Efficient Removal Of Bisphenol Research Articles

A new understanding of the regulatory mechanism by which Fe/Mn nanoparticles boost Bisphenol A removal using Comamonas testosteroni

Green synthesized iron/manganese nanoparticles (Fe/Mn NPs), acted as an exogenous promoter to enhance the lignin-degrading bacteria Comamonas testosteroni FJ17 resulting in more efficient removal of bisphenol A (BPA). Batch experiments demonstrated that removal efficiency of BPA via cells at a BPA concentration of 10 mg·L−1 increased by 20.9 % when exposed to 100 mg·L−1 Fe/Mn NPs after 48 h (93.63 %) relative to an unexposed control group (72.70 %). TEM and 3D-EEM analysis confirmed that the cell membrane thickness increased from 47 to 80 nm under Fe/Mn NPs exposure, and the TB-EPS secretion was promoted. Meanwhile, Fe/Mn NPs facilitated greater electron transfer capacity of c-cytochrome (0.55 V reduction peak) and an unknown cytochrome substance (0.7 V oxidation peak) on the surface of cells. Studies of the effect of Fe/Mn NPs on both the growth and activity of laccase cells showed that both biomass and laccase secretion increased significantly during the logarithmic growth period (6–36 h). LC-MS analysis and toxicity assessment indicated that Fe/Mn NPs decreased the degradation time of BPA and efficiently reduced the toxicity of its by-products. Transcriptomic analysis revealed 315 up-regulation of the key genes associated with energy supply, membrane translocation, and metabolic pathways upon exposure to Fe/Mn NPs. Such as MFS transporter (2.27-fold), diguanylate cyclase (1.76-fold) and protocatechuate-3,4-dioxygenase (1.62-fold). Overall, Fe/Mn NPs accelerated proliferation by enhancing metabolic capacity and nutrient transport processes, which serves to improve the efficiency of BPA removal.

Efficient removal of bisphenol A from water using a novel organic–inorganic hybrid heterojunction

Organic-inorganic hybrid heterojunctions have the ability to efficiently remove trace pollutants from water due to efficient photosensitivity. In this work, an organic–inorganic hybrid S-scheme heterojunction photosensitizer (RCP-BW) was successfully fabricated by growing cross-linked β-CD/riboflavin copolymer on the surface of bismuth tungstate (Bi2WO6). The fabrication of the copolymer retains the photosensitivity of riboflavin and the confinement effect of β-CD and forms an internal electric field with Bi2WO6 to enhance the photoelectron transport ability. Photogenerated electrons are transferred and stacked from Bi2WO6 to β-CD/riboflavin copolymers, which greatly enhances the ability of organic copolymers to reduce oxygen and produce superoxide radicals. We combined electrochemistry, free radical chemistry and DFT to study the photoelectron migration mechanism and photocatalytic performance enhancement mechanism in S-scheme heterojunctions. The pseudo-first-order reaction kinetic constant (kRCP-BW = 0.081 min−1) for BPA degradation was four times that of unmodified BW (kBW = 0.020 min−1). β-CD regulates the band structure of riboflavin to match with Bi2WO6, and utilizes charged contaminants and intermediate degradation products to promote the production of reactive oxygen species through interface electron transfer and excited state transition energy transfer. This work provides theoretical support and technical means for photocatalytic oxidation technology to control endocrine disruptors.

Efficient removal of bisphenol A by carbon nitride/peroxymonosulfate/solar system: multi-radical association mechanism by the morphology and crystallinity optimization

Efficient removal of bisphenol A by carbon nitride/peroxymonosulfate/solar system: multi-radical association mechanism by the morphology and crystallinity optimization

Construction of Z-type heterojunction BiVO4/Sm/α-Fe2O3 photoanode for selective degradation: Efficient removal of bisphenol A based on multifunctional Sm-doped modification

Metal Sm was doped in the BiVO4 to form B-Sm, and then B-Sm is combined with α-Fe2O3 to form B-Sm/α-Fe2O3 Z-type heterojunction to determine the mechanism of Sm in the photoanode heterojunction and oxidation system for lanthanide metal application in water treatment. In the photoanode mechanism, Sm utilizes near-infrared light at 980 nm to increase the light absorption intensity at 400–500 nm. It also decreases the transmission resistance from 25.91 Ω to 20.47 Ω, increases the number of oxygen vacancies in the system, and improves the carrier life and conductivity of the photoanode. In the oxidation system, the metal Sm acts as a photosensitizer to convert the O2 adsorbed on oxygen vacancies to 1O2, which increases the degradation rate of bisphenol A by 36%. Finally, the B-Sm-F photoanode was able to achieve 100% degradation within 60 min. Furthermore, the DFT results showed that the active species were selectively aggressive towards different sites of the bisphenol analogues. This provides a pathway for the selective degradation of bisphenol analogues.

Novel cubical Ag(NP) decorated titanium dioxide supported bentonite thin film in the efficient removal of bisphenol A using visible light.

The persistent endocrine-disrupting chemical bisphenol A is posing serious health concerns; hence, it is known to be an emerging and potential water contaminant. The present investigation aims to synthesize novel cubical Ag(NP) decorated titanium dioxide-supported bentonite (Ag/TiO2@Clay) nanocomposite using a novel synthetic process. The nanocomposite materials were characterized by several analytical methods viz., transmission electron microscopy (TEM), X-ray diffraction (XRD) analyses, energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and diffuse reflectance spectroscopy (DRS). Further, the photocatalytic removal of bisphenol A was conducted utilizing the thin film catalyst under the LED (light emitting diode; visible light) and UV-A (ultra violet-A) light sources. The parametric studies solution pH (6.0-12.0), pollutant concentrations (1.0-20.0mg/L), and the interaction of several scavengers and co-existing ions are studied extensively to demonstrate the insights of the removal mechanism. The mineralization of bisphenol A and repeated use of the thin filmcatalyst showed the potential usage of photocatalysts in the devised large-scale operations. Similarly, the natural matrix treatment was performed to evaluate the suitability of the process for real implications.

Efficient removal of bisphenol A by a novel biochar-based Fe/C granule via persulfate activation: Performance, mechanism, and toxicity assessment

Fe–C microelectrolysis is an efficient wastewater treatment technology for biorefractory pollutants. However, the poor stability and complicated separation mechanism of microelectrolytic materials hinder their application in advanced oxidation processes. Thus, herein, catalytic Fe–C microelectrolysis granules (FeBCGs) were prepared using Fe powder and sawdust and were used as persulfate (PS) activators for bisphenol A (BPA) removal. The effects of the calcination temperature, Fe/sawdust mass ratio, FeBCG concentration, PS concentration, initial pH, and initial BPA concentration were investigated. Under optimal conditions ([FeBCG]0 = 0.5 g/L, [PS]0 = 1 mM, without pH adjustment), the BPA removal efficiency reached 100% within 20 min. The FeBCGs presented numerous functional groups and a porous structure, which are beneficial for PS activation and BPA removal. The BPA degradation mechanism was elucidated via radical capture experiments, electron paramagnetic resonance spectroscopy, electrochemical analysis, density functional theory calculations, and high-performance liquid chromatography–mass spectrometry, which revealed that SO4•−, •OH, O2•−, 1O2, and electron transfer contributed to BPA removal. Additionally, the ecotoxicity of the intermediates was evaluated. The FeBCGs exhibited high stability and resistance to inorganic anions and natural organic matter. These findings may provide guidelines for the design and development of integrated microelectrolysis materials coupled with advanced oxidation processes for water treatment.

Efficient removal of bisphenol A and Cr(VI) simultaneously in an advanced redox photoelectrocatalytic system over dual 3D TiO2 photoelectrodes

An adventurous strategy on the premise of synergistic photoelectrocatalysis (PEC) system based on three-dimensional (3D) TiO2 is proposed to realize the simultaneous removal of BPA and Cr(VI). The TiO2 photoelectrode demonstrates a 3D configuration, meanwhile supplies a multilevel facet heterojunction (FH). The dual-FH-TiO2/Ti PEC system is constructed via the application of 3D FH-TiO2/Ti as both cathode and anode, where the redox efficiency of BPA and Cr(VI) increased by 1.07 and 4.28 times of the single system. The visible growth accounts for more exposure of active sites and a higher utilization of active species, proved by EPR and quenching experiments. In the practical wastewater, the removal efficiency of BPA and Cr(VI) reaches 97.04% and 81.18% in 1 h. The effects of various influence factors such as pH, electrolyte concentration and coexisting ions on BPA and Cr(VI) removal are studied for practical applications.

Stoichiometric carbocatalysis via epoxide-like C−S−O configuration on sulfur-doped biochar for environmental remediation

Heteroatom doping is a promising technique to enhance biochar for effective environmental remediation. However, development of electroactive heteroatom-doped biochars, e.g., sulfur-doped biochar, has been hindered due to complex nature of non-stoichiometric biomass-derived carbon and changeable electrochemical state of dopants. Herein, we produced a series of wood waste-derived biochars with customized levels of minerals and redox-active moieties, aiming to unravel the crucial factors for sulfur doping. Calcium (Ca) in biochar was found to preferentially coordinate with sulfur to form inactive inorganic sulfur minerals (i.e., CaSO4 and CaS) with inferior catalytic reactivity. After diminishing the inherent Ca minerals beforehand, we could introduce surface phenoxyl-type radicals (C−O•) and vacancy defects on the biochar to develop an electrophilic C−S−O bonding configuration, which guaranteed a high affinity towards peroxymonosulfate (PMS, 2.08 mM g−1, 30 min) and efficient removal of bisphenol A (BPA, 91.1%, 30 min). Scavenging experiments and in-situ Raman analyses indicated that the epoxide-like C−S−O structure induced nucleophilic addition of PMS to generate surface-bound singlet oxygen (1O2, major) and hydroxyl radicals (•OH, minor) through a preservative and stoichiometric interfacial reaction. Overall, the proposed approach overcomes the major hurdles in science-informed fabrication of sulfur-doped biochar and advances its development for environmental remediation.

Facile synthesis of novel multifunctional β-cyclodextrin microporous organic network and application in efficient removal of bisphenol A from water

Here, a novel multifunctional β-cyclodextrin microporous organic network (CD-MON) has been successfully synthesized and used to remove bisphenol A (BPA) from water. The morphology and composition of the synthesized CD-MON were confirmed. The combination of hydrophobic interaction, π-π interaction inclusion mechanism and hydrogen bonding endowed CD-MON to exhibit superior adsorption capacity toward BPA. The adsorption kinetics and isotherms of BPA and other four model aromatic pollutants on CD-MON were studied. CD-MON could maintain adsorption efficiency toward BPA over wide pH ranges and without being affected by the ionic strengths, co-existing inorganic ions and humic acid. The optimal conditions and removal efficiency of BPA were screened by response surface analysis. In addition, nearly unchanged in the adsorption efficiency toward BPA was observed after five regeneration cycles on CD-MON. CD-MON can adsorb about 80% of five model aromatic pollutants from the water within 40 s in the flow-through experiments. This novel adsorbent gives great promise for practical wastewater remediation.

The efficient removal of bisphenol A from aqueous solution using an assembled nanocomposite of zero-valent iron nanoparticles/graphene oxide/copper: Adsorption isotherms, kinetic, and thermodynamic studies

In this study, nanoparticles of zero-valent iron (nZVI) along with graphene oxide (GO) and copper (Cu) was synthesized to apply as a promising adsorbent for the rapid removal of bisphenol A (BPA) from aqueous solution. The characteristics of nZVI-GO-Cu were analyzed by field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), and vibrating sample magnetometer (VSM). The average particle size of nZVI-GO-Cu was found to be 20.89 nm. The effective experimental variables such as pH, adsorbent dosage, contact time, initial BPA concentration, and temperature were surveyed to assess optimum conditions. Results revealed that the maximum removal percentage was obtained at pH of 7, adsorbent dosage of 0.2 g, contact time of 10 min, the BPA concentration of 10 mg/L, and a temperature of 35 °C as optimum conditions. Experimental data were fitted to the Langmuir and pseudo second-order models with a coefficient of determination (R2) equal to 1 and 0.995, respectively. The obtained maximum adsorption capacity (qmax) of the Langmuir isotherm was 21.59 mg g−1. Thermodynamic parameters under the various temperatures confirmed that the adsorption process was endothermic (ΔH = 17,459.4 J/mol and ΔS = 61.23 J/mol/K) and spontaneous (ΔG < 0). As a conclusion, nZVI-GO-Cu can be selected as an efficient adsorbent for the treatment of aqueous media from BPA and the other pollutants, due to its low-cost, high removal efficiency (97%), and rapid adsorption with the minimum time of 10 min compared with the other adsorbents.

Investigation of Electrocoagulation Process for Efficient Removal of Bisphenol A from the Aqueous Environment: Promising Treatment Strategy

Introduction: Endocrine disruptive compounds as a class of organic contaminants in the aquatic environment received severe attention in the last decades. The release of bisphenol A (BPA) as a hazardous organic chemical into the environment has caused high health and environmental concerns. Therefore, its removal from aquatic environments is strongly recommended. The present study deals with BPA removal efficiency from an aqueous environment using the electrocoagulation process (ECP). Materials and Methods: The effects of parameters including BPA concentration (1-10 mg L-1), current density (3-15 mA cm-2), pH (4-10), and reaction time (5-30 min) on the treatment process were investigated. Response surface methodology (RSM) was employed for optimization of the ECP. The significance of the developed model was investigated by the obtained F-value and P-value. Results: The maximum BPA removal of 98.2% was attained at pH of 8.5, BPA concentration of 3.25 mg L-1, the current density of 12.0 mA cm-2, and reaction time of 23 min. The significance of the developed model was confirmed by the high F-value of 46.69 and the very low P-value of &lt; 0.0001. Furthermore, the electrical energy consumption of the process was found to be 0.308 kWh m-3 in the optimum condition. Conclusion: The obtained experimental results revealed that the co-precipitation and the adsorption process through the electrostatic interactions as the main removal mechanisms controlled the treatment process.

Efficient removal of bisphenol S by non-radical activation of peroxydisulfate in the presence of nano-graphite

An environmentally friendly and efficient catalyst is important for the persulfate activation and pollutants removal from water. In this study, nano-graphite (NG) prepared by detonation method, was firstly applied as the superb carbon catalyst to activate peroxydisulfate (PDS) for the degradation of bisphenol S (BPS) via a non-radical pathway. Results showed that NG had a very high catalytic performance and degraded most of BPS within 20.0 min, out-performing many popular metal-based catalysts. The doped N atoms (i.e. graphitic N and pyridinic N) in NG were identified as the possible reactive sites for the PDS activation. It is proposed that PDS could form the metastable surface-bound PDS complexes on the NG surface, which promoted the BPS degradation. The NG/PDS system had a strong anti-interference ability for the environmental background substances and a wide operative pH range, so it had a good application prospect in the actual wastewater environment. This study not only provides an efficient method for the removal of bisphenol pollutants, but also deepens the insight into the reaction mechanisms.

Efficient removal of Bisphenol A in water via piezocatalytic degradation by equivalent-vanadium-doped SrTiO3 nanofibers

A new strategy was reported for removal of low-concentration BPA in water via piezocatalytic degradation of equivalently V-doped SrTiO3 nanofibers (V-STO NFs), which can effectively convert mechanical vibration into chemical energy under ultrasound only. The optimal doped 0.5% V-STO NFs exhibited excellent piezocatalytic performance of complete removal of BPA within 24 min, which could be ascribed to the localized surface piezoelectricity of SrTiO3 itself and increased local asymmetry of the crystal originating from equivalent vanadium substitution. The influence of ultrasonic power, pH, BPA concentration and coexisting inorganic anions on BPA degradation were analyzed. Moreover, a suitable piezocatalytic mechanism was proposed through the free radical capture test and ESR characterization. The results suggested that the •O2– and •OH are the main active radicals in BPA oxidation. It provides a feasible approach for removal of phenolic pollutants by a perovskite-based nano-piezoelectric material.

Pyrrolic N-rich biochar without exogenous nitrogen doping as a functional material for bisphenol A removal: Performance and mechanism

Nitrogen configurations doped in carbon matrix serve as the catalytically active sites for the metal-free activation of persulfates (peroxydisulfate PDS, and peroxymonosulfate PMS). Herein, a series of pyrrolic N-rich biochars (BDKx, where x represents the pyrolysis temperature) were facilely prepared by using waste bean dregs as the feedstocks. The resulted BDK900 possessed ultra-high specific surface area (SBET, > 3000 m2 g−1). Accordingly, it exhibited superior catalytic activity in PDS activation, as evidenced by the efficient removal of bisphenol A (BPA, 1358.4 mg g−1) with 0.05 g L−1 BDK900 and 5 mM PDS. Surface-bound radicals and electron-transfer mechanism were discovered to contribute to the BPA oxidation, during which BDK900 played vital roles in PDS activation, BPA accumulation, and regulating electron shuttle from BPA to PDS. Overall, this study sheds new light on the rational design of N-rich biochar and develops a low-cost technology toward remediation of BPA-contaminated wastewater.

Synthesis of a novel mesoporous Fe3O4@SiO2/CTAB-SiO2 composite material and its application in the efficient removal of bisphenol A from water

Synthesis of a novel mesoporous Fe3O4@SiO2/CTAB-SiO2 composite material and its application in the efficient removal of bisphenol A from water

Efficient removal of bisphenol A with activation of peroxydisulfate via electrochemically assisted Fe(III)-nitrilotriacetic acid system under neutral condition

In this work, an innovative electrochemically assisted Fe(III)-nitrilotriacetic acid system for the activation of peroxydisulfate (electro/Fe(III)-NTA/PDS) was proposed for the removal of bisphenol A (BPA) at neutral pH with commercial graphite electrodes. The efficient BPA decay was mainly originated from the continuous activation of PDS by Fe(II) reduced from Fe(III)-NTA complexes at the cathode. Scavenger experiments and electron paramagnetic resonance (EPR) measurements confirmed that the removal of BPA occurred through graphite adsorption, direct electron transfer (DET) and radical oxidation. Sulfate and hydroxyl radicals were primarily responsible for the oxidation of BPA while graphite adsorption and DET played a minor role in BPA removal. The influence of Fe(III) concentration, PDS dosage, input current, NTA to Fe(III) molar ratio as well as coexisting inorganic anions (Cl−, NO3−, H2PO4− and HCO3−) on BPA elimination was explored. The BPA removal efficiency reached 93.5 % after 60 min reaction in the electro/Fe(III)-NTA/PDS system under the conditions of initial pH 7.0, 0.30 mM Fe(III), 0.15 mM NTA, 5 mM PDS and 5 mA constant current. Overall, this research provided a novel perspective and potential for remediation of organic wastewater using NTA in combination with electrochemistry in the homogeneous Fe(III)/persulfate system.

Efficient Removal of Bisphenol A Using Nitrogen-Doped Graphene-Like Plates from Green Petroleum Coke.

Green petroleum coke, a form of industrial waste produced in the oil-refining process, was used to synthesize nitrogen-doped graphene-like plates (N-GLPs) together with melamine. In this study, characterization and batch experiments were performed to elucidate the interaction mechanism of N-GLPs and bisphenol A (BPA). Structural analysis of N-GLPs, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS), showed an obvious graphene-like structure and successful nitrogen doping. In addition, compared with 8.0 m2/g for green petroleum coke, the BET surface area of N-GLPs markedly increased to 96.6 m2/g. The influences of various factors, including contact time, temperature, and initial pH on BPA removal efficiency were investigated. It was found that 92.0% of BPA was successfully removed by N-GLPs at 50 °C. Based on the adsorption experiments, it was shown that electrostatic attraction, hydrogen bonding, and π-π interaction enhanced the adsorption capacity of N-GLPs for BPA. According to the thermodynamic data, the adsorption process was spontaneous, physical, and endothermic in nature. Therefore, N-GLPs are efficient adsorbent material to remove BPA from wastewater.

Efficient removal of bisphenol A and disinfection of waterborne pathogens by boron/nitrogen codoped graphene aerogels via the synergy of adsorption and photocatalysis under visible light

It is widely acknowledged that doping of carbon materials by multi-elements with different electronegativities can result in unique electron-donor properties and novel functionalities because of the strong synergistic interaction among the dopant atoms. In this study, boron and nitrogen codoped graphene aerogels (BNGAs) are synthesized and their photocatalytic activity towards decomposition of bisphenol A (BPA) under visible light irradiation is systematically examined. The BPA molecules are rapidly adsorbed onto the 3D interconnected pore system of the BNGAs under dark conditions, and eventually mineralized upon exposure to visible light, indicating the synergy between adsorption-enrichment and photocatalysis during degradation of BPA. Notably, almost 96 % of BPA is removed and over 88 % of total organic carbon is eliminated by the as-prepared BNGAs. More importantly, the BNGAs can retain approximately 92 % of their initial activity even after repeated cycling. In addition, the BNGAs display great potential for the disinfection of harmful pathogens like Escherichia coli, with a photocatalytic decontamination rate of 1.2 × 103 CFU h−1 gcat−1. In view of their attractive multi-functional performance, the as-developed BNGAs merit further consideration for eliminating emerging organic contaminants and pathogens from freshwater sources.

Efficient removal of bisphenol A from wastewaters: Catalytic wet air oxidation with Pt catalysts supported on Ce and Ce–Ti mixed oxides

Catalytic wet air oxidation (CWAO) of an aqueous solution of bisphenol A (BPA) was investigated at 160 ℃ and 2.0 MPa of air in a batch reactor. Activity of supported platinum catalysts (2.5 wt%), prepared by wet impregnation, was compared with pure cerium and cerium–titanium oxide catalysts. Supported platinum catalysts showed higher activities in the removal of BPA than pure CeO2, Ce0.8Ti0.2O2 and Ce0.2Ti0.8O2. The oxidation reaction was followed the pseudo-first order rate law and the highest BPA removal, 97% and 95%, was achieved with Pt/CeO2 and Pt/Ce0.8Ti0.2O2 catalysts respectively. The CWAO of BPA aqueous solution was not a surface area specific reaction but the more important factor affecting the activity of studied catalysts was the amount of chemisorbed oxygen of these samples.

Waste control by waste: efficient removal of bisphenol A with steel slag, a novel activator of peroxydisulfate

Activated persulfates are efficient reagents for oxidation of organic contaminants and water treatment. Various compounds are currently used to activate persulfates, but there is a need for cheap and efficient activators. Here, we report the first use of steel slag, an industrial solid waste, as a solid activator for peroxydisulfate activation. We tested this system for bisphenol A degradation. Results indicate that about 70% of bisphenol A can be removed within 1 h. Conditions were 50 μg/L of bisphenol A, 2 g/L of peroxydisulfate, 3 g/L of steel slag and temperature of 298 K. The components and surface morphology of unused and recycled steel slag were analyzed by X-ray diffraction and scanning electron microscopy, whereas the main reactive oxygen species were elucidated by using radical scavengers. Findings show that both base oxides and iron oxides are responsible for peroxydisulfate activation. A redox mechanism involving liquid and solid phases is proposed. Overall, this study reveals the successful recycling of steel slag to activate persulfates for water treatment, following the principle of ‘waste control by waste.’