Green remediation: Casuarina equisetifolia fruit-based activated carbon for pharmaceutical removal

Abstract

This work utilized Casuarina equisetifolia fruit-based activated carbon (CEAC) to investigate the simultaneous removal of paracetamol (PA), caffeine (CAF), and acetylsalicylic acid (AS) from aqueous solutions. The efficacy of adsorbent removal was investigated using adsorption factors such as pH, CEAC amount, initial pharmaceutical concentration, and adsorption period. Fourier-transform infrared spectroscopy, scanning electron microscopy, and UV-visible analysis confirmed the simultaneous adsorption of the pharmaceutical mixture onto the CEAC surface. The results showed a slight effect of pH on the simultaneous adsorption efficiencies with a CEAC dose of 110 mg. The ideal initial concentration for the pharmaceutical mixture was determined to be 15 mg L⁻¹. The perfect contact duration for the simultaneous removal of the three pharmaceuticals was found to be 30 min. Kinetic tests demonstrated that the pharmaceutical mixture adsorbs using a pseudo-second-order process. The Freundlich isotherm model describes the equilibrium data. The maximum adsorption capabilities were PA (84.15.23 mg g⁻¹), CAF (79.16 mg g⁻¹), and AS (61.32 mg g⁻¹). A thermodynamic study reveals that these adsorption processes are endothermic and spontaneous. Finally, regeneration experiments confirm the reusability of CEAC.

Keywords

Activated carbon acetylsalicylic acid adsorption caffeine paracetamol

Introduction

Pharmaceutical waste has emerged as a major environmental issue due to the persistence and toxicity of pharmaceutical chemicals in aquatic habitats, leading to water pollution. These toxins often enter water bodies via several pathways, including effluents from wastewater treatment plants, poor disposal methods, and discharges from pharmaceutical production sites. Authentic production establishments.¹ Paracetamol (PA; acetaminophen), caffeine (CAF), and acetylsalicylic acid (AS; aspirin) are frequently utilized medications that can infiltrate aquatic ecosystems via wastewater treatment plant discharges and other routes. Although these substances provide considerable health advantages to humans, they may adversely affect aquatic organisms.² Fish that take PA may experience reproductive problems due to endocrine disruption. Scientific research illustrates that CAF creates effects on fish behavior and growth, alongside reproduction. AS produces adverse effects on fish respiration, disrupts blood coagulation mechanisms, and leads to oxidative stress. Such effects lead to population changes in fish species and impaired aquatic environment health, which can disrupt entire aquatic ecosystems. Creating effective wastewater treatment methods alongside reducing medication release into aquatic systems remains essential to protecting delicate ecosystems.³

Adsorption on activated carbon helps pharmaceuticals to be efficiently removed from water. On its enormous surface area, many micropores and mesopores allow activated carbon to effectively absorb many chemical compounds, including pharmaceuticals.⁴ The implementation of this technique serves well for existing water treatment facilities because it requires minimal effort and financial costs. Activated carbon remains sustainable and environmentally friendly since both thermal and chemical processes enable its renewal. Activated carbon functions as an effective multi-medication water purification solution because it provides flexible removal capabilities for different types of medications in the water supply.⁵ Activated carbon derived from agricultural waste produces several advantages when created from Casuarina equisetifolia fruit. The utilization of agricultural waste promotes long-term waste management by drawing from simple yet renewable biomass materials. The high carbon content, together with the porous structure of the Casuarina equisetifolia fruit, makes it a superior material for activated carbon synthesis. The synthesized activated carbon shows a high surface area along with excellent adsorption properties and stable chemical structure, which makes it suitable for water treatment and wastewater purification as well as air filtration while functioning as a catalyst support system.⁶ The dual approach addresses environmental problems in agricultural waste handling through cost-effective waste management practices that produce an important material for multiple industrial applications and environmental projects.⁷ The adsorbent material that prepared in this study was investigated for the removal of several types of pollutants, including heavy metals and organic compounds. Most of these studies have illustrated the effectiveness of this adsorbent material in diverse environmental applications, but none of them focused on the simultaneous removal of a group of structurally diverse pharmaceutical compounds. This study designs an assessment of activated carbon made from Casuarina equisetifolia fruit-based activated carbon (CEAC) to serve as an efficient absorbent for simultaneously removing three pharmaceutical substances from water solutions: PA, CAF, and AS. The study works to optimize the adsorption process so that water treatment benefits from a cost-effective simultaneous removal technique of these contaminants through sustainable water treatment methods. The novelty of this study stems from both the unique precursor material and the comprehensive optimization of a cost-effective, multi-target removal process, offering a significant advancement in sustainable water purification technologies.

Materials and methods

Chemicals

All chemicals used in this study were purchased from Sigma Aldrich. Table 1 shows the utilized pharmaceuticals in this study with their chemical structure:

Table 1.

Pharmaceutical names, chemical formula, and chemical structure.

Pharmaceutical name	Chemical formula	Essay
Paracetamol	C₈H₉NO₂	99.9%
Caffeine	C₈H₁₀N₄O₂	98.5%
Acetylsalicylic acid	C₉H₈O₄	99.5%–101%

The preparation of solutions

A 250 mg L⁻¹ stock solution of PA, CAF, and AS was formulated in a 250 mL volumetric flask utilizing double-distilled water to ensure purity. Subsequently, this stock solution was diluted with double-distilled water to achieve the requisite final concentrations. A mixture including PA, CAF, and AS was generated for the concurrent studies by combining measured aliquots of the diluted stock solution. The pH of the solutions was modified using 0.1 M NaOH and HCl to provide the required experimental conditions.

Adsorbent preparation and characterization

The Jordanian Casuarina equisetifolia fruit was obtained at the Isra University Campus. After that, the fragments were washed and dried at 100°C for 48 h. They were then crushed, impregnated with 98% phosphoric acid, heated to 450°C, and neutralized with a 5.0 M NaOH solution.⁸ CEAC was crushed and sieved into 180 µm particles. Fourier-transform infrared spectroscopy (FTIR, TENSOR 27 model from BRUKER, Germany) with an ATR unit was utilized to assign functional groups to the CEAC surface. The scanning electron microscope (Apreo 2 S LoVac, USA) was used to verify the simultaneous adsorption process.

Batch adsorption experiment

Solutions of PA, CAF, and AS with different concentrations were shaken with a stated mass of CEAC for a set time. The study inspected adsorption parameters such as CEAC dosage (30–180 min), initial adsorbate concentration (10–50 mg L⁻¹) pH,^3–11 and shaking time (10–120 min). Further experiments were performed using a solution of the three pharmaceuticals to investigate the simultaneous adsorption process. The concentrations of the pharmaceuticals were determined using a UV-6100 PC double-beam spectrophotometer by measuring absorbance at the wavelengths of 244, 215, and 271 nm for PA, CAF, and AS, respectively. The amount of adsorbed pharmaceutical (q_e in mg g⁻¹) was calculated using (q_e = (C_i − C_eq) × V/W) in which C_i and C_eq (mg L⁻¹) are the initial and equilibrium concentrations, respectively. V and W are the volume (L) and weight of CEAC adsorbent (g), respectively. The percentage of uptake was also calculated using (% uptake = (C_i − C_eq) × 100/C_i). Each experiment was conducted in triplicate.

Results and discussion

Characterization of adsorbent

The results from FTIR spectroscopy (Figure 1(a)) offered critical insights into the functional groups present on the CEAC adsorbent and their role in pharmaceutical adsorption. The distinct peaks in the spectra confirm the presence of various functional groups on the CEAC surface, which are key to understanding its adsorption capabilities and potential applications in the simultaneous removal of stated pharmaceuticals. Shifts in peak positions, particularly in regions corresponding to O-H stretching (∼3400 cm⁻¹), O-H stretching shoulder for carboxylic acid (2666 cm⁻¹), (C = O stretching (1600–1800 cm⁻¹), and C-O stretching (1000–1200 cm⁻¹), suggest interactions between the pharmaceuticals and the functional groups on CEAC, such as hydrogen bonding or π–π interactions.⁹ Additionally, reductions in peak intensity and broadening in specific regions reflect surface modifications due to the occupation of active sites by the pharmaceuticals. The fingerprint region also shows notable changes, further confirming structural alterations on the CEAC surface. These observations highlight the active role of CEAC's functional groups in pharmaceutical adsorption, demonstrating its potential as an effective adsorbent for water treatment applications.

Figure 1.

(a) FTIR spectra for the adsorbent (CEAC) before and after adsorption, (b) SEM of CEAC, and (c) SEM of CEAC-pharm.mix.

Additionally, scanning electron microscopy (SEM) analysis further corroborates the successful adsorption of PA, CAF, and AS onto the CEAC adsorbent. Figure 1(b) shows the pristine CEAC, displaying a highly porous structure with numerous evenly distributed pores, ideal for efficient contaminant capture (Figure 1(c)). The SEM images obtained before and after the simultaneous adsorption process (Figure 1(a) and (b)) show a significant decrease in pore visibility, indicating that the surface pores have been effectively filled by the adsorbed pharmaceuticals. This visual confirmation provides compelling support for the effectiveness of the adsorption process.

Factors affecting adsorption

The adsorption of PA, CAF, and AS onto CEAC was found to be significantly influenced by the amount of CEAC used (Figure 2(a)). As the CEAC amount increased, the percentage uptake of all three compounds generally increased, indicating that the availability of adsorption sites on the CEAC surface primarily governs the adsorption process. However, among the three pharmaceuticals, CAF exhibited the highest affinity for CEAC, as evidenced by its greater uptake in the adsorption experiments (Figure 2). The adsorption of all chemicals approached saturation at increasing CEAC levels, implying that the accessible adsorption sites got saturated. These results show the potential of CEAC as a useful adsorbent for the elimination of these pollutants from aqueous solutions. It was revealed that the initial concentration of the three pharmaceuticals affected their simultaneous adsorption onto CEAC (Figure 2(b)). Because of possible mass transfer restrictions and competition for adsorption sites, the simultaneous adsorption often dropped as the concentration increased. These results imply that the adsorption process is more efficient at lower concentrations, therefore stressing the need to optimize operating parameters for the efficient removal of these pollutants by CEAC. Figure 2(c) shows that the percentage uptake was increased by increased contact time, and equilibrium was reached after half an hour. Finally, Figure 2(d) shows a slight effect of pH on the simultaneous adsorption of the three pharmaceuticals onto the surface of CEAC. The adsorption of PA, CAF, and AS onto the adsorbent was found to be significantly influenced by pH. This influence is due to change in both the surface charge of the CEAC and the ionization state of the pharmaceutical. The zero point of charge (pHpzc) of CEAC was determined to be 7.4, meaning the surface is positively charged at pH < 7.4 and negatively charged at pH > 7.4. The three compounds exhibited different responses to changes in pH. AS has a pKa of ∼3.5 and exists mostly in anionic form above this pH, which may lead to electrostatic repulsion at higher pH values (negative CEAC), resulting in slightly reduced adsorption. PA, with a pKa value of ∼9.4, remains mostly neutral under the studied pH range, and its removal appears to be governed by weak interactions, leading to moderate uptake (∼70%–72%). CAF, with a high pKa value of ∼14, remains neutral across the entire pH range, and its consistently high adsorption (∼96%–97%) suggests that strong non-electrostatic interactions (e.g. π–π stacking and hydrogen bonding) dominate its affinity for CEAC.

Figure 2.

Effect of (a) CEAC mass, (b) initial pharmaceutical concentration, (c) contact time, and (d) pH on the simultaneous adsorption of PA, CAF, and AS. Data are presented as mean ± standard deviation (SD) from three independent experiments (n = 3).

Kinetic and mechanism

Kinetic investigations of adsorption are essential for comprehending the pace and mechanism of the adsorption process. These studies offer significant insights into factors including the rate-controlling step (e.g. mass transfer, chemical reaction), the adsorption mechanism (e.g. physical adsorption, chemisorption), and the influence of various parameters such as temperature and adsorbate concentration on the adsorption process.¹⁰ This information is crucial for enhancing adsorption processes in diverse applications, such as water treatment, environmental remediation, and catalysis. Comprehending the kinetics enables researchers and engineers to devise more efficient and effective adsorption systems, resulting in enhanced performance and decreased costs.

Figure 3 provides compelling evidence that the pseudo-second-order kinetic model best describes the adsorption behavior of the pharmaceutical mixture onto CEAC. This finding is detailed in Table 3.

Figure 3.

Linear kinetic models for the simultaneous adsorption of PA, CAF, and AS onto CEAC: (a) pseudo-first-order (PFO), (b) pseudo-second-order (PSO), and (c) intra-particle diffusion (IPD). Data points represent mean ± SD of three independent replicates.

The equations presented in Table 2 evaluated the contribution of intra-particle diffusion to the simultaneous adsorption mechanism of a pharmaceutical mixture onto CEAC.

Table 2.

Linear equations and parameters for pseudo-first-order (PFO), pseudo-second-order (PSO), and intra-particle diffusion (IPD) kinetic models used to evaluate adsorption behavior.

Kinetic model	Linear equation	Parameters
PFO	$\log (q_{e} - q_{t}) = l o g (q_{e}) - (\frac{k_{1}}{2.303}) t$	q_e: the amount of pharmaceutical (mg g⁻¹) at equilibrium. q_t: the amount of pharmaceutical (mg g⁻¹) k₁: the rate constant in min⁻¹
PSO	$\frac{t}{q_{t}} = \frac{1}{k_{2} q_{e}^{2}} - \frac{1}{q_{e}} t$	k₂: the rate constant in g mg⁻¹ min⁻¹
IPD	$q_{t} = K_{i d} t^{\frac{1}{2}} + C$	K_id: the rate constant (mg g⁻¹ min^−0.5). $t^{\frac{1}{2}}$ : the square root of time (min^0.5)

The intraparticle diffusion model, as depicted in Figure 3(c), revealed multiple linear regions for all pharmaceuticals (PA, CAF, and AS), suggesting a multi-step adsorption process involving film diffusion and intraparticle diffusion. Disparities in the slopes of the linear regions for each adsorbate indicated differences in their intraparticle diffusion rates. Furthermore, the non-zero y-intercepts suggested the influence of other factors, such as film diffusion, on the overall adsorption kinetics. These findings highlight the complex nature of the adsorption process and emphasize the importance of considering multiple factors, including adsorbent properties and external mass transfer limitations, for a comprehensive understanding of the adsorption mechanism.¹¹

The values of R² and constants for all kinetics models were summarized in Table 3.

Table 3.

Kinetic parameters and correlation coefficients (R²) for PFO, PSO, and IPD models describing the adsorption of PA, CAF, and AS onto CEAC.

			Linear models
Kinetic model		R ²	Related constants
PFO	PA CAF AS	0.5611 0.8901 0.9218	K₁ = 1.60 × 10⁻³ (min⁻¹) K₁ = 1.00 × 10⁻³ (min⁻¹) K₁ = 3.0 × 10⁻³ (min⁻¹)
PSO	PA CAF AS	0.9958 0.9978 0.9985	K₂ = 3.02 × 10⁻¹ (g mg⁻¹ min⁻¹) K₂ = 2.6 × 10⁻¹ (g mg⁻¹ min⁻¹) K₂ = 2.8 × 10⁻¹ (g mg⁻¹ min⁻¹)
IPD	PA CAF AS	0.6323 0.5227 0.5622	K_id = 0.4687 (mg g⁻¹ min^−0.5) K_id = 0.7779 (mg g⁻¹ min^−0.5) K_id = 5.4366 (mg g⁻¹ min^−0.5)

Adsorption isotherms

Various adsorption isotherm models were utilized to comprehend the nature and characteristics of the adsorption process for PA, CAF, and AS CEAC. The Langmuir, Freundlich, and Temkin models (see Table 4 for details) facilitated the evaluation of the interaction between the adsorbent (CEAC) and the adsorbates (pharmaceuticals). Analyzing the fit of these models may provide information on whether the adsorption process is predominantly physical or chemical.

Table 4.

Linear forms of Langmuir, Freundlich, and Temkin adsorption isotherm models and related parameters.

Isothermal model	Linear equation	Parameters
Langmuir	$\frac{C_{e}}{q_{e}} = \frac{1}{k_{L} q_{m}} + \frac{C_{e}}{q_{m}}$	q_e: is the equilibrium quantity of the adsorbate (mg g⁻¹). C_e: is the equilibrium concentration of the adsorbate (mg L⁻¹). K_L: the constant of Langmuir isotherm. q_m: is the adsorption capacity (mg g⁻¹)
Freundlich	$\log q_{e} = \log K_{f} + \frac{1}{n} \log C_{e}$	K_f: the Freundlich isotherm constant, measured in units of mg g⁻¹. n: denotes the adsorption intensity.
Temkin	$q_{e} = B l n A + B l n C_{e}$	A: the binding constant (g⁻¹) when the system is at equilibrium. B: the adsorption heat.

Figure 4(a) to (c) presents the linear forms of the three isotherm models for visual analysis: Langmuir, Freundlich, and Temkin. The key parameters derived from these plots are summarized in Table 5, featuring correlation coefficients (R²) and pertinent constants. The Freundlich isotherm demonstrated the highest R² values for PA (0.9915), CAF (0.9941), and AS (0.9949) adsorption onto CEAF. The elevated R² values indicate a strong alignment with the Freundlich model, reflecting a non-uniform CEAC surface characterized by heterogeneous adsorption sites for these pharmaceuticals. The values of the Temkin constant, B (38.96, 26.53, and 6.56 for PA, CAF, and AS, respectively), suggest a notable interaction between the pharmaceutical and the CEAF adsorbent.¹²

Figure 4.

Adsorption isotherm models for PA, CAF, and AS onto CEAC: (a) Langmuir, (b) Freundlich, and (c) Temkin models. Data points represent mean values ± SD from three independent replicates (n = 3).

Table 5.

Isotherm parameters and correlation coefficients (R²) for Langmuir, Freundlich, and Temkin models describing the adsorption of PA, CAF, and AS onto CEAC.

Isotherm	Related isotherm constants	Pharmaceutical species
Isotherm	Related isotherm constants	PA	CAF	AS
Langmuir	$R_{L}^{2}$	0.3325	0.3771	0.4722
	K_L	0.0193	0.0513	0.1228
	q_m (mg g⁻¹)	239.23	134.95	45.93
Freundlich	$R_{F}^{2}$	0.9915	0.9941	0.9949
	K_F (mg g⁻¹)	2.69	3.01	3.33
	n	2.0	2.0	5.0

Temkin	R ²	0.7677	0.6882	0.6909
	B	38.96	26.53	6.56
	A	0.0654	0.446	80.89

Thermodynamics

In order to comprehend and optimize adsorption processes, thermodynamic parameters like enthalpy change (ΔH), entropy change (ΔS), and Gibbs free energy change (ΔG) are essential. The energy shifts, spontaneity, and viability of adsorption are all shown by these metrics. Thermodynamic parameters were established under carefully monitored conditions to comprehend the effectiveness of pharmaceutical removal by CEAC.¹⁰ Three constant temperatures (298 K ± 1.0 K, 308 K ± 1.0 K, and 318 K ± 1.0 K) and constant agitation (1.0 h) were used for the experiments. The results are presented in Table 6. The value of ΔG° was calculated using the ΔG° = ΔH° − TΔS° formula. The van’t Hoff equation was used to determine ΔH° and ΔS° from the slope and intercept of a plot of ln(K) vs. 1/T:

\ln (K) = \frac{Δ S^{o}}{R} - \frac{Δ H^{o}}{T} (\frac{1}{T})

Table 6.

Thermodynamic parameters (ΔG°, ΔH°, ΔS°) for the adsorption of PA, CAF, and AS onto CEAC at 298, 308, and 318 K.

Pharmaceutical	T (K)	Thermodynamic parameters
Pharmaceutical	T (K)	ΔG° (kJ mol⁻¹)	ΔH° (kJ mol⁻¹)	ΔS° (kJ K⁻¹ mol⁻¹)
PA	298	1.602 ± 0.02	25.087 ± 0.02	0.0787 ± 0.015
	308	0.930 ± 0.02
	318	0.0239 ± 0.02

CAF	298	1.998 ± 0.01	44.979 ± 0.01	0.0676 ± 0.015
	308	1.210 ± 0.01
	318	0.651 ± 0.01

AS	298	1.590 ± 0.01	22.350 ± 0.01	0.0697 ± 0.015
	308	0.828 ± 0.01
	318	0.199 ± 0.01

In the best-fitted model, K represents the adsorption equilibrium constant, while R is the universal constant of ideal gases, 8.314 J K⁻¹ mol⁻¹. The thermodynamic parameters presented in Table 6 reveal that the adsorption of PA, CAF, and AS onto CEAC is endothermic (positive ΔH°) and non-spontaneous (positive ΔG°). However, with increasing temperature, the magnitude of ΔG° decreases, and the process becomes spontaneous at higher temperatures. This indicates that the adsorption process is favored at elevated temperatures. The positive values of ΔS° for all pharmaceuticals suggest an increase in randomness at the solid–solution interface during adsorption. These thermodynamic findings suggest that the adsorption can be effectively driven at elevated temperatures, making it a feasible process under suitable conditions.¹³

Regeneration of CEAC adsorbent

It has been determined over a series of experiments that absolute ethanol is suitable for the recovery study of the three pharmaceuticals. Because PA, CAF, and AS are rapidly adsorbed, column experiments were utilized for the regeneration step. The pharmaceuticals that were eluted from CEAC were measured for absorbance by a UV-visible spectrophotometer. The recovery percentage was calculated using the following equation¹⁴:

% Recovery = \frac{C_{de}}{C_{ad}} \times 100

C_ad represents the adsorbed concentration of the pharmaceutical, and C_de represents the desorbed concentration. The value of C_ad was calculated using the relationship of (C_ad = (C_i − C_eq) × V/W). After three cycles, Figure 5 demonstrates that the recovery of the three pharmaceuticals decreased, going from 96.07% to 86.99% for PA, from 85.65% to 73.56% for CAF, and from 99.32% to 86.12% for AS. These results indicate that CEAC has reuse capabilities. Comparable results were achieved for the combination of the three pharmaceuticals (Figure 5).

Figure 5.

Regeneration of CEAC adsorbent.

Comparison with other activated carbon

The comparison of CEAC's maximum pharmaceutical removal capabilities with those attained by other activated carbon adsorbents is presented in Table 7. From the comparison, CEAC has an adsorption capacity of 84.15, 79.16, and 61.32 mg·g⁻¹ for Pa, CAF, and AS, respectively, which is attained by several other reported adsorbents.

Table 7.

Comparison of pharmaceutical adsorption onto CEAC with other reported adsorbents.

Adsorbent	q_max (mg/g)
AC—WD-extra (granulated) ¹⁵	99.0 PA
AC—peanuts skin waste material ¹⁶	35.98 PA
AC—coconut ¹⁷	90.80 PA
AC—mango seeds ¹⁸	7.23 PA
AC—oak cupules ¹⁹	97.1 PA
AC—coffee waste ²⁰	60.02 AS
AC—pineapple plant leaves ²¹AC—Luffa cylindrica ²²AC—Acacia mangium wood ²³	155.5 CAF59.9 CAF30.3 CAF
AC—date stone (Phoenix dactylifera) ²⁴	8.7 CAF
Casuarina equisetifolia fruit AC (present study)	84.15 PA, 79.16 CAF, 61.32 AS

Limitations and future perspectives

This study demonstrates the promising potential of CEAC for the simultaneous removal of pharmaceuticals (PA, CAF, and AS). There are several limitations of the study that should be acknowledged. First, synthetic pharmaceutical mixtures were used in conducted experiments under controlled laboratory conditions. Real wastewater typically contains a wide range of organic and inorganic constituents that may compete for adsorption sites, and this complexity was not addressed in the current study. Second, although regeneration tests indicated reusability of CEAC, the long-term stability and efficiency of the adsorbent after multiple regeneration cycles require further verification. Third, the study was limited to batch adsorption experiments; continuous flow or pilot-scale studies are essential to better evaluate CEAC performance under realistic operational conditions. Finally, economic analysis of large-scale production and practical implementation was beyond the scope of this work but should be explored in future research.

Conclusion

This study successfully demonstrates the potential of CEAC as an efficient adsorbent for the simultaneous removal of PA, CAF, and AS from aqueous solutions. The simultaneous adsorption process was impacted by key parameters such as pH, adsorbent dosage, initial pharmaceutical concentration, and contact time. It was found that the most effective simultaneous adsorption took place at conditions of 110 mg CEAC, 15 mg L⁻¹ initial concentration, and 30 min contact time. Characterization techniques (FTIR, SEM, and UV-visible analysis) confirmed the successful adsorption of the pharmaceutical mixture onto CEAC. Kinetic studies revealed that the adsorption followed a pseudo-second-order model, while equilibrium data were best described by the Freundlich isotherm, indicating monolayer adsorption. The maximum adsorption capacities were notable for PA (84.15 mg·g⁻¹), CAF (79.16 mg·g⁻¹), and AS (61.32 mg·g⁻¹). Thermodynamic analysis further confirmed that the adsorption process was endothermic and spontaneous, highlighting its feasibility for practical applications. These results suggest that CEAC is a promising, low-cost, and sustainable adsorbent for the removal of pharmaceutical contaminants from water. Further research could focus on scaling up the process and testing CEAC's efficiency in a real wastewater system to enhance its practical applicability. Overall, this study contributes to the advancement of eco-friendly solutions for pharmaceutical wastewater treatment. Future studies were recommended to focus on scaling up the application of CEAC for real-world wastewater treatment systems. Evaluating its performance in continuous flow systems and pilot-scale treatment units would provide valuable insights into its practical feasibility. In addition to focusing on the economic studies.

Footnotes

Acknowledgments

The authors would like to express their appreciation to the Isra University Innovation Center (IUIC) for its vital role in testing the samples. The state-of-the-art infrastructure at IUIC significantly contributed to the accuracy of our findings, and we are grateful for its commitment and professionalism.

ORCID iDs

Alaa M. Al-Ma’abreh

Gada Edris

Fida' F. Odeh

Ethical approval

We confirm that this work is original and has not been published elsewhere, nor is it currently under consideration for publication elsewhere.

Author contributions

Alaa M. Al-Ma’abreh led the project and was responsible for the conceptualization, methodology design, and overall supervision of this work. Preparation, data collection, and analysis were performed by all authors. The first draft of the manuscript was written by Alaa M. Al-Ma’abreh. All authors read and approved the final manuscript.

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Isra University funded this research with a grant number 15-53/2023/2024.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data availability

The article contains the data that substantiates the results of this investigation.

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