Impregnation of Silver Nanoparticles onto Polymers Based on Sugarcane Bagasse for the Remediation of Endocrine Disruptor

Abstract

This present study introduces a contemporary innovation of synthesized polymer–silver nanoparticle nanocomposite adsorbent based on sugarcane bagasse (AgNP-SB-βCD) for the sequestration of emerging micropollutant–bisphenol A from water matrix. Batch adsorption mode was carried out to assess the effectiveness of AgNP-SB-βCD nanocomposites towards eliminating bisphenol A (BPA). Characterization techniques including SEM, FTIR, and XRD have confirmed the successful incorporation of silver nanoparticles (AgNPs) onto bagasse–polymer. At 25°C, pH 7, and contact time of 120 min, the nanocomposites had a maximum uptake capacity of 158.4 mg g^-1on BPA. The equilibrium isotherm of BPA on AgNPs-SB-βCD has fitted effectively with Langmuir model while the adsorption kinetics conformed to pseudo-second order. The adsorption phenomenon was controlled mainly by physisorption (via host–guest inclusion van der Waals bonding and pore filling effect). In addition, oxidative degradation of BPA by AgNPs-SB-βCD could marginally contribute the removal of BPA due to oxidative dissolution of AgNPs at pH 7. The thermodynamic results substantiate the spontaneity and exothermic behaviors of the adsorption phenomenon. The polymeric nanocomposite adsorbent was regenerated five times (using 75% ethanol) without considerable loss of its adsorption capacity. This authenticates its reusability and consistency performances; accordingly, it can be a market competitor adsorbent for the treatment of water contaminated with BPA.

1. Introduction

Water is amid the most fundamental natural resources in the life of living organisms, and therefore, it must be properly consumed to prevent future clean water scarceness [1, 2]. In recent decades, the incident of emerging micropollutants (EMPs), including bisphenol A (BPA) in water bodies, has become a growing concern due to their toxicological consequences on aquatic organisms, human health, and ecosystem [3–5]. For humans, the consumption of water tainted with BPA can result a number of health complications including renal disorders [6], neurological problems, cardiovascular diseases, cancer, infertility, and sexual dysfunction [7].

BPA is among the primary manufactured and consumed chemicals worldwide [6, 8]. Since the last few decades, the utilization of BPA in the industries for the fabrication of epoxy resins and polycarbonate plastic products has been observed to augment significantly. This has led to generation of immense amount of BPA wastewaters from the industries. Intentionally, most of these wastewater effluents are released to the environment without being completely treated; as a result, it causes adverse effects to the ecosystem [9].

As yet, several remediation techniques including adsorption [10–13], membrane process [14, 15], photocatalytic degradation [16, 17], and biological treatment process [18, 19] have been applied to treat water systems contaminated with BPA. Nonetheless, among these techniques, adsorption process has been regarded as a promising technology for effective remediation of wastewater polluted with BPA [20]. Adsorption technique possesses a facile, cost-effective and flexible operation, fast BPA removal, eco-friendly, and generates no indirect pollution [21–24].

In general, many researchers have focused on synthesized novel adsorbents as promising materials for remediation of water and wastewater to avoid human health complications and deterioration of the ecosystems [25]. Therefore, different adsorbents have been so far synthesized to adsorb BPA from water systems. These include the adsorbent based on natural materials, carbon and graphene, polymers, composite materials, nanomaterials, and agricultural waste materials [8]. However, a portion of adsorbents have demonstrated poor adsorptive and regeneration performances on bisphenol A [26], while some possess poor mechanical behaviors and are susceptible to extreme temperature and pH of the water surroundings. These limitations pose great challenges to the adsorbents for remediation of BPA and other noxious pollutants in water and wastewater. To surmount this challenge, in recent times, there has been an increasing concern on the application of polymer nanocomposite adsorbents (as a new class of adsorbents) for the treatment of noxious contaminants from aqueous systems. These advanced polymer nanocomposites are economical, highly stable, and effective adsorbents on removing a broad spectrum of chemical and biological pollutants [27]. They possess beneficial characteristics including dimensional flexibility, functionalities, film forming capability [28], medium mobility, porosity behaviors, and sturdy mechanical characteristics [29–31]. Thus, in this present research, we have reported for the first time the amalgamation of silver nanoparticles onto polymers based on sugarcane bagasse and applied for the sequestration of emerging micropollutant–bisphenol A from water. Incorporation of silver nanoparticles was done to increase the surface features, stability, and functional moieties on bagasse–polymers, whereby all these properties are accountable for increasing the uptake of bisphenol A.

Herein, the colloidal silver nanoparticles (AgNPs) were synthesized using reduction method, and then, a wet impregnation protocol was performed to immobilize AgNPs onto bagasse–β–cyclodextrin polymer to form novel bagasse–polymer–silver nanoparticle nanocomposites (AgNP-SB-βCD). These nanocomposites were characterized using various analytical techniques and then assessed their adsorptive performance towards bisphenol A in water matrix.

2. Materials and Methods

2.1. Materials

Pristine sugarcane bagasse material (SB) was obtained from Zanzibar Sugar Factory Limited (ZSFL) Mahonda, Tanzania, and used as a starting material for synthesized polymeric nanocomposites. Bisphenol A (BPA, C₁₆H₁₈O₂, 228.29 g mol⁻¹), silver nitrate (AgNO₃, 169.87 g mol⁻¹), beta-cyclodextrin (β-CD, 1134.98 g mol⁻¹), citric acid (CA, 192.12 g mol⁻¹), poly(N-vinyl pyrrolidone) (PVP), hydrazine monohydrate (N₂H₄·H₂O, 50.06 g mol⁻¹), calcium chloride (CaCl₂, 110.98 g mol⁻¹), sodium hydroxide (NaOH, 39.997 g mol⁻¹), absolute ethanol (CH₃CH₂OH, 46.07 g mol⁻¹), sodium sulfate (Na₂SO₄, 142.04 g mol⁻¹), hydrochloric acid (HCl, 36.458 g mol⁻¹), and sodium dihydrogen phosphate (NaH₂PO₄, 119.98 g mol⁻¹) were used in this study. All chemicals and standard solutions were of highest purity and applied as delivery without additional modification and were purchased from Macklin Biochemical Co., Ltd (Shanghai, China), Loba Chemie Pvt. Ltd (Mumbai, India), Kas Medics Ltd, and Lab Equip Ltd (Dar es Salaam, Tanzania).

2.2. Preparation of the Novel Bagasse–Polymer–Silver Nanoparticle Nanocomposites and Bisphenol A Solution

Optimization protocols were implemented to synthesize bagasse–polymer–silver nanoparticle nanocomposite (AgNP-SB-βCD) adsorbent. Herein, sugarcane bagasse (SB) material was thoroughly cleaned with water to eliminate unwanted materials and then rinsed with distilled water to remove other inorganic impurities. The clean SB was cured for over 12 h at 60°C and then milled to particle size of 150 μm. An accurate 1.5 g of SB was placed in vessel containing a solution mixture prepared by mixing CA (4.5 g), β-CD (9.0 g), and NaH₂PO₄ (0.95 g) in 200 mL of distilled water. The mixture was agitated and cured at 180°C for 30 min to obtain bagasse-β-cyclodextrin (SB-βCD) polymers as explained by Mpatani et al. [26]. Then, preparation of colloidal silver nanoparticles (AgNPs) by reduction method was performed in fume hood with minor modification as described by Abdelwahab and Shukry [32]. 0.08 mol L^-1 of AgNO₃ solution was prepared and added (while stirring) to a solution obtained by incorporating 1.0 g of PVP into 200 mL of ethanol. Then, N₂H₄·H₂O solution (0.02 mol L^-1) was added in drops with constant stirring to the solution containing AgNO₃ and PVP. The solution was altered to pH 8 by 0.1 mol L^-1 NaOH. Then, the formed solution was cured at 60°C under constant stirring till the solution color changed to yellow (AgNP colloidal solution). The SB-βCD polymer material was then introduced into colloidal solution and agitated at 120 rpm for overnight to allow sufficient amalgamation of AgNPs into polymer network of SB-βCD. The resulting polymeric nanocomposites were then filtered and cleaned with distilled water and cured at 60°C for 4 h. The AgNP-SB-βCD nanocomposite adsorbent was then stored in the container and used for adsorption process.

A concentrated solution of bisphenol A (BPA, 1000 mg L⁻¹) was prepared by placing 1 g of BPA into a 1 L graduated flask containing a methanol : water solution (1 : 1 ratio). BPA working solutions were obtained by diluting a concentrated BPA solution using distilled water to the desirable concentration. BPA solutions were regulated to pH of 2.0 to 11.0 using 0.1 mol L^-1 of HCl or NaOH solution.

2.3. Characterizations of Polymeric Nanocomposite Adsorbent

The physicochemical properties of the novel bagasse–polymer–silver nanoparticle nanocomposite (AgNP-SB-βCD) adsorbent were characterized with point of zero charge (pH meter, Mettler Toledo FP30-standard), Fourier-Transform Infrared Spectroscopy (FTIR, Laser class 1 Bruker Alpha with ATR), X-ray diffraction (XRD, Inxitu BTX-231 Benchtop), scanning electron microscopy (SEM, JSM-7600F Thermo NORAN System7), and Brunauer-Emmett-Teller technique (Quantachrome NOVA 4200e BET Analyzer, UK).

2.4. Batch Adsorption Experiments

An assortment of adsorption factors including solution pH, adsorption temperature, adsorbent dose, contact time, salt concentration, and regeneration study was performed to assess the steadiness and adsorption capacity of AgNPs-SB-βCD towards removing bisphenol A. Batch adsorption experiments were done by considering three approaches: (i) the use of different temperatures (25, 35, and 45°C) at constant BPA concentration (100 mg L^-1) and AgNP-SB-βCD dose (0.01 g), (ii) the use of different AgNP-SB-βCD doses (0.0025, 0.005, 0.01, 0.015, and 0.02 g) at constant BPA concentration (100 mg L^-1) and temperature (25°C), and (iii) the use of different BPA concentrations (25–200 mg L^-1) at stable temperature (25°C) and AgNP-SB-βCD dose (0.01 g). CaCl₂ and Na₂SO₄ solutions (0–0.1 mol L^-1) were employed to examine the influence of ionic strength (salt concentration) on uptake of bisphenol A. All adsorption experiments were performed in water bath shaker at rotation speed of 140 rpm using different contact time (5, 10, 15, 30, 45, 60, and 120 min). At given time, the concentration of BPA in the supernatant sample was measured at 276 nm using a UV-Vis spectrophotometer (Hewlett-Packard Co. Palo Alto). The adsorption capacity ( $q_{e}$ ) and removal efficiency (% $P$ ) of bisphenol A at equilibrium were calculated from Equations (1) and (2), respectively. $\begin{matrix} (1) & q = \frac{V (C_{0} - C_{e})}{m}, \\ (2) & P = \frac{(C_{0} - C_{e})}{C_{0}} \times 100 % . \end{matrix}$

In general, 0.01 g of AgNP-SB-βCD nanocomposites, 100 mg L of BPA, 10 mL of BPA, pH 7.0, adsorption temperature of 25°C, and contact duration of 120 min were used as the optimal experimental parameters for adsorption and regeneration studies.

2.4.1. Kinetic and Isotherm Determination

Adsorption isotherm and kinetic can assist in understanding the adsorption affinity, surface chemistry of the adsorbent, the rate, and mechanisms that control adsorption phenomenon [33]. Herein, pseudo-first-order (PFO) and pseudo-second-order (PSO) models were employed to determine the kinetic study, while Freundlich and Langmuir models were employed to evaluate the equilibrium isotherms [1, 34]. The expressions of isotherm and kinetic models are presented in Table 1.

Table 1

The expressions of isotherm and kinetic models applied to examine the uptake of bisphenol A onto AgNP-SB-βCD nanocomposites.

Model	Equation	Description
Pseudo-first order	$q_{t} = q_{e} (1 - e^{- k_{1} t})$	$k_{1}$ (min⁻¹) is the specific rate constant of PFO; $q_{e}$ or $q_{t}$ (mg g⁻¹) are the uptake capacity at equilibrium or any time $t$ .
Pseudo-second order	$q_{t} = k_{2} q_{e}^{2} t / 1 + k_{2} q_{e} t$	$k_{2}$ (g mg⁻¹ min⁻¹) is the PSO reaction rate coefficient.
Langmuir	$q_{e} = q_{m} K_{L} C_{e} / 1 + K_{L} C_{e}$	$q_{m}$ is the highest uptake capacity (mg g⁻¹); $K_{L}$ is associated to the adsorption attraction of the binding energy (L mg⁻¹).
Freundlich	$q_{e} = K_{F} C_{e}^{1 / n}$	$K_{F}$ is the Freundlich constant (mg g⁻¹)/(mg L⁻¹)ⁿ and 1/ $n$ is the heterogeneity factor indicating the affinity of the BPA to the AgNP-SB-βCD nanocomposite.

2.4.2. Thermodynamic Approach

The domination of temperature on BPA uptake was examined at 25, 35, and 45°C. This thermodynamic study can help to understand the adsorption behavior, interaction, and mechanisms involved [26]. The Gibbs free change ( $Δ G^{0}$ ), change in entropy ( $Δ S^{0}$ ), and standard enthalpy of the reaction ( $Δ H^{0}$ ) were resolute using the subsequent equations. $\begin{matrix} (3) & K_{d} = \frac{q_{e}}{C_{e}}, \\ (4) & Δ G^{0} = - R T \ln K_{d}, \\ (5) & \ln K_{d} = \frac{- Δ H^{0}}{R T} + \frac{Δ S^{0}}{R}, \end{matrix}$

where $K_{d}$ (L mg⁻¹) is the partition coefficient of the least BPA concentration, $q_{e}$ (mg g⁻¹) is the uptake capacity at equilibrium, $C_{e}$ (mg L⁻¹) is the equilibrium mass concentration of the BPA, $T$ (K) is the adsorption temperature, and $R$ (8.314 J mol⁻¹ K⁻¹) is the molar gas constant. The Van’t Hoff equation (Equation (5)) was employed to find $Δ S^{0}$ and $Δ H^{0}$ from the intercept and slope by sketching a graph of $\ln K_{d}$ versus 1/ $T$ .

2.5. Regeneration Approaches

Three desorption solutions (0.1 M NaOH, 0.1 M HCl, and 75% ethanol) were used to assess the adsorption performance (effectiveness, firmness, and reusability) of nanocomposite adsorbent towards decontaminating bisphenol A from water systems. Desorption–regeneration analysis is one of the important adsorption procedures which can be applied to define the economical and environmental perspective of the adsorbent [35]. In this study, desorption and regeneration procedures were carried out in quintuplicate. 0.01 g of AgNP-SB-βCD adsorbent was put into 50 mL Erlenmeyer flask having 10 mL of 100 mg L⁻¹ BPA solution with pH 7.0 and agitated at 140 rpm for 120 min. After equilibrium time (120 min), the nanocomposite adsorbent loaded with BPA was then separated by centrifugation and thoroughly washed with distilled water and dried up at 60°C for 8 h. A dried AgNP-SB-βCD was weighed up and put into Erlenmeyer flask having 10 mL of desorption solution. The flask was shaken in a water bath with rotation speed of 140 rpm at 25°C for 120 min. AgNP-SB-βCD sample was centrifuged, cleaned with distilled water, and cured at 60°C for 8 h. The desorption solution containing BPA was then measured at 276 nm to calculate the BPA concentration desorbed. These approaches were carried out independently to all desorption solutions (0.1 M NaOH, 0.1 M HCl, and 75% ethanol). The desorption effectiveness ( $d$ ) and regeneration effectiveness ( $r$ ) of AgNPs-SB-βCD were calculated from Equations (6) and (7), respectively. $\begin{matrix} (6) & d = \frac{m_{d}}{m_{0}} \times 100 %, \\ (7) & r = \frac{q_{d}}{q_{0}} \times 100 %, \end{matrix}$ where $m_{d}$ is the weight (g) of AgNPs-SB-βCD desorbed, $m_{0}$ (g) is the weight of the BPA left over on the AgNPs-SB-βCD before desorption, $q_{0}$ (mg g⁻¹) is the uptake capacity of AgNPs-SB-βCD in the initial running experiment, $q_{n}$ (mg g⁻¹) is the uptake capacity of AgNPs-SB-βCD after reused, and $n$ is the sum total of regeneration cycles performed.

2.6. Statistical Data Approach

Adsorption isotherm and kinetic results were accomplished using nonlinear regression in Origin 8.5.1. Microsoft excel 2016 was applied in advance to analyze the data. All tests were carried out in triplicates (with the exception of regeneration analysis which was done in quintuplicate), and the results were expressed as $mean \pm standard error$ .

3. Results and Discussion

3.1. Characterization of AgNP-SB-βCD Nanocomposite Adsorbent

Taking into consideration that adsorption process is a surface incident, the nature of surface chemistry and structure of adsorbent can considerably influence the uptake of pollutants from water systems. The possession of surface features (such as functional groups, pores, particle sizes, and higher surface area) on adsorbent can attribute to the removal of BPA [20]. Herein, characterization of AgNP-SB-βCD nanocomposites was performed, and the results obtained are discussed as follows:

3.1.1. Point of Zero Charge

Determination of adsorbent point zero charge (pH_pzc) is imperative as it helps to understand the surface charge of adsorbent and an appropriate pH medium that suit adsorption process [1]. Analysis of pH_pzc of AgNPs-SB-βCD was carried out with some modification using drift method as described by Doczekalska et al. [36]. As shown in Figure 1, AgNP-SB-βCD nanocomposites have pH_pzc of 4.4. This indicated that, at $pH solution < p H_{pzc}$ (acidic medium), the AgNP loaded onto nanocomposites destabilized and aggregates causing lower uptake of BPA. However, at $pH solution > p H_{pzc}$ , the embedded AgNPs existed into two forms: oxidative dissolution state at neutral pH medium or stable suspension at alkaline condition [37, 38]. The AgNPs-SB-βCD in the neutral pH solution had higher removal capacity towards BPA due to the occurrence of both adsorption and oxidative degradation of BPA.

Figure 1

Point zero charge of AgNP-SB-βCD nanocomposites.

3.1.2. FTIR Examination

FTIR analysis was carried out to identify the functional groups that are accountable for adsorption of bisphenol A onto polymeric nanocomposites. The change of band position and intensities of SB-βCD polymer after impregnation process were considered to confirm the successful incorporation of AgNPs onto bagasse–polymer. As appeared in Figure 2, the band intensity of AgNP-SB-βCD spectrum had lessened due to the integration of AgNPs. Moreover, the peak corresponding to the stretching vibration of –OH has slightly decreased from 3420 cm^-1 (SB-βCD) to 3410 cm^-1 (AgNPs-SB-βCD). This suggests that there was an interaction (during impregnation process) between the bagasse–polymers’ hydroxyl groups and AgNPs to form linkages. In addition, the new peaks on AgNP-SB-βCD spectrum at 2930, 2860, 1690, 1620, 1460, 1370, and 860 cm^-1 designating the existence of silver nanoparticles capped on the surface of bagasse–polymer [39].

Figure 2

FTIR spectra of SB-βCD polymer and AgNP-SB-βCD nanocomposites.

3.1.3. SEM and BET Examination

Scanning electron microscopy images of SB, SB-βCD, and AgNPs-SB-βCD are presented in Figure 3. The surface morphology of SB is appeared to be smooth with parallel fibers connected with pith. However, after being crosslinked with β-cyclodextrin, the SB-βCD became irregular, cracked, and possessed polymer networks. The amalgamation of silver nanoparticles with SB-βCD had resulted the formation of nanocomposites (AgNPs-SB-βCD) that have the surface area, average pore size, and total pore volume of 20.83 m²g⁻¹, 15.4 nm, and 0.061 cm³g⁻¹, respectively (Table 2). The AgNPs seem to increase the pore volume, surface area, and pore size of bagasse–polymer. As reported by Mpatani et al. [26], SB-βCD polymer adsorbent had a respective pore size, surface area, and pore volume of 9.28 nm, 8.56 m²g⁻¹, and 0.0434 cm³g⁻¹. As seen in Figure 3, the AgNPs are scattered and clustered on the surface of AgNPs-SB-βCD. This means that during impregnation process, AgNPs were diffused on the surface of bagasse–polymer, breaking the fibrous network of cellulose, dispersed in the polymer network, and resulting bond formation between AgNPs and bagasse–polymer. These interaction phenomena have led to development of mesopores, micropores, and cracks. The nanostructure of AgNPs together with the bond-breaking-bond-forming phenomenon could contribute to the increasing of total pore volume and surface area of AgNPs-SB-βCD. These interaction incidents are consistent with the results reported by Trinh et al. [40].

Figure 3

Scanning electron microscopy pictures present the morphology of (a) raw SB, (b) SB-βCD polymers, and (c) AgNP-SB-βCD nanocomposites.

(b)

(c)

Table 2

Textural characteristics of a novel bagasse–polymer–silver nanoparticle nanocomposite (AgNP-SB-βCD) adsorbent.

Nanocomposite absorbent	$S_{BET}$ (m²g⁻¹)	$V_{M}$ (cm³g⁻¹)	$D_{P}$ (nm)	$V_{T}$ (cm³g⁻¹)
AgNPs-SB-βCD	20.83	0.022	15.4	0.061

$S_{BET}$ : BET surface area; $V_{M}$ : micropore volume; $D_{P}$ : pore diameter; $V_{T}$ : total pore volume.

3.1.4. XRD Analysis

As seen in Figure 4, the peak intensity of SB-βCD polymer adsorbent has increased after being impregnated with silver nanoparticles (AgNPs). Besides, the position of diffraction peak at 19.2° that attributed to amorphous nature of SB-βCD polymer had slightly shifted to 20.4° after impregnation process. In addition, three new peaks were formed at 35.5, 43.6, and 63.7° which are, respectively, attributed to crystal plane (111), (200), and (220) of cubic Ag nanoparticles [41]. These AgNPs have relative influences on altering bagasse–polymer signals. The shift of the peak (from 19.2 to 20.4°), development of new peaks (35.5, 43.6, and 63.7°), and formation of crystalline nature of AgNPs-SB-βCD confirm the successful incorporation of silver nanoparticles onto cyclodextrin polymer based on sugarcane bagasse.

Figure 4

X-ray diffraction pattern of SB-βCD polymers and AgNP-SB-βCD nanocomposites.

3.2. Batch Adsorption Studies

3.2.1. Contribution of Contact Time on BPA Uptake

Adsorption experiments were conducted to assess the influence of contact duration on the uptake of 100 mg L^-1 BPA onto AgNPs-SB-βCD. At both temperatures, the adsorption equilibrium for the uptake of BPA was attained within 120 min (Figure 5). However, approximately half of adsorptive–oxidative capacity of AgNPs-SB-βCD on BPA has been achieved in the first 5 min, and afterward, the uptake became slowly increased until the equilibrium was reached. At 25°C, 40.3, and 75.2% of 100 mg L^-1, BPA was eliminated from the solution at 5 and 120 min. This means that the active sites of AgNPs-SB-βCD (through adsorption and oxidation processes) were more accessible at the beginning of contact process and then became occupied as the time goes.

Figure 5

Contact duration influence on uptake of BPA onto AgNP-SB-βCD nanocomposites ( $C_{0} = 100$ mg L^-1, $V = 10$ mL, and $m = 0.01$ ).

Pseudo-first-order and pseudo-second-order models were regarded to give the kinetic information on the removal of BPA using AgNPs-SB-βCD. The values obtained from the determined coefficient ( $R^{2}$ ), chi-square statistics ( $χ^{2}$ ), and calculated adsorption capacity ( $q_{e}$ calc.) were considered to determine the best fitted kinetic model. The kinetic model data and plotted curves are presented in Table 3 and Figure 5, respectively. As it can be seen in Table 3, the calculated $q_{e}$ obtained from pseudo-second-order model at 25, 35, and 45°C were moderately similar with experimental $q_{e}$ . Moreover, the values of coefficient of determination ( $R^{2}$ ) of pseudo-second-order model were higher ( $R^{2} > 0.98$ ) compared to that of pseudo-first-order ( $R^{2} < 0.89$ ). In addition, the chi-square statistics ( $χ^{2}$ ) values from the pseudo-second-order model were relatively smaller, and the plotted curves were closer to experimental points. This implied that the adsorption kinetics for the uptake of BPA onto AgNPs-SB-βCD was governed by PSO reaction.

Table 3

Kinetic data for the uptake of BPA onto AgNP-SB-βCD nanocomposites.

(a)

Temperature/°C	$q_{e (meas)}$ (mg g^-1)	PFO model $q_{e (theo)}$ (mg g^-1)	$k_{1} \times 10^{- 1}$ (min⁻¹)	$R^{2}$	$χ^{2}$
25	$75.2 \pm 2.2$	$66.2 \pm 5.7$	1.27 ± 0.18	0.879	20.54
35	$69.6 \pm 1.7$	$58.1 \pm 4.9$	1.16 ± 0.16	0.872	25.76
45	$64.5 \pm 2.6$	$52.6 \pm 3.6$	1.06 ± 0.15	0.845	27.68

(b)

Temperature/°C	$q_{e (meas)}$ (mg g^-1)	PSO model $q_{e (theo)}$ (mg g^-1)	$k_{2} \times 10^{- 3}$ (g mg⁻¹ min⁻¹)	$R^{2}$	$χ^{2}$
25	$75.2 \pm 2.2$	$77.5 \pm 1.8$	$2.19 \pm 0.28$	0.989	3.95
35	$69.6 \pm 1.7$	$71.4 \pm 1.6$	$2.26 \pm 0.25$	0.991	2.94
45	$64.5 \pm 2.6$	$66.1 \pm 1.4$	$1.95 \pm 0.17$	0.992	2.52

$χ^{2} = \sum {(q_{e (meas)} - q_{e (theo)})}^{2} / q_{e (theo)}$ , where $q_{e (meas)}$ and $q_{e (theo)}$ are experimental measured and theoretical calculated adsorption capacities, respectively.

3.2.2. Contribution of BPA Concentration on Adsorption Capacity of AgNPs-SB-βCD and Isotherm Studies

The sequestration of bisphenol A using 0.01 g of AgNPs-SB-βCD was assessed at different mass concentrations of BPA (25, 50, 75, 100, 125, 150, 175, and 200 mg L^-1) and temperatures (25, 35, and 45°C). The deviation between the uptake capacity ( $q_{e}$ ) and equilibrium concentration ( $C_{e}$ ) is shown in Figure 6. At individual temperature, the uptake of BPA onto AgNPs-SB-βCD was steadily improved with the increase of bisphenol A concentration till the highest uptake capacity of AgNPs-SB-βCD was reached. Increasing of BPA concentration seemed to facilitate the interaction between AgNPs-SB-βCD and BPA molecules. These results are comparable with the findings described by Han et al. [42] and Aryee et al. [43].

Figure 6

Adsorption equilibrium isotherms of BPA onto AgNP-SB-βCD nanocomposites.

In this study, the adsorption isotherm data were fit to Freundlich and Langmuir models using nonlinear regression analysis. The chi-square statistics ( $χ^{2}$ ), coefficient of determination ( $R^{2}$ ), separation factor ( $R_{L}$ ), and fitted curves were considered mostly to predict the best isotherm model that governed adsorption phenomenon. It is apparent that the experimental data on the fitted curves are much closer for Langmuir than Freundlich model (Figure 6). Moreover, Langmuir model had higher coefficient of determination ( $R^{2} > 0.991$ ) and lower chi-square statistics ( $χ^{2} < 1.3$ ) at both temperatures compared to Freundlich model ( $R^{2} < 0.970$ and $χ^{2} > 4.1$ ) (Table 4). In addition, the $R_{L}$ values calculated from initial concentration of BPA ( $C_{0} = 100$ mg L^-1) were less than unit ( $R_{L} < 1$ ). These results confirm that adsorption isotherm is well governed by Langmuir model, and monolayer adsorption was occurred on the uniform surface of AgNPs-SB-βCD.

Table 4

The data of isotherm model parameters obtained on adsorption of BPA by AgNPs-SB-βCD.

Model	Parameters	Temperature/°C
Model	Parameters	25	35	45
Langmuir	$q_{m}$ (mg g^-1)	$158.4 \pm 5.1$	$149.1 \pm 4.3$	$141.2 \pm 7.5$
	$K_{L}$ (L mg^-1)	$0.0176 \pm 0.003$	$0.0296 \pm 0.001$	$0.062 \pm 0.005$
	$R^{2}$	0.994	0.999	0.997
	$R_{L}$	0.362	0.253	0.138
	$χ^{2}$	1.273	0.144	0.584
Freundlich	1/ $n$	$0.416 \pm 0.027$	$0.519 \pm 0.032$	$0.574 \pm 0.028$
	$K_{F}$ [(mg L^-1)(L mg^-1)^1/n]	$18.81 \pm 1.91$	$11.19 \pm 1.33$	$7.44 \pm 1.15$
	$R^{2}$	0.962	0.958	0.954
	$χ^{2}$	4.454	4.263	5.851

$R_{L} = 1 / (1 + K_{L} C_{0})$ where $R_{L}$ is the separation factor and $C_{0}$ is the initial concentration of BPA (100 mg L^-1).

In this present study, the maximum adsorption uptake of AgNPs-SB-βCD for bisphenol A at 25, 35, and 45°C is 158.4, 149.1, and 141.2 mg g^-1 (Table 4). By comparing from the study of Mpatani et al. [26], the adsorption capacity of bagasse–polymer towards BPA (at 25°C) has improved from 121 mg g^-1 (SB-βCD) to 158.4 mg g^-1 (AgNPs-SB-βCD) after amalgamation process. This increasing of adsorption capacity is due to the incorporation of AgNPs that led the improvement of surface features and functional moieties on the bagasse–polymer, whereby all these together brought adsorption and oxidation processes on BPA. In addition, these polymeric nanocomposites (AgNPs-SB-βCD) have demonstrated stability and reusability behaviors and possess higher removal capacity compared with a number of adsorbents (including 2-vinylpyridine functionalized magnetic nanoparticle, modified carbon nanotubes, magnetic nanoparticles, alfafa-derived biochar, molecularly imprinted polymer, bagasse–polymer, and CTAB-walnut shell) reported from the previous studies on removal of BPA from water system (Table 5). Therefore, there is market competent on AgNPs-SB-βCD for BPA wastewater remediation.

Table 5

Adsorption performance of different adsorbents towards bisphenol A removal.

Adsorbent	pH	Temperature/K	$q_{e}$ /(mg g^-1)	Reference
AgNPs-SB-βCD	7.0	298	158.4	This study
2-Vinylpyridine functionalized magnetic nanoparticle	6.0–7.0	293	115.9	[10]
Modified carbon nanotubes	6.0	280	70	[44]
SB-βCD	7.0	298	121	[26]
Magnetite nanoparticles	6.0	303	4.785	[45]
Molecularly imprinted polymer	—	298	40.31	[46]
CTAB-walnut shell	6.0	303	38.5	[13]
Alfafa-derived biochar (AF 650)	6.0	295	38	[47]

3.2.3. Contribution of pH Solution on BPA Uptake

The pH solution had a major influence on the characteristics of bagasse–polymer–silver nanoparticle nanocomposites (AgNP-SB-βCD) on removing BPA. The removal efficiency of AgNPs-SB-βCD was lower at both acidic and alkaline media (Figure 7). This might be elucidated by the, respectively, existence of AgNPs in aggregation and stable suspension states [38], whereby the removal of BPA was mostly governed by adsorption process through host–guest inclusion and pore diffusion mechanisms. However, at neutral medium, the uptake of BPA onto AgNPs-SB-βCD was much enhanced due to the dissolution of AgNPs which brought degradation of BPA. In this circumstance, the interaction of BPA and nanocomposites was managed by both adsorption and oxidative degradation processes, consequently resulted higher removal of BPA from water solution.

Figure 7

Solution pH impact on uptake of bisphenol A onto AgNP-SB-βCD nanocomposites ( $C_{0} = 100$ mg L^-1, $V = 10$ mL, $m = 0.01$ g, $T = 25$ °C, and $t = 120$ min).

3.2.4. Contribution of AgNP-SB-βCD Dosage on BPA Uptake

The impact of nanocomposite dosage on BPA removal was carried out by altering AgNP-SB-βCD mass and maintains other factors constant. Different masses of AgNPs-SB-βCD (0.0025, 0.005, 0.01, 0.015, and 0.02 g) were put individually into Erlenmeyer flask containing 100 mg L^-1, and then, adsorption process was done at 25°C. At equilibrium, the uptake capacity ( $q_{e}$ ) of AgNPs-SB-βCD towards 100 mg L^-1of BPA was appeared to diminish from 197.2 to 46.8 mg g^-1, while the removal effectiveness (% $P$ ) increased from 49.3 to 93.7% with the raise of nanocomposite dosage from 0.0025 to 0.02 g (Figure 8). The higher uptake capacity ( $q_{e}$ ) was achieved when the AgNP-SB-βCD dosage was low. This is because at higher dosage, most of the active sites become vacant, resulting lower BPA uptake. The same facts have been described in the studies by Ponnusami et al. [48], Mpatani et al. [26], and Kani et al. [49].

Figure 8

Influence of AgNP-SB-βCD dosage on uptake of BPA at 25°C.

3.2.5. Influence of Cations and Anions on BPA Uptake

Usually, the wastewater influents generated from the industries are accompanied with enormous amount of ions. These ions may greatly affect the performance of adsorbent for removing designated pollutants. Therefore, assessing the influence of coexisting ions on BPA uptake onto AgNPs-SB-βCD is of compulsory. The findings of this present study demonstrate that the presence of CaCl₂ in the water system can affect the uptake capacity of AgNPs-SB-βCD on BPA. At 25°C, the initial uptake capacity (75.2 mg g^-1) of AgNPs-SB-βCD had decreased to 60.8 and 50.7 mg g^-1 when a respective CaCl₂ concentration of 0.02 and 0.1 mol L^-1 was used. Both coexistence ions (Ca–cations and Cl–anions) had positive effects of adsorption process. Ca²⁺ ions have affinity of resulting complex formation with AgNPs-SB-βCD via interaction with βCD cavities. This incident can reduce the adsorption performance by lessening the adsorption sites of AgNPs-SB-βCD for adsorbing BPA. The same phenomenon was reported by Mpatani et al. [26] on SB-βCD polymer adsorbent. At the same time, the Cl^- ions in solution can act as inorganic ligands that strongly have affinity to oxidized AgNPs into dissolution state [50, 51] and resulting oxidative degradation of BPA. However, since adsorption incident (through βCD cavities and mesopores) contributed much for the uptake of BPA onto AgNPs-SB-βCD than oxidative degradation (through AgNPs), therefore the adsorption capacity of AgNPs-SB-βCD was reduced in the presence of CaCl₂ (Figure 9).

Figure 9

Influence of ion interference on uptake of BPA onto AgNP-SB-βCD nanocomposites ( $C_{0} = 100$ mg L^-1, $V = 10$ mL, $m = 0.01$ g, $T = 25$ °C, and $t = 120$ min).

On the other side, the existence of Na₂SO₄ had a positive effect of increasing the AgNP-SB-βCD capacity for eliminating BPA. According to the findings by Mpatani et al. [26], Na₂SO₄ has a tendency of diminishing BPA solubility in the solution; as a result, more BPA can be taken onto AgNPs-SB-βCD through host–guest inclusion, pore filling effect, and oxidative degradation process. At 25°C, the initial adsorption capacity of AgNPs-SB-βCD (75.2 mg g^-1) had escalated to 79.8 and 88.3 mg g^-1 when a particular Na₂SO₄ concentration of 0.02 and 0.1 mol L^-1 was introduced (Figure 9).

3.3. Thermodynamic Study

Thermodynamic study stands as among the important analyses in adsorption process. This study can assist to know the adsorption behavior (nature) and temperature that suits adsorption interaction. As shown in Table 6, the negative Gibbs free change ( $Δ G^{0}$ ) values imply the spontaneous comportment of adsorption phenomenon [26, 52]. Since all $Δ G^{0}$ values are less than ⁻20 kJ mol^-1, the interaction of BPA and AgNPs-SB-βCD could be mostly controlled by physical adsorption [53] through host–guest inclusion (van der Waals bonding). Negative enthalpy change ( $Δ H^{0}$ ) data suggests the exothermic character of the adsorption incident, while negative entropy change ( $Δ S^{0}$ ) value indicates the lessening of degree of randomness at the interface of BPA and AgNPs-SB-βCD [44].

Table 6

Thermodynamic data on elimination of bisphenol A onto AgNPs-SB-βCD.

$Δ G^{0}$ /(kJ mol^-1)			$Δ H^{0}$ /(kJ mol^-1)	$Δ S^{0}$ /(J mol^-1 K^-1)
25°C	35°C	45°C	$Δ H^{0}$ /(kJ mol^-1)	$Δ S^{0}$ /(J mol^-1 K^-1)
−5.83	−3.41	−2.38	−57.4	−173.7

3.4. Regeneration Analysis

The tendency of an adsorbent to be reused for removing pollutant can promote its practical application and economical worth. This analysis can be used to confirm the stability and effectiveness of adsorbent on pollutant remediation [26, 54, 55]. According to the results, 75% ethanol had an uppermost desorption and regeneration ability of 72 and 95%, respectively, followed by 0.1 mol L^-1 HCl solution. The slight lower desorption efficiency of AgNP-SB-βCD nanocomposites (72%) could be explained by the fact that not all BPA molecules presented in the aqueous solution were adsorbed via host–guest inclusion and pore filling mechanisms, but some were disintegrated (degraded) by the oxidative activity of AgNPs loaded onto bagasse–polymer. Therefore, this 72% could represent the BPA desorbed on AgNPs-SB-βCD from the total BPA concentration removed (adsorbed) by means of adsorption process. AgNP-SB-βCD nanocomposites have possessed a stable adsorption performance by not being affected greatly by desorption process and have demonstrated a great desorption and regeneration performances. Its regeneration capacity was lessened by 5% after five succeeding cycles. This confirms the market competition of AgNPs-SB-βCD towards remediation of wastewater tainted with BPA.

3.5. Adsorption and Oxidation Mechanisms

The surface features of AgNP-SB-βCD nanocomposites have played momentous roles in adsorption mechanisms. Figure 10 is a diagrammatic representation of the mechanism involved in the elimination of BPA from water matrix. The adsorbate–adsorbent interaction mechanism was mainly operated by host–guest inclusion through involvement of van der Waals bonding. The 2 $^{'}$ hydroxyl (–OH) groups on the beta-cyclodextrin (β-CD) cavities of AgNPs-SB-βCD were accountable for the uptake of bisphenol A through intermolecular hydrogen bonding and resulted the formation of inclusion complexes. These results are analogous to the findings reported by Ragavan et al. [56] and Mpatani et al. [26].

Figure 10

Illustration of the mechanisms for the BPA uptake onto AgNPs-SB-βCD.

In addition to host–guest inclusion, pore diffusion effect has also participated in removing BPA from water matrix. The presence of mesopores (15.4 nm) on AgNP-SB-βCD surfaces had caused the diffusion of BPA into the interior part of polymeric nanocomposites; consequently, it brought adsorption process. On the other hand, oxidative dissolution of AgNPs embedded onto polymers has initiated the degradation of BPA. The dissolution incident of AgNPs assisted by poly(N-vinyl pyrrolidone) can trigger the generation of HO. radicals in the sunlight’s presence; as a result, it causes the decomposition of BPA through benzene ring cleavage [17, 57].

4. Conclusions

This research offers a comprehensive understanding on the greener synthesis of an innovative bagasse–polymer–silver nanocomposite adsorbent and its application in remediation of emerging micropollutant–bisphenol A (BPA) from water system. The process synthesis is reliable and sustainable and approaches on a cleaner and facile route. The impregnation of AgNPs onto bagasse–polymer material had increased the surface features (active sites/species, surface area, pore sizes, and cracks) and removal performance of polymeric nanocomposites towards BPA. The uptake of BPA onto AgNPs-SB-βCD is significantly dependent on the solution pH. In this present study, pH 7 had resulted the best removal performance due to the simultaneous occurrence of both adsorption and oxidative degradation processes. The kinetics and isotherms of adsorption followed pseudo-second-order and Langmuir models, respectively. The adsorption incident was governed mainly by physical adsorption via host–guest inclusion (van der Waals bonding) and pore filling effect. Besides, oxidative degradation had contributed marginally on the removal of BPA due to oxidative dissolution of AgNPs at pH 7. AgNP-SB-βCD had a maximum uptake capacity of 158.4 mg g^-1 and was reused five times without substantial loss on its efficiency. This novel AgNP-SB-βCD nanocomposite adsorbent had provided good removal capacity and higher steadiness on BPA compared to a number of adsorbents reported from the literature, consequently substantiates its practical application by offering a competition for BPA wastewater remediation.

Footnotes

Data Availability

All data generated and analyzed in this study are included within the article.

Additional Points

Highlights. (i) Novel AgNP-SB-βCD was fabricated to eliminate bisphenol A from aqueous matrix. (ii) AgNPs-SB-βCD had a highest uptake capacity of 158.4 mg g^-1on bisphenol A. (iii) AgNP-SB-βCD possesses both adsorptive and oxidative properties on bisphenol A. (iv) AgNP-SB-βCD nanocomposites are stable and reusable; this promotes their market competition for remediation of BPA wastewater.

Conflicts of Interest

The authors declare that they have no competing interests.

Authors’ Contributions

Farid Mzee Mpatani contributed to the supervision, conceptualization, methodology, formal analysis, investigation, writing—original draft, writing—review and editing, and visualization. Ussi Makame Kombo and Khamis Rashid Kheir contributed to the methodology, formal analysis, investigation, and review and editing. Nahya Khamis Nassor, Daniel Joshua, Salma Saleh Mussa, Salama Abubakar Mohamed, Saide Abdulla Mbarak, Ali Shehe Hamad, and Salum Ali Ahmada contributed to the formal analysis and review and editing.

Acknowledgments

The authors acknowledge financial support by Tanzania Commission for Science and Technology (COSTECH) through MAKISATU (National Competition for Science, Technology and Innovation) program. Special thanks go to Nelson Mandela African Institution of Science and Technology (NM–AIST) and University of Dar es Salaam (UDSM), Tanzania, for characterization analysis. The authors also recognize Mr. Hassan Buda Juma (Data Manager) for his assistance on statistical analysis.

References

Mpatani

F. M.

Aryee

A. A.

Kani

A. N.

Wen

Dovi

L. B.

Z. H.

Han

R. P.

Removal of methylene blue from aqueous medium by citrate modified bagasse: kinetic, equilibrium and thermodynamic study

Bioresource Technology Reports 2020 11, article 110463

4997205

100463

10.1016/j.biteb.2020.100463

Ali

Basheer

A. A.

Mbianda

X. Y.

Burakov

Galunin

Burakova

Mkrtchyan

Tkachev

Grachev

Graphene based adsorbents for remediation of noxious pollutants from wastewater

Environment International 2019 127

4997205

160 180

Gasser

C. A.

Svojitka

Wintgens

Ammann

E. M.

Shahgaldian

Corvini

P. F. X.

Hommes

Advanced enzymatic elimination of phenolic contaminants in wastewater: a nano approach at field scale

European journal of applied microbiology and biotechnology 2014 98

4997205

7 3305 3316

10.1007/s00253-013-5414-8

2-s2.0-84898846545

24305739

Mpatani

F. M.

Aryee

A. A.

Kani

A. N.

Han

R. P.

Z. H.

Dovi

L. B.

A review of treatment techniques applied for selective removal of emerging pollutant-trimethoprim from aqueous systems

Journal of Cleaner Production 2021 308, article 127359

4997205

10.1016/j.jclepro.2021.127359

Spadoto

Sueitt

A. P. E.

Galinaro

C. A.

Pinto

T. . S.

Pompei

C. M. E.

Botta

C. M. R.

Vieira

E. M.

Ecotoxicological effects of bisphenol A and nonylphenol on the freshwater cladoceransCeriodaphnia silvestrii and Daphnia similis

Drug and Chemical Toxicology 2018 41

4997205

4 449 458

10.1080/01480545.2017.1381109

2-s2.0-85033398221

29115172

Gowder

S. J. T.

Nephrotoxicity of bisphenol A (BPA)–an updated review

Current Molecular Pharmacology 2013 6

4997205

3 163 172

10.2174/1874467207666140410115823

2-s2.0-84901256524

24720537

Maqbool

Mostafalou

Bahadar

Abdollahi

Review of endocrine disorders associated with environmental toxicants and possible involved mechanisms

Life Sciences 2016 145

4997205

265 273

Bhatnagar

Anastopoulos

Adsorptive removal of bisphenol A (BPA) from aqueous solution: a review

Chemosphere 2017 168

4997205

885 902

Ali

New generation adsorbents for water treatment

Chemical Reviews 2012 112

4997205

5073 5091

10.

Pan

Xia

Enhanced adsorption of bisphenol A from aqueous solution with 2-vinylpyridine functionalized magnetic nanoparticles

Polymers 2018 10

4997205

1136

11.

Fan

Yang

Adsorption of phenol, bisphenol A and nonylphenol ethoxylates onto hypercrosslinked and aminated adsorbents

Reactive and Functional Polymers 2011 71

4997205

10 994 1000

10.1016/j.reactfunctpolym.2011.07.001

2-s2.0-79960893431

12.

Heo

Yoon

Lee

Kim

Han

Park

C. M.

Enhanced adsorption of bisphenol A and sulfamethoxazole by a novel magnetic CuZnFe₂O₄-biochar composite

Bioresource Technology 2019 281

4997205

179 187

13.

Dovi

Kani

A. N.

Aryee

A. A.

Jie

J. J.

Z. H.

L. B.

Han

R. P.

Decontamination of bisphenol A and Congo red dye from solution by using CTAB functionalised walnut shell

Environmental Science and Pollution Research 2021 28

4997205

22 28732 28749

10.1007/s11356-021-12550-4

33550551

14.

Yüksel

Kabay

Yüksel

Removal of bisphenol A (BPA) from water by various nanofiltration (NF) and reverse osmosis (RO) membranes

Journal of Hazardous Material 2013 263

4997205

307 310

10.1016/j.jhazmat.2013.05.020

2-s2.0-84889088123

23731784

15.

Zhang

Wang

Mechanism of bisphenol A removal by a submerged membrane bioreactor in the treatment of synthetic municipal sewage: staged analyses

Desalination and Water Treatment 2016 57

4997205

26 12364 12374

10.1080/19443994.2015.1046948

2-s2.0-84929240441

16.

Molkenthin

Olmez-Hanci

Jekel

M. R.

Arslan-Alaton

Photo-Fenton-like treatment of BPA: effect of UV light source and water matrix on toxicity and transformation products

Water Research 2013 47

4997205

14 5052 5064

10.1016/j.watres.2013.05.051

2-s2.0-84883273749

23866146

17.

Park

C. M.

Heo

Yoon

Oxidative degradation of bisphenol A and 17α–ethinyl estradiol by Fenton–like activity of silver nanoparticles in aqueous solution

Chemosphere 2017 168

4997205

617 622

18.

Guerra

Kim

Teslic

Alaee

Smyth

Bisphenol-A removal in various wastewater treatment processes: Operational conditions, mass balance, and optimization

Journal of EnvironmentalManagement 2015 152

4997205

192 200

19.

Frankowski

Zgoła-Grześkowiak

Smułek

Grześkowiak

Removal of bisphenol a and its potential substitutes by biodegradation

Applied Biochemistry and Biotechnology 2020 191

4997205

1100 1110

20.

Mpatani

F. M.

Han

R. P.

Aryee

A. A.

Kani

A. N.

Z. H.

L. B.

Adsorption performance of modified agricultural waste materials for removal of emerging micro-contaminant bisphenol A: a comprehensive review

Science of the Total Environment 2021 780, article 146629

4997205

10.1016/j.scitotenv.2021.146629

21.

Gao

B. Y.

Jin

Yue

Q. Y.

Removal of anionic pollutants from liquids by biomass materials: a review

Journal of Molecular Liquids 2016 215

4997205

565 595

10.1016/j.molliq.2015.12.101

2-s2.0-84955477825

22.

Tsai

W. T.

Lai

C. W.

T. Y.

Adsorption of bisphenol A from aqueous solution onto minerals and carbon adsorbents

Journal of Hazardous Materials 2006 134

4997205

169 175

23.

Shi

Liu

Huang

Preparation and adsorption behaviors of sodium alginate-based adsorbent-immobilized β-cyclodextrin and graphene oxide

RSC Advances 2017 7

4997205

50 31549 31557

10.1039/C7RA02313H

2-s2.0-85021676060

24.

Sonal

Mishra

B. K.

A comprehensive review on the synthesis and performance of different zirconium-based adsorbents for the removal of various water contaminants

Chemical Engineering Journal 2021 424, article 130509

4997205

10.1016/j.cej.2021.130509

25.

Awual

M. R.

Yaita

Kobayashi

Shiwaku

Suzuki

Improving cesium removal to clean-up the contaminated water using modified conjugate material

Journal of Environmental Chemical Engineering 2020 8

4997205

2, article 103684

10.1016/j.jece.2020.103684

26.

Mpatani

F. M.

Aryee

A. A.

Kani

A. N.

Guo

Q. H.

Dovi

L. B.

Z. H.

Han

R. P.

Uptake of micropollutant-bisphenol A, methylene blue and neutral red onto a novel bagasse-β-cyclodextrin polymer by adsorption process

Chemosphere 2020 259, article 127439

4997205

10.1016/j.chemosphere.2020.127439

32593825

27.

Pandey

Shukla

S. K.

Singh

N. B.

Water purification by polymer nanocomposites: an overview

Nano 2017 3

4997205

47 66

28.

Lofrano

Carotenuto

Libralato

Domingos

R. F.

Markus

Dini

Gautam

R. K.

Baldantoni

Rossi

Sharma

S. K.

Chattopadhyaya

M. C.

Polymer functionalized nanocomposites for metals removal from water and wastewater: an overview

Water Research 2016 92

4997205

22 37

29.

Pang

Liu

Wang

Chen

Wang

Environmental remediation of heavy metal ions by novel-nanomaterials: A review

Environmental Pollution 2019 246

4997205

608 620

10.1016/j.envpol.2018.12.076

2-s2.0-85059616739

30605816

30.

Tang

W. W.

Zeng

G. M.

Gong

J. L.

Impact of humic/fulvic acid on the removal of heavy metals from aqueous solutions using nanomaterials: a review

Science of the Total Environment 2014 468-469

4997205

1014 1027

10.1016/j.scitotenv.2013.09.044

2-s2.0-84885035988

31.

Daer

Kharraz

Giwa

Hassan

S. W.

Recent applications of nanomaterials in water desalination: a critical review and future opportunities

Desalination 2015 367

4997205

37 48

10.1016/j.desal.2015.03.030

2-s2.0-84961290374

32.

Abdelwahab

N. A.

Shukry

Synthesis, characterization and antimicrobial properties of grafted sugarcane bagasse/silver nanocomposites

Carbohydrate Polymers 2015 115

4997205

276 284

33.

De Castro

M. L. F. A.

Abad

M. L. B.

Sumalinog

D. A. G.

Abarca

R. R. M.

Paoprasert

de Luna

M. D. G.

Adsorption of methylene blue dye and Cu (II) ions on EDTA-modified bentonite: isotherm, kinetic and thermodynamic studies

Sustainable Environment Research 2018 28

4997205

197 205

34.

Tran

H. N.

You

S.-J.

Hosseini-Bandegharaei

Chao

H.-P.

Mistakes and inconsistencies regarding adsorption of contaminants from aqueous solutions: a critical review

Water Research 2017 120

4997205

88 116

35.

Islam

M. A.

Awual

M. R.

Angove

M. J.

A review on nickel(II) adsorption in single and binary component systems and future path

Journal of Environmental Chemical Engineering 2019 7

4997205

5, article 103305

10.1016/j.jece.2019.103305

2-s2.0-85070185537

36.

Doczekalska

Kusmierek

Swiatkowski

Bartkowiak

Adsorption of 2,4-dichlorophenoxyacetic acid and 4-chloro-2-metylphenoxyacetic acid onto activated carbons derived from various lignocellulosic materials

Journal of Environmental Science and Health, Part B 2018 53

4997205

290 297

37.

Paramelle

Sadovoy

Gorelik

Free

Hobley

Fernig

D. G.

A rapid method to estimate the concentration of citrate capped silver nanoparticles from UV–visible light spectra

Analyst 2014 139

4997205

4855 4861

38.

Fernando

Zhou

Impact of pH on the stability, dissolution and aggregation kinetics of silver nanoparticles

Chemosphere 2019 216

4997205

297 305

10.1016/j.chemosphere.2018.10.122

2-s2.0-85056000868

30384298

39.

Jyoti

Baunthiyal

Singh

Characterization of silver nanoparticles synthesized usingUrtica dioicaLinn. leaves and their synergistic effects with antibiotics

Journal of Radiation Research and Applied Sciences 2016 9

4997205

3 217 227

10.1016/j.jrras.2015.10.002

40.

Trinh

V. T.

Nguyen

T. M. P.

Van

H. T.

Hoang

L. P.

Nguyen

T. V.

L. T.

X. H.

Pham

T. T.

Nguyen

T. N.

Quang

N. V.

Nguyen

X. C.

Phosphate adsorption by silver nanoparticles-loaded activated carbon derived from tea residue

Scientific Reports 2020 10

4997205

3634

41.

Prakash

Gnanaprakasam

Emmanuel

Arokiyaraj

Saravanan

Green synthesis of silver nanoparticles from leaf extract of _Mimusops elengi_, Linn. for enhanced antibacterial activity against multi drug resistant clinical isolates

Colloids and Surfaces B: Biointerfaces 2013 108

4997205

255 259

10.1016/j.colsurfb.2013.03.017

2-s2.0-84875863200

23563291

42.

Han

R. P.

Wang

Sun

Wang

L. L.

Song

J. Y.

X. T.

Dou

C. C.

Malachite green adsorption onto natural zeolite and reuse by microwave irradiation

Journal of Hazardous Materials 2010 175

4997205

1-3 1056 1061

10.1016/j.jhazmat.2009.10.118

2-s2.0-72049124286

19954885

43.

Aryee

A. A.

Mpatani

F. M.

Y. Y.

Kani

A. N.

Dovi

Han

R. P.

Z. H.

L. B.

Fe₃O₄ and iminodiacetic acid modified peanut husk as a novel adsorbent for the uptake of Cu (II) and Pb (II) in aqueous solution: characterization, equilibrium and kinetic study

Environmental Pollution 2021 268

4997205

Part A, article 115729

10.1016/j.envpol.2020.115729

33011610

44.

Kuo

C. Y.

Comparison with as-grown and microwave modified carbon nanotubes to removal aqueous bisphenol A

Desalination 2009 249

4997205

976 982

45.

Orimolade

B. O.

Adekola

F. A.

Adebayo

G. B.

Adsorptive removal of bisphenol A using synthesized magnetite nanoparticles

Applied Water Science 2018 8

4997205

1 46

10.1007/s13201-018-0685-y

46.

Zhao

Zhang

Novel molecularly imprinted polymer prepared by palygorskite as support for selective adsorption of bisphenol A in aqueous solution

Desalination and Water Treatment 2016 57

4997205

12433 12442

47.

Choi

Y.-K.

Kan

E. S.

Effects of pyrolysis temperature on the physicochemical properties of alfalfa- derived biochar for the adsorption of bisphenol A and sulfamethoxazole in water

Chemosphere 2019 218

4997205

741 748

10.1016/j.chemosphere.2018.11.151

2-s2.0-85059316778

30504049

48.

Ponnusami

Gunasekar

Srivastava

S. N.

Kinetics of methylene blue removal from aqueous solution using gulmohar (_Delonix regia_) plant leaf powder: Multivariate regression analysis

Journal of Hazardous Materials 2009 169

4997205

1-3 119 127

10.1016/j.jhazmat.2009.03.066

2-s2.0-67649776614

19395158

49.

Kani

A. N.

Dovi

Aryee

A. A.

Mpatani

F. M.

Z. H.

Han

R. P.

L. B.

Polyethyleneimine modified tiger nut residue for removal of Congo red from solution

Desalination and Water Treatment 2021 215

4997205

209 221

10.5004/dwt.2021.26765

50.

Levard

Mitra

Yang

Jew

A. D.

Badireddy

A. R.

Lowry

G. V.

Brown

G. E.

Jr.

Effect of chloride on the dissolution rate of silver nanoparticles and toxicity to E. coli

Environmental Science & Technology 2013 47

4997205

11 5738 5745

10.1021/es400396f

2-s2.0-84878633342

23641814

51.

Garg

Rong

H. Y.

Miller

C. J.

Waite

T. D.

Oxidative dissolution of silver nanoparticles by chlorine: implications to silver nanoparticle fate and toxicity

Environmental Science & Technology 2016 50

4997205

7 3890 3896

10.1021/acs.est.6b00037

2-s2.0-84964224996

26986484

52.

Zhang

Chen

Removal of methylene blue from aqueous solution by a solvothermal-synthesized graphene/magnetite composite

Journal of Hazardous Materials 2011 192

4997205

1515 1524

53.

Kumar

Rashid

Barakat

M. A.

Synthesis and characterization of a starch–AlOOH–FeS2nanocomposite for the adsorption of Congo red dye from aqueous solution

RSC Advances 2014 4

4997205

72 38334 38340

10.1039/C4RA05183A

2-s2.0-84906872019

54.

Aryee

A. A.

Dovi

Han

R. P.

Z. H.

L. B.

One novel composite based on functionalized magnetic peanut husk as adsorbent for efficient sequestration of phosphate and Congo red from solution: characterization, equilibrium, kinetic and mechanism studies

Journal of Colloid and Interface Science 2021 598

4997205

69 82

10.1016/j.jcis.2021.03.157

33892443

55.

Wang

J. L.

Liu

Yang

M. M.

Han

H. Y.

Zhang

S. S.

Ouyang

G. F.

Han

R. P.

Removal of tetracycline using modified wheat straw from solution in batch and column modes

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4997205

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Ragavan

K. V.

Rastogi

N. K.

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28457432

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Vincent

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Prévost

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Impregnation of Silver Nanoparticles onto Polymers Based on Sugarcane Bagasse for the Remediation of Endocrine Disruptor–Bisphenol A from Water

Abstract

1. Introduction

2. Materials and Methods

2.1. Materials

2.2. Preparation of the Novel Bagasse–Polymer–Silver Nanoparticle Nanocomposites and Bisphenol A Solution

2.3. Characterizations of Polymeric Nanocomposite Adsorbent

2.4. Batch Adsorption Experiments

2.4.1. Kinetic and Isotherm Determination

2.4.2. Thermodynamic Approach

2.5. Regeneration Approaches

2.6. Statistical Data Approach

3. Results and Discussion

3.1. Characterization of AgNP-SB-βCD Nanocomposite Adsorbent

3.1.1. Point of Zero Charge

3.1.2. FTIR Examination

3.1.3. SEM and BET Examination

3.1.4. XRD Analysis

3.2. Batch Adsorption Studies

3.2.1. Contribution of Contact Time on BPA Uptake

3.2.2. Contribution of BPA Concentration on Adsorption Capacity of AgNPs-SB-βCD and Isotherm Studies

3.2.3. Contribution of pH Solution on BPA Uptake

3.2.4. Contribution of AgNP-SB-βCD Dosage on BPA Uptake

3.2.5. Influence of Cations and Anions on BPA Uptake

3.3. Thermodynamic Study

3.4. Regeneration Analysis

3.5. Adsorption and Oxidation Mechanisms

4. Conclusions

Footnotes

Data Availability

Additional Points

Conflicts of Interest

Authors’ Contributions

Acknowledgments

References