Bisphenol A Removal Efficiency Research Articles

Removal of bisphenol A by integrated adsorption and biodegradation using immobilized laccase onto defective PCN-224

Environmentally widespread endocrine-disrupting chemicals, such as bisphenol A (BPA), have posed a risk to living things. Laccase, a kind of oxidoreductase, can effectively catalyze the degradation of phenolic compounds like BPA. Herein, a defective metal-organic framework (dPCN-224) with BPA adsorption capability was synthesized and used for laccase immobilization. The material was extensively characterized and successful immobilization of laccase via hydrophobic interaction was confirmed. The immobilization reached an enzyme loading density of 80 mg/g onto dPCN-224 and the laccase@dPCN-224 showed high activity recovery (90.0% vs. free laccase) and increased thermostability, pH tolerance, and organic co-solvent resistance over the free enzyme. Moreover, at various concentrations (0.5–20 mg/L), the BPA removal efficiencies of laccase@dPCN-224 were 3.3–5.0 times higher than those of free laccase due to the cooperative effect of adsorption and enzymatic degradation. The BPA bound on laccase@dPCN-224 could be almost completely biodegraded by adding 0.5 mM of electro-mediator (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)). In addition, after five consecutive batch cycles, the BPA removal efficiency of laccase@dPCN-224 kept as high as 98.1% at 5 mg/L BPA. Taken together, the results proved the potential of laccase@dPCN-224 for applications in addressing environmental BPA pollutions.

Fe/Fe3C nanoparticles embedded in N-doped porous carbon as the heterogeneous electro-Fenton catalyst for efficient degradation of bisphenol A

Heterogeneous electro-Fenton is a promising technology for the degradation of organic contaminants. To ensure its effectiveness, it is in urgent demand to design cathode materials with the integrated capability of sufficient H2O2 generation and subsequent activation into reactive oxygen species (ROS) together with catalytic stability. Herein, a composite constituted by Fe/Fe3C nanoparticles embedded into N-doped porous carbon (NPC), designated as Fe/Fe3C@NPC, was successfully fabricated from Fe3+-loaded poly(imine dioxime) (PIDO) membrane via the thermal treatment in N2 atmosphere and employed as the heterogeneous electro-Fenton catalyst to degrade bisphenol A (BPA). By optimizing the pyrolysis temperature and loading level of iron species, the catalyst obtained at 800 °C (i.e. Fe/Fe3C@NPC-800) achieved almost 100% of BPA removal efficiency within 120 min via the electro-Fenton system, accompanied by 69.2% of the total organic carbon (TOC) removal rate. Furthermore, the proposed composite catalyst also exhibited satisfactory reusability and stability, as reflected by low decrease in removal efficiency after six successive degradation tests and limited iron leaching (<0.5 mg/L). This work might provide valuable instruction for the rational design of highly efficient and stable heterogeneous electro-Fenton catalysts for organic pollutant control.

Carbon electrochemical membrane functionalized with flower cluster-like FeOOH catalyst for organic pollutants decontamination

Decorating active catalysts on the reactive electrochemical membrane (REM) is an effective way to further improve its decontamination performance. In this work, a novel carbon electrochemical membrane (FCM-30) was prepared through coating FeOOH nano catalyst on a low-cost coal-based carbon membrane (CM) through facile and green electrochemical deposition. Structural characterizations demonstrated that the FeOOH catalyst was successfully coated on CM, and it grew into a flower cluster-like morphology with abundant active sites when the deposition time was 30 min. The nano FeOOH flower clusters can obviously boost the hydrophilicity and electrochemical performance of FCM-30, which enhance its permeability and bisphenol A (BPA) removal efficiency during the electrochemical treatment. Effects of applied voltages, flow rates, electrolyte concentrations and water matrixes on BPA removal efficiency were investigated systematically. Under the operation condition of 2.0 V applied voltage and 2.0 mL·min−1 flow rate, FCM-30 can achieve the high removal efficiency of 93.24% and 82.71% for BPA and chemical oxygen demand (COD) (71.01% and 54.89% for CM), respectively, with only a low energy consumption (EC) of 0.41 kWh·kgCOD-1, which can be ascribed to the enhancement on OH yield and direct oxidation ability by the FeOOH catalyst. Moreover, this treatment system also exhibits good reusability and can be adopted on different water background as well as different pollutants.

Environmental Applications of 3D g-C3N4-Based Hydrogel with Synergistic Effect of Adsorption and Photodegradation.

In this paper, g-C3N4-based hydrogel with a 3D network structure was synthesized via a simple and cheap reaction, using hydroxyethyl cellulose (HEC) and graphitic carbon nitride (g-C3N4) as the main materials. Electron microscope images revealed that the microstructure of g-C3N4-HEC hydrogel was rough and porous. The luxuriant scaly textures of this hydrogel were due to the uniform distribution of g-C3N4 nanoparticles. It was found that this hydrogel showed great removal ability of bisphenol A (BPA) through a synergistic effect of adsorption and photodegradation. The adsorption capacity and degradation efficiency of g-C3N4-HEC hydrogel (3%) for BPA were 8.66 mg/g and 78% under the conditions of C0 = 9.94 mg/L and pH = 7.0, which were much higher than those for the original g-C3N4 and HEC hydrogel. In addition, g-C3N4-HEC hydrogel (3%) exhibited excellent removal efficiency (98%) of BPA (C0 = 9.94 mg/L) in a dynamic adsorption and photodegradation system. Meanwhile, the mechanism of removal was investigated in depth. The superior batch and continuous removal capability of this g-C3N4-based hydrogel make it promising for environmental applications.

Facet tailoring and Cu doping promoted photo-assisted peroxymonosulfate activation by oxygen-deficient α-MnO2 for efficient mineralization of bisphenol a

Revealing the synergistic mechanism between facets and metal doping during catalytic processes is an efficient approach to improve the catalytic performance. Herein, the synergetic effects between Cu doping and crystal facets over α-MnO2 on the peroxymonosulfate (PMS) activation towards bisphenol A (BPA) degradation under full-spectrum light irradiation were studied in details for the first time. The Cu-doped α-MnO2 with (100), (110), and (310) facets were synthesized by hydrothermal method. The Cu-doped (110)/PMS/Light system presented the highest BPA removal efficiency with high 1O2 generation and selectivity, being superior over the Cu-doped (100), Cu-doped (310) and pristine (110) counterparts. The corresponding mechanism showed that Cu doping for α-MnO2 enhanced the absorption of light, the formation of oxygen vacancies and electronic conductivity as well as PMS activation, especially for the (110) facet, as compared to the (100) and (310) facets. In addition, density functional theory (DFT) calculations and characterizations indicated that the synergetic effect between facet and oxygen vacancies played an important role in 1O2 generation. Moreover, oxygen vacancies accelerated the complexation of PMS with surface Mn(IV) and improved the generation of 1O2, different to that due to Mn(III). Toxicity assessment showed that BPA was partially decomposed into highly toxic intermediates during the degradation process. However, Cu doping and light synergistically improved the mineralization rate of pollutants, removing 95% of the total organic carbon (TOC) and reducing the toxicity of the intermediates. The ultrahigh TOC removal was attributed to the joint effect of 1O2, O2− and electron transfer. This work therefore provides an efficient and highly selective PMS catalyst for 1O2 generation, and reveals the synergistic mechanism between metal doping and crystal facets of the catalyst in advanced oxidation processes.

The potential roles of carotenoids in enhancing phytoremediation of bisphenol A contaminated soil by promoting plant physiology and modulating rhizobacterial community of tobacco

The widespread occurrence of bisphenol A (BPA), a typical endocrine-disrupting compound, poses potential threat to ecosystem and public health. Carotenoids are essential natural pigments, playing important roles in photosynthesis and antioxidant defense of plants. This study aimed to verify the value of carotenoids in enhancing plant tolerance to BPA stress and improving phytoremediation efficiency of tobacco (Nicotiana tabacum L.), through exogenous application of β-carotene (a typical carotenoid) and endogenous upregulation of carotenoids by overexpression of β-carotene hydroxylase (chyb) gene in tobacco. The results demonstrated that exogenous applied β-carotene alleviated the toxic effects of BPA exposure (100 mg kg−1) on wild-type (WT) tobacco plants after being cultivated for 40 d, reflecting by the increase of biomass (201.2%), chlorophyll content (27.5%) and the decrease of malondialdehyde (MDA) content (70.7%). Similar with the results of exogenous application of β-carotene, chyb gene overexpressing tobacco showed less phytotoxicity exposed to BPA, through enhancing photosynthetic efficiency (42.1%) and reducing reactive oxygen species (ROS) production (18%). Notably, about 94.8% BPA in contaminated soil was removed under the cultivation of transgenic tobacco for 40 d, however, only 82.7% was removed in that of WT tobacco. Moreover, transgenic tobacco is beneficial for the growth of plant roots, thus upregulating the abundance of bacteria contributing to BPA degradation or soil nutrient cycling (e.g., Proteobacteria, Acidobacteria, Actinobacteria, Sphingomonas and MND1), which might further help to enhance plant growth and improve BPA removal efficiency in soil. This study extended our understanding of the possible mechanisms of carotenoids-involved alleviation of BPA stress in tobacco, providing a novel strategy to improve phytoremediation efficiency of plants in BPA contaminated soil.

Copyrolysis of microalga Chlorella sp. and alkali lignin with potassium carbonate impregnation for synergistic Bisphenol A plasticizer adsorption

Composite functional materials offer promising opportunities for the development of tailored adsorbents with enhanced bioremediation potential towards toxic, carcinogenic endocrine disrupters such as Bisphenol A (BPA). Copyrolysis of microalga Chlorella sp. (CH) alkali lignin (L) with K2CO3 impregnation yielded a carbon-based composite (CHL-AC) with a micro–mesoporous structure of 0.643 cm3/g, surface area of 1414 m2/g, and BPA adsorption capacity of Qmax 316.858 mg/g. Enhanced BPA removal efficiency indicated a positive synergistic effect upon a combination of L and CH, resulting in a 73.24 % removal efficiency compared with the individual carbon components of 52.33 % for L-AC and 67.35 % for CH-AC. The kinetics and equilibrium results were described well by the pseudo second-order kinetic model and Freundlich isotherm, respectively. This paper elucidates the blending of microalgae and lignin into high-value carbon composite material, CHL-AC, with immense potential for the treatment of BPA-contaminated waters to contribute to Goal 6 (clean water and sanitation).

Boosting persulfate activation via paper mill sludge-based biochar for efficient degradation of bisphenol A: Inherent multiple active sites

Paper mill sludge generated from the pulp and papermaking industries has inherent iron and carbon contents. Herein, the biochar derived from paper mill sludge (PSBC) was synthesized via simple pyrolysis processes and applied as an efficient persulfate (PDS) activator for the removal of Bisphenol A (BPA) in water. The unique properties of PSBC endowed it with multiple active sites including Fe(II) species, oxygen vacancy, CO, and graphite sp2-C with defects, owing to which, the PSBC/PDS process presented satisfactory performance with BPA removal efficiency up to 98 % within 60 min. Both of the radical and non-radical pathways were revealed to be involved in the BPA degradation. Based on the results of theoretical calculation, the existences of some special structures in PSBC effectively facilitated the electron transfer process of PDS activation. The process also exhibited a high anti-interference capability to coexisting substances and the universality toward various organic contaminants degradation. And the used PSBC can be recovered by simple thermal treatment. This work provided a promising heterogeneous PDS activator with plentiful active sites and satisfactory efficiency, which can be beneficial to the cost reduction of wastewater treatment and promotes the application of paper mill sludge in the area of environmental remediation.

A new biocomposite based on microbial autocrine laccase-rice straw: Preparation, characterization and application

The immobilization of laccase on crop residues is a promising way to treat water containing bisphenol A (BPA), but the high cost of commercially available solutions of this enzyme indicates a need for research into feasible cost-effective alternatives. Here, a new biocomposite was developed based on a microbial autocrine laccase process, where rice straw served as the sole carbon source and as a carrier mixed with Comamonas testosteroni FJ17 ( C. testosteroni FJ17). A laccase-rice straw biocomposite (RS-Lac) was prepared via a one-step synthesis and subsequently evaluated for the removal of BPA. A response surface methodology was used to optimize the synthesis of RS-Lac, where the subsequent removal efficiency of BPA (500 μg L −1 ) by RS-Lac biocomposite increased from 46.1 (unoptimized) to 57.0% (optimized). The molecular weight (Mw) of laccase was identified by SDS-PAGE to be 34 kDa. SEM, CLSM , FTIR, and XRD results confirmed laccase secreted by C. testosteroni FJ17 was coated with polysaccharides , and these were successfully immobilized on rice straw. The specific surface area of RS-Lac increased from 2.79 to 5.37 m 2 g −1 following synthesis optimization, and zeta potential analyzer indicated that it carried a strong negative charge. In addition, RS-Lac was also used to successfully remove estrone (E1), 17β-estradiol (E2), Cu(II), Sb(Ⅲ), As(Ⅲ), and As(Ⅴ) to varying degrees, with removal efficiencies of 68.7%, 66.4%, 77.5%, 84.0%, 83.7%, and 91.6%, respectively. This broad versatility indicated that RS-Lac has great potential as a low-cost biocomposite for treating wastewater. • A rice straw-i autocrine laccase biocomposite was prepared in one-step. • Various characterizations confirmed that crude laccase immobilized on rice straw. • The rice straw was coated with polysaccharides and immobilized laccase. • Degradation of bisphenol A (57%) to small molecular fragments in solution. • Heavy metal ions (>77.5%) and estrogen (>66.4%) were removed.

N Doped Activated Biochar from Pyrolyzing Wood Powder for Prompt BPA Removal via Peroxymonosulfate Activation

In the present study, nitrogen doped biochar (N-PPB) and nitrogen doped activated biochar (AN-PPB) were prepared and used for removing bisphenol A (BPA) in water through activating peroxymonosulfate. It was found from the results that N-PPB exhibited superior catalytic performance over pristine biochar since nitrogen could brought about abundant active sites to the biochar structure. The non-radical singlet oxygen (1O2) was determined to be the dominant active species responsible for BPA degradation. Having non-radical pathway in the N-PPB/PMS system, the BPA degradation was barely influenced by many external environmental factors including solution pH value, temperature, foreign organic, and inorganic matters. Furthermore, AN-PPB had richer porosity than N-PPB, which showed even faster BPA removal efficiency than N-PPB through an adsorptive/catalytic synergy. The finding of this study introduces a novel way of designing hieratical structured biochar catalysts for effective organic pollutant removal in water.

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.

E-waste derived CuAu bimetallic catalysts supported on carbon cloth enabling effective degradation of bisphenol A via an electro-Fenton process

Extensive utilization and excessive accumulation of bisphenol A (BPA) has posed a serious threat to the whole ecosystem, necessitating the rational design of metal-based catalysts capable of complete mineralization of BPA via electrochemical oxidation. Considering the shortage of metals resources and ever-increasing generation of electronic waste (e-waste), converting e-waste into high-performance catalysts is highly expected to offer an economical and feasible means to achieve the degradation of BPA. To this end, CuAu bimetallic catalysts are in situ electro-codeposited on the carbon cloth (CC) support with the waste central processing unit (CPU) leachate as electrolyte. Significantly, the recovered CuAu/CC composites can be directly applied as an efficient electrocatalyst for the decontamination of BPA via the electro-Fenton process. The electrocatalytic activities of the fabricated CuAu/CC electrodes can be regulated by tuning the reduction potentials during electro-deposition process. Under the optimized operational conditions, 99.5 % of BPA (50 mg/L) is removed within 120 min at a constant cathodic potential of −1.0 V (vs Ag/AgCl) in the CuAu/CC-mediated electro-Fenton system, accompanied by 64.2 % of total organic carbon (TOC) removal, highlighting a satisfactory performance of the BPA electrochemical oxidation. In addition, the proposed CuAu/CC electrode material can be facilely regenerated and reused for at least ten cycles without significant decline in BPA removal efficiency. Our work offers valuable guidance for upcycling of bimetallic alloy catalysts from e-waste and further application in electrochemical decontamination of organic pollutants, achieving the innovative target of “using waste to treat waste.”

Polydopamine/graphite sheet electrode for highly efficient electrocatalytic hydrogen peroxide generation and bisphenol A removal

Electrocatalytic processes, are greatly limited by acid conditions during water/wastewater treatment, and lead to higher disposal costs. Herein, based on the principle of strong adhesion of invertebrate mussels, polydopamine with multiple functional groups was immobilized on graphite sheet electrodes for constructing the electrocatalytic system (GS-PDA), which achieved favorable stability in hydrogen peroxide (H2O2) yield and model pollutant Bisphenol A (BPA) removal at pH = 3–9. At natural pH (∼5.8), GS-PDA had a higher BPA removal efficiency with 113 % increase in degradation rate and an 1100 % increase in productivity of H2O2 than control group. O2 bubbling was the original contributor of oxidant and its two-electron reduction product (H2O2) had a significant contribution for BPA removal in GS-PDA. High pH (pH ≥ 5) increased the selectivity toward the four-electron oxygen reduction process (to H2O) in control group, while GS-PDA could inhibit this process, thus promoting the production of H2O2 from two-electron oxygen reduction process. Both hydroxyl radicals and singlet oxygen were effective in removing BPA and the former was the primary pathway. Furthermore, 18 dominant degradations were identified in GS-PDA by high resolution hybrid quadrupole time-of-flight mass spectrometer, and BPA degradation pathway was proposed. This work found a way to decrease the effects of pH on electrocatalytic purification of water and generation of H2O2, and provided a strategy for treating wastewater at neutral pH.

Fe3O4 loaded on ball milling biochar enhanced bisphenol a removal by activating persulfate: Performance and activating mechanism.

In this study, pristine biochar (BC), ball milling biochar (MBC), Fe3O4 modified BC (Fe3O4@BC), and Fe3O4 modified MBC (Fe3O4@MBC) were prepared to compare the Bisphenol A (BPA) removal efficiency by activating persulfate (PDS). All catalysts exhibited excellent degradation rather than adsorption in the PDS system, and Fe3O4@MBC800 had the best BPA removal efficiency, with 96.73% degradation and negligible 1.43% adsorption due to the synergistic effect between MBC800 and Fe3O4 particles. Radical quenching experiments and electron paramagnetic resonance analysis indicated radical pathways, namely, SO4∙- and ∙OH, O2∙-, and non-radical pathway (1O2) involving BPA degradation. The abundant oxygen-containing groups, increased graphitization and mesopores of MBC800, and Fe3+/Fe2+ conversion of Fe3O4 particles facilitated PDS activation to produce reactive oxygen species. In addition, the superior electrochemical performance accelerated the electron transfer between the catalyst and PDS, promoting BPA degradation in the Fe3O4@MBC800/PDS system. More importantly, Fe3O4@MBC800 is resistant to environmental interference, including pH, anions, cations, and humic acid, and has good catalytic reusability and stability, which fulfills the requirements of engineering applications. Therefore, Fe3O4 loaded on ball-milled biochar provides a convenient strategy for preparing environmentally friendly, economical, and efficient carbon-based catalysts to remove organic contaminants.

Current progress in treatment technologies for plastic waste (bisphenol A) in aquatic environment: Occurrence, toxicity and remediation mechanisms

Bisphenol-A (BPA) is a type of endocrine disrupting compound (EDC) that is being widely used in the production of polycarbonate and epoxy resins. In the last few years, human exposure to BPA has been extensively high due to the continuous increment in the Annual Growth Rate (AGR) of the BPA global market. The presence and transportation of BPA in the environment could cause serious damage to aquatic life and human health. This paper reviewed the literature on the exposure and toxicity mechanisms of BPA and advanced analytical techniques for the detection of BPA in the environment and human beings. The study indicated that BPA can cause damaging effects on numerous tissues and organs, including the reproductive system, metabolic dysfunction, respiratory system, immune system and central nervous system. On the basis of reported studies on animals, it appears that the exposure of BPA can be carcinogenic and responsible for causing a variety of cancers like ovarian cancer, uterine cancer, prostate cancer, testicular cancer, and liver cancer. This review paper focused mainly on the current progress in BPA removal technologies within last ten years (2012–2022). This paper presents a comprehensive overview of individual removal technologies, including adsorption, photocatalysis/photodegradation, ozonation/advance oxidation, photo-fenton, membranes/nanofilters, and biodegradation, along with removal mechanisms. The extensive literature study shows that each technology has its own removal mechanism and their respective limitations in BPA treatment. In adsorption and membrane separation process, most of BPA has been treated by electrostatic interaction, hydrogen boning and π-π interations mechanism. Whereas in the degradation mechanism, O* and OH* species have played a major role in BPA removal. Some factors could alter the removal potential and efficiency of BPA removal. This review paper will provide a useful guide in providing directions for future investigation to address the problem of BPA-containing wastewater treatment.

Facile construction of Z-scheme AgBr/BiO(HCOO)0.75I0.25 photocatalyst for visible-light-driven BPA degradation: Catalytic kinetics, selectivity and mechanism

Herein, a novel AgBr/BiO(HCOO)0.75I0.25 Z-scheme photocatalyst was constructed through a facile hydrothermal and post-precipitation method for visible-light (VL) driven wastewater remediation. The 10 wt% AgBr/BiO(HCOO)0.75I0.25 composite (10%ABB) could completely decompose bisphenol A (BPA) within 25 min, and multiple coexisting inorganic anions and natural organic matters only slightly affected the BPA removal efficiency. The wonderful photocatalytic performance could attribute to the construction of Z-scheme heterojunction, which modulated the energy band, accelerated the electron transfer and also raised the redox ability of the system. Since the superoxide radicals (O2−) and non-radical pathway (1O2 and h+) were proved to be the dominating reactive species, 10%ABB/VL system exhibited a highly selective oxidation on aromatics with electron donating groups, whereas a relatively low value for organics with electron with drawing groups. By investigating the ionization potential (IP) of five representative organics, a negative correlation between IP value and reaction kinetics was reported. Moreover, the possible photocatalytic mechanism and elimination pathway were proposed via a series of photoelectrochemical analysis and LC-MS/MS. This work provides a strategy for engineering novel Bi-based photocatalyst and establishing selective oxidation system for organic contamination removal.

Degradation of bisphenol A and S in wastewater during cold atmospheric pressure plasma treatment.

Developing novel, fast and efficient ecologically benign processes for removing organic contaminants is important for the continued development of water treatment. For this reason, this study investigates the implementation of Cold Atmospheric pressure Plasma (CAP) generated in ambient air as an efficient tool for the removal of Bisphenol A (BPA) and Bisphenol S (BPS)-known endocrine disrupting compounds in water and wastewater, by monitoring degradation kinetics and its transformation products. The highest removal efficiencies of BPA (>98%) and BPS (>70%) were obtained after 480 s of CAP exposure. A pseudo-first-order kinetic revealed that BPA (-kt = 4.4 ̶ 9.0 ms-1) degrades faster than BPS (-kt = 0.4 ̶ 2.4 ms-1) and that the degradation is also time- and CAP power-dependent, while the initial concentration or matrix type had a negligible effect. This study also tentatively identified three previously reported and one novel transformation product of BPA and four novel transformation products of BPS. Their postulated structures suggested similar breakdown mechanisms, i.e., hydroxylation followed by ring cleavage. The results demonstrate that CAP technology is an effective process for the degradation of both BPA and BPS without the need for additional chemicals, indicating that CAP is a promising technology for water and wastewater remediation worthy of further investigation and optimization.

Laccase-coupled photoelectrocatalytic system for highly efficient degradation of bisphenol A

In the present work, a hybrid advanced oxidation process that combined laccase with photoelectrocatalysis (PEC) was explored for highly efficient degradation of bisphenol A (BPA). Visible light-responsive BiVO4 film electrode with good optical and photoelectrochemical properties was prepared via an electrodeposition method and employed as photoanode for PEC degradation of BPA. After laccase was facilely introduced into the PEC system, the BPA removal efficiency was significantly promoted, attributed to the synergistic effect of enzymatic catalysis and PEC processes. To obtain the optimum operation conditions, the effects of initial pH and applied bias potential were investigated systematically. Radicals trapping experiments revealed that •O2− dominated the biophotoelectrocatalytic degradation process, and the possible degradation pathway for BPA was proposed by identifying intermediates using liquid chromatography-mass spectrometry.

Mechanistic and structure investigation of the KOH activation ZIF-8 derived porous carbon as metal-free for unprecedented peroxymonosulfate activation degradation of bisphenol A

The high-performance and free secondary pollution of the catalysts are the most critical issues in the peroxymonosulfate-based advanced oxidation processes (PMS-AOPs). In this research, the KOH was used to activate ZIF-8 derived carbon materials to synthesize the NC-KOH-x (x = 700, 800, 900 °C), which was an effective metal-free PMS activator. As-prepared NC-KOH-x showed significant improvement not only pore structure and BET surface area but also CO groups, and graphite N content, which were beneficial for the adsorptive and oxidative reaction. The NC-KOH-900 as an excellent metal-free carbon-catalyst exhibited considerable reactivity for bisphenol A (BPA) removal in broad pH ranges. Almost 100% of BPA was eliminated using 9 mg NC-KOH-900, 0.5 mM PMS within 60 min. Interestingly, It was found that the BPA removal efficiency by adding PMS after saturated adsorption of NC-KOH-x was better than that by adding NC-KOH-x and PMS simultaneously. Electronic paramagnetic resonance (EPR) and quenching experiments results demonstrated that the BPA degradation relied mainly on the nonradical (1O2) pathways and the defects (ID/IG), graphitic nitrogen, pyridinic nitrogen, and CO were verified as leading catalytic sites for BPA degradation via PMS activation. Finally, degradation pathways of BPA were proposed and the Toxicity Estimation Software Tool (T.E.S.T.) result implicated that the intermediates of BPA were environmentally friendly to the microorganism and recycled in the ecosystem. The outcomes of this study illustrated the NC-KOH-x owned many merits of state-of-the-art, eco-friendly, and high-performance for great potential practical application value.

Effects of Bisphenol A Stress on Activated Sludge in Sequential Batch Reactors and Functional Recovery

This study assessed the toxic effects of bisphenol A (BPA) on the microbial community and the function of activated sludge in sequencing batch reactors (SBRs). The toxicity of BPA was mitigated through dosing sludge with Rhodococcus Req-001. BPA reduced the biomass of sludge, and the proportion of viable bacteria decreased with the aggravation of BPA pollution. BPA affected the secretion of extracellular polymeric substances (EPSs), increased the ratio of polysaccharide to protein, and deteriorated the sedimentation performance of sludge. BPA decreased the abundances of functional bacteria involved in the degradation of organic matter and water purification, including Polaromonas, Dechloromonas, and Nitrospira, and the water purification capacity of the reactor decreased. Req-001 enhanced the BPA removal efficiency by 15%, and increased ammonia nitrogen and phosphorus removal by 8.8% and 22.7%, respectively. The functional recovery ability of the sludge system and the high removal ability of Req-001 make it a promising specie for use in BPA bioremediation. This study combined the effect of BPA on activated sludge and reactor performance with the microbial community, clarified the toxic mechanism of BPA on activated sludge, and therefore provides a theoretical basis and potential solutions to help WWTPs cope with the toxic effects of BPA.