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Abstract

Green synthesis approach was successful used extract was successful in preparing bimetallic zero-valent Iron/Copper nanoparticles [FB-nZVFe/Cu]. Scanning Electron Microscope [SEM], Fourier Transform Infrared Spectroscopy [FTIR], and Dispersive X-ray Spectroscopy [EDX] showing the synthesizing of FB-nZVFe/Cu. The removal efficiency of Caffeine [5 mg L⁻¹] reached 86% under the conditions [0.2 g L⁻¹, 45 min, and pH 5]. The adsorption data are more appropriate by the Langmuir model [R² = 0.9987] with q_max = 34.34 mg g ⁻¹. Kinetic results showed that Caffeine uptake is following pseudo-second-order. Langmuir and pseudo-second-order are more appropriate in linear and non-linear models. Overall, FB-Fe/Cu is a committed green substance for removal Caffeine from aqueous solutions. Functional parameters affect investigated using the Linear regression analysis, we found them to account for over 98% of the variables affecting the removal procedure.

Keywords

Caffeine bimetallic nZVFe/Cu Ficus Benjamina green synthesized linear and non-linear models

Introduction

Caffeine [CAF, C₈H₁₀N₄O₂], an alkaloid belonging to the methylxanthine family (Al-Qaim et al., 2015). It is the most used pharmaceutical material worldwide which has a psychological effect (Elhalil et al., 2018; Ganzenko et al., 2015). Caffeine is founds in many products such as coffee, tea, energy drinks, and drugs, and acts as a psychomotor stimulant (Buerge et al., 2003; Yamal-Turbay et al., 2012). Caffeine is a primary compound in the manufacture of many medicines. It is one component of the medication for a migraine, fatigue, breathing problems, drowsiness, and pain relievers (Bueno et al., 2011; Indermuhle et al., 2013). Caffeine is safe in moderate doses, but can increase alertness, and cause nervousness, insomnia, a headache, and dizziness (Aly et al., 2013; Guo et al., 2011; Habibi et al., 2012). Extensive use of Caffeine lead to mutation effects such as DNA inhibition, irritation, tremors and anxiety (Zhang et al., 2011). It mobilizes calcium from cells which leads to bone mass loss and risk factor for cardiovascular mobilizes (Ali et al., 2012; Torres et al., 2014).

Caffeine is resistant to natural degradation. It detected with an exorbitant amount in wastewater treatment plants and water bodies worldwide (Ghosh et al., 2019). The concentration of CAF in several surface streams and WWTP effluents is as high as 230 μg/L (Rosal et al., 2010). The presence of Caffeine in the water will produce negative effects on human life and aquatic organisms (Elhalil et al., 2018). Wastewater processes can remove CAF include Fenton process (Elhalil et al., 2016), biologic treatments (Bonakdarpour et al., 2011), coagulation/flocculation (Freitas et al., 2015), and membrane process (Taheran et al., 2016), but these techniques have limits in removing CAF contaminant from water effluents (Bolong et al., 2009). Therefore, an alternative environmentally friendly and efficient method must implement for the removal of CAF from wastewater.

Researchers have focused on developing new techniques using Nano-technology to overcome these restrictions (Abdel-Aziz, 2020; Abdel-Gawad et al., 2016; Farag et al., 2018). Since the 1990s, Fe nanoscale particles [Fe-NPS] used for water treatment because of its advantages e.g. good surface area, wide dispersion of reactive sites, and unique adsorption (Abdel-Gawad et al., 2016; El-Shafei et al., 2016; Farag et al., 2018; Mostafa et al., 2017).Copper nanoparticles [Cu-NPS] have considered [chemical–physical] properties, high surface area, and less cost (Fathima et al., 2018; Khani et al., 2018). Cu-NPS are the most stable in comparison with these zero-valent metals (Mahmoud et al., 2019; Zhang et al., 2017). Nanoparticles play a serious role in contaminants removal from the aquatic surroundings (Tatarchuk et al., 2019, 2020a, 2020b). In current years, nanoscale particles prepared by NaBH4 (Mahmoud, 2017; Mahmoud et al., 2018a; SaryEl-deen et al., 2017), but they cause major contamination. It is critical to find alternate, low-cost, ecologically friendly techniques (Zhu et al., 2018). Traditional methods adopted for the synthesis of Fe-NPS or Cu-NPS by sonochemical synthesis, vacuum sputtering, physical method [attrition], and thermal decomposition. These methods have many restrictions viz. high temperature and pressure or energy requirement, and so they relative cost (Danish et al., 2017).

Green chemistry approaches become the most significant ecology friendly and low-cost alternative (Farag and Peters, 2018; Mahmoud et al., 2019a). Green leaves contain an extensive amount of reducing and capping agents via. polyphenols, flavonoids, and other reducing substances, which can reduce iron and copper salts to zero-valent and protecting them from agglomeration (Abdel-Aziz et al., 2020).

Bimetallic Iron/Copper is more efficient than mono-metallic NPS to remove several pollutants (Danish et al., 2017). Green nanoparticles prevent fungi, bacteria, and microbes from growing (, 2017b). Plants abundance, cost, efficiency, and non-toxic nature, all these advantages are important in the water treatment process (Abdel-Aziz et al., 2019; Shanehsaz et al., 2015). Ficus Benjamina-nZVFe/Cu is a novel idea used for the removal of Caffeine.

Therefore, the present study is to assess the ability of FB-nZVFe/Cu and applied to contaminated water of Caffeine removal.

Experimental

Chemicals and reagents

All chemicals used were of the analytical reagent grade and the highest purity. We adjusted the change of pH using 0.1 M NaOH and 0.1 M HCl solutions.

Methods

Preparation of Ficus Benjamina extract

Ficus Benjamina leaves were washed with Tap water to remove dust, then with distilled water, then were dried in the oven at 50 °C. The leaves were grinded into small pieces and sieved using a 2.5 mm sieve. In an Erlenmeyer flask, 20 g of leaves were added to 100 ml distilled water, and the previous solution was boiled for 5 min at 60 °C followed by filtrating using Whatman no. 1 filter paper, and the filtrate was stored at 4 °C until used as capping and reducing agent.

Synthesis of FB-nZVFe/Cu

About 0.18 g CuSO₄.5H₂O, 0.94 g FeSO₄.2H₂O were dissolved with distilled water in a 100 ml volumetric flask. Ficus extract [50 ml] was added drop by drop to Fe/Cu solution, followed stirred for 20 min. Changing of the solution color from yellowish to brown then to black was indicating the synthesizing of zero-valent nanoparticles (Asghar et al., 2018; Katata-Seru et al., 2018). FB-ZVFe/Cu was separated using centrifugation for 10 min, then washed with anhydrous alcohol. Ficus-ZVFe/Cu was placed at 65^° C for 3 hr, then was stored at 4 °C until used (Abdel-Aziz et al., 2019).

Characterization of FB-nZVFe/Cu

The prepared FB-nZVFe/Cu sample was examined using SEM with EDX [QUANTA FEG250], and FTIR spectroscopy [Shimadzu IRAffinity-1]. Before field emission, SEM FB-ZVFe/Cu nanoparticles were layered by gold which rises electrons scatter to give a notable contrast. EDX was used for defining the composition of the sample. FTIR spectroscopy to prove the formation of nanoparticles.

Batch adsorption studies

About 100 mg of CAF was dissolved in 1000 ml water [Stock 100 mg L⁻¹]. From the stock with volumetric pipettes we took various mills to volumetric flasks to get different concentrations [5, 10, 15, and 20 mg L⁻¹]. The removal was studied by mixing 0.2 g L⁻¹ of FB-nZVFe/Cu particles to the CAF solutions. The removal was calculated using the following equation:

Sorption [%] = [C o - C e] / C o \times 100

Where C_o is the initial CAF concentration [mg L⁻¹] and C_e is the equilibrium CAF concentration [mg L⁻¹]. The amount of CAF removed by Ficus-nZVFe/Cu particles was calculated using the following equation:

qe [{mg g}^{- 1}] = [[Co - Ce] V] / m

where q_e is the equilibrium adsorption capability [mg g⁻¹], V is the volume of aqueous solution [L] and m is the weight of the adsorbent [g].

Effect of different operating parameters

pH

About 0.2 g of FB-nZVFe/Cu was added to 1000 ml of CAF [5 mg L¹], at different pH values [3, 5, 7, and 9], different times [15, 30, and 45] minutes, respectively, and stirring rate was fixed at 100 rpm at room temp.

Contact time

About 0.2 g of FB-nZVFe/Cu was added to 1000 ml of CAF [5 mg L⁻¹] at different contact times; [15, 30, 45, 60, 90, and 120 min], at pH 5, and stirring rate was fixed at 100 rpm.

Adsorbent dose

Different weights of FB-nZVFe/Cu were varied between [0.1 and 0.3 g L⁻¹] were added to 1000 ml of CAF [5 mg L⁻¹], and other operational influences via. pH 5, and time 45 min, and stirring rate was fixed at 100 rpm at room temp.

Stirring rate

About 0.2 g of FB-nZVFe/Cu was added to 1000 ml of CAF [5 mg L⁻¹] at contact time 45 min, room temp, at pH 5, at a different stirring rate [100, 150, 200, and 250] rpm.

Initial concentration

About 0.2 g of FB-nZVFe/Cu was added to 1000 ml of different concentrations of CAF [5, 10, 15, and 20 mg L⁻¹], at pH 5, time 45 min, and stirring rate was fixed at 100 rpm at room temp.

Adsorption study

Freundlich and Langmuir isotherm models are the most two public isotherms applications (Abdel-Gawad and Abd El-Aziz, 2019).

Freundlich adsorption isotherm

Freundlich is an empirical calculation used for labeling dissimilar adsorption surface and is given by:

L n q e = 1 / n l n C e + l n K_{f}

Where n [dimensionless] and K_f [[mg g⁻¹] [mg L⁻¹]^−1/n] are Freundlich constant related to the adsorption intensity and adsorption capacity, respectively, [K_f] and [n] evaluated by plotting Ln q_e and Ln C_e.

Langmuir adsorption isotherm

Langmuir assumes mono-layer coverage of CAF over a similar surface of FB-nZVFe/Cu. The Langmuir is given by the equation:

C e / q e = 1 / (K L q_{\max}) + C e / q_{\max}

Where q_e [mg g⁻¹] is, the mass of CAF adsorbed per mass of adsorbent used, C_e [mg L⁻¹] is the equilibrium concentration of Caffeine, q_max [mg g⁻¹] is the maximum monolayer capability of adsorption, and K_L [L/mg] is the Langmuir constant correlated to binding sites affinity and adsorption energy. The plot of C_e/q_e versus C_e used to generate the values of q_max and K_L.

Kinetic study

Factors from two kinetic models, including pseudo-first-order and pseudo-second-order, have been used for describe adsorption kinetics in solid-liquid systems.

Pseudo-first-order kinetic model (PFO)

The adsorption rate can be labeled using the PFO and is expressed as follows:

l n (q e - q t) = l n q e - K_{1} t

Where qe and qt [mg/g] represent adsorption value of CAF in aqueous mediums at equilibrium and at time [min], respectively, and k₁ is the first-order equilibrium constant which calculated the plot of ln [qe-qt] against t.

Pseudo-second-order kinetic model (PSO)

PSO equation is the most simplified and frequently used kinetic equation. The pseudo-second-order kinetic model is usually described as thus:

t / q t = 1 / K 2 q e 2 + t / q e

Where qe and qt are the adsorption capability [mg/g], at equilibrium, and at time [min], respectively, and k₂ [g/[mg. min] represents the rate constant of the adsorption. We can calculate values of k2 from the plot of t/qt against t.

Reusability of ficus-ZVI/Cu NPS

Reusability of the adsorbent is a significant factor for estimating the cost-effective applicability, and to satisfy the ecology and economic thresholds. Caffeine removal by FB-nZVFe/Cu was carried out at [5 mg L⁻¹]. To further examine the reusability, the experiments were reiterated [up to 5 times] by exposing a reacted FB-nZVFe/Cu to a fresh CAF solution. Each time following the reaction, the FB-nZVFe/Cu was collected immediately from the solution by centrifugation [10 min] and was washed with ethanol, then was dried in an oven at 45 °C before being used for the next adsorption recycle.

Results and discussion

Characterization and analysis of FB-nZVFe/Cu

SEM and EDX

Figure 1 displays the SEM image of a semi-spherical shape FB-ZVFe/Cu nanoparticles, and the size of these particles range around 19–63 nm. Many pores allow the CAF to be transported better and the spread of pollution mass to the inner FB-nZVFe/Cu.

Figure 1.

SEM of FB-nZVFe/Cu nanoparticles.

Figure 2 shows the EDX analysis of FB-ZVFe/Cu nanoparticles. Fe and Cu peaks indicate the occurrence of bimetallic. Other beaks via C, O, Si, and S of Ficus-leaves extract (Abdel-Aziz et al., 2019).

Figure 2.

EDX of prepared FB-nZVFe/Cu sample.

FTIR measurements

Figure 3 displays that the FTIR of FB-nZVFe/Cu before the reaction between 4000 and 400 cm⁻¹. The broad-band at 3400 to 3000 cm¹ was attributed to O-H stretching vibration, indicates the occurrence of polyphenols. The strength of phenolic peaks can reduce metals and is a strong indicator for the synthesizing of the zero-valent nanoparticles. The band at 1539 cm⁻¹ indicates the existence of the Ficus amid group; the peak at 1362 cm⁻¹ signposts the occurrence of polyphenols Ar-ring C = C stretching vibration (Abdel-Aziz et al., 2019).

Figure 3.

FTIR spectrum of FB-nZVFe/Cu.

Effect of operating parameters

Effect of pH

pH system plays the most role in the CAF removal efficiency process. The removal efficiency of CAF at different pH values [3, 5, 7 and 9], at a different time [15, 30, and 45] min, respectively, when the dose of Ficus-nZVFe\Cu was 0.2 g L⁻¹, concentration 5 mg L⁻¹, and stirring rate was fixed at 100 rpm at room temp, the CAF removal efficiency was [43, 78, 69, and 23%], [44, 81, 71, and 23%], and [45, 86, 73, and 24%], respectively, as shown in Figure 4. Ficus Benjamina has a low Zero charge point of 4.85, because of the high acidity of the solution of leaves extract (Abdel-Aziz et al., 2019). It was observed that the most appropriate pH for the removal was 5. At pH is PZC the high removal efficiency due to increasing the number of e^- are generated from the zero-valent adsorbent which enhance the degradation of the CAF, and a lot of available vacant adsorption sites, which allows CAF mass to be transported better and the spread to the inner FB-nZVFe/Cu. At pH<pHpzc [pH 3], Low in the removal capacity due to the presence of an excess of H⁺ ions that occupy available vacant adsorption sites, and the free e^- neutralize the solution, and portion of nanoparticles dissolve in the medium (Mahmoud et al., 2018c). At pH> PZC [pH 9], because of the repulsion between OH^- ions and negatively surface of FB-nZVFe/Cu is negative (Misra et al., 2018; Shan et al., 2016); and maybe the low availability of nanoparticles which precipitates in the solution (Mahmoud et al., 2018b), thus leading to low removal efficiency. Based on the above pHpzc is the optimal removal of Caffeine.

Figure 4.

Effect of pH on caffeine removal (dose 0.2 g L−1, stirring100 rpm, initial concentration 5 mg L−1).

Effect of contact time

Different time effect at [15, 30, 45, 60, 90 and 120 min], was studied on the Caffeine removal [5 mg L⁻¹], using 0.2 g L⁻¹ of Ficus-Fe/Cu at pH 5, and the stirring rate was fixed at 100 rpm; and the removal percent was [78, 81, 86, 88, 89 and 89%], as shown in Figure 5. The increase in connection time gradually, lead to increase the interfere of the mass contaminant in the unfilled sites of the nano-particles, and increasing the generation of the amount of degradation free e^-, all this has led to increasing the removal.

Figure 5.

Effect of contact time on Caffeine removal (pH 5, dose 0.2 g L−1, stirring100 rpm, initial concentration 5 mg L−1).

Effect of adsorbent dose

Caffeine removal efficiency was studied as a function of the adsorbents dose effects, which was varied between [0.1 and 0.3 g L⁻¹], and other operational influences were pH 5, and time 45 min. Caffeine concentration was [5 mg L⁻¹], and the removal ratios were [48, 86, and 100%], as shown in Figure 6. The optimal adsorbent dose for the removal of CAF was found to be 0.2 g L⁻¹, as shown in Figure 7. As expected, increasing the FB-nZVFe/Cu dose leads to an increase in the number of both free e^- and unoccupied sites; so, the removal increased.

Figure 6.

Effect of adsorbent dose on Caffeine removal (pH 5, time 45 min, stirring100 rpm, initial concentration 5 mg L−1).

Figure 7.

The optimum effective dose for caffeine removal.

Effect of stirring rate

Figure 8 displays Caffeine removal by Ficus-nZVFe/Cu as a function of stirring rate. The stirring rate was varied between 100 and 250 rpm, and other operational influences were pH 5, and time 45 min. Caffeine concentration was [5 mg L⁻¹] and the removal ratios were [86, 87, 88, and 88%]. The optimal stirring rate for CAF removal was found to be 100 rpm. The increase in the stirring rate from [100 to 250 rpm] has not a significant effect on the removal efficiency.

Figure 8.

Effect of stirring rate on caffeine removal (pH 5, dose 0.2 g L−1, time 45 min, initial concentration 5 mg L−1).

Effect of the concentration

The removal experiments using Ficus-ZVFe/Cu particles were carried out on Caffeine solution having several concentrations of [5, 10, 15 and 20 mg L⁻¹], at pH 5, time 45 min, and adsorbents dose was 0.2 g L⁻¹, and the removal percentage was [86, 60, 45, and 33%], as shown in Figure 9. At the beginning of the study process at low concentration, the removal ratio was high, which compared to the high concentration of the pollutant.

Figure 9.

Effect of concentration on caffeine removal (pH 5, dose 0.2 g L−1, stirring100 rpm, time 45 min).

Adsorption isotherm studies for caffeine removal

The adsorption capability of the Ficus-nZVFe/Cu predicted and estimated by Freundlich and Langmuir adsorption isotherms models, as shown in Figures 10 to 13, which are the two most common isotherms applications (Abdel-Gawad, and Abd El-Aziz, 2018; Soha et al., 2017). Langmuir model was fitted well with isotherm in both linear and non-linear by higher determination coefficients R² and low Error sum compared to Freundlich, and maximum adsorption capability of 34.34 mg g⁻¹, as shown in Table 1.

Figure 10.

Effect of equilibrium concentration on caffeine removal.

Figure 11.

Freundlich for caffeine contributing component.

Figure 12.

Langmuir for caffeine contributing component.

Figure 13.

Isotherm studies for nonlinear models.

Table 1.

Isotherm models for the adsorption of caffeine.

Parameters	Freundlich	Langmuir
	Kf = 23.227 n = 6.373	Q_o = 34.34 b = 2.369
	- Linear
R²	0.9473	0.9987
	- Non-Linear
Errors:
CHI	0.2186	0.0749
ERRSQ	7.0822	2.3889
HYBRD	0.2206	0.0751
MPSD	0.0069	0.0024
ARE	0.1584	0.0799
EABS	4.8994	2.5118
Error sum	12.5861	5.1330

Kinetics studies

Table 2 realized that the PSO model is a better fit for the data in both linear and non-linear than the PFO, as shown in Figures 14 to 16. The value qe [cal] = 46.26 is approximately same to qe [exp] 44.5 for Caffeine. Results show that CAF uptake on FB-nZVFe\Cu is following the PSO.

Table 2.

Kinetic models for the adsorption of caffeine.

Parameters	PFO	PSO
	Qe = 42.42 K₁ = 0.055	Qe = 46.26 K₂ = 0.006
	- Linear
R²	0.9524	0.9989
	- Non-Linear
Errors:
CHI	0.130	0.107
ERRSQ	14.156	10.376
HYBRD	0.130	0.104
MPSD	0.003	0.002
ARE	0.096	0.085
EABS	4.050	3.641
Error sum	18.566	14.316

Figure 14.

The PFO kinetics model d.

Figure 15.

The PSO kinetics model data for caffeine.

Figure 16.

Kinetic studies for nonlinear models.

Statistical analysis

The effect of the variables on the removal process [e.g. pH, time, dose, concentration, and stirring rate] have been studied using the entered technique, where it was found that R² = 0.953. This means that the studied variables profane conquer over 95% of the total of the variables affecting the removal procedure as that the standard error of the estimate is 4.03260, so the percentage of error in this study is low.

ANOVA program was applied, and the data was presented the sum of squares and the effect of the complete model. It was observed that the P-value < 0.001, where all variables had an effect on the removal technique but the effect of the stirring rate was being not significant where the P-value [0.065] is over 0.05, where this means that it can be neglected during the removal process.

Response surface methodologies (RSM)

The effect of various parameters was examined using Linear regression analysis [IBM-SPSS Statistics] where results support the practical results. By applying the B values shown in Table 3, the removal equation can be deduced whereas:

R%=Bo+B 1 X_{1} +B 2 X_{2} +B 3 X_{3} +B 4 X_{4} +B 5 X_{5}

Table 3.

Coefficients.^a

Model	B	Sig.
[Constant]	62.403	0.000
pH	–4.852	0.002
Time	0.117	0.009
Dose	260.000	0.000
Stirring	0.046	0.065
Concentration	–3.511	0.000

Where R is the removal percent, B is constant, X₁ is the effect of pH, X₂ is the effect of contact time, X₃ is the effect of adsorbent dose, X₄ is the effect of stirring rate, and X₅ is the effect of concentration.

Reusability of FB-ZVI/Cu NPS

Figure 17 represents the removal efficiencies decreased with each reuse cycle. Thus, the removal efficiency was [82, 78, 83, 70, and 69%] after being used in the 1st, 2nd, 3rd, 4th, and 5th recycles, respectively. Yet the removal efficiency of Caffeine was still high even in the fifth recycle. The slight decrease in the removal efficiency was mainly happened in the second cycle, this may be caused by the loss of nanoparticles or by an irreversible occupation of partial-adsorption sites. The regenerated adsorbent still kept good adsorption efficiency after the five rounds of adsorption recycles. This showed that the synthesized FB-ZVFe/Cu NPs had good stability and durability and possesses excellent reusability for the removal of Caffeine from aqueous mediums. These results reveal that FB-nZVFe/Cu offered a high potential to be used repeatedly in removing CAF without a considerable decrease in its removal efficiency. One of the advantages of FB-ZVFe/Cu NPs is their easy to separate from the reaction mixture.

Figure 17.

Reuse the performance of the synthesized FB-nZVFe/Cu.

Conclusions

In this study, the green nanoscale zero-valent Fe/Cu [FB-nZVFe/Cu] is accomplished of Caffeine removal under various operational factors. Maximum Caffeine removal was observed at pH 5. Caffeine removal efficiency between [86 and 33%] was achieved after using different CAF concentrations [5, 10, 15, and 20 mg L⁻¹] with 0.2 g L⁻¹ of FB-nZVFe/Cu, stirring rate 100 rpm, pH 5, and contact time 45 min, and when the dose increased from [0.1 to 0.3 mg L⁻¹], the removal of CAF increased by 52% [C₀ = 5 mg L⁻¹]. The adsorption data were fitted well with the Langmuir isotherm study with the highest [R² = 0.9987]. PSO kinetic model is a better fit to the experimental data than PFO kinetic model. According to the results in this study, there is no difference between linear and non-linear models. The removal efficiency of CAF was still over 68% after reusing the material for five times. FB-nZVFe/Cu being an eco-friendly alternative procedure and can lead to success in wastewater treatment and produce high-quality treated effluent.

Footnotes

Declaration of Conflicting Interests

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

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Hossam Mohammed Abdel-Aziz

References

Abdel-Aziz

Farag

Abdel-Gawad

(2019) Carbamazepine removal from aqueous solution by green synthesis Zero-Valent iron/Cu nanoparticles with ficus benjamina leaves’ extract. International Journal of Environmental Research 13(5): 843–810.

Abdel-Aziz

Farag

Abdel-Gawad

Paracetamol removal by bimetallic Zero-Valent Fe/Cu with benjamina leaves’ extract. Journal of Environmental Engineering and Science. Epub ahead of print 26 March 2020. DOI: 10.1680/jenes.19.00047.

Abdel-Gawad

Abdel-Aziz

(2019) Removal of ethinylestradiol by adsorption process from aqueous solutions using entrapped activated carbon in alginate biopolymer: isotherm and statistical studies. Applied Water Science 9(4): 75.

Abdel-Gawad

Baraka

El-Shafei

, et al. (2016) Effects of nano zero valent iron and entrapped nano zero valent iron in alginate polymer on poly aromatic hydrocarbons removal. Journal of Environment & Biotechnology Research 5: 18–28.

Abdel-Gawad

Abd El-Aziz

(2018) Effective removal of chemical oxygen demand and phosphates from aqueous medium using entrapped activated carbon in alginate. MOJ Biology and Medicine 26(6): 227‒236.

Abdel-Gawad

Abd El-Aziz

(2019) Removal of pharmaceuticals from aqueous medium using entrapped activated carbon in alginate. Air, Soil and Water Research 12: 1178622119848761.

Al-Qaim

Mussa

Othman

, et al. (2015) Removal of caffeine from aqueous solution by indirect electrochemical oxidation using a graphite-PVC composite electrode: a role of hypochlorite ion as an oxidising agent. Journal of Hazardous Materials 300: 387–397.

Ali

Eisa

Idrees Tah

, et al. (2012) Determination of caffeine in some sudanese beverages by high performance liquid chromatography. Pakistan Journal of Nutrition 11(4): 336–342.

Aly

Kassem

Amin

(2013) Determination of caffeine in roasted and irradiated coffee beans with gamma rays by high performance liquid chromatography. Food Science and Quality Management 22: 28–34.

10.

Asghar

Zahir

Shahid

, et al. (2018) Iron, copper and silver nanoparticles: Green synthesis using green and black tea leaves extracts and evaluation of antibacterial, antifungal and aflatoxin B1 adsorption activity. LWT 90: 98–107.

11.

Bolong

Ismail

Salim

, et al. (2009) A review of the effects of emerging contaminants in wastewater and options for their removal. Desalination 239(1–3): 229–246.

12.

Bonakdarpour

Vyrides

Stuckey

(2011) Comparison of the performance of one stage and two stage sequential anaerobic–aerobic biological processes for the treatment of reactive-azo-dye-containing synthetic wastewaters. International Biodeterioration & Biodegradation 65(4): 591–599.

13.

Bueno

Uclés

Hernando

, et al. (2011) Evaluation of selected ubiquitous contaminants in the aquatic environment and their transformation products. A pilot study of their removal from a sewage treatment plant. Water Research 45(6): 2331–2341.

14.

Buerge

Poiger

Müller

, et al. (2003) Caffeine, an anthropogenic marker for wastewater contamination of surface waters. Environmental Science & Technology 37(4): 691–700.,

15.

Danish

, et al. (2017) Efficient transformation of trichloroethylene activated through sodium percarbonate using heterogeneous zeolite supported nano zero valent iron-copper bimetallic composite. Chemical Engineering Journal 308: 396–407.

16.

El-Shafei

Mahmoud

Mostafa

, et al. (2016) Effects of entrapped nZVI in alginate polymer on BTEX removal. In: AIChE annual meeting, San Francisco, CA, pp.13–18.

17.

Elhalil

Elmoubarki

Farnane

, et al. (2018) Photocatalytic degradation of caffeine as a model pharmaceutical pollutant on Mg doped ZnO-Al₂O₃ heterostructure. Environmental Nanotechnology, Monitoring & Management 10: 63–72.

18.

Elhalil

Tounsadi

Elmoubarki

, et al. (2016) Factorial experimental design for the optimization of catalytic degradation of malachite green dye in aqueous solution by fenton process. Water Resources and Industry 15: 41–48.

19.

Farag

Elshfai

Mahmoud

(2018) Adsorption and kinetic studies using nano zero valent iron (nZVI) in the removal of chemical oxygen demand from aqueous solution with response surface methodology and artificial neural network approach. Journal of Environment & Biotechnology Research 7: 12–22.

20.

Fathima

Pugazhendhi

Oves

, et al. (2018) Synthesis of eco-friendly copper nanoparticles for augmentation of catalytic degradation of organic dyes. Journal of Molecular Liquids 260: 1–8.

21.

Freitas

Oliveira

DE Souza

, et al. (2015) Optimization of coagulation-flocculation process for treatment of industrial textile wastewater using okra (A. esculentus) mucilage as natural coagulant. Industrial Crops and Products 76: 538–544.

22.

Ganzenko

Oturan

Huguenot

, et al. (2015) Removal of psychoactive pharmaceutical caffeine from water by electro-Fenton process using BDD anode: effects of operating parameters on removal efficiency. Separation and Purification Technology 156: 987–995.

23.

Ghosh

Manoli

Shen

, et al. (2019) Solar photocatalytic degradation of caffeine with titanium dioxide and zinc oxide nanoparticles. Journal of Photochemistry and Photobiology A: Chemistry 377: 1–7.

24.

Guo

Zhu

Yang

, et al. (2011) Determination of caffeine content in tea based on poly (safranine T) electroactive film modified electrode. Food Chemistry 129(3): 1311–1314.

25.

Habibi

Abazari

Pournaghi-Azar

(2012) A carbon nanotube modified electrode for determination of caffeine by differential pulse voltammetry. Chinese Journal of Catalysis 33(11–12): 1783–1790.

26.

Hossam

Abdel

ASAA-G

(2020) Removal of sunset YellowAzo dye using activated carbon entrapped in alginate from aqueous solutions. Open Access Journal of Science 4: 1–6.

27.

Indermuhle

De Vidales

MJM

Sáez

, et al. (2013) Degradation of caffeine by conductive diamond electrochemical oxidation. Chemosphere 93(9): 1720–1725.

28.

Katata-Seru

Moremedi

Aremu

, et al. (2018) Green synthesis of iron nanoparticles using Moringa oleifera extracts and their applications: Removal of nitrate from water and antibacterial activity against Escherichia coli. Journal of Molecular Liquids 256: 296–304.

29.

Khani

Roostaei

Bagherzade

, et al. (2018) Green synthesis of copper nanoparticles by fruit extract of ziziphus spina-christi (L.) willd.: Application for adsorption of triphenylmethane dye and antibacterial assay. Journal of Molecular Liquids 255: 541–549.

30.

Mahmoud

El-Tayieb

Ahmed

, et al. (2018a) Algorithms and statistics for municipal wastewater treatment using nano zero valent iron (nZVI). Journal of Environment & Biotechnology Research 7: 30–44.

31.

Mahmoud

(2017) Study the removal of most hazardous pollutants from aqueous solutions using nanoparticles. Available at: http://lis.cl.cu.edu.eg/search*ara (accessed 22 July 2020).

32.

Mahmoud

El-Tayieb

Ahmed

NAS

, et al. (2018b) Algorithms and statistics for municipal wastewater treatment using nano zero valent iron (nZVI). Journal of Environment & Biotechnology Research 7: 30–44.

33.

Mahmoud

Ismail

Mostafa

, et al. (2020) Isotherm and kinetic studies for heptachlor removal from aqueous solution using Fe/Cu nanoparticles, artificial intelligence, and regression analysis. Separation Science and Technology 55(4): 684–613.

34.

Mahmoud

Mostafa

Abdel-Gawad

(2018c) Artificial intelligence for the removal of benzene, toluene, ethyl benzene and xylene (BTEX) from aqueous solutions using iron nanoparticles. Water Supply 18(5): 1650–1663.

35.

Mahmoud

Saryel-Deen

Mostafa

, et al. Artificial intelligence for organochlorine pesticides removal from aqueous solutions using entrapped nZVI in alginate biopolymer.

36.

Misra

Mitra

Sen

(2018) Adsorption studies of carbamazepine by green-synthesized magnetic nanosorbents. Nanotechnology for Environmental Engineering 3(1): 11.

37.

Mostafa

Mahmoud

Saryel-Deen

, et al. (2017) Application of entrapped nano zero valent iron into cellulose acetate membranes for domestic wastewater treatment. In: Environmental aspects, applications and implications of nanomaterials and nanotechnology 2017 – Topical conference at the 2017 AIChE annual meeting, Minneapolis, MN, 29 October-3 November, pp.27–34.

38.

Rosal

Rodríguez

Perdigón-Melón

, et al. (2010) Occurrence of emerging pollutants in urban wastewater and their removal through biological treatment followed by ozonation. Water Research 44(2): 578–588.

39.

Saryel-Deen

Mahmoud

, et al. (2017) Adsorption and kinetic studies of using entrapped sewage sludge ash in the removal of chemical oxygen demand from domestic wastewater, with artificial intelligence approach. In: Annual AIChE meeting, Minneapolis, MN, 29 October-3 November 2017.

40.

Shan

Deng

Zhao

, et al. (2016) Preparation of ultrafine magnetic biochar and activated carbon for pharmaceutical adsorption and subsequent degradation by ball milling. Journal of Hazardous Materials 305: 156–163.

41.

Shanehsaz

Seidi

Ghorbani

, et al. (2015) Polypyrrole-coated magnetic nanoparticles as an efficient adsorbent for RB19 synthetic textile dye: Removal and kinetic study. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 149: 481–486.

42.

Siddiqui

Chaudhry

(2017b) Iron oxide and its modified forms as an adsorbent for arsenic removal: A comprehensive recent advancement. Process Safety and Environmental Protection 111: 592–626.

43.

Soha

Abdel Gawad

MSM

Abdel–

Azez HM

(2017) Adsorption study for chemical oxygen demand removal from aqueous solutions using alginate beads with entrapped activated carbon. Journal of Indian Water Resources Society 37: 461–470.

44.

Taheran

Brar

Verma

, et al. (2016) Membrane processes for removal of pharmaceutically active compounds (PhACs) from water and wastewaters. The Science of the Total Environment 547: 60–77.

45.

Tatarchuk

Mironyuk

Kotsyubynsky

, et al. (2020a) Structure, morphology and adsorption properties of titania shell immobilized onto cobalt ferrite nanoparticle core. Journal of Molecular Liquids 297: 111757.

46.

Tatarchuk

Myslin

Mironyuk

, et al. (2020b) Synthesis, morphology, crystallite size and adsorption properties of nanostructured Mg–Zn ferrites with enhanced porous structure. Journal of Alloys and Compounds 819: 152945.

47.

Tatarchuk

Shyichuk

Mironyuk

, et al. (2019) A review on removal of uranium (VI) ions using titanium dioxide based sorbents. Journal of Molecular Liquids 293: 111563.

48.

Torres

Barsan

Brett

(2014) Simple electrochemical sensor for caffeine based on carbon and nafion-modified carbon electrodes. Food Chemistry 149: 215–220.

49.

Yamal-Turbay

Graells

Pérez-Moya

(2012) Systematic assessment of the influence of hydrogen peroxide dosage on caffeine degradation by the photo-Fenton process. Industrial & Engineering Chemistry Research 51(13): 4770–4778.

50.

Zhang

Guo

, et al. (2017) Efficient activation of ozone by zero-valent copper for the degradation of aniline in aqueous solution. Journal of the Taiwan Institute of Chemical Engineers 81: 335–342.

51.

Zhang

Wang

Guo

, et al. (2011) Sensitive differential pulse stripping voltammetry of caffeine in medicines and cola using a sensor based on multi-walled carbon nanotubes and nafion. International Journal of Electrochemical Science 6: 997–1006.

52.

Zhu

Liu

, et al. (2018) Green synthesis of nano zero-valent iron/Cu by green tea to remove hexavalent chromium from groundwater. Journal of Cleaner Production 174: 184–190.

Removal of caffeine from aqueous solution by green approach using Ficus Benjamina zero-valent iron/copper nanoparticles

Abstract

Keywords

Introduction

Experimental

Chemicals and reagents

Methods

Preparation of Ficus Benjamina extract

Synthesis of FB-nZVFe/Cu

Characterization of FB-nZVFe/Cu

Batch adsorption studies

Effect of different operating parameters

pH

Contact time

Adsorbent dose

Stirring rate

Initial concentration

Adsorption study

Freundlich adsorption isotherm

Langmuir adsorption isotherm

Kinetic study

Pseudo-first-order kinetic model (PFO)

Pseudo-second-order kinetic model (PSO)

Reusability of ficus-ZVI/Cu NPS

Results and discussion

Characterization and analysis of FB-nZVFe/Cu

SEM and EDX

FTIR measurements

Effect of operating parameters

Effect of pH

Effect of contact time

Effect of adsorbent dose

Effect of stirring rate

Effect of the concentration

Adsorption isotherm studies for caffeine removal

Kinetics studies

Statistical analysis

Response surface methodologies (RSM)

Reusability of FB-ZVI/Cu NPS

Conclusions

Footnotes

Declaration of Conflicting Interests

Funding

ORCID iD

References