Adsorption Of Bisphenol A Research Articles

Competitive adsorption of two phenolic pollutants compounds using a novel biosorbent: Analytics (HPLC), Statistical (experimental design), and theoretical studies (DFT)

In this study, we focused on a novel agricultural waste material, specifically a plant known as Nicotiana glauca Graham (NgG), which is highly abundant in Morocco. The investigation involved testing four activating agents H3PO4, H2SO4, NaOH, and ZnCl2 on Nicotiana glauca Graham (NgG) to assess their effects. By employing an experimental design, we successfully determined the optimal conditions for this activation process. The resulting activated carbon was then evaluated for its effectiveness in removing two phenolic pollutants, Bisphenol A (BPA) and β-naphthol (BNL). Analysis using FTIR revealed various functional groups on the activated carbon surface, including P = O, P-O-C aromatics, and O-H groups, which played a crucial role in the adsorption of BPA and BNL. XRD analysis indicated that the optimal adsorbent was amorphous, while Zeta potential measurements showed a significant decrease in pollutant removal rates after reaching a pH level of nearly 10. The activated carbon produced from H3PO4 exhibited a surface area of 1078 m2/g. Experimental adsorption results at the highest removal rate showed qBPAs = 125.82 mg/g for BPA and qBNLs = 62.82 mg/g for BNL in individual mode, while in the mixed mode, qBPAm = 16.22 mg/g for BPA and qBNLm = 16.04 mg/g for BNL were observed. To enhance our study, we utilized Density Functional Theory (DFT) calculations to identify the most electrophilic and nucleophilic regions on BPA and BNL. The analysis highlighted the hydroxyl groups (–OH) of BNL and BPA as the most significant negative zones, crucial for understanding the underlying mechanisms and explaining the experimental observations. In the isotherm analysis, we identified the Temkin model in a singular mode and the Langmuir model in a mixture mode, showcasing a notable distinction between the two modes.

Artificial intelligence -driven insights into bisphenol A removal using synthesized carbon nanotubes

Water quality nowadays, under climate change, has become a risk and challenging problem to save water from deterioration. Advanced solutions such as nanomaterials and artificial intelligence for simulation have become some of the best and essential solutions. Therefore, this study assessed the artificial intelligence models' accuracy in simulating the elimination of Bisphenol A (BPA) using synthesized carbon nanotubes (CNTs). We concluded that the pseudo-second-order model's (R2) correlation coefficient is (0.999) significantly higher than the other models. Because the findings between the Model and Actual Values are so accurate, the adsorption of BPA on CNT could be modeled using the pseudo-second-order model, qe = 144.928(mg/g) and K2 = 0.0016. The correlation coefficient of Pseudo-First-Order model's (R2) is (0.825) qe = 27.107(mg/g) and K1 = 0.0161, and the Intraparticle diffusion model's (R2) is (0.821),qe = 151.98(mg/g) and Kd = 2.4. The Langmuir model performed the best in isothermal experiments, with correlation coefficients of R2 = 0.9441, qm = 181.81, and RL = 0.0375. Based on the information provided, we may conclude that the Langmuir model accounts for more BPA adsorption than the other models. We employed the feedforward neural network (FFNN) and the recurrent neural network (RNN). The FFNN achieved a coefficient of 0.971, while the RNN obtained a higher correlation coefficient of 0.98.

Adsorptive Removal of Bisphenol A by Polyethylene Meshes Grafted with an Amino Group-Containing Monomer, 2-(Dimethylamino)ethyl Methacrylate

The adsorptive removal of Bisphenol A (BPA) with the PE meshes photografted with 2-(dimethylamino)ethyl methacrylate (DMAEMA) was performed by varying the grafted amount, pH value, BPA concentration, and temperature, and the adsorption performance was correlated by the equilibrium, kinetic, and isotherm models. In addition, the regeneration of DMAEMA-grafted PE (PE-g-PDMAEMA) meshes was discussed from the repetitive adsorption/desorption process. The adsorption capacity had the maximum value at the grafted amount of 2.6 mmol/g and at the initial pH value of 8.0. The increase in the protonation of dimethylamino groups on grafted PDMAEMA chains and the dissociation of phenol groups of BPA present in the outer solution during the adsorption process results in the increase in BPA adsorption. The adsorption process followed the pseudo second-order equation. The BPA adsorption was enhanced by increasing the BPA concentration and the equilibrium data fit to Langmuir equation. The adsorption capacity stayed almost constant with the increase in the temperature, whereas the k2 value increased against the temperature. These results comprehensively emphasized that BPA adsorption occurred through the chemical interaction or ionic bonding of a BPA anion to a terminal protonated dimethylamino group. Desorption of BPA increased by increasing the NaOH concentration and BPA was entirely desorbed at more than 20 mM. The cycle of adsorption at pH 8.0 and desorption in a NaOH solution at 100 mM was repeated five times without loss or structural damage. These results indicate PE-g-PDMAEMA meshes can be used as a regenerative adsorbent for BPA removal from aqueous medium.

Activated carbons prepared from stump wood of various tree species by chemical activation and their application for water purification

Activated carbons (ACs) were produced from stump wood of different tree species, such as pine, bearded birch, and American black cherry using chemical activation with KOH and NaOH. The activated carbons were characterized and evaluated as adsorbents for eliminating bisphenol A (BPA) from aqueous solutions. The kinetics of adsorption and equilibrium adsorption, as well as the impact of solution pH and ionic strength, were examined. The kinetics were analyzed using the pseudo-first-order, pseudo-second-order, intra-particle diffusion, and Boyd kinetic models. The findings suggest that the adsorption kinetics followed the pseudo-second-order model. Additionally, the film diffusion was found to be the rate-determining step for the adsorption of BPA on all of the activated carbons. The data for adsorption equilibrium were tested using the Langmuir, Freundlich, and Sips equations, with results indicating that the Langmuir model was the most applicable. The capacity of activated carbons to adsorb BPA was dependent on their surface area. Higher BET surface areas resulted in increased adsorption. The birch-derived AC activated by NaOH had a monolayer adsorption capacity of 1.980 mmol/g, while the AC from black cherry activated with KOH had 2.195 mmol/g. The adsorption of BPA was pH-dependent, and no effect of ionic strength was observed. The activated carbons had very high adsorption capacities, indicating that stump wood is an excellent precursor for the production of highly effective adsorbents.

Sustainable hydrochar as an efficient persulfate activator for cost-effective degradation of bisphenol A

This study explored Mason pine-derived hydrochar (MPHC) as an effective adsorbent and persulfate (PS) activator for degrading bisphenol A (BPA). Increasing MPHC dosage from 0.25 to 2.0 g L−1 raised BPA removal from 42% to 87%. Similarly, at the same MPHC dosage range and fixed PS concentration (8 mM), BPA removal by MPHC/PS increased from 66% to 91%. Additionally, at a fixed MPHC dosage (1.0 g L−1), higher PS concentrations (2–32 mM) resulted in an overall BPA removal increase from 78% to 99%. The optimal pH for BPA removal by MPHC was at pH 3, while for MPHC/PS was at pH 9. BPA degradation by MPHC was optimal at pH 3, whereas MPHC/PS was at pH 3 and pH 9. Additionally, pH 7 favored BPA adsorption for both MPHC and MPHC/PS. The study also considered the influence of coexisting anions and humic acid (HA). PO43− and NO3− influence adsorption on MPHC, but these anions' effect on MPHC/PS is limited. Furthermore, the existence of HA had minimal influence on BPA removal by MPHC/PS. The contributions of different reactive species by MPHC for BPA degradation are as follows: electron-hole (h+) 2%, singlet oxygen (1O2) 7%, superoxide radicals (O2•–) 13%, electron (e–) 2%, hydroxyl radical (•OH) 3%, whereas the remaining 48% removal was the contribution of adsorption. For MPHC/PS, adsorption accounted for 39 %, more reactive species were involved in degradation, and the donations are (h+) 3%, sulfate radicals (SO4•–) 3%, (1O2) 19%, (O2•–) 15%, (e–) 2%, and (•OH) 2%. Additionally, the performance of MPHC remains stable after three operational cycles. The preparation cost of MPHC is 3.01 € kg−1. These results highlight the potential of MPHC as an environmentally friendly material for activating PS and removing organic pollutants, suggesting its promising application in future environmental remediation efforts.

Removal of bisphenol A (BPA) from aqueous solution by potassium carbonate modified wetland plant biochars

Bisphenol A (BPA) is a known endocrine disruptor that is acutely toxic to the living organisms. In this study, the wetland plants Phragmites australis and Typha orientalis were subjected to carbonize at 500 °C for different durations (4, 5, and 6 h) and varying mass ratios of wetland plants to potassium carbonate (1:2, 1:1, and 2:1). The prepared modified biochars were used to treat BPA in solution to explore the effect of contact time and initial concentration of BPA on adsorption performance. Both adsorption kinetic models and isotherm models were also studied. The results demonstrated a gradual increase in the adsorption capacity of Phragmites australis and Typha orientalis biochars for BPA with prolonged contact time. Furthermore, an enhancement in the adsorption capacity was observed with increasing initial BPA concentration. The modified biochars significantly enhanced BPA removal and adsorption capacities for BPA compared to the unmodified biochars. L55C (Phragmites australis carbonized at 500 °C for 5 h with a mass ratio of 2:1) and X54C (Phragmites australis carbonized at 500 °C for 4 h with a mass ratio of 2:1) exhibited the largest total surface areas, total pore volumes, microporous surface areas and microporous volumes, and achieved maximum adsorption capacities of 8.547 and 8.117 mg/g, respectively. The adsorption processes were fitted with pseudo-second-order adsorption kinetic models and Langmuir models. The adsorption processes were monolayer chemical adsorption.

Novel polyvinyl alcohol/gum tragacanth molecularly imprinted-electrospun nanofibers as adsorbent for selective solid phase extraction of bisphenol A

A polyvinyl alcohol/gum tragacanth molecularly imprinted nanofiber fabricated by electrospinning (PVA/GT-MIN) was used as an efficient adsorbent for the solid phase extraction (SPE) of bisphenol A (BPA) in water samples. PVA and GT were functional polymers and BPA was the template for molecular imprinting. BPA was bound to the polymer matrix through hydrogen bonding. The SEM image of PVA/GT-MIN demonstrated a rough morphology with pores and a diameter of 501 nm. The data for the adsorption of BPA on PVA/GT-MIN fitted the Freundlich isotherm and pseudo-second-order kinetics models. The proposed SPE using PVA/GT-MIN coupled with high performance liquid chromatography-diode array detection presented good linearity from 50 μg/L–5 mg/L (R2 = 0.9999) and yielded a limit of detection of 21 μg/L. The PVA/GT-MIN was applied to extract bottled water for BPA analysis and recoveries were 93.1–97.7 % (RSDs ≤ 3.6 %). This study presents a novel, easily prepared PVA/GT-MIN adsorbent for the extraction of BPA in water.

Exploring zero-valent iron nanoparticles (nZVI) for Bisphenol A removal: Experimental investigations and Monte-Carlo simulation insights

ABSTRACT Numerous personal care products contain Bisphenol-A (BPA), a hormone disruptor that ultimately finds its way into waterways. A combination of experimental investigations and Monte-Carlo simulations (MCS) were used to explore zerovalent iron nanoparticles (nZVI) for their removal. The nZVI exhibited an absorption peak (λmax) at 373 nm with a mesoporous structure (pore size 2.138 nm), 159.419 m2 g−1 surface area, and crystalline peaks. The adsorption processes were positively influenced by batch parameters. BPA adsorption on nZVI varied with temperature as predicted by Freundlich and Langmuir isotherms, achieving a maximum adsorption capacity (qmax) of 982.13 mgg−1 at 308 K and pH 2. The adsorption process at 303 and 308 K was physisorption, whereas, at 313 K, it was chemisorption suitably described by pseudo-second-order kinetics. The exothermic and spontaneous nature of the adsorption processes were demonstrated by the negative values of enthalpy (−ΔH°) and free energy (−ΔG°) that decreased with increasing temperatures (308–328 K). The density function theory and MCS studies showed that BPA's phenyl ring, isopropyl, and hydroxyl groups interacted electrostatically with nZVI, specifically crystal plane 121 with the most negative adsorption energy (ΔEads), enhancing BPA removal. Through optimized adsorption mechanisms, nZVI can effectively remove BPA from wastewater.

Two Birds with One Stone: High-Quality Utilization of COVID-19 Waste Masks into Bio-Oil, Pyrolytic Gas, and Eco-Friendly Biochar with Adsorption Applications

As a common necessity, masks have been used a lot in recent years, and the comprehensive utilization of waste masks has become a research priority in the post-COVID-19 pandemic era. However, traditional disposal methods suffer from a range of problems, including poor utilization and insecurity. To explore new solution ideas and efficiently utilize waste resources, waste masks and biomass wastes were used as raw materials to prepare mask-based biochar (WMB), bio-oil, and pyrolytic gas via oxygen-limited co-pyrolysis in this study. The obtained solid–liquid–gas product was systematically characterized to analyze the physicochemical properties, and the adsorption properties and mechanisms of WMB on the environmental endocrine bisphenol A (BPA) were investigated. The co-pyrolysis mechanisms were also studied in depth. Furthermore, the strengths and weaknesses of products prepared by co-pyrolysis and co-hydrothermal synthesis were discussed in comparison. The results indicated that the waste masks could shape the microsphere structure, leading to richer surface functional groups and stable mesoporous of WMB. Here, the risk of leaching of secondary pollutants was not detected. The theoretical maximum adsorption of BPA by WMB was 28.73 mg·g−1. The Langmuir and Pseudo-second-order models optimally simulated the isothermal and kinetic adsorption processes, which are a composite of physicochemical adsorption. Simultaneous pyrolysis of mask polymers with biomass polymers produces bio-oil and pyrolytic gas, which is rich in high-quality aliphatic and aromatic compounds. This could have potential as an energy source or chemical feedstock. The co-pyrolysis mechanisms may involve the depolymerization of waste masks to produce hydrocarbons and H radicals, which in turn undergo multi-step cleavage and oligomerization reactions with biomass derivatives. It is recommended to use the co-pyrolysis method to dispose of waste masks, as the products obtained are significantly better than those obtained by the co-hydrothermal method. This work provides a new contribution to the resourcing of waste masks into high-quality products.

Adsorption characteristics and mechanisms of bisphenol A on novel nitrogen-modified biochar derived from waste masks and biomass.

Resource utilization of waste masks has become an urgent scientific issue. In this work, with sustainably, waste masks and biomass were co-pyrolysis with oxygen limitation to prepare mask-based biochar (MB). Then, urea was introduced to prepare novel nitrogen modified mask-based biochar (NMB) via a one-step hydrothermal synthesis method. The adsorption characteristics of NMB on the emerging environmental pollutant, bisphenol A (BPA), were evaluated via batch adsorption tests. Moreover, the physicochemical properties of the materials were characterized with various advanced techniques. Also, the roles of waste masks and nitrogen modification were explored. The adsorption mechanisms of NMB on BPA were revealed as well as the performance differences between different adsorbents. The results showed that waste masks participated in thermochemical reactions, shaped the microsphere structure of biochar, and increased the types of surface functional groups. The nitrogen modification enriched the surface elemental composition and activated the specific surface area via the mesopore. These would enhance the adsorption performance. The maximum adsorption of BPA by NMB was 62.63mg·g-1, which was approximately 2.35-5.58 times higher than that of the control materials. Temkin model and pseudo-second-order model optimally simulate the isothermal and kinetic adsorption, respectively. The adsorption mechanisms are jointly by physical and chemical adsorption, which mainly includes π-π interaction, hydrogen bonding, intraparticle diffusion, surface adsorption, and ion exchange. After discussion and evaluation, NMB has lower preparation process cost (7.21 USD·kg-1) and safety, with potential for environmental applications. This study aims to expand new ideas for the comprehensive utilization of waste masks and the preparation of eco-friendly materials. Moreover, it provides a theoretical basis for the removal of BPA.

Efficient removal of Cr(VI) and bisphenol A by a tannic acid-functionalized porous biochar

Heavy metals and organic compounds pose significant environmental risks. In this study, tannic acid-functionalized porous biochar (T-PBC) was prepared at room temperature to remove Cr(VI) and bisphenol A (BPA) from aqueous solutions. Porous biochar was synthesized using a self-blowing method. The modification of TA aimed to increase the surface oxygen-containing functional groups (OFGs). The characteristics and structure of the T-PBC were investigated by SEM, BET, XRD, FTIR, particle size analysis, and XPS. The maximum adsorption capacities for Cr(VI) and BPA at pH 2.50 were 218.71 and 320.51 mg/g, respectively. The adsorption kinetics and isotherms for Cr(VI) on T-PBC were best described by pseudo-second-order kinetic and Langmuir models. Conversely, the adsorption of BPA was best fitted with the pseudo-second-order kinetic and Freundlich models. Two phenomena occur in the binary system of Cr(VI) and BPA: the promotion with adding a low concentration of another pollutant and inhibition by adding high concentrations toward to target pollutant adsorption (Cr(VI)/BPA). In addition, the removal efficiency of Cr (VI) by T-PBC from an electroplating wastewater reached 83.04 %. The main adsorption mechanisms for Cr(VI) and BPA on T-PBC were revealed in this study. This work provides a reference for the co-adsorption of heavy metals and organics and indicates the potential application of T-PBC for adsorption of complex pollutants.

Modulation of metal-organic frameworks by anionic surfactants for rapid adsorption of organic pollutants bisphenol A and chrome black T

With the accelerated development of industry, which generates large quantities of sewage discharged into the aquatic environment, serious impacts on both environmental and human health. Detecting various organic contaminants in water sources has become common, presenting huge challenges for water treatment. Metal-organic frameworks are characterized by their rich porous structures and high chemical activity, making them ideal adsorbents for removing organic pollutants from water. In this study, sodium dodecylbenzene sulfonate is added to the precursor solution of MIL-101(Cr)-Cl2 and synthesized hierarchical porous structure adsorbents MIL-SDBS-X, using hydrothermal synthesis to enhance their adsorption capacity, making efficient and rapid removal of bisphenol A(BPA) and chromium black T(EBT), two common organic pollutants in water, which MIL-SDBS-0.7 was the most effective. MIL-SDBS-0.7 exhibites great potential in the adsorption of BPA and EBT for its high adsorption capacity (260.5 mg-1·g-1 and 272.3 mg-1·g-1) and rapid adsorption (equilibrium could be achieved in 15 minutes), The findings reveal adsorption kinetics aligns with the pseudo-second-order model and the Langmuir equation best fits to study adsorption of MIL-SDBS-0.7 to BPA and EBT. Thermodynamic parameters affirm the exothermic and higher spontaneity behavior of the adsorption process. Moreover, the adsorption mechanism of MIL-SDBS-0.7 was explored, illustrating the crucial roles of effects of hydrogen bonding π-π stacking and pore filling in the adsorption of BPA and EBT. Therefore, this work not only provided a convenient strategy for the preparation of efficient and fast MIL-SDBS-0.7 hierarchical porous material but also highlighted the promising potential of synthesized absorbents as an effective adsorbent for organic pollutants in wastewater treatment and environmental remediation.

Porous activated carbons derived from waste Moroccan pine cones for high-performance adsorption of bisphenol A from water

Porous-activated carbons (ACs) derived from Moroccan pine cones (PC) were synthesised by a two step-chemical activation/carbonisation method using phosphoric acid (PC-H) and zinc chloride (PC-Z) as activating agents and used for the adsorption of bisphenol A (BPA) from water. Several techniques (TGA/DTA, FT-IR, XRD, SEM and BET) were used to determine the surface area and pore characterisation and variations during the preparation of the adsorbents. The modification significantly increased the surface area of both ACs, resulting in values of 1369.03 m2 g−1 and 1018.86 m2 g−1 for PC-H and PC-Z, respectively. Subsequent adsorption tests were carried out, varying parameters including adsorbent dosage, pH, initial BPA concentration, and contact time. Therefore, the highest adsorption capacity was observed when the BPA molecules were in their neutral form. High pH values were found to be unfavourable for the removal of bisphenol A from water. The results showed that BPA adsorption kinetics and isotherms followed pseudo-second-order and Langmuir models. Thermodynamic studies indicated that the adsorption was spontaneous and endothermic. Besides, the regeneration of spent adsorbents demonstrated their reusability. The adsorption mechanisms can be attributed to physical adsorption, hydrogen bonds, electrostatic forces, hydrophobic interactions, and π-π intermolecular forces.

The Selective Removal of Bisphenol A Using a Magnetic Adsorbent Fused with Bisphenol A-Binding Peptides.

The potential of bisphenol A (BPA)-binding peptides fused to magnetic beads is demonstrated as novel adsorbents that are reusable and highly selective for BPA removal from aqueous environments, in which various interfering substances coexist. Magnetic beads harboring peptides (peptide beads) showed a higher BPA removal capacity (8.6 mg/g) than that of bare beads without peptides (2.0 mg/g). The BPA adsorption capacity of peptide beads increased with the number of peptides fused onto the beads, where monomeric, dimeric, or trimeric repeats of a BPA-binding peptide were fused to magnetic beads. The BPA-adsorbing beads were regenerated using a methanol-acetic acid mixture, and after six regeneration cycles, the adsorption capacity remained above 87% of its initial capacity. The selective removal of BPA was confirmed in the presence of BPA analogs with high structural similarity (bisphenol F and bisphenol S) or in synthetic wastewater. The present work is a pioneering study that investigates the selective affinity of peptides to remove specific organics with high selectivity from complex environmental matrices.

PDA@UiO-66-NH2-derived nitrogen and oxygen-doped hierarchical porous carbon for efficient adsorption of BPA and dyes

MOF-derived carbon materials have garnered significant attention in the field of adsorption due to their abundant porosity, excellent stability, and structural diversity. In this study, nitrogen and oxygen-doped hierarchical porous carbon materials were obtained by carbonizing PDA@UiO-66-NH2 at various temperatures and subsequently etching with hydrofluoric acid for different times. The adsorption capacity of these materials towards bisphenol a (BPA), methyl orange (MO), and methylene blue (MB) was evaluated. The results suggest excessive carbonization temperature and etching time may cause the collapse of the pore structure. In addition, the introduction of a PDA carbon layer can reduce the nitrogen–oxygen ratio and modify the nitrogen species in the materials. Among these materials, UPCH800, which was carbonized at 800 °C followed by etching for 6 h, exhibits the best adsorption performance towards BPA and MO, with a maximum adsorbed amount of 350.51 and 417.34 mg/g respectively. For MB, the maximum adsorption amount is 227.53 mg/g. All adsorptions reach equilibrium within 1 h. Thermodynamic studies reveal that the adsorption of MO by UPCH800 is an entropy-driven adsorption process, while the adsorption of BPA and MB is an enthalpy-driven exothermic process. Based on experimental and characterization results, the primary adsorption mechanisms involve π-π interactions, n-π interactions, pore-filling, and hydrogen bonding between the pollutants and the material. Moreover, UPCH800 exhibits high removal efficiency after 5 adsorption cycles, making it a promising material for the adsorption of BPA and MO.

Custom and definitive screening designs for evaluating multiple adsorbents: bisphenol-A adsorption onto villi-structured polyaniline/carboxymethyl cellulose composites

ABSTRACT Polyaniline composites consisting of carboxymethyl cellulose (CMC) have enhanced adsorption properties, but recent studies indicate that the oxidised species – dialdehyde carboxymethyl cellulose (DCMC) – outperforms CMC-based composites. However, these studies fail to study the effect of DCMC's aldehyde content and compare the composites with CMC-based composites; numerous experiments required to investigate each adsorbent for each factor limit such studies. We explored a way to study whether villi-structured polyaniline (VSPANI), its CMC composite (CMC/PANI), and its DCMC composites with 35% (DCMC(A)/PANI) and 77% (DCMC(B)/PANI) aldehyde content would be great adsorbents for removing bisphenol-A (BPA). We first customised a D-optimal screening design to alleviate the pitfalls of definitive screening design (DSD), hence estimating all the main effects: initial concentration, pH, flow rate, adsorbent amount, sample volume and type of adsorbent. We excluded CMC/PANI and DCMC(A)/PANI composites, both with low adsorption capacities of 56.57 and 57.27 mg/g from further investigation. The DSD followed to estimate all second-order effects through which we projected a response surface method (RSM) to optimise and model the active factors. Increasing the aldehyde content on the composites favoured adsorption, but there lacked evidence to suggest VSPANI and DCMC(B)/PANI differed significantly in performance. The models were numerically and graphically proven adequate, explaining 80% and 99% of the variation when predicting removal efficiency and adsorption capacity. VSPANI showed potential as an adsorbent for BPA removal with 85% removal efficiency and 129 mg/g adsorption capacity. This comprehensive approach, combining both designs, allows for sustainable investigation of multiple adsorbents and factors, minimising experimental waste.

Recyclable and selective PVDF-based multifunctional molecular imprinted membranes for the removal of Bisphenol A

Bisphenol A (BPA) has been widely detected in environmental and human products and has significant health and environmental impacts. Consequently, an innovative molecularly imprinted membrane was fabricated for the selective adsorption of BPA within water environment. Tannic acid (TA), abundant in plants, was employed to effectuate the reduction of AgNO3 in an environmentally friendly, and gentle manner, imbuing the membrane with antibacterial properties. A functional hydrophilic layer was created utilizing TA and polyimide (PEI), and mild and efficient imprinting was accomplished through dopamine (DA) self-polymerization. Compared with the blank membrane, the contact angle of the molecularly imprinted membranes (PVDF@Ag@P@MIMs) was reduced to 67.62°, and the optimal adsorption capacity was 33.41 mg g−1. The imprinting factor of the PVDF@Ag@P@MIMs membrane was 2.90, indicating that the membrane could effectively separate BPA. After 6 cycles of utilization, the adsorption loss was only 4.55 %. In addition, the synthesis of PVDF@Ag@P@MIMs is simple and free of pollutants. The experimental results and green synthesis process of the molecularly imprinted membranes indicate that these materials have potential applications in environmental protection, selective separation, chemical industry, and other fields.

Synergism between polyethyleneimine, graphene oxide, and MgFeAl-layered triple hydroxide in removing acid red 1 dye and bisphenol A from contaminated water samples

Water pollution is rapidly growing, requiring the development of effective treatment processes. In this work, a novel adsorbent (composed of polyethyleneimine, graphene oxide, MgFeAl-layered triple hydroxide, abbreviated as PEI@GO/MgFeAl-LTH) was synthesized, characterized, and applied to remove two hazardous water pollutants (i.e., acid red 1 and bisphenol A). The adsorption performance of the synthesized PEI@GO/MgFeAl-LTH nanocomposite was benchmarked to its parental materials (i.e., GO, PEI@GO, MgFeAl-LTH, and GO/MgFeAl-LTH). The results demonstrated that the adsorption capacity of bisphenol A (BPA) and acid red 1 (AR1) onto the nanocomposite are 352.0 and 155.5 mg/g, respectively, which are higher than their adsorption on GO, PEI@GO, MgFeAl-LTH, and GO/MgFeAl-LTH. The obtained adsorption isotherms and kinetics data were fitted using different models, which showed that Redlich-Peterson isotherm and Avrami kinetics models provide excellent fits for the obtained experimental data; the other models provided mixed results. The zeta potential measurements and the study of the pH effect suggest that the adsorption of BPA and AR1 onto the PEI@GO/MgFeAl-LTH nanocomposite is governed by more than a single mechanism. Furthermore, thermodynamics analysis demonstrated that the adsorption of AR1 and BPA is an exothermic (the respective ∆H values are −27.59 and −11.21 kJ/mol), spontaneous, and physical in nature. With respect to the reusability of this nanocomposite, the results revealed that it is highly stable and easily regenerable using a cheap solvent (i.e., 0.2 M NaOH). Accordingly, this study demonstrates the efficacy and superiority of the synthesized PEI@GO/MgFeAl-LTH nanocomposite in efficiently capturing toxic organic pollutants from aqueous environments.

Composite hydrogel derived iron/nitrogen co-doped carbon for bisphenol A removal

Conventional carbon-based adsorbents encounter insufficient active sites, low adsorption efficiency and poor anti-interference ability for bisphenol A (BPA) removal. Herein, we developed a cellulose nanocrystal/polyacrylic acid hydrogel derived strategy for the preparation of a novel iron/nitrogen co-doped carbon (FeN@CP800) via simple immersion of iron (III) acetylacetonate and melamine in hydrogel precursors and further carbonization at 800 °C. The precursor scaffold interacted with active species source by swelling behavior to form hydrogen bonds and Fe coordination, thereby facilitating subsequent growth of multiple active conformations without aggregation. The hierarchical porous surface morphology, abundant N doping, multi-active site structure and large specific surface area significantly improved the accessible BPA adsorption of FeN@CP800. The maximum adsorption capacity calculated by Langmuir model was 309.17 mg·g−1, 4.5 times higher than that of bare CP. Benefited from pore filling, hydrogen bonds, π-π stacking and hydrophobic interactions, the excellent adsorption performance of FeN@CP800 was retained under varied coexisting ions species, ionic strength and solution pH with 84 % capacity retention after 5 cycles. DFT calculations disclosed the Fe4N component was the predominant active sites to improve the adsorption and interfacial transfer process. Thus, these findings provide a new strategy to design high-performance adsorbent for phenolic pollutants removal in water.

Statistical physics modeling study of an environmentally friendly and efficient adsorbent derived from the brown macroalgae Bifurcaria bifurcata for the removal of Bisphenol A

The brown macroalgae Bifurcaria bifurcata was valued and used to develop a carbonaceous material activated by H2SO4 (AC-BB@H2SO4), with the goal of assessing its adsorption ability against Bisphenol A (BPA). During the adsorption experiments, the effects of the adsorbent dose, solution pH, and contact time were examined, and the results were m = 0.4 g/L, pH = 8.3, and t = 120 min, with an elimination yield of 91.6 %. With comparatively high R2 values, the pseudo-second-order kinetic model perfectly fitted the experimental data. Langmuir's model was found to be the best appropriate for describing the adsorption equilibrium of BPA on AC-BB@H2SO4. The thermodynamic findings show that BPA adsorption on AC-BB@H2SO4 was spontaneous, favorable, and endothermic in nature. Even after six cycles of reuse, regeneration testing demonstrated that our adsorbent could eliminate BPA by >50 %. The BPA adsorption mechanism's statistical physics control parameters were determined and analyzed. BPA's adsorption energies were <40 kJ/mol, indicating that the interactions between BPA and AC-BB@H2SO4 were governed by physical forces (i.e., hydrogen bonding and van der Waals and electrostatic interactions). All of these intriguing findings indicate that our carbonaceous material might have direct ramifications in the field of wastewater treatment, notably for the clearance of BPA, which is difficult to biodegrade.