani, R., and Ragadhita, R., 2019, How to read and interpret FTIR spectroscope of organic material, Indones. J. Sci. Technol., 4 (1), 97–118.

[24] Tiwari, D., Bhunia, H., and Bajpai, P.K., 2016, Urea-formaldehyde derived porous carbons for adsorption of CO2, RSC Adv., 6 (113), 111842–111855.

[25] Shen, Y., Lin, H., Gao, W., and Li, M., 2020, The effects of humic acid urea and polyaspartic acid urea on reducing nitrogen loss compared with urea, J. Sci. Food Agric., 100 (12), 4425–4432.

[26] Wang, J., and Guo, X., 2020, Adsorption kinetic models: Physical meanings, applications, and solving methods, J. Hazard. Mater., 390, 122156.

[27] Li, J., and Zhang, Y., 2021, Morphology and crystallinity of urea-formaldehyde resin adhesives with different molar ratios, Polymers, 13 (5), 673.

[28] Zehra, T., Lim, L.B.L., and Priyantha, N., 2015, Removal behavior of peat collected from Brunei Darussalam for Pb(II) ions from aqueous solution: Equilibrium isotherm, thermodynamics, kinetics and regeneration studies, Environ. Earth Sci., 74 (3), 2541–2551.

[29] Yang, X., Yang, S., Yang, S., Hu, J., Tan, X., and Wang, X., 2011, Effect of pH, ionic strength and temperature on sorption of Pb(II) on NKF-6 zeolite studied by batch technique, Chem. Eng. J., 168 (1), 86–93.

[30] Dubinin, M.M., and Radushkevich, L.V., 1947, The equation of the characteristic curve of the activated charcoal, Proc. Acad. Sci. USSR Phys. Chem. Sect., 55, 331–337.

[31] Tempkin, M.I., and Pyzhev, V., 1940, Kinetics of ammonia synthesis on promoted iron catalyst, Acta Phys. Chim. USSR, 12 (1), 327–356.

[32] Basuki, R., Yusnaidar, Y., and Rusdiarso, B., 2018, Different style of Langmuir isotherm model of non-competitive sorption Zn(II) and Cd(II) onto horse dung humic acid (HD-HA), AIP Conf. Proc., 2026, 020009.

[33] Freundlich, H., 1907, Über die Adsorption in Lösungen, Z. Phys. Chem., 57U (1), 385–470.

[34] Bartczak, P., Norman, M., Klapiszewski, Ł., Karwańska, N., Kawalec, M., Baczyńska, M., Wysokowski, M., Zdarta, J., Ciesielczyk, F., and 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 J. Chem., 11 (8), 1209–1222.

[35] Qu, P., Li, Y., Huang, H., Wu, G., Chen, J., He, F., Wang, H., and Gao, B., 2020, Foamed urea-formaldehyde microspheres for removal of heavy metals from aqueous solutions, Chemosphere, 241, 125004.

[36] Kushwaha, A., Rani, R., and Patra, J.K., 2020, Adsorption kinetics and molecular interactions of lead [Pb(II)] with natural clay and humic acid, Int. J. Environ. Sci. Technol., 17 (3), 1325–1336.

[37] El-Korashy, S.A., Elwakeel, K.Z., and El-Hafeiz, A.A., 2016, Fabrication of bentonite/thiourea-formaldehyde composite material for Pb(II), Mn(VII) and Cr(VI) sorption: A combined basic study and industrial application, J. Cleaner Prod., 137, 40–50.

[38] Ming, G., Duan, H., Meng, X., Sun, G., Sun, W., Liu, Y., and Lucia, L., 2016, A novel fabrication of monodisperse melamine-formaldehyde resin microspheres to adsorb lead(II), Chem. Eng. J., 288, 745–757.

[39] Saha, P., Chowdhury, S., Gupta, S., and Kumar, I., 2010, Insight into adsorption equilibrium, kinetics and thermodynamics of Malachite Green onto clayey soil of Indian origin, Chem. Eng. J., 165 (3), 874–882.

[40] Duran, C., Ozdes, D., Gundogdu, A., and Senturk, H.B., 2011, Kinetics and isotherm analysis of basic dyes adsorption onto almond shell (Prunus dulcis) as a low cost adsorbent, J. Chem. Eng. Data, 56 (5), 2136–2147.

[41] Lagergren, S., 1898, About the theory of so called adsorption of soluble substances, K. Sven. Vetenskapsakad. Handl., 24 (4), 1–39.

[42] Ho, Y.S., McKay, G., Wase, D.A.J., and Forster, C.F., 2000, Study of the sorption of divalent metal ions on to peat, Adsorpt. Sci. Technol., 18 (7), 639–650.

[43] Santosa, S.J., 2014, Sorption kinetics of Cd(II) species on humic acid-based sorbent, CLEAN - Soil Air Water, 42 (6), 760–766.

[44] Rusdiarso, B., Basuki, R., and Santosa, S.J., 2016, Evaluation of Lagergren kinetics equation by using novel kinetics expression of sorption of Zn2+ onto horse dung humic acid (HD-HA), Indones. J. Chem., 16 (3), 338–346.

[45] Basuki, R., Ngatijo, Santosa, S.J., and Rusdiarso, B., 2018, Comparison the new kinetics equation of noncompetitive sorption Cd(II) and Zn(II) onto green sorbent horse dung humic acid (HD-HA), Bull. Chem. React. Eng. Catal., 13 (3), 475–488.

[46] Ngatijo, N., Basuki, R., Rusdiarso, B., and Nuryono, N., 2020, Sorption-desorption profile of Au (III) onto silica modified quaternary amines (SMQA) in gold mining effluent, J. Environ. Chem. Eng., 8 (3), 103747.

[47] Baker, H.M., Khalili, F.I., and Aldulaimy, B.I.A., 2020, Removal of lead ions from aqueous solutions by insolubilized Iraqi humic acid, Desalin. Water Treat., 206, 286–296.


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