Skip to main content
NCBI home page
Scientific Reports logoLink to Scientific Reports
. 2026 Mar 18;16:14056. doi: 10.1038/s41598-026-42318-0

Environmental remediation and wastewater treatment using silver incorporated dual metal oxide polyaniline nano composites kinetic insights into Pb (II) and As (III) adsorptive removal

E Parthiban 1, S Sudarsan 2, Haiter Lenin Allasi 3,8,✉, Mary Vasanthi Soosaimariyan 4, D Arun kumar 5, A Kistan 6, K Ranganathan 7
PMCID: PMC13136384  PMID: 41851154

Abstract

Adsorption plays an important role in the elimination of toxic metal ions from wastewater. The Fe₃O₄/CuO–itaconic acid/polyaniline@Ag nanocomposite composed of itaconic acid (IA), polyaniline (PANI), dual metal oxides (Fe₃O₄/CuO), and silver nanoparticles in a 2:2:1:1 ratio was investigated. This nanocomposite was analyzed in FTIR, SEM/EDAX, TEM, and XRD spectra. The adsorption process has been influenced by pH, contact time, size of sorbent, and concentration of toxic metal ions in solution. The capacity of Pb(II) and As(III) ions equilibrium adsorption on nanocomposites increased with metal concentration characterized by the Langmuir isotherm exhibited qm values at 47.915 and 61.012 mg/g. Adsorption of Pb(II) and As(III) followed pseudo-first-order and pseudo-second-order kinetic parameters. Both models were applied. The pseudo-second-order kinetic analysis revealed maximum adsorption capacities (qₑ) of 123.76 mg/g for Pb (II) and 119.33 mg/g for As (III), corresponding to R2 values of 0.95694 and 0.94696, respectively.

Keywords: Polyaniline, Heavy metal adsorption, Adsorption capacity, Nanocomposites, Kinetic parameters

Subject terms: Chemistry, Environmental sciences, Materials science

Introduction

Environmental contamination of heavy metal ions in worldwide complications for the high toxicity of some of these elements, with sources of increased industrial activities like painting, manufacture of batteries, tanneries, agriculture, refineries, and mining. These heavy metals ions Pb2+, Co2+, Hg2+, Ni2+, Cd2+, Cr3+, As3+, and Cr6+ are caused by their non-biodegradable and not destroyed. High concentrations of heavy metal ions in natural environments, water, and soil affect the ecological system1. Inorganic salts Pb and As are present in the human body parts, causing liver, kidney, lungs, and other organs and environment. Currently, the removal of heavy metal ions can be broadly characterized into membrane filtration, cementation, ion exchange, electrodialysis, biosorption, solvent extraction, adsorption, and electrochemical precipitation2,3.

In this study, we have chosen the removal of Pb (II) and As (III) metal ions due to harmful to aquatic life and human health. An excessive intake of Pb (II) and As (III) can lead to digestive problems like nausea, headaches, liver, and kidney damage4. According to the WHO and US Environmental Protection Agency (EPA) the maximum permissible limit of Pb (II) and As (III) in drinking water is 0.01 mg/L and 0.010 mg/L. Lead and arsenic are a serious inorganic pollutant, their ingestion can cause blood pressure, reproductive problems, anemia, skin, kidney, liver and lung cancer, and cardiovascular disease5.

A polymer metal oxide-based nanocomposite has shown an excellent heavy metal ions removal from various industrial wastewater. Among them, polyaniline contains π-electron conjugated structures and difunctional polymers with imine (NH+) and amine (:NH2) as more dynamic functional groups. The green polyaniline nanocomposite showed an excellent adsorption capacity, which supports an efficient adsorbent for Pb (II) and As (III) ions removed from industrial contaminated wastewater6,7. The unique properties of polyaniline such as environmental stability, versatility, high conductivity, and cost efficiency are useful for applications in tissue engineering, photoelectric cells, electrochromic devices, light-emitting diodes, heavy metal ions removal, adsorption, and EMI shielding8,9.

Itaconic acid is a non-toxic white crystalline powder and possesses various industrial applications viz., adhesives, pharmaceuticals, food additives, wound dressing, agriculture, fiberglass, plastics, etc.10,11. Silver nanoparticles (AgNPs) is shows an excellent photocatalytic activity and enhance the biological properties15. AgNPs production is commonly used in synthetic methods like physical, chemical, and biological processes. However, recent studies have shown that eco-friendly, greener approach methods using plant extract act as a capping and reducing agent. Pathania et al., studied the newly described plant extracts for metal NPs such as Aloe vera, Tridax procumbens, Cucumis prophetarum aqoues, Piper betal leaf extract, etc. The piper betel plant leaves act as a reducing agent using solvent-free, eco-friendly synthesized AgNPs13.

The inorganic compound of copper (II) oxide (CuO) contains two stable oxides of Cu and monoclinic crystal. The CuO is used in pyrotechnics, fireworks, pigment in ceramics, wood preservatives, and dietary supplements in animal feed. Magnetite contains Fe2+ and Fe3+ ions and exhibits higher electrical resistivity, magnetic, and conductivity properties. It is used for MRI scanning, catalysts, ingredients, medicine, and magnetic inks14. The catalytic/electrocatalytic performance of CuO is utilize to discuss the degradation of different organic pollutants15. The role of CuO and conductive PANI are used to discussing the present adsorption approach in the broader, modern context of advanced electrochemical wastewater treatments16.

In recent years, different types of metal oxide nanocomposite material derived from conducting polymers like Pd@PANI/CS/Fe3O4 NCs, PANI-CuO nanostructures, CS/clay/Fe3O4 composite, Fe3O4/PANI microspheres, Fe3O4–SiO2-poly(1,2-diaminobenzene) core–shell, MWCNT/ZnO NCs and CS/Ny 6/PUF blend has been working for the elimination of Pb2+, Co2+, Hg2+, Ni2+, Cd2+, Cr3+, As3+, and Cr6+ from drinking water and wastewater. Michal et al. have examined the TiO2(Eu)/CuO nanocomposite with good antibacterial, antifungal, and photocatalytic properties14–23. The recent work such as Ag/TiO₂ photocatalyst prepared utilizing, in combination with AgNO3 and TiO₂, was found to be an active and environmentally sustainable material for the degradation of both ciprofloxacin (CIP) and azo Carmine G dye (ACGD). For ciprofloxacin, the removal efficacy reached 62.88% within 15 min and continued to increase over time, attaining 82.46% after 300 min of irradiation. Similarly, in the case of azo dye degradation, the removal efficacy was 28.08% after 15 min and progressively increased to 83.64% at 300 min24. A nanocomposite material based on polypyrrole (PPy) and cobalt ferrite (CoFe₂O₄) was prepared and evaluated for Hg(II) ion exclusion. Batch adsorption experiments revealed that PPy@CoFe₂O₄ possesses exceptional removal recital, with a maximum adsorption ability of 609.8 mg g⁻1 and an equilibrium time of 90 min25. A novel method was working to decrease fouling of polyethersulfone membranes by coating them with silver-decorated condensed graphene oxide (rGO). The resulting rGO A500 membrane established excellent antifouling recital, with a flux recovery ratio of 98% and an irreversible fouling ratio of only 1.7% throughout Bovine Serum Albumin filtration26. We obviously specify the surviving gaps, such as lack of analysis on low filtration performance, reduction of permeability, time duration of adsorption process, selectivity of components and recyclability. To addresses these gaps by our study to explain the novel synthesis process, removal performance of metal ion and kinetic model and their significance.

The main purpose of the prepared complex is based on dual metal oxide polyaniline with silver combined nanocomposites. Although the availability of bimetallic-based adsorbents with high adsorption abilities, lies in addressing restrictions that are frequently discounted when adsorption tendency alone is used as the performance metric. Several reported bimetallic compounds illustration high abilities under ideal laboratory circumstances but suffer from poor constancy, restricted reusability, low selectivity, agglomeration throughout repetitive cycles. The strategic nanocomposite aims to overcome these real-world limitations. They possess multiple active adsorption sites to increasing the interaction of various pollutants. These nanocomposites enhance the metal dispersion, to protect the aggregation of particle size, to increase the mechanical stability via electrostatic interaction and hydrogen bonding. Further, the addition of silver ion present in the matrix to enhance the biological activity and rate of catalytic activity.

The present investigation mainly focuses on the synthesis of Fe3O4/CuO-IA/PANI@Ag NCs to remove Pb (II) and As (III) ions through adsorption process. AgNPs were synthesized using Piper betel leaf extract. The resulting NCs material was investigated by various analytical techniques, such as FT-IR, SEM, EDAX, TEM and XRD spectra. The influence of different parameters on pH, initial concentration of metal ions, adsorbent dosage, and adsorption efficiency of nanocomposite materials.

Experimental materials and methods

The raw materials

Aniline hydrochloride, Itaconic acid, CuSO4, NaOH, HCl, ethanol, and ammonia were received from Merck Chemicals, India. Anhydrous ferric chloride (FeCl3, 98%), (Lead (II) Nitrate) Pb(NO3)2, (sodium Arsenite) NaAsO2, and silver nitrate (AgNO3) were obtained from Sigma Aldrich, India. The Fresh Piper betel leaves are purchased from the local market in Vellore, Tamil Nadu, India.

Preparation of silver NPs

Piper betel (PB) leaves (30 g) were cut into a small piece taken into a beaker and added with distilled water has been boiled at 100 ℃ for 15 min. The plant extract was filtered, and collected for further use of nanocomposites. 1 mmol of AgNO3 aqueous solution 30 ml was transferred to a beaker containing 15 ml of PB leaf extract for one hour to reduce the Ag+ into Ag0 NPs. The samples are filtered, collected, and dried. The formation of AgNPs could be indicated by the change of solution color to be a typical dark-red solution.

Synthesis of Fe3O4/CuO-IA/PANI@Ag nanocomposite

Initially, the itaconic acid stoichiometric amount was completely dissolved in distilled water with mixing for 30 min. After this solution is added to aniline monomer into a polymerized flask with constant an agitation for one hour. After production, the homogenized liquid compound was kept in an ice bath and the reaction mixture added to FeCl3 was stirred through overnight at 10 °C. The CuO NPs embedded into aniline polymerization. Finally, this nanocomposite was washed multiple times with distilled water and ethanol solvent and collected after being dried in an oven at 50 °C for 24 h. 50 ml of ammonia hydroxide was added to prepare Fe3O4/CuO-IA/PANI NCs for complete deprotonation. The NCs (1 g) were added to an aqueous silver nanoparticle solution and stirred for three hours. Finally, the Fe3O4/CuO-IA/PANI@Ag NCs product was washed in distilled water with ethanol and collected after drying samples at 25 °C for two days.

Characterization

The FT-IR spectrum was recorded on a Shimadzu spectrometer at 400–4000 cm-1 from KBr pellets. XRD powder patterns were recorded on a Bruker, D8 instrument with Cu Kα radiation. An elemental analysis (EDX) spectra analysis an using a Philips model (XL30). TEM spectroscopy studies of the samples an examined with a LaB6 JEM 2000 model microscope.

Adsorption studies

The performance of adsorption experiments with the Fe3O4/CuO-IA/PANI@Ag NCs to consider the capacity of heavy metals removal to determine key parameters, such as solution pH, adsorbent dosage, contact time and initial Pb (II) and As (III) concentration has been investigated. The NCs were firm through adding adsorbent dosage 5 g/100 mL solution of Pb (II) and As (III) ions with various concentrations and also prepared from 0.5 g/L of stock solution of lead nitrate and sodium arsenite respectively. The Pb (II) and As (III) ions concentrations were estimated to before and after the adsorption process. The adsorption isotherm (Langmuir, Freundlich, and Redlich-Peterson) and kinetic models were studied for the adsorption of Pb (II) and AS (III).

Results and discussion

XRD studies

The XRD pattern of nanocomposite Fe3O4 peaks has been observed at 2θ of 15.22°, 37.55°, 53.69°, 65.94°, which were identified as the [111], [220], [511], [440] planes of crystal structure (JCPDS No. 19–0629). The diffraction pattern of CuO exhibited peak position at 2θ of 32.86°, 35.84°, 39.82°, 53.69°, 61.74°, and 66.15° due to [110], [002], [111], [020], [202], [113], and [311] planes, respectively (JCPDS No. 48–1548). Figure 1 has Ag crystals peaks observed at 2θ of 38.90°, 46.30°, 66.14°, and 75.54° corresponding to the [111], [200], [220], and [311] crystallographic planes (JCPDS No. 04–0783). The peaks were proven with uniform molecular dispersion of dual metal oxide (Fe3O4 and CuO) polyaniline based silver incorporated NCs has been supported by FTIR spectra results with XRD structure27,28.

Fig. 1.

Fig. 1

Open in a new tab

XRD diffractions of Fe3O4/CuO-IA/PANI@Ag NCs.

SEM and EDAX Analysis

The SEM micrograph of the nanocomposite, which contains different amounts of Fe3O4/CuO particles has been displayed in Fig. 2a and b. It indicates a relatively uniform presence of granular structure with rough and porous at the surface of Ag-Fe3O4/CuO without aggregation on an average diameter range of 10 μm, 5 μm21. The influence of surface morphology of CuO causes to enhance the catalytic activity of Sb2O3-CuO nanocomposites29. The elemental analysis of nanocomposite has been showed a silver signals pointed out that the AgNO3 was successfully reduced to AgNPs. The mass normality % of Ag, Cu, and Fe were calculated from elemental mapping to be 2.87, 5.82, and 3.64, respectively. Furthermore, Fig. 2c shows the atomic weight % of Ag, Cu, and Fe were equivalent to 1.05, 1.48, and 0.72, respectively28–30. The presence of nitrogen (N) in the EDS spectrum of the Fe₃O₄/CuO-IA/PANI@Ag nanocomposites is not because to residual nitrate (NO₃⁻) ions from AgNO₃, but is mainly ascribed to the polyaniline (PANI) and itaconic acid (IA) components of the composite. The polyaniline polymer backbone contains the nitrogen atoms in its amine (–NH–) and imine (= N–) functional groups are essential. Since PANI forms a coating around the inorganic phases, its nitrogen content readily detected by EDS study. Further, IA-assisted polymerization, which promotes resilient interfacial bonding between PANI and metal oxides stabilizing nitrogen within the nanocomposite.

Fig. 2.

Fig. 2

Open in a new tab

(a-b) SEM images of Fe3O4/CuO-IA/PANI@Ag NCs (c) EDX images of Fe3O4/CuO-IA/PANI@Ag NCs.

TEM morphologies

Figure 3 shows the high-resolution TEM images of nanocomposite has been appeared as a lager thick dark cloudy region with a more constituent active center. The sizes of the Fe3O4/CuO and Ag nanoparticles are appeared at 50 nm, and 20 nm. Series agglomeration of Fe and Cu NPs with IA/PANI has shown the spherical and oval-shaped circle structure and silver nanoparticles as the lattice fringe spacing is 10 nm, which is dependable with moon shape structure and the arrays with bright circle shape were supported the crystallinity of NPs (SAED)32,33.

Fig. 3.

Fig. 3

Open in a new tab

(a-d) TEM images of Fe3O4/CuO-IA/PANI@Ag NCs.

FT-IR spectral studies

The itaconic acid peaks has been observed at 3012 cm–1 (O–H), 1687 cm–1 (C=O), 1433 cm–1 (C–O–H), and 1215 cm–1 (C–O) shown in Fig. 4a. The peaks at 470 cm−1 and 567 cm−1 are indicated to the formation of Fe3O4 and CuO NCs. The interaction between polyaniline and itaconic acid leads to the presence of Fe3O4/CuO-IA/PANI peak at 3465 cm-1, 1615 cm-1, 1440 cm-1 (Fig. 4b). The polyaniline-itaconic acid vibration band of the dopant anion peak has been noticed at 1088 cm–1 and the C–N+ stretching mode peak at 1240 cm–1 in the Ar–N linked peak at 1165 cm–12,18. Various modes of bending vibration of Fe3O4 and CuO indicate the new absorption peaks at 480 and 560 cm−134. Figure 4b and c show a small shift of stretching vibration (NH=1615 cm-1) and (OH=3465 cm-1) to (NH=1550 cm-1) and (OH=3444 cm-1) corresponding to (Ag=751 cm-1) silver metal reduction and its deposition over Fe3O4/CuO-IA/PANI@Ag NCs35,36.

Fig. 4.

Fig. 4

Open in a new tab

FT-IR spectra of (a) Itaconic acid, (b) Fe3O4/CuO-IA/PANI and (c) Fe3O4/CuO-IA/PANI@Ag NCs.

Adsorption experiments

pH variation

One of the main pH parameters that can have an influence on the adsorption. The pH effective removal of Pb (II) and As (III) ions from aqueous solution has been showed in Fig. 5 (a). An adsorption increased with pH from 2.0—6.0 and decrease as the pH more alkaline through removal ions. The adsorption capacity of nanocomposite shows at low pH values due to polyaniline chains are highly protonated, ensuing an electrostatic repulsion of ions and adsorbent. The highest absorption rate at pH 6.0, which increase in the elimination of lead and arsenic with removal percentage of 43.2 to 94.5% and 60.3 to 96.7%, respectively. Furthermore, the pH 2–6 is increases the removal adsorption efficiency of toxic ions on to the nanocomposite has been outstandingly increased and reached to its optimum condition37,38. The adsorption efficacy of Fe₃O₄/CuO-IA/PANI@Ag nanocomposites is strongly pH-dependent due to the combined effects of surface charge, adsorbate performance and ionization of functional group. The following are the main factor to enhance the adsorption tendency. The electrostatic attraction and partial protonation of amine groups. The deprotonated carboxylate groups (–COO⁻) from itaconic acid (IA), permitting hydrogen bonding and chelation with adsorbate metal ions. More active adsorption increases the interface near neutral pH because the more concentration of H+ existing in the adsorbate. These to enhance the strong protonation of PANI. Therefore, adsorption tendency has been decline under acidic medium. The developed metal hydroxide complexes in solution decreases the adsorption efficiency in basic medium. Environmentally stabile metal oxide components are also one of the parameters for surface. Based on the above facts, the synergistic effect of composite to increase the adsorption efficacy at pH6, which is due the interaction of Fe₃O₄ (magnetic core), CuO (active adsorption sites), PANI (electrostatic and π–π interactions), IA (chelating groups), and Ag nanoparticles.

Fig. 5.

Fig. 5

Open in a new tab

(a) Influence of pH on the adsorption of Pb (II) and As (III) onto Fe3O4/CuO-IA/PANI@Ag NCs. (b) The effect of adsorbent dosage on the adsorption of Pb (II) and As (III) ions onto a Fe3O4/CuO-IA/PANI@Ag NCs. (c) The variation of interaction time on the adsorption of Pb (II) and As (III) ions onto nanocomposites. (d) The variation of temperature on the adsorption of Pb (II) and As (III) ions onto nanocomposites.

Dosage variation

Figure 5 (b), the outcome of adsorbent dosage on the Pb (II) and As (III) ions adsorption an investigated is using a various amount of 1 – 10 mg/L. The nanocomposites dosage increased; the removal adsorption efficiency of toxic ions has been improved. The amount of absorption proportion for Pb (II) and As (III) from 2 to 6 mg/L has been removal efficiency increased and decreased, respectively. However, Arsenic has been displayed a rapid reduction from 6 to 8 mg/L and another uniform reduction from 8 to 10 mg/L. It is noticeable removal % of As and Pb increases with expanding dosage of adsorbent owing to the accessibility of more adsorption sites. Additionally, the absorption mechanism for Pb was slightly different from that of As. The results found showed that increasing the absorber concentration from 6 to 8 mg/L resulted in a significant increase in the absorption rate, which then levelled off from 8 to 10 mg/L. In light of these modifications, the ideal absorber content was determined to 5 mg/L, which demonstrated an absorption rate of over 90% for both harmful components. Accordingly, the graph makes it evident that the adsorbent dosage increases the removal percentage, which is also enhanced because of the nature of the ionic interaction that occurs gradually39,40.

Interaction time variation

The influence of contact time has been observed from 0 to 60 min. Fig. 5c depicts the removal percentage of toxic metal ions using nanocomposite. Initially, adsorption increases with increases of contact time till 42 min, then it decline gradually due to maximum absorption sites of nanocomposite was occupied through Pb (II) and As (III) ions. The obtained results revealed that the optimal contact time for highest expulsion percentage of Pb (II) (82.1) and As (III) (91.9) is 42 min41,42. The absence of a separate equilibrium plateau in the time-dependent adsorption analysis. Even though a sharp equilibrium point is not evidently perceived, the adsorption method tactics a quasi-equilibrium (steady state) condition, which is adequate for adsorption isotherm analysis. In the kinetic study, the negligible adsorption rate has been noticed after certain contact time duration. The equilibrium state has reached at dynamic equilibrium condition. The metal oxide nanocomposites donot exhibit the sharp plateau because the availability of surface active site frequently. The rate of diffusion also very slow and weak interaction of metal ions. As a result, High correlation coefficients (R2) and low error values acquired for the fitted models. Further, the multi-step adsorption mechanisms lead to enhance the adsorption kinetics.

Effect of temperature

The impact of temperature on the nanocomposite has been shown in Fig. 5 (d). The efficient rate of absorption for Pb (II) and As (III) toxic elements to find the optimum temperature range 25 to 80 ℃. The absorption rate of Pb (II) and As (III) has been raised in the temperature range between 25 to 55 ℃ through absorber significantly increased, whereas additional increase in temperature range to 75 ℃ after rate of absorption reduced. So, the optimal temperature is 60℃, which results in 96.3 and 95.4% absorption of Pb (II) and As (III), respectively43,44. The decrease in adsorption efficacy of Fe₃O₄/CuO-IA/PANI@Ag nanocomposites at higher pH value is mainly multiple interaction, reversal surface charge and deprotonation of functional group. In the basic pH medium deprotonation, more number of surface charge, surface hydroxylation, weak metal–ligand interactions, and enhancement of active site leads to combined effect causes reduction of adsorption in alkaline medium. Moderate temperature increases the adsorption process due to greater electrostatic physical interaction than the strong interaction. The stability has confrmed by thermal, structural and chemical stability.

Adsorption isotherms

The background of Fe₃O₄/CuO-IA/PANI@Ag Nanocomposites are multifunctional hybrid materials that integrate the magnetic separability of Fe₃O₄, the high surface reactivity of CuO, the conductive and functionalized polymer network of polyaniline (PANI), and the enhanced surface activity of Ag nanoparticles, with itaconic acid (IA) acting as an effective interfacial linker. This synergistic combination provides a high density of active adsorption sites, improved stability, and easy post-treatment recovery, making the composite particularly attractive for wastewater treatment applications. This adsorption isotherm process are essential for understanding the interaction mechanism. Adsorption isotherm models are essential for understanding the interaction mechanism between the adsorbent and adsorbate, as they describe the relationship between adsorption capacity and equilibrium concentration at constant temperature. Application of isotherm models such as Langmuir and Freundlich helps determine the maximum adsorption capacity, surface homogeneity, and adsorption nature (monolayer or multilayer), which are critical parameters for evaluating the efficiency, scalability, and practical applicability of Fe₃O₄/CuO-IA/PANI@Ag nanocomposites in real water treatment systems. To analyze the different isotherms were observed by interaction between adsorbate and adsorbent performance of the Fe3O4/CuO-IA/PANI@Ag NCs utilized for Pb (II) and As (III) metal ions adsorption in terms of adsorption isotherm models45. The model of Langmuir and Freundlich isotherm is formed linear can be expressed as,

graphic file with name d33e859.gif 1
graphic file with name d33e863.gif 2

where qe (mg/g) and Ce (Mg/L) amount of metal ions adsorbed per mass unit and, adsorbate concentration at equilibrium respectively. The qm is the amount of maximum adsorption and KL is a Langmuir constant. The qm and KL values were acquired by plotting Ce/qe vs Ce. Where KF-Freundlich adsorption coefficient and n related to sorption intensity. The Freundlich adsorption isotherm limits found from the linear plot log qe vs log Ce.

The present parameter has been calculated through adjusting data to the model of Langmuir and Freundlich isotherms process. The adsorption process of Pb (II) and As (III) metal ions onto the nanocomposites fitted to Langmuir isotherm with correlation coefficient (R2) values about 0.98759 and 0.99111, respectively. Also, result of Langmuir isotherm has been showed a maximum adsorption (qm) values of Pb (II) and As (III) absorption by nanocomposite was 47.915 and 61.012 mg/g respectively. When the correlation coefficients (R2) of multiple kinetic models (e.g., pseudo-first-order (PFO) and pseudo-second-order (PSO) are very similar and “best-fit” model. In such cases, the following methods are considered: The Fe₃O₄/CuO-IA/PANI@Ag nanocomposite if the PSO model predicts qₑ, cal closer to qₑ, exp, it shows that adsorption is likely chemisorption. Further, the PFO often defines physisorption (physical adsorption, diffusion-controlled) and PSO describes chemisorption (surface complexation or chemical interactions). Based on the surface complexation and interaction which constant with PSO behaviour. Lower error values show a better model fit even when R2 is comparable. Further, the nanocomposite shows higher adsorption for As vs Pb (qm As > Pb) which is due to the formation of multiple bonding modes can increase on their adsorption materials with the presence of different functional groups. The PANI and IA based adsorbent displays heteroatom functionalities, which increase the increase the intake of metal ions through complex interactions. Iron oxides readily bind arsenic oxyanions due to their strong affinity toward arsenic species. Silver and copper nanoparticle s can increase the adsorption because of electron donation and surface polarization with strong interaction. In addition, the ionic radius and hydration effects to causes adsorption strength and the interactions of functional groups. Additionally, confirm the very lower concentration has been important role of nanocomposite in case on lead and arsenic metal ions removal. The result clearly showed that the monolayer absorption process of all heavy metal ions occur at binding sites with uniform energy46. The maximum adsorption efficacy (qₘ) acquired from adsorption isotherm models (e.g., Langmuir) signifies the amount of metal ions adsorbed per unit mass of adsorbent (mg g⁻1), rather than the total amount of metal ions detached from the solution. This is due to the following factors; inadequate number of active sites, greater metal ion concentration to causes saturation of active sites, effective metal ions adsorption capacity (qm), low adsorbent dosage, diffusion limitations Fig. 6.

Fig. 6.

Fig. 6

Open in a new tab

(a) Langmuir plot for Pb (II) ions and (b) As (III) ions removal of nanocomposite.

Figure 7 (a) and (b) shows the linearized Freundlich isotherms of Pb (II) and As (III) toxic ions. The nanocomposite an adsorption process fitted to Freundlich isotherms parameters with relationship coefficient (R2) values 0.9653 and 0.9792, respectively. In Table 1, the related data from linear Langmuir and Freundlich isotherms parameters for adsorption of Pb(II) and As(III) on Fe3O4/CuO-IA/PANI@Ag nanocomposites6.

Fig. 7.

Fig. 7

Open in a new tab

(a) Freundlich plot for Pb (II) and (b) As (III) ions onto the nanocomposite.

Table 1.

The Langmuir and Freundlich isotherms parameters for Pb (II) and (b) As (III) ions on Fe3O4/CuO-IA/PANI@Ag nanocomposites.

Adsorbent Metal ions Langmuir model Freundlich model
Qm (mg/g) B (L/mg) R2 KF (mg/g) 1/n R2

Fe3O4/CuO-IA/

PANI@Ag nanocomposite

 Pb (II) 47.915 0.334 0.98759 2.9682 1.4936 0.9653
As(III) 61.012 2.47 0.99111 5.0164 1.8807 0.9792
Open in a new tab

Comparison with other works

The Fe3O4/CuO-IA/PANI@Ag nanocomposite has been determined through Langmuir adsorption models were obtained a maximum adsorption capacity 47.915 and 61.012 mg/g of Lead and Arsenic adsorbent and related with other relevant literature an investigated in the removal of lead (II) and Arsenic (III) ions from wastewater (Table 2). As shown in Table 2, the Fe3O4/CuO-IA/PANI@Ag nanocomposite adsorbent has been comparable room temperature adsorption capacity than other adsorbents used an elimination of Pb (II) and AS (III) ions from aqueous medium. Therefore, this adsorbent can be a good option for removing Pb (II) and As (III) ions.

Table 2.

Comparison of room temperature adsorption capacity for the Fe3O4/CuO-IA/PANI@Ag NCs with various adsorbents reported in the literature.

Toxic elements Adsorbents pH Adsorption
capacity (mg/g)		 Ref
Pb (II) PANI-Chitosan 6 13.23 mg/g 42
PET/PANI/GO/Fe3O4 nanofibrous 6 97 mg/g 47
PES/PANI/GO 6 98 mg/g 48
Aminated Fe3O4 NPs filled CS/PVA/PES 6 21.2 mg/g 49
PANI-F-S nanostructure 6 40.3480 mg/g 6
PANI-NSA@Ni0 5 414.6 mg/g 44
S-nZVI@HPAC 5 295.30 mg/g 50
PPY-PEI Nano adsorbent 8 75.6 mg/g 51
Fe3O4-CS Nanocomposite beads 3–6 23.75 mg/g 52
PANI-Co-CNRs 5 1130 mg/g 53
Fe3O4/CuO-IA/PANI@Ag NCs 2–6 47.915 Present study
As (III) Fe–Mn binary oxide 5 73.5 mg/g 54
PANI-PS 8 56 mg/g 55
PANI/Fe0 composite nanofibers 7 232.5 mg/g 56
Magnetite-Graphene oxide composite 7 85 mg/g 57
Concrete- Fe3O4 5 2.03–11.12 mg/g 58
PANI-F-S nanostructure 6 175.430 mg/g 6
Fe/AlO(OH) from authentic acid mine drainage 2–10 102–129 mg/g 59
PNHM/ Fe3O4 7.7 28.27 mg/g 60
ZrVBZmetallopolymeric microsphere 7 6.5 mg/g 61
Fe3O4/CuO-IA/PANI@Ag NCs 2–6 61.012 Present study
Open in a new tab

In Table 2, shows the comparison of room temperature adsorption capacity for Fe3O4/CuO-IA/PANI@Ag NCs with various adsorbents reported in the literature.

Kinetic study of adsorption process

The kinetic reaction of adsorption of Pb (II) and As (III) ions of prepared were studied using nanocomposites Lagergren first order and second-order Equations62. The linearized kinetic equation for first-order is given by:

graphic file with name d33e1421.gif 3
graphic file with name d33e1425.gif 4

where, k1 is a 1st order rate constant, qe and qt are an uptake competency at equilibrium and quantity of metal uptake at a certain time t. The kinetic parameters are acquired by plotting log (qe—qt) versus t. Where, K2 is a second-order rate constant. By plotting t/qt Vs to get the kinetic parameters of adsorption.

Figures 8 (a-b) and 9 (a-b) show the curve of Pseudo-first order and pseudo-second-order kinetic, respectively. The results confirmed the coefficient ‘R2’ of Pb (II) ion well fits into pseudo-first order (0.96763) than pseudo-second-order (0.95694) indicating a chemisorption process63,64, whereas for As (III) pseudo-first-order (0.94845) are reasonably greater than pseudo-second-order model (0.94696) has been shown in Table 3. The correlation equation reflects the adsorption characteristics, which arise from the interaction between the nanocomposite adsorbent and the toxic metal ions present in industrial wastewater.

Fig. 8.

Fig. 8

Open in a new tab

(a-b) Pseudo-first-order curve for the adsorption of Pb (II) and As (III) onto nanocomposite.

Fig. 9.

Fig. 9

Open in a new tab

(a-b) Pseudo-second-order curve for the adsorption of Pb (II) and As (III) onto nanocomposite.

Table 3.

Compares the kinetic models for the adsorption of Pb (II) and As (III) ions onto a nanocomposite.

Metal ions Pseudo-first order Pseudo-second order
qe (mg/g) K1 (l/min) R2 qe (mg/g) K2 (g/mg min) R2
Pb (II) 19.926 0.02942 0.96763 123.7624 0.004174 0.95694
As (III) 20.194 0.01264 0.94845 119.3317 0.022083 0.94696
Open in a new tab

Re-usability studies

The reusability studies have been utilized adsorbents for Fe3O4/CuO-IA/PANI@Ag NCs was recovery and reuse process. The nanocomposite has been observed the various concentration by desorption substance like basic, acidic and impartial medium were shown in Fig. 10. The nanocomposite was employed through Pb (II) and As (III) particles operated to 50 mL solution at room temperature, an interaction time of 5 h, pH (2), and fomentation rate (250 rpm). The adjusted at pH 2.0–4.0 with acidic media and resolve reusability studies 92% and 90% of adsorbents 5 times desorption cycles repetitive consecutively56,65. These types of recycle process used an expulsion toxic metal ion in different industrial and environmental applications.

Fig. 10.

Fig. 10

Open in a new tab

Reusability of Fe3O4/CuO-IA/PANI@Ag NCs.

Conclusions

In summary, we have developed a green synthetical method for the synthesized nanocomposite that has investigated the structural modification of conducting polymers using polyaniline and itaconic acid with silver nanoparticles. The structure amendment of Fe3O4/CuO-IA/PANI@Ag NCs has been examined by FTIR spectral studies. XRD analysis of NCs has been exposed in their crystal nature, which is confirmed by XRD. The nanocomposite has been observed in different surface morphology sizes viz., 200–10 nm by TEM. The incorporation of AgNPs into polymer matrix for the detection of elemental composition of nanocomposite by using EDX analysis. We performed an exhaustive comparative study of the adsorption capacity of nanocomposite for dissolved Pb (II) and As (III) ions role of contact time, pH, dosage, concentration and temperature. The attain a fitting of our adsorption related data to the Langmuir, Freundlich and the adsorption process could be described through a pseudo-second order mechanism. The maximum adsorption capacity of 47.915 and 61.012 mg/g for lead and arsenic determined through non-linear fitting of Langmuir isotherm. Moreover, the nanocomposite has been recycled and used for five adsorption cycles without significant losses in their adsorption capacities. The nanocomposite after comparing these results with adsorbents reported in the literature, we are confident in suggesting that these materials hold a strong potential in adsorption process. Adsorption of Pb (II) and As (III) followed pseudo-first-order and pseudo-second-order kinetic parameters. In particular, they could be applied in standard potable water treatment protocols or in specialized units for the remediation of industrial wastewater.

Author contributions

EP; SS: Research Concept & Design, HLA: Reviewing and Editing, MVS: Interpretation of data, DAK: Manuscript preparation, AK; KR: Design and Analysis, all authors reviewed the manuscript. All authors were involved in editing the final manuscript. The author(s) read and approved the final manuscript.

Data availability

Data available on request from the authors.

Declarations

Competing interests

The authors declare no competing interests.

Footnotes

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  • 1.Sall, M. L., Diaw, A. K. D. & Gningue-Sall, D. Toxic heavy metals: Impact on the environment and human health, and treatment with conducting organic polymers, a review. Environ. Sci. Pollut. Res.27, 29927–29942. 10.1007/s11356-020-09354-3 (2020). [DOI] [PubMed] [Google Scholar]
  • 2.Jagaba, A. et al. Degradation of Cd, Cu, Fe, Mn, Pb and Zn by Moringa oleifera, zeolite, ferric-chloride, chitosan and alum in an industrial effluent. Ain. Shams. Eng. J.12, 57–64. 10.1016/j.asej.2020.06.016 (2021). [Google Scholar]
  • 3.Samadi, A. et al. Polyaniline-based adsorbents for aqueous pollutants removal: A review. Chem. Eng. J.418, 129425. 10.1016/j.cej.2021.12942 (2021). [Google Scholar]
  • 4.Jomova, K. et al. Arsenic: Toxicity, oxidative stress and human disease: Toxicity of arsenic. J. Appl. Toxicol.31, 95–107. 10.1002/jat.1649 (2011). [DOI] [PubMed] [Google Scholar]
  • 5.Hajjaoui, H., Soufi, A., Boumya, W., Abdennouri, M. & Barka, N. Polyaniline/nanomaterial composites for the removal of heavy metals by adsorption: A review. J. Compos. Sci.5, 233. 10.3390/jcs5090233 (2021). [Google Scholar]
  • 6.Alireza Hashemi, S., Mojtaba Mousavi, S. & Ramakrishna, S. Effective removal of mercury, arsenic and lead from aqueous media using Polyaniline-Fe3O4-silver diethyldithiocarbamate nanostructures. J. Clean. Prod.239, 118023. 10.1016/j.jclepro.2019.118023 (2019). [Google Scholar]
  • 7.Ansari, R., Feizy, J. & Delavar, A. F. Removal of arsenic ions from aqueous solutions using conducting polymers. J. Chem.5, 853–863. 10.1155/2008/908937 (2008). [Google Scholar]
  • 8.Abirami, S. & Kumar, E. A review on metal oxide-doped Polyaniline nanocomposites. J. Mater. Sci.59, 14141–14171. 10.1007/s10853-024-10020-z (2024). [Google Scholar]
  • 9.Hua, Z. & Fang, X. Effective design for long-range polymer ordering using Triptycene-containing side chains. Macromolecules56(19), 8047–8053. 10.1021/acs.macromol.3c00795 (2023). [Google Scholar]
  • 10.Bouazizi, N., Bargougui, R., Oueslati, A. & Benslama, R. Effect of synthesis time on structural, optical and electrical properties of CuO nanoparticles synthesized by reflux condensation method. Adv. Mater. Lett.6, 158–164. 10.5185/amlett.2015.5656 (2015). [Google Scholar]
  • 11.Zeghioud, H., Lamouri, S., Safidine, Z. & Belbachir, M. Chemical synthesis and characterization of highly soluble conducting polyaniline in mixtures of common solvents. J. Serb. Chem. Soc.80, 917–931. 10.2298/JSC140719003Z (2015). [Google Scholar]
  • 12.Zada, A. & Azizi, S. Cutting edge advancements in biochar applications: Bridging environmental remediation through adsorption and photocatalysis. RSC Adv.16(2), 1722–1756. 10.1016/j.ijoes.2023.01.005 (2026). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Pathania, D. et al. Studies on anticancerious and photocatalytic activity of carboxymethyl cellulose-cl-poly(lactic acid-co-itaconic acid)/ZnO-Ag nanocomposite. Arab. J. Chem.13, 6966–6976. 10.1016/j.arabjc.2020.07.001 (2020). [Google Scholar]
  • 14.Michal, R. et al. Photocatalytic properties and selective antimicrobial activity of TiO2 (Eu)/CuO nanocomposite. Appl. Surf. Sci.371, 538–546. 10.1016/j.apsusc.2016.03.003 (2016). [Google Scholar]
  • 15.Li, Y. et al. Efficient degradation of norfloxacin by synergistic activation of PMS with a three-dimensional electrocatalytic system based on Cu-MOF. Sep. Purif. Technol.356, 129945. 10.1016/j.seppur.2024.129945 (2025). [Google Scholar]
  • 16.Zhang, Z. et al. Deep learning-based transmembrane pulsed electro-chemisorption for improved energy efficacy of recovering ammonia from wastewater. Energy Environ. Sustain.1(3), 100029. 10.1016/j.eesus.2025.100029 (2025). [Google Scholar]
  • 17.Ayad, M. M., Amer, W. A. & Kotp, M. G. Magnetic polyaniline-chitosan nanocomposite decorated with palladium nanoparticles for enhanced catalytic reduction of 4-nitrophenol. Mol. Catal.439, 72–80. 10.1016/j.mcat.2017.06.023 (2017). [Google Scholar]
  • 18.Shano, A. M., Ali, I. M. & Bakr, N. A. Photodetector properties of polyaniline/CuO nanostructures synthesized by hydrothermal technique. J. Nano-Electron. Phys.11, 06016. 10.21272/jnep.11(6).06016 (2019). [Google Scholar]
  • 19.Cho, D. W. et al. A novel chitosan/clay/magnetite composite for adsorption of Cu(II) and As(V). Chem. Eng. J.10.1016/j.cej.2012.06.126 (2012). [Google Scholar]
  • 20.Han, X. et al. Core–shell structured Fe3O4/PANI microspheres and their Cr(VI) ion removal properties. Synth. Met.171, 1–6. 10.1016/j.synthmet.2013.02.025 (2013). [Google Scholar]
  • 21.Zhang, F. et al. Removal of heavy metal ions from aqueous solution using Fe3O4–SiO2-poly(1,2-diaminobenzene) core–shell sub-micron particles. J. Colloid Interface Sci.387, 205–212. 10.1016/j.jcis.2012.07.066 (2012). [DOI] [PubMed] [Google Scholar]
  • 22.Saleh, T. A., Gondal, M. & Drmosh, Q. Preparation of a MWCNT/ZnO nanocomposite and its photocatalytic activity for the removal of cyanide from water using a laser. Nanotechnology21, 495705. 10.1088/0957-4484/21/49/495705 (2010). [DOI] [PubMed] [Google Scholar]
  • 23.Jayakumar, S. et al. Synthesis, characterization, and performance of chitosan/nylon 6/polyurethane blend for the removal of chromium (VI) and lead (II) ions from aqueous solutions for enhanced kinetic adsorption studies. Water Reuse13, 319–328. 10.2166/wrd.2023.019 (2023). [Google Scholar]
  • 24.Abd El-Lateef, H. M., Zeng, C. Q., Khalaf, M. M. & Mohamed, I. M. Green synthesis of silver-incorporated rutile TiO2 for enhanced photocatalytic degradation of Ciprofloxacin and Carmine G dye pollutants. Catalysts14(12), 904. 10.3390/catal14120904 (2024). [Google Scholar]
  • 25.Srivastava, A., Nkole, I. U., Srivastava, K., Singh, V. K. & Srivastava, N. Sustainable polypyrrole@ CoFe2O4 nanocomposite for the enhanced removal of toxic mercury (II): kinetic modeling and mechanistic approach. Pure Appl. Chem.10.1515/pac-2025-0653 (2026). [Google Scholar]
  • 26.Jose, J. K. et al. Silver–graphene composite: A coating on polyethersulfone membrane for superior water purification with antibacterial, catalytic and antifouling properties. Clean Technol. Environ. Policy10.1007/s10098-025-03224-7 (2025). [Google Scholar]
  • 27.Weldegebrieal, G. K. Photocatalytic and antibacterial activityof CuO nanoparticles biosynthesized using Verbascum thapsus leaves extract. Optik204, 164230. 10.1016/j.ijleo.2020.164230 (2020). [Google Scholar]
  • 28.Khamwichit, A., Dechapanya, W. & Dechapanya, W. Adsorption kinetics and isotherms of binary metal ion aqueous solution using untreated venus shell. Heliyon8, e09610. 10.1016/j.heliyon.2022.e09610 (2022). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29.Lu, J. Y. et al. Facile microwave-assisted synthesis of Sb2O3-CuO nanocomposites for catalytic degradation of p-nitrophenol. J. Mol. Liq.409, 125503. 10.1016/j.molliq.2024.125503 (2024). [Google Scholar]
  • 30.Ashokkumar, S. P. et al. Structure, morphology, thermal and electrochemical studies of electrochemically synthesized polyaniline/copper oxide nanocomposite for energy storage devices. Mater. Res. Express6, 125557. 10.1088/2053-1591/ab5dde (2019). [Google Scholar]
  • 31.Singh, R. P., Tiwari, A. & Pandey, A. C. Silver/polyaniline nanocomposite for the electrocatalytic hydrazine oxidation. J. Inorg. Organomet. Polym. Mater.21, 788–792. 10.1007/s10904-011-9554-y (2011). [Google Scholar]
  • 32.Neisi, Z., Ansari-Asl, Z. & Dezfuli, A. S. Polyaniline/Cu(II) metal-organic frameworks composite for high performance supercapacitor electrode. J. Inorg. Organomet. Polym.29, 1838–1847. 10.1007/s10904-019-01145-9 (2019). [Google Scholar]
  • 33.Kumar, H., Boora, A., Yadav, A. & Rajni, R. Polyaniline-metal oxide-nano-composite as a nano-electronics, opto-electronics, heat resistance and anticorrosive material. Results. Chem.2, 100046. 10.1016/j.rechem.2020.100046 (2020). [Google Scholar]
  • 34.Qin, X., Cui, H. & Zhou, Q. Physisorption behaviors of organochlorine pesticides on the InP3 monolayer from theoretical insight. ACS Omega8(35), 32168–32175. 10.1021/acsomega.3c04665 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 35.Ramachandran, K. et al. A facile green synthesis of Ag/TiO2 nanocomposite using Averrhoa carambola leaf extract for enhanced photocatalytic and antibacterial applications. J. Ind. Eng. Chem.35, 29–35. 10.1016/j.jiec.2016.03.044 (2016). [Google Scholar]
  • 36.Jundale, D. M. et al. Polyaniline-CuO hybrid nanocomposites: Synthesis, structural, morphological, optical and electrical transport studies. J. Mater. Sci. Mater. Electron.24, 3526–3535. 10.1007/s10854-013-1280-5 (2013). [Google Scholar]
  • 37.Lata, S. & Samadder, S. R. Removal of arsenic from water using nano adsorbents and challenges: A review. J. Environ. Manage.166, 387–406. 10.1016/j.jenvman.2015.10.039 (2016). [DOI] [PubMed] [Google Scholar]
  • 38.Amen, R. et al. Lead and cadmium removal from wastewater using eco-friendly biochar adsorbent derived from rice husk, wheat straw, and corncob. Clean. Eng. Technol.1, 100006. 10.1016/j.clet.2020.100006 (2020). [Google Scholar]
  • 39.Gupta, K. & Ghosh, U. C. Arsenic removal using hydrous nanostructure iron(III)–titanium(IV) binary mixed oxide from aqueous solution. J. Hazard. Mater.161, 884–892. 10.1016/j.jhazmat.2008.04.034 (2009). [DOI] [PubMed] [Google Scholar]
  • 40.Zhang, J., Han, J., Wang, M. & Guo, R. Fe3O4 /PANI/MnO2 core–shell hybrids as advanced adsorbents for heavy metal ions. J. Mater. Chem. A.5, 4058–4066. 10.1039/C6TA10499A (2017). [Google Scholar]
  • 41.Jabeen, T., Rashid, M. & Khan, A. A comparative analysis of the removal of arsenic from water using magnetite/polyaniline-polypyrrole nanocomposite. Int. J. Environ. Sci. Technol.10.1007/s13762-025-06573-4 (2025). [Google Scholar]
  • 42.Karthik, R. & Meenakshi, S. Removal of Pb (II) and Cd (II) ions from aqueous solution using polyaniline grafted chitosan. Chem. Eng. J.263, 168e–1177. 10.1016/j.cej.2014.11.015 (2015). [Google Scholar]
  • 43.Li, Z., Deng, S., Yu, G., Huang, J. & Lim, V. C. As(V) and As(III) removal from water by a Ce–Ti oxide adsorbent: Behavior and mechanism. Chem. Eng. J.161(1–2), 106–113. 10.1016/j.cej.2010.04.039 (2010). [Google Scholar]
  • 44.Bhaumik, M., Maity, A. & Brink, H. G. Zero valent nickel nanoparticles decorated polyaniline nanotubes for the efficient removal of Pb(II) from aqueous solution: Synthesis, characterization and mechanism investigation. Chem. Eng. J.417, 127910. 10.1016/j.cej.2020.127910 (2021). [Google Scholar]
  • 45.Deng, M., Wu, X., Zhu, A., Zhang, Q. & Liu, Q. Well-dispersed TiO2 nanoparticles anchored on Fe3O4 magnetic nanosheets for efficient arsenic removal. J. Environ. Manage.237, 63–74. 10.1016/j.jenvman.2019.02.037 (2019). [DOI] [PubMed] [Google Scholar]
  • 46.Jain, N., Singh, P., Bhatnagar, A. & Maiti, A. Arsenite oxidation and adsorptive arsenic removal from contaminated water: A review. Environ. Sci. Pollut. Res.31, 42574–42592. 10.1007/s11356-024-33963-x (2024). [DOI] [PubMed] [Google Scholar]
  • 47.Koushkbaghi, S., Jafari, P., Rabiei, J., Irani, M. & Aliabadi, M. Fabrication of PET/PAN/GO/Fe3O4 nanofibrous membrane for the removal of Pb(II) and Cr(VI) ions. Chem. Eng. J.301, 42–50. 10.1016/j.cej.2016.04.076 (2016). [Google Scholar]
  • 48.Ghaemi, N., Zereshki, S. & Heidari, S. Removal of lead ions from water using PES–based nanocomposite membrane incorporated with polyaniline modified GO nanoparticles: Performance optimization by central composite design. Process Saf. Environ. Prot.111, 475–490. 10.1016/j.psep.2017.08.011 (2017). [Google Scholar]
  • 49.Koushkbaghi, S. et al. Aminated- Fe3O4 nanoparticles filled chitosan/PVA/PES dual layers nanofibrous membrane for the removal of Cr (VI) and Pb (II) ions from aqueous solutions in adsorption and membrane processes. Chem. Eng. J.337, 169–182. 10.1016/j.cej.2017.12.075 (2018). [Google Scholar]
  • 50.Qu, J. et al. Green synthesis of hydrophilic activated carbon supported sulfide nZVI for enhanced Pb(II) scavenging from water: Characterization, kinetics, isotherms and mechanisms. J. Hazard. Mater.403, 123607. 10.1016/j.jhazmat.2020.123607 (2021). [DOI] [PubMed] [Google Scholar]
  • 51.Birniwa, A. H. et al. Polymer-based nano-adsorbent for the removal of lead ions: Kinetics studies and optimization by response surface methodology. Separations9, 356. 10.3390/separations9110356 (2022). [Google Scholar]
  • 52.Atasoy, S. M. M. & Yildiz, A. Y. Removal of Ni(II), Cu(II), Pb(II), and Cd(II) from aqueous phases by silver nanoparticles and magnetic nanoparticles/nanocomposites. ACS Omega8, 34834–34843. 10.1021/acsomega.3c04054 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 53.Bhaumik, M., Maity, A. & Brink, H. G. Highly efficient removal of Pb2+ from aqueous solution using polyaniline-cobalt composite nanorods: Kinetics, isotherm and mechanistic investigation. Chemosphere370, 143929. 10.1016/j.chemosphere.2024.143929 (2025). [DOI] [PubMed] [Google Scholar]
  • 54.Zhang, G. S., Qu, J. H., Liu, H. J., Liu, R. P. & Wu, R. C. Preparation and evaluation of a novel Fe–Mn binary oxide adsorbent for effective arsenite removal. Water Res.41, 1921–1928. 10.1016/j.watres.2007.02.009 (2007). [DOI] [PubMed] [Google Scholar]
  • 55.Davodi, B. & Jahangiri, M. Determination of optimum conditions for removal of as (III) and as (V) by polyaniline/polystyrene nanocomposite. Synth. Met.194, 97e–101. 10.1016/j.synthmet.2014.04.020 (2014). [Google Scholar]
  • 56.Bhaumik, M., Noubactep, C. & Gupta, V. K. Polyaniline/Fe0 composite nanofibers: An excellent adsorbent for the removal of arsenic from aqueous solutions. Chem. Eng. J.271, 135–146. 10.1016/j.cej.2015.02.079 (2015). [Google Scholar]
  • 57.Yoon, Y., Park, W. K. & Hwang, T. M. 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. 10.1016/j.jhazmat.2015.10.053 (2016). [DOI] [PubMed] [Google Scholar]
  • 58.Hernandez-Flores, H., Pariona, N., Herrera-Trejo, M., Hdz-García, H. M. & Mtz-Enriquez, A. I. Concrete/maghemite nanocomposites as novel adsorbents for arsenic removal. J. Mol. Struct.1171, 9e–16. 10.1016/j.molstruc.2018.05.078 (2018). [Google Scholar]
  • 59.Muedi, K. L., Brink, H. G., Masindi, V. & Maree, J. P. Effective removal of arsenate from wastewater using aluminium enriched ferric oxide-hydroxide recovered from authentic acid mine drainage. J. Hazard. Mater.414, 125491. 10.1016/j.jhazmat.2021.125491 (2021). [DOI] [PubMed] [Google Scholar]
  • 60.Dutta, S., Manna, K., Kumar Srivastava, S., Gupta, A. & Yadav, M. Hollow polyaniline microsphere/ Fe3O4 nanocomposite as an effective adsorbent for removal of arsenic from water. Sci. Rep.10, 4982. 10.1038/s41598-020-61763-z (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 61.Gupta, A. R., Joshi, V. C., Yadav, A. & Sharma, S. Synchronous removal of arsenic and fluoride from aqueous solution: A facile approach to fabricate novel functional metallopolymer microspheres. ACS Omega7, 4879–4891. 10.1021/acsomega.1c05456 (2022). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 62.Zhou, Q., Wang, J., Liao, X., Xiao, J. & Fan, H. Removal of As(III) and As(V) from water using magnetic core-shell nanomaterial Fe3O4 @ polyaniline. Int. J. Green Tech.1, 54–64. 10.30634/2414-2077.2015.01.6 (2015). [Google Scholar]
  • 63.Rashed, M. N., Arifien, A. S. A. & El-Dowy, F. A. Muscovite based polyaniline nanocomposite as effective adsorbent for removal of Cd2+ and Pb2+ ions from liquid waste. Sci. Rep.15, 20234. 10.1038/s41598-025-99686-2 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 64.Yang, H., Wang, Y., Bender, J. & Xu, S. Removal of arsenate and chromate by lanthanum-modified granular ceramic material: The critical role of coating temperature. Sci. Rep.9, 7690. 10.1038/s41598-019-44165-8 (2019). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 65.Nikic, J. et al. Arsenic removal from water using a one-pot synthesized low-cost mesoporous Fe-Mn-modified biosorbent. J. Serb. Chem. Soc.84, 327–342. 10.2298/JSC180809099N (2019). [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

Data available on request from the authors.

Articles from Scientific Reports are provided here courtesy of Nature Publishing Group

RESOURCES