Pollutant Bisphenol Research Articles

A BODIPY-Containing Covalent Organic Framework as a Highly Porous Photosensitizer for Environmental Remediation and Pollutants Adsorption.

The direct incorporation of borondipyrromethene (BODIPY) subunits into the structural backbone of covalent organic frameworks (COFs) gives facile access to porous photosensitizers but is still a challenging task. Here, we introduceβ‑ketoenamine-linkedBDP‑TFP‑COF, which crystallizes in AA‑stacking mode withhcbtopology. A comprehensive characterization reveals high crystallinity and enhanced stability in a variety of solvents, excellentmesoporosity (SABET=1042m2g-1), broad light absorption in the visible region, and red emission upon the exfoliation of few-layer COF nanosheets. The versatility of multifunctional BODIPY-COFs is highlighted in various applications. Pollutants Bisphenol A (BPA,qmax=426mgg-1) and Methylene Blue (MB,qmax=96mgg-1) have been efficiently removed from H2O. Fluorescence quenching or enhancement of exfoliatedBDP‑TFP‑COFnanosheets have been utilized for dual-mode sensing of MB or NEt3, respectively. Ultimately, the photosensitizing effect of the BODIPY units is retained in the COF. Thus,BPD‑TFP‑COFwas established as a metal-free triplet photosensitizer, which efficiently oxidized a mustard gas simulant under visible light irradiation.

Mn-periodate complex in situ formed at Mn-N coordinate site in Mn-doped g-C3N5 for efficient and rapid water purification

Aggravating organic pollutants in water matrices have led to a great challenge for the safety of ecosystems and human health. Periodate-based advanced oxidation processes (PI-AOPs) using Mn-based catalysts with Mn-N coordinates formed by doping Mn to activate PI have gained much attention as they address potential challenges for water purification. However, inefficient utilization efficiency of Mn atoms and the limited Mn-N coordinates in the heterogeneous system remains two formidable challenges. Herein, we first propose exploiting a nitrogen-rich carbonaceous material g-C3N5 as Mn doping parent material to form Mn-N coordinates to activate PI (Mn-doped g-C3N5/PI) for efficient and rapid degradation of organic pollutant Bisphenol F (BPF). Mn-doped g-C3N5/PI exhibits rapid degradation efficiency for BPF (100 % removal ratio in only 5 min) with the rate constant two orders of magnitude higher (149 times) than the g-C3N5/PI. This strategy exhibits the following novelties: (i) N coordination sites employed for the doping of Mn to form Mn-N coordinate bonds for activating PI are directly provided by g-C3N5 rather than by external doping and (ii) abundant N coordination sites in g-C3N5 substantially augment the utilization efficiency of Mn, paving the way for efficient rapid water purification.

Cd2+ enhancing the bromination of bisphenol A in Brassica chinensis L.: Pathways and mechanisms

Traditional heavy metal pollution, such as cadmium, impacts the transformation and risks of bisphenol pollutants (like bisphenol A, BPA), in plants, especially due to the ubiquitous presence of bromide ion. Although it has been discovered that the bromination of phenolic pollutants occurs in plants, thereby increasing the associated risks, the influence and mechanisms of bromination under complex contamination conditions involving both heavy metals and phenolic compounds remain poorly understood. This study addresses the issue by exposing Brassica chinensis L. to cadmium ion (Cd2+, 25–100 μM), with the hydroponic solution containing BPA (15 mg/L) and bromide ion (0.5 mM) in this work. It was observed that Cd2+ primarily enhanced the bromination of BPA by elevating the levels of reactive oxygen species (ROS) and the activity of peroxidase (POD) in Brassica chinensis L. The variety of bromination products within Brassica chinensis L. increased as the concentration of Cd2+ rose from 25 to 100 μM. The substitution positions of bromine were determined using Gaussian calculations and mass spectrometry analysis. The toxicity of bromination products derived from BPA was observed to increase based on Ecological Structure-Activity Relationships analysis and HepG2 cytotoxicity assays. This study provides new insights into the risks and health hazards associated with cadmium pollution, particularly its role in enhancing the bromination of bisphenol pollutants in plants.

Analysis of environmental pollutant Bisphenol F elicited prostate injury targets and underlying mechanisms through network toxicology, molecular docking, and multi-level bioinformatics data integration

Bisphenol F (BPF) has gained prominence as an alternative to bisphenol A (BPA) in various manufacturing applications, yet being detected in diverse environments and posed potential public health risk. This research aims to elucidate the putative toxic targets and underlying molecular mechanisms of prostate injury induced by exposure to BPF through multi-level bioinformatics data, integrating network toxicology and molecular docking. Systematically leveraging multilevel databases, we determined 276 targets related to BPF and prostate injury. Subsequent screenings through STRING and Cytoscape tool highlighted 27 key targets, including BCL2, HSP90AA1, MAPK3, ESR1, and CASP3. GO and KEGG enrichment analyses demonstrated enrichment of targets involved in apoptosis, abnormal hormonal activities, as well as cancer-related signal transduction cascades, ligand-receptor interaction networks, and endocrine system signaling pathways. Molecular docking simulations conducted via Autodock corroborated high-affinity binding interaction between BPF and key targets. The results indicate that BPF exposure can contribute to the initiation and progression of prostate cancer and prostatic hyperplastic by modulating apoptosis and proliferation, altering nerve function in blood vessel endothelial cells, and disrupting androgen metabolism. This study offers theoretical underpinnings for comprehending the molecular mechanisms implicated in BPF-elicited prostatic toxicity, while concomitantly establishing foundational framework for the development of prophylactic and therapeutic strategies for prostatic injuries related to polycarbonate and epoxy resin plastics incorporated with BPF, as well as environments afflicted by elevated levels of these compounds.

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.

Functionalized Chitosan and Alginate Composite Hydrogel-Immobilized Laccase with Sustainable Biocatalysts for the Effective Removal of Organic Pollutant Bisphenol A

The immobilization of enzymes is an important strategy to improve their stability and reusability. Enzyme immobilization technology has broad application prospects in biotechnology, biochemistry, environmental remediation, and other fields. In this study, composites of chitosan (CS) and sodium alginate (SA) with Cu2+ forming a double-network crosslinked structure of hydrogels were prepared and used for the immobilization of laccase. Fourier infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy tests revealed that laccase molecules were immobilized on the composite hydrogel surface by a covalent bonding method. Compared to free laccase, the pH, temperature, and storage stability of the immobilized laccase were markedly improved. In addition, the immobilized laccase could be easily separated from the reaction system and reused, and it maintained 81.6% of its initial viability after six cycles of use. Bisphenol A (BPA) in polluted water was efficiently degraded using immobilized laccase, and the factors affecting the degradation efficiency were analyzed. Under the optimal conditions, the BPA removal was greater than 82%, and the addition of a small amount of ABTS had a significant effect on BPA degradation, with a removal rate of up to 99.1%. Experimental results indicated that immobilized laccases had enormous potential in actual industrial applications.

Activation of periodate by biocarbon-supported multiple modified nanoscale iron for the degradation of bisphenol A in high-temperature aqueous solution.

As reported, the persistent toxic and harmful pollutant bisphenol A (BPA) from industrial emissions has been consistently found in aquatic environments inhabited by humans. Periodate (PI)-based advanced oxidation processes (AOPs) have been employed to degrade BPA, although activating PI proves more challenging compared to other oxidants. A novel nano iron metal catalyst, sulfided nanoscale iron-nickel bimetallic nanoparticle supported on biocarbon (S-(nFe0-Ni)/BC) was synthesized and utilized to activate PI for the removal of BPA. The morphology, structure, and composition of S-(nFe0-Ni)/BC were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy dispersive spectrometer (SEM-EDS), and fourier-transform infrared spectrum (FTIR). The catalyst demonstrates an excellent ability to activate PI, achieving a BPA removal efficacy of 86.4%, accompanied by a 33% reduction in total organic carbon (TOC) in the {S-(nFe0-Ni)/BC}/PI system. BPA degradation exhibited a significant change at the 5-min mark. In the first stage (0-5min), nonlinear dynamic fitting research, combined with scavenging experiments, unveiled the competitive degradation of pollutants primarily driven by iodate radical ( ), singlet oxygen , and hydroxyl radical ( ). The competitive dynamics aligned with the ExpAssoc model. The contribution rates of different active species during the second stage (5-120min) were calculated. The contributions of main species to BPA removal follow the order of > > throughout the entire process. The influence of various parameters, such as the dosage of S-(nFe0-Ni)/BC, initial PI concentration, BPA concentration, pH, temperature, and the presence of coexisting anions, was also examined. Finally, a plausible reaction mechanism in the system is proposed, suggesting that the {S-(nFe0-Ni)/BC}/PI system involves a heterogeneous synergistic reaction occurring primarily on the surface of S-(nFe0-Ni)/BC. Therefore, this study proposes a promising approach for PI-based AOPs to degrade organic pollutants, aiming to mitigate the irreversible harm caused by such pollutants to organisms and the environment.

A Novel Magnetic β-Cyclodextrin-Modified Graphene Oxide and Chitosan Composite as an Adsorbent for Trace Extraction of Four Bisphenol Pollutants from Environmental Water Samples and Food Samples.

In this study, a novel functionalized magnetic composite (MNCGC) for magnetic solid-phase extraction of bisphenols from environmental and food samples was developed, featuring a multistep synthesis with Fe3O4, chitosan, graphene oxide, and β-cyclodextrin, crosslinked by glutaraldehyde. Characterization confirmed its advantageous morphology, intact crystal structure of the magnetic core, specific surface area, and magnetization, enabling efficient adsorption and separation via an external magnetic field. The optimized MSPE-HPLC-FLD method demonstrated excellent sensitivity, linearity, and recovery rates exceeding 80% for bisphenol pollutants, validating the method's effectiveness in enriching and detecting trace levels of bisphenols in complex matrices. This approach offers a new avenue for analyzing multiple bisphenol residues, with successful application to environmental water and food samples, showing high recovery rates.

Cyanidin Ameliorates Bisphenol A-Induced Alzheimer's Disease Pathology by Restoring Wnt/β-Catenin Signaling Cascade: an In Vitro Study.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder causing memory loss and cognitive decline, linked to amyloid-beta (Aβ) plaques and hyperphosphorylated tau protein accumulation in the brain. Environmental pollutant bisphenol A (BPA) has been implicated in AD pathology due to its neurotoxic effects. This study aims to evaluate cyanidin from flower bracts of Musa acuminata Colla (red variety; AAA group) for its neuroprotective properties against BPA-induced AD pathology. The extraction of cyanidin was optimized using 70% ethanol in acidified water, showing promising anti-acetylcholinesterase activity. Cyanidin was effectively purified from the resultant extract and characterized using spectroscopic techniques. Two gradient doses of cyanidin (90 and 10µg/ml) were determined based on cell viability assay. The role of cyanidin in promoting nerve growth and differentiation was assessed in PC12 cells for up to 72h. A discernible and statistically significant difference was assessed in neurite extension at both doses at 72h, followed by pre-treatment with cyanidin. BPA stimulation significantly increased the p-tau expression compared to the control (p < 0.0001). Pre-treatment with cyanidin reduced the tau expression; however, a significant difference was observed compared to control cells (p = 0.0003). Cyanidin significantly enhanced the mRNA expression of Wnt3a (p < 0.0001), β-catenin (p = 0.0004), and NeuroD1 (p = 0.0289), and decreased the expression of WIF1(p = 0.0040) and DKK1 (p < 0.0001), which are Wnt antagonist when compared to cells stimulated with BPA. Conclusively, our finding suggests that cyanidin could agonize nerve growth factor and promote neuronal differentiation, reduce tau-hyperphosphorylation by restoring the Wnt/β-catenin signaling cascade, and thereby render its neuroprotective potential against BPA-induced AD pathology.

Design of magnetic multivariate metal–organic framework for high-efficient adsorption and rapid magnetic separation of bisphenol pollutants

Herein, a magnetic multivariate metal–organic framework (MTV-MOF) named as 95.7 %BTB/MOF-525@Fe3O4 was synthesized by one-pot mixing ligand strategy. The magnetic MTV-MOF exhibited large specific surface area (320 m2·g−1) and high porosity. The 95.7 %BTB/MOF-525@Fe3O4 was used as sorbent for extraction and enrichment of bisphenol pollutants (BPs). The experimental results demonstrated that adsorption kinetics and isotherms conform to pseudo-second-order model and Langmuir model. The maximum adsorption capacities for bisphenol F, bisphenol A, bisphenol B, bisphenol AF were 275.1, 233.6, 302.1 and 277.2 mg·g−1, respectively. With 95.7 %BTB/MOF-525@Fe3O4 as sorbent, the magnetic solid phase extraction coupling HPLC was used to detect trace BPs in environmental water. The limits of detection were determined as between 0.067 and 0.167 ng·mL−1. The enrichment factors were in the range of 242–295. The recoveries were ranged from 79.4 to 103 % with relative standard deviations not higher than 8.85 %. In addition, the recovery rate of sorbent remained above 80 % after 21 times of reuse. The work provides an effective material for extraction and removal of BPs in the environment.

Microbial-assisted synthesis of Schwertmannite@g-C3N4 composite for bisphenol AF degradation through visible light-driven peroxymonosulfate activation

Iron-based materials are considered as excellent environmental catalysts due to the characteristics of abundant reserves, low biological toxicities, and rich chemical states for redox reactions. The sea urchin-like microscopic morphology of biosynthesized schwertmannite (Sch) with abundant surface active sites is beneficial to the environmental catalytic process. In this study, flake-type graphitic carbon nitride (g-C3N4) was introduced into the mineralization process of Acidithiobacillus ferrooxidans (A. ferrooxidans) as the additive to regulate the biomineralization process and directly control the morphology and structure of iron-based minerals. Schwertmannite@g-C3N4 composites (Sch-CN) with a desired structure of sea urchin-like well-dispersed biosynthesized Sch loaded on flaky g-C3N4 were successfully prepared by A. ferrooxidans-induced biomineralization process. A Light/Peroxymonosulfate/Sch-CN catalytic system was constructed to degrade the model organic pollutant bisphenol AF (BPAF). The system combined two advanced oxidation systems of photocatalysis and peroxymonosulfate (PMS) activation, showing excellent catalytic degradation ability and wide pH adaptability. In addition, the system was also applicable to the catalytic degradation of other bisphenol pollutants. The mechanism was deduced by the results of quenching experiments and electron paramagnetic resonance (EPR) measurements. Several degradation intermediate products were identified and the probable degradation pathways of BPAF were proposed. The toxicity activities of BPAF solution towards Raphidocelis subcapitata were largely reduced after treatment by the photochemical process. Overall, the Light/PMS/Sch-CN system has great potential in treating bisphenol wastewater.

Bisphenol A accelerates the vascular complications in patients with Type 2 diabetes mellitus through vascular calcification-a molecular approach.

Environmental pollutant Bisphenol A (BPA) strongly interacts with insulin resistance, which leads to type 2 diabetes mellitus (T2DM). Uncontrolled glucose levels in both blood and urine develops vascular complications in T2DM patients. However, glucose-controlled diabetic patients are also affected by vascular complications due to vascular calcification, and there is a lack of clinically relevant data on BPA levels available in patients with T2DM-associated vascular complications due to vascular calcification. Therefore, we measured BPA levels in T2DM-associated vascular complications and correlated systemic BPA levels with vascular calcification-related gene expression. This study included 120 participants with T2DM and its associated vascular complications. Serum and urinary BPA were estimated using an ELISA kit, and gene expression of the study participants in peripheral blood mononuclear cells (PBMCs) was studied with quantitative real-time PCR. Serum and urinary BPA levels were higher in T2DM and its associated vascular complications with CVD and DN patients compared to control. Both Serum and urinary BPA had higher significance with Sirt1 (p < 0.001, p < 0.001), Runx2 (p < 0.01, p < 0.001) and IL-1beta (p < 0.001, p < 0.02) gene expression in the study groups, but, TNF-alpha significant with Serum BPA (p < 0.04), not urinary BPA (p < 0.31). BPA levels were positively correlated with lower Sirt1 and increased Runx2 in T2DM-associated vascular complications patients. Also, higher expression of IL-1beta and TNF-alpha was observed in T2DM-associated vascular complications patients. Our study is the first to associate BPA levels with vascular calcification in patients with T2DM and its associated vascular complications.

Hepatoprotective effect of Artemisia Argyi essential oil on bisphenol A-induced hepatotoxicity via inhibition of ferroptosis in mice.

The environmental pollutant bisphenol A (BPA), used in the manufacture of plastic packaging materials for various diets, is widely distributed in the environment and causes severe hepatotoxicity by inducing oxidative stress. Artemisia argyi essential oil (AAEO), a volatile oil component isolated from Artemisia argyi H.Lév. & Vaniot, has pharmacological effects, especially for hepatoprotective actions. However, the potential effect of AAEO in BPA induced hepatotoxicity has not been characterized. First, we analyzed the chemical composition in AAEO by gas chromatography-mass spectrometry. Herein, we investigated the effect of AAEO on hepatic metabolic changes in mice exposed to BPA. Results showed that compared with the BPA group, AAEO could reduce the level of liver function enzymes in BPA mice serum, and ameliorate hepatic lesions and fibrosis. Additionally, 20 differential metabolites screened by metabolomics were mainly involved in the reprogramming of glutathione metabolism, purine metabolism, and polyunsaturated fatty acid synthesis. Moreover, AAEO could reduce hepatic ferroptosis induced by BPA, as demonstrated by reducing xanthine oxidase activity, up-regulating the activities of glutathione peroxidase 4 (GPX4), superoxide dismutase, and catalase and the expression of SLC7A11 to promote the glutathione synthetic, while inhibiting transferrin receptor 1 (TFR1) expression to reduce the accumulation of Fe2+ in cells. Therefore, our study identified AAEO as a hepatic protectant against BPA-induced hepatotoxicity by reversing the occurrence of ferroptosis.

Dopant-driven recombination delay and ROS enhancement in nanoporous Cd1-xCuxS heterogeneous photocatalyst for the degradation of DR-23 dye under visible light irradiation

Developing an efficient heterogeneous photocatalyst for environmental remediation and treatment strategies using visible light harvesting processes is promising but challenging. Herein, Cd1-xCuxS materials have been synthesized and characterized by precise analytical tools. Cd1-xCuxS materials exhibited excellent photocatalytic activity for direct Red 23 (DR-23) dye degradation in visible light irradiation. The operational parameters, like dopant concentration, photocatalyst dose, pH, and initial concentration of dye were investigated during the process. The photocatalytic degradation process follows pseudo-first-order kinetics. As compared to other tested materials, 5% Cu doped CdS material revealed superior photocatalytic performance for the degradation of DR-23 (k = 13.96 × 10−3 min−1). Transient absorption spectroscopy, EIS, PL, and transient photocurrent indicated that adding copper to the CdS matrix improved the separation of photo-generated charge carriers by lowering the recombination rate. Spin-trapping experiments recognized the photodegradation primarily based on secondary redox products, i.e., hydroxyl and superoxide radicals. According to by Mott-Schottky curves, photocatalytic mechanism and photo-generated charge carrier density were elucidated regarding dopant-induced valence and conduction bands shifting. Thermodynamic probability of radical formation in line with the altered redox potentials by Cu doping has been discussed in the mechanism. The identification of intermediates by mass spectrometry study also showed a plausible breakdown mechanism for DR-23. Moreover, samples treated with nanophotocatalyst displayed excellent results when tested for water quality metrics such as DO, TDS, BOD, and COD. Developed nanophotocatalyst shows high recyclability with superior heterogeneous nature. 5% Cu-doped CdS also exhibit strong photocatalytic activity for the degradation of colourless pollutant bisphenol A (BPA) under visible light (k = 8.45 × 10−3 min−1). The results of this study offer exciting opportunities to alter semiconductors' electronic band structures for visible-light-induced photocatalytic activity for wastewater treatment.

Simple high-performance liquid chromatography-ultraviolet method for simultaneous separation and detection of 14 bisphenol pollutants in building materials.

A high-performance liquid chromatography-ultraviolet method was developed for rapidly and simultaneously analyzing novel and typical bisphenols in building materials, including bisphenol S, diphenolic acid, bisphenol F, bisphenol E, bisphenol A, bisphenol B, bisphenol AF, bisphenol AP, bisphenol C, bisphenol FL, bisphenol Z, bisphenol BP, bisphenol M, and bisphenol P. By using a Kromasil 100-5 C18 column, these bisphenols were completely separated in 40min via gradually increasing the concentration of methanol in the mobile phase from 45 to 80% during the elution process. In particular, this method achieved the synchronous analysis of bisphenol S, diphenolic acid, bisphenol FL, bisphenol BP, and bisphenol M through HPLC, which were difficult to separate and had to be identified and detected through mass spectrometry. The limits of detection of the method ranged from 0.002 to 0.040mg/L for these 14 bisphenols, with a precision of less than 4.9% (n=7, c=0.05mg/L). The analytical results for five types of building materials (phenolic, epoxy, polycarbonate, polyester, and polysulfone resins) indicated that the proposed method is appropriated for the rapid measurement of bisphenols in real samples.

Ultra-rapid and long-lasting activation of peracetic acid by Cu-Co spinel oxides for eliminating organic contamination: Role of radical and non-radical catalytic oxidation

Peracetic acid (PAA)-based advanced oxidation processes (AOPs) have attracted considerable attention in organic wastewater purification for yielding reactive oxidative species (ROS) with high performance and long lifetime. However, searching for economical and stable activators is a huge obstacle. In this work, we used a facile second transition metal embedding approach to prepare bimetallic spinel oxides (CuCo2O4) through embedding Cu to Co3O4, which was used as the activator for the rapid and durable activation of PAA to remove model organic pollutant bisphenol A (BPA). Under identical conditions, the rate constant of the constructed CuCo2O4/PAA system (0.0412 min−1) was 21.7 and 3.3 times that of CuO/PAA (0.0019 min−1) and Co3O4/PAA (0.0125 min−1) system alone, respectively. The CuCo2O4/PAA system had better resistance to co-existed ions and natural organic compounds. Meanwhile, the as-prepared materials maintained excellent stability during four-cycle tests and gradient experiments, confirming their perfect application potential. Combining the capture experiments, chemical probe, electron paramagnetic resonance, and theoretical calculations, the singlet oxygen (1O2) and organic radicals (R-O•, e.g., CH3C(O)O• and CH3C(O)OO•) were validated to be the dominant ROS. The density functional theory (DFT) calculations indicated that both BPA and PAA were more easily adsorbed onto the CuCo2O4 surface and bimetallic internal cycle opening was more likely to occur, which accelerated the PAA activation and the contaminants decomposition for rapid electron supply. This study provides new ideas for the design of alternative alloy oxides as efficient PAA activators, and further broadens the applicability of non-homogeneous PAA-based AOPs in wastewater decontamination.

MgFeAl-layered double oxides supported on hollow carbon microsphere composited with carbonitride for peroxymonosulfate activation to efficiently decontaminate organic pollutants under high salinity conditions

Layered double oxides (LDOs)-based materials have received widespread interests in advanced oxidation processes (AOPs) due to their adjustable layered structure and superior stability, while the evolution of LDOs as high-efficiency catalysts is hindered by their easy aggregation and weak conductivity. Here, we report a novel strategy to simultaneously overcome the agglomeration and poor conductivity of LDOs via calcining the mixture of polystyrene microsphere supported MgFeAl-LDH and urea, in which the introduction of hollow structure and nitrogen-doped carbon composition can not only significantly increase the specific surface area to expose more active sites, but also remarkably improve conductivity to accelerate electron transfer, giving rise to the outstanding performance of the final catalyst (HC@LDH-CN) in peroxymonosulfate (PMS) activation. Systematic characterizations and experiments further confirm that O2•− radicals play the dominant role in HC@LDO-CN/PMS system, which can altogether remove the model pollutant bisphenol A (BPA) in 10 min with kobs to be 0.403 min−1. Particularly, the HC@LDO-CN still maintains extraordinary catalytic activity for BPA degradation in an extremely high-salt wastewater (100 mM). Our strategy thereby provides an innovative notion to synthesize efficient PMS-based catalysts for organic pollutant degradation in high saline water.

Advanced oxidation via the synergy of C-defective/ C–O band modified ultrathin porous g-C3N4 and PMS for efficient photothermal degradation of bisphenol pollutants and lignin derivatives

This work uses thermal polymerization of urea nitrate, oxyacetic acid and urea as the raw material to prepare ultra-thin porous carbon nitride with carbon defects and C–O band (OA-UN-CN). Density functional theory (DFT) calculations showed OA-UN-CN had narrower band gap, faster electron transport and a new internal construction electric field. Additionally, the prepared OA-UN-CN significantly enhanced photocatalytic activation of peroxymonosulfate (PMS) due to enhanced light absorption performance and faster electron overflow. As the result, the OA-UN-CN/PMS could entirely degrade bisphenol A (BPA) within 30 min, where the photodegradation rate was 81.8 and 7.9 times higher than that of g-C3N4 and OA-UN-CN, respectively. Beyond, the OA-UN-CN/PMS could likewise degrade other bisphenol pollutants and sodium lignosulfonate efficiently. We suggested possible photocatalytic degradation pathways accordingly and explored the toxicity of its degradation products. This work provides a new idea on the development of advanced photocatalytic oxidation processes for the treatment of bisphenol pollutants and lignin derivatives, via a metal-free photothermal-catalyst.

The Kinetic Simulation of Persulfate Activation by Nano-Ferrosoferric Oxide

Nano-ferrosoferric-oxide (nFe3O4)-activated persulfate (PS) technology was used to remove pollutant bisphenol A (BPA) in water. The effects of nFe3O4 concentration, PS concentration, BPA concentration, temperature, and pH were investigated in terms of the degradation effect of BPA. The results showed that more PS dosage and lower BPA concentration could improve the degradation rate of BPA. When other conditions were constant, the degradation rate of BPA increased with the increase of temperature. When pH was 5, the degradation rate of BPA was the highest. When the initial PS concentration and pH were changed, the degradation rate of BPA was consistent with the pseudo-secondary kinetic model. Under other conditions, the degradation rate of BPA was consistent with the pseudo-first-order kinetic model. Sulfate radical (SO4•−) produced by nFe3O4/PS system was mainly responsible for the degradation of BPA.

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.