In this research, we explored the synthesis and application of iron oxide magnetic nanoparticles functionalized with watermelon peel extract (NP-FeO-CL) using an eco-friendly approach. These nanoparticles were characterized by FT-IR, SEM, and UV-Visible spectroscopy, confirming their structure, magnetic properties, and purity. Their efficiency was evaluated in removing lead (Pb) ions from aqueous solutions under various experimental conditions, including variations in contact time, adsorbent mass, pH, temperature, and initial Pb concentration. The results showed a maximum Pb removal of 91.40% under optimum conditions (pH = 4, temperature = 25 ℃, and contact time = 5 min). Adsorption isotherms indicated an excellent fit to the Freundlich model (R2 = 0.94, KF = 16.99 mg/g, n = 1.97), reflecting heterogeneous and multi-layered adsorption. Likewise, a good fit to the Langmuir model (R2 = 0.91) was observed, suggesting a single-layer adsorption with a maximum adsorption capacity qmax of 47.16 mg/g. As for the kinetics, the pseudo-second order model adequately described the process (R2 = 0.99), suggesting that the adsorption rate is controlled by the availability of active sites. Thermodynamic analysis evidenced that the process is spontaneous and favorable at moderate temperatures, although the efficiency decreases at higher temperatures. This study highlights the potential of NP-FeO-CL as a sustainable and efficient solution for the remediation of water contaminated with heavy metals. Moreover, the green synthesis method used not only minimizes the environmental impact but also promotes the reuse of agro-industrial waste, contributing to the circular economy. Tests conducted under real conditions, such as in mining waters fortified with Pb, validated its practical applicability, achieving efficiencies above 90% in the first minutes of the process. These results position NP-FeO-CL as a versatile tool for treating contaminated water, with a significant impact on the sustainable management of water resources and environmental protection.
Citation: Hugo Sánchez-Moreno, Kevin Altamirano, Sandra Escobar, Nelly Guananga-Díaz, Verónica Cando, Luis Anilema, Israel Heredia. Removal of lead (Ⅱ) from aqueous solutions using iron nanoparticles synthesized from watermelon peel extract[J]. AIMS Environmental Science, 2025, 12(4): 653-682. doi: 10.3934/environsci.2025029
In this research, we explored the synthesis and application of iron oxide magnetic nanoparticles functionalized with watermelon peel extract (NP-FeO-CL) using an eco-friendly approach. These nanoparticles were characterized by FT-IR, SEM, and UV-Visible spectroscopy, confirming their structure, magnetic properties, and purity. Their efficiency was evaluated in removing lead (Pb) ions from aqueous solutions under various experimental conditions, including variations in contact time, adsorbent mass, pH, temperature, and initial Pb concentration. The results showed a maximum Pb removal of 91.40% under optimum conditions (pH = 4, temperature = 25 ℃, and contact time = 5 min). Adsorption isotherms indicated an excellent fit to the Freundlich model (R2 = 0.94, KF = 16.99 mg/g, n = 1.97), reflecting heterogeneous and multi-layered adsorption. Likewise, a good fit to the Langmuir model (R2 = 0.91) was observed, suggesting a single-layer adsorption with a maximum adsorption capacity qmax of 47.16 mg/g. As for the kinetics, the pseudo-second order model adequately described the process (R2 = 0.99), suggesting that the adsorption rate is controlled by the availability of active sites. Thermodynamic analysis evidenced that the process is spontaneous and favorable at moderate temperatures, although the efficiency decreases at higher temperatures. This study highlights the potential of NP-FeO-CL as a sustainable and efficient solution for the remediation of water contaminated with heavy metals. Moreover, the green synthesis method used not only minimizes the environmental impact but also promotes the reuse of agro-industrial waste, contributing to the circular economy. Tests conducted under real conditions, such as in mining waters fortified with Pb, validated its practical applicability, achieving efficiencies above 90% in the first minutes of the process. These results position NP-FeO-CL as a versatile tool for treating contaminated water, with a significant impact on the sustainable management of water resources and environmental protection.
| [1] |
Hou L, Xing B, Guo H, et al. (2023) Effect of mineralogical characteristics evolution of vermiculite upon thermal and chemical expansions on its adsorption behavior for aqueous Pb (Ⅱ) removal. Powder Technol 430: 119040. https://doi.org/10.1016/j.powtec.2023.119040 doi: 10.1016/j.powtec.2023.119040
|
| [2] |
Ramos D C (2018) Adsorción de cadmio, cobre y plomo en bentonita, caolín y zeolita naturales y modificadas: una revisión de los parámetros de operación, isotermas y cinética. Ingeniería 23: 252–273. https://doi.org/10.14483/23448393.13418 doi: 10.14483/23448393.13418
|
| [3] |
Sun X, Tang Z, Zheng G, et al. (2024) Effects of different cellular and subcellular characteristics on the atmospheric Pb uptake, distribution and morphology in Tillandsia usneoides leaves. Plant Physiology and Biochemistry 207: 108400. https://doi.org/10.1016/j.plaphy.2024.108400 doi: 10.1016/j.plaphy.2024.108400
|
| [4] |
De los Santos C R, Barajas F, Pérez H, et al. (2019) Adsorption of copper (Ⅱ) and cadmium (Ⅱ) in aqueous suspensions of biogenic nanostructured CaCO 3. Boletin de la Sociedad Espanola de Ceramica y Vidrio 58: 2–13. https://doi.org/10.1016/j.bsecv.2018.05.003 doi: 10.1016/j.bsecv.2018.05.003
|
| [5] |
De la Cueva F, Naranjo A, Puga Torres B, et al. (2021) Presence of heavy metals in raw bovine milk from Machachi, Ecuador. Granja 33: 21–30. https://doi.org/10.17163/lgr.n33.2021.02 doi: 10.17163/lgr.n33.2021.02
|
| [6] |
Qian S, Qiongyao Y, Bailin R E N (2025) Adsorption/desorption characteristics of Cd, Cu and Pb on/from soil aggregate fractions from a calcareous soil profile in single and ternary systems. Pedosphere 35: 516–525. https://doi.org/10.1016/j.pedsph.2024.02.004 doi: 10.1016/j.pedsph.2024.02.004
|
| [7] |
Moreno-Perez B, Matamoros-Veloza Z, Rendon-Angeles J C, et al. (2020) Synthesis of silicon-substituted hydroxyapatite using hydrothermal process. Boletin de la Sociedad Espanola de Ceramica y Vidrio 59: 50–64. https://doi.org/10.1016/j.bsecv.2019.07.001 doi: 10.1016/j.bsecv.2019.07.001
|
| [8] |
Deepa K, Prasad C, Jyothi N V V, et al. (2018) Adsorptive removal of Pb (Ⅱ) metal from aqueous medium using biogenically synthesized and magnetically recoverable core-shell structured AM@ Cu/Fe3O4 nano composite. Desalination Water Treat 111: 278–285. https://doi.org/10.5004/dwt.2018.22200 doi: 10.5004/dwt.2018.22200
|
| [9] |
Calderón-Tapia C, Medina-Barrera E, Chuquin-Vasco N, et al. (2024) Exploration of bacterial strains with bioremediation potential for mercury and cyanide from mine tailings in 'San Carlos de las Minas, Ecuador. AIMS Environ Sci 11: 381–400. https://doi.org/10.3934/environsci.2024019 doi: 10.3934/environsci.2024019
|
| [10] |
Gómez Aguilar D L, Esteban Muñoz J A, Baracaldo Guzmán D (2020) Tecnologías no convencionales para la remoción de plomo presente en aguas residuales: una revisión bibliográfica 2010-2019. Tecnura 24: 97–116. https://doi.org/10.14483/22487638.15849 doi: 10.14483/22487638.15849
|
| [11] | M. de Lourdes Chávez García, A. R. González, A. R. Mejía, et al. Teaching experimental proposal for the synthesis of magnetic nanomaterials. Magnetic nanoparticles in montmorillonite. Educacion Quimica 35: 27–42. https://doi.org/10.22201/fq.18708404e.2024.1.85753 |
| [12] |
Srivastava A, Dutta S, Jain R (2023) Waste mediated synthesis of iron nanoparticles using Aegle marmelos peel extract for catalytic degradation of toxic dye contaminants. RSC Sustainability 1: 2261–2269. https://doi.org/10.1039/D3SU00246B doi: 10.1039/D3SU00246B
|
| [13] |
De la Cueva F, Naranjo A, Puga Torres B, et al. (2021) Presence of heavy metals in raw bovine milk from Machachi, Ecuador. Granja 33: 21–30. https://doi.org/10.17163/lgr.n33.2021.02 doi: 10.17163/lgr.n33.2021.02
|
| [14] |
Chávez García M L, Rodríguez González A, Ramos Mejía A, et al. (2024) Teaching experimental proposal for the synthesis of magnetic nanomaterials. Magnetic nano-particles in montmorillonite. Educacion Quimica 35: 27–42. https://doi.org/10.22201/fq.18708404e.2024.1.85753 doi: 10.22201/fq.18708404e.2024.1.85753
|
| [15] |
Sánchez-Moreno H, García-Rodríguez L, Recalde-Moreno C (2025) Natural cellulose fibers (Agave Americana L. ASPARAGACEAE) impregnated with magnetite nanoparticles as a novel adsorbent of mercury (Hg) in aqueous solutions. Adsorption 31: 1-22. https://doi.org/10.1007/s10450-024-00577-1 doi: 10.1007/s10450-024-00577-1
|
| [16] |
Castillo-Granada A L, Ríos-Calderón O S, Soto-Páez R, et al. (2021) Cómics para el aprendizaje de la espectroscopia infrarroja. Educación Química 32: 11-20. https://doi.org/10.22201/fq.18708404e.2021.2.76493 doi: 10.22201/fq.18708404e.2021.2.76493
|
| [17] |
Valenzuela-Amaro H M, Vázquez-Ortega P G, Zazueta-Alvarez D E, et al. (2022) Síntesis verde de nanopartículas de magnetita (NPs-Fe3O4): factores y limitaciones. Mundo Nano. Revista Interdisciplinaria en Nanociencias y Nanotecnología 16: 1e–18e. https://doi.org/10.22201/ceiich.24485691e.2023.30.69744 doi: 10.22201/ceiich.24485691e.2023.30.69744
|
| [18] |
Tan H L, Lim Y C, Ng L Y, et al. (2023) Plant-mediated synthesis of iron nanoparticles for environmental application: Mini review. Materials Today: Proceedings 87: 64-69. https://doi.org/10.1016/j.matpr.2023.02.101 doi: 10.1016/j.matpr.2023.02.101
|
| [19] |
Rodríguez A, Fernández L, de Posada J D, et al. (2021) Elucidación de la fórmula estequiométrica de nanohidrotalcitas de mg y ni sintetizadas por el método de coprecipitación. infoANALÍ TICA 9: 111-134. https://doi.org/10.26807/ia.v9i2.212 doi: 10.26807/ia.v9i2.212
|
| [20] |
Sánchez-Moreno H, García-Rodríguez L, Recalde-Moreno C (2025) Natural cellulose fibers from Agave Americana L. ASPARAGACEAE as an effective adsorbent for mercury in aqueous solutions. Adsorption 31: 40. https://doi.org/10.1007/s10450-024-00590-4 doi: 10.1007/s10450-024-00590-4
|
| [21] |
Xia H, Zhang Y, Chen Q, et al. (2023) Unraveling adsorption characteristics and removal mechanism of novel Zn/Fe-bimetal-loaded and starch-coated corn cobs biochar for Pb (Ⅱ) and Cd (Ⅱ) in wastewater. J Mol Liq 391: 123375. https://doi.org/10.1016/j.molliq.2023.123375 doi: 10.1016/j.molliq.2023.123375
|
| [22] |
Rojas-Bracho L, Farías-Serra P, Santos-Burgoa C, et al. (2023) Epidemia de intoxicación por plomo: su atención desde las normas oficiales mexicanas para proteger la salud de la población. 2023, Instituto Nacional de Salud Publica 65: 543-546. https://doi.org/10.21149/15269 doi: 10.21149/15269
|
| [23] | Naranjo-Jiménez C, WingChing-Jones R (2023) Arsenic, cadmium, mercury, and lead in imported pet food in Costa Rica. Agronomia Mesoamericana 34. |
| [24] |
Calderón H I B, Hernández-Cárabes P, Padilla-Sánchez A J, et al. (2022) Intoxicación por plomo y su impacto en la práctica clínica: artículo de revision. Ciencia Latina Revista Científica Multidisciplinar 6: 4176-4189. https://doi.org/10.37811/cl_rcm.v6i1.1792 doi: 10.37811/cl_rcm.v6i1.1792
|
| [25] |
Xu W, Yang T, Liu S, et al. (2022) Insights into the Synthesis, types and application of iron Nanoparticles: The overlooked significance of environmental effects. Environment International 158: 106980. https://doi.org/10.1016/j.envint.2021.106980 doi: 10.1016/j.envint.2021.106980
|
| [26] |
Ramos D C (2018) Adsorción de cadmio, cobre y plomo en bentonita, caolín y zeolita naturales y modificadas: una revisión de los parámetros de operación, isotermas y cinética. Ingeniería 23: 252-273. https://doi.org/10.14483/23448393.13418 doi: 10.14483/23448393.13418
|
| [27] |
Kalam S, Abu-Khamsin S A, Kamal M S, et al. (2021) Surfactant adsorption isotherms: A review. American Chemical Society 6: 32342-32348. https://doi.org/10.1021/acsomega.1c04661 doi: 10.1021/acsomega.1c04661
|
| [28] |
Al-Dhawi B, Kutty S, Alawag A, et al. (2024) Lithium recovery in a batch adsorption study: Synthesis, characterization, optimization, regeneration, kinetics, and isotherm studies. Sci Afr Sci Afr 26: e02449. https://doi.org/10.1016/j.sciaf.2024.e02449 doi: 10.1016/j.sciaf.2024.e02449
|
| [29] | de Lourdes Colín-Álvarez M, Calderón-Domínguez G, Rojas-Candelas L E, et al. Aplicación de la nanotecnología como innovación en recubrimientos alimentarios. Pädi Boletín Científico de Ciencias Básicas e Ingenierías del ICBI 12: 21–33. https://doi.org/10.29057/icbi.v12iEspecial.12127 |
| [30] |
Ciobanu C S, Iconaru S L, Le Coustumer P, et al. (2012) Antibacterial activity of silver-doped hydroxyapatite nanoparticles against gram-positive and gram-negative bacteria. Nanoscale Res Lett 7. https://doi.org/10.1186/1556-276X-7-324 doi: 10.1186/1556-276X-7-324
|
| [31] |
Maleki S, Abedi E, Hashemi S M B (2024) Insights into kinetic, isotherm, and thermodynamic of ultrasound mode-and amplitude-dependent carotenoid and chlorophyll degradation or/and adsorption. Ultrason Sonochem 111: 107130. https://doi.org/10.1016/j.ultsonch.2024.107130 doi: 10.1016/j.ultsonch.2024.107130
|
| [32] |
Chu K H, Hashim M A, Basirun A A (2025) Removal of antibiotic contaminants from water via adsorption: Analysis of equilibrium isotherms. Environmental Pollution and Management https://doi.org/10.1016/j.epm.2025.06.001 doi: 10.1016/j.epm.2025.06.001
|
| [33] |
Tran H N (2023) Applying linear forms of pseudo-second-order kinetic model for feasibly identifying errors in the initial periods of time-dependent adsorption datasets. Water (Switzerland) 15: 1231. https://doi.org/10.3390/w15061231 doi: 10.3390/w15061231
|
| [34] |
Liu Y, Chen Y, Li Y, et al. (2024) Immobilization of Pb in waste water and soil by tourmaline-biochar composites (TBs): Characteristics and mechanisms. Science of the Total Environment 920: 170803. https://doi.org/10.1016/j.scitotenv.2024.170803 doi: 10.1016/j.scitotenv.2024.170803
|
| [35] |
Martini S, Afroze S, Roni K A, et al. (2021) A review of fruit waste-derived sorbents for dyes and metals removal from contaminated water and wastewater. Desalination Water Treat 235: 300–323. https://doi.org/10.5004/dwt.2021.27658 doi: 10.5004/dwt.2021.27658
|
| [36] |
Pascua M J, Romero M L (2020) Remoción de plomo en solución acuosa usando criogeles basados en polyacrylamide como adsorbente: Estudio de equilibrio en modo batch. Revista Torreón Universitario 9: 77–93. https://doi.org/10.5377/torreon.v9i25.9855 doi: 10.5377/torreon.v9i25.9855
|
| [37] |
Morsa A, Yazhenskikh E, Ziegner M, et al. (2025) Experimental study and thermodynamic assessment of the MgSO4-CaSO4 system. Calphad 90: 102855. https://doi.org/10.1016/j.calphad.2025.102855 doi: 10.1016/j.calphad.2025.102855
|
| [38] |
Hakim L, Widiarman M (2024) Adsorbent performance of nipa (nypafruticans) frond in methylene blue dye degradation: Response surface methodology optimization. AIMS Environ Sci 11: 38–56. https://doi.org/10.3934/environsci.2024003 doi: 10.3934/environsci.2024003
|
| [39] |
Elles-Pérez C J, Muñoz-Acevedo A, Guzmán A, et al. (2025) Optimized diclofenac sodium adsorption on Lecythis minor-derived activated carbon: Kinetics and isotherm analysis. J Mol Liq 2025: 127987. https://doi.org/10.1016/j.molliq.2025.127987 doi: 10.1016/j.molliq.2025.127987
|
| [40] |
Lavado-Meza C, Sun-Kou M R, Castro-Arroyo T K, et al. (2020) Biosorción de plomo (Ⅱ) en solución acuosa con biomasa de los cladodios de la tuna (opuntia ficus indica). Revista Colombiana de Quimica 49: 36–46. https://doi.org/10.15446/rcq.v49n3.85823 doi: 10.15446/rcq.v49n3.85823
|
| [41] |
Siraj K, Aballa J S, Danish M, et al. (2024) The effect of microwave and muffle furnace-assisted heating on the surface characteristics of teff husk activated carbons: Thermodynamic, isotherm, and kinetics study of Pb removal. Diam Relat Mater 143: 110912. https://doi.org/10.1016/j.diamond.2024.110912 doi: 10.1016/j.diamond.2024.110912
|
| [42] |
Trong N T, Le Tan P H, Ngoc D N, et al. (2024) Optimizing the synthesis conditions of aerogels based on cellulose fiber extracted from rambutan peel using response surface methodology. AIMS Environ Sci 11: 576–592. https://doi.org/10.3934/environsci.2024028 doi: 10.3934/environsci.2024028
|
| [43] |
Marcelo R V (2022) Kinetics and Adsorption Mechanisms of Lead (Ⅱ) Using Gis-NaP Zeolite Obtained from Brick Waste. Revista Politecnica 50: 63–70. https://doi.org/10.33333/rp.vol50n2.07 doi: 10.33333/rp.vol50n2.07
|
| [44] |
Rodrigues D S, Alves L F, Meyer J F C A, et al. (2025) IN VITRO POPULATION GROWTH OF HUMAN GLIOBLASTOMAS: REAL PATIENTS AND CURVE FITTING. Hematol Transfus Cell Ther 47: 103807. https://doi.org/10.1016/j.htct.2025.103807 doi: 10.1016/j.htct.2025.103807
|
| [45] |
De los Santos C R, Barajas F, Pérez H, et al. (2019) Adsorption of copper (Ⅱ) and cadmium (Ⅱ) in aqueous suspensions of biogenic nanostructured CaCO 3. Boletin de la Sociedad Espanola de Ceramica y Vidrio 58: 2–13. https://doi.org/10.1016/j.bsecv.2018.05.003 doi: 10.1016/j.bsecv.2018.05.003
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Figures(22) / Tables(4)
Hugo Sánchez-Moreno, Kevin Altamirano, Sandra Escobar, Nelly Guananga-Díaz, Verónica Cando, Luis Anilema, Israel Heredia. Removal of lead (Ⅱ) from aqueous solutions using iron nanoparticles synthesized from watermelon peel extract[J]. AIMS Environmental Science, 2025, 12(4): 653-682. doi: 10.3934/environsci.2025029
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