Tc Concentration Research Articles

Experimental and Kinetic Simulations of Technetium-Catalyzed Hydrazine Oxidation in Nitric Acid Solution

The catalytic reaction of Tc plays a significant role in the chemical separation process during spent fuel reprocessing. However, few studies have been conducted on the chemical reaction mechanism between Tc and hydrazine. Moreover, the instability of Tc(V) and Tc(VI) makes their measurement difficult, rendering many aspects of the reaction process and mechanism unclear. This study investigates the catalytic reaction between Tc and hydrazine in a nitric acid solution. To this end, we obtained the kinetic laws of the reaction under various conditions of acidity, hydrazine concentration, and Tc concentration by monitoring the concentrations of hydrazine and Tc(VII) over time. The reaction kinetics model demonstrated that numerical simulations could effectively predict the reaction process. Results indicated that hydrazine promotes the reduction of Tc(VII) to Tc(IV), constituting the basis for establishing the Tc(IV, V, VI, VII) catalytic cycle. Among these, Tc(V) and Tc(VI) were important active intermediates and the main consumers of hydrazine. The research results may be useful for actinide separation processes based on valence control.

Continuous and funnel-gate configurations of a permeable reactive barrier for reclamation of groundwater laden with tetracycline: experimental and simulation approaches

The current study investigates removing tetracycline from water using batch, column, and tank experiments with statistical modelling using ANN for continuous tests. An artificial neural network (ANN) using the Levenberg-Marquardt back-propagation (LMA) training algorithm is constructed to compare the effectiveness of Tetracycline removal from aqueous solution using the sorption technique with prepared adsorbent. Several characterization analyses XRD, FT-IR, and SEM are employed for prepared Brownmillerite (Ca2Fe2O5)–Na alginate beads. The operating conditions of batch tests involved, contact time (0.1–3 h), initial of tetracycline (Co) of (100–250 mg/L), pH (3–12), agitation speed (50–250) rpm and dosage of adsorbent (0.2–1.2 g/50 mL). The outcomes of experiments have demonstrated that the optimum conditions for the batch test to achieve the maximum adsorbent capacity (qmax =7.845 mg/g) are achieved at pH 7, contact time 1.5 h, adsorbent dose 1.2 g/50 mL, agitation speed of 200 rpm, and initial concentration of TC 100 mg/L. Minimum mean square error (MSE) values of 7.09E-04 for 30 hidden neurons and 0.0029 for 59 hidden neurons in the 1D and 2D systems are accomplished, respectively. The artificial neural network model has exhibited excellent performance with correlation coefficients exceeding 0.980 for the operating variables, demonstrating its accuracy and effectiveness in predicting the experimental outcomes. According to sensitivity analysis, the influential parameter in the column test (1D) is the flow rate (mL/min), with a relative importance of 32.769%. However, in the tank test (2D), time (day) is signified as an influential parameter with a relative importance of 31.207%.

Enhanced tetracycline degradation using UV/Fenton/titanium dioxide (TiO2) hybrid process

TiO2 was synthesized using neem leaf extract as soft bio template and Titanium (IV) isopropoxide (C12H28O4Ti) as a precursor. Morphological properties revealed well crystalline anatase phase of 19.8 nm size for the biotemplated TiO2 (B-TiO2) compared to 24.2 nm of the non-templated TiO2 (N-TiO2). TEM revealed a nano sheet-like structure for the B-TiO2 and it exhibited a larger SBET surface area (35.45 m2/g) and average pore diameter (5.74 nm) compared to the N-TiO2 (19.72 m2/g) and (2.028 nm) respectively. XPS results showed carbon peaks indicating small bio-carbon doping on the lattice of the TiO2, which can promote charge transfer upon light excitation during photocatalyst reactions. The results of the photoluminescence study indicate reduced PL intensity of the B-TiO2 which signifies the suppression of recombination of charge carriers or electron-hole pairs in the B-TiO2. The photocatalytic activity was assessed by the photodegradation of tetracycline (TC: 50 mg/L) under UV irradiation and the B-TiO2 was employed as a photocatalyst. In the absence of UV light, B-TiO2 catalyst slightly removed TC due to limited active species. However, the degradation of TC increases significantly due to the synergetic effect of the UV/Fenton/B-TiO2 hybrid system. Moreover, the biotemplate exposes the surface of the B-TiO2 which permits improved utilization of all surface-active sites. Quenching experiments were also performed via scavengers, results confirmed that hydroxyl radicals, superoxide radicals and electrons are the key reactive species in the TC degradation. The effects of influential parameters such as B-TiO2 dosage, TC concentration, pH, and Fe2+ to H2O2 molar ratio were also investigated, in addition, the catalyst is stable, as it achieved > 80 % TC degradation efficiency after five reuse cycles.

Exploring the formation of S-scheme heterojunctions in CuFe2O4/Bi2MoO6 porous cubes for photocatalytic removal of tetracycline

Exploring highly active and noble metal-free photocatalysts for the efficient photocatalytic degradation of antibiotics is of great significance. The CuFe2O4 nanostructured cube is synthesized by using a self-sacrificial template strategy, and two-dimensional Bi2MoO6 nanosheets are grown on the surface of CuFe2O4 through a solvothermal method to construct CuFe2O4/Bi2MoO6 S-scheme heterostructure. The CuFe2O4/Bi2MoO6 composite material exhibits eminent photocatalytic activity for the degradation of TC under simulated sunlight, with the optimal ratio CFO/BMO-2 achieving a degradation rate of 98.54 % within 30 min (initial concentration of TC: 50 mg L−1). In addition, CFO/BMO-2 also has excellent magnetic recyclability and cycling ability. Rice cultivation tests demonstrate that the biotoxicity of TC is effectively removed. Density functional theory calculations and in-situ irradiated X-ray spectroscopy deeply reveal the mechanisms of charge separation and transfer of S-scheme heterojunctions in CuFe2O4/Bi2MoO6. The construction of S-scheme heterojunctions promotes the separation of photo-induced charge carriers and improves photocatalytic degradation performance by retaining holes and electrons with strong redox ability. The work provides a practicable method for constructing efficient spinel photocatalysts to drive wastewater treatment reactions, and the constructed magnetically recyclable photocatalysts have certain practical application potential.

Enhanced removal of tetracycline by vitamin C-modified cow manure biochar in water

Vitamin C (VC), due to its chemical properties, can provide more oxygen-containing functional groups such as hydroxyl groups for biochar (BC), which promotes the adsorption of tetracycline on biochar. Therefore, in this study, cow dung biochar (CDBC) was modified with VC and VC-modified CDBC (CDBC-VC) was synthesized. The modified biochar was characterized and related factors, adsorption kinetics, isotherms and adsorption mechanisms were investigated. Adsorption kinetics indicate a fast rate of adsorption. The adsorption isotherms showed that the maximum adsorption capacity was 31.72 mg/g (CDBC) and 50.90 mg/g (CDBC-VC), respectively, and the adsorption process was inhomogeneous with multiple molecular layers and the adsorbent has a higher affinity. Mechanistic studies showed that hydrogen bonding interactions, π-π electron donor-acceptor interactions, hydrophobic interactions, and electrostatic interactions were the key to the adsorption process. The analysis of adsorbent regeneration showed that CDBC-VC had good adsorption performance. CDBC and CDBC-VC showed the best performance in simulated industrial wastewater with removal rates of 78.81% and 93.69%. The adsorption mechanism was comprehensively analyzed using six machine learning models. The extreme gradient boosting model gave the best fit. Analysis of the weights of the input variables for predicting adsorption efficiency showed that the ratio of initial TC concentration to BC dosage (29.8%), specific surface area (23%), isoelectric point (8.8%), and ash content (7.7%) had a significant effect on the predicted results.

Enhanced Fenton Degradation of Tetracycline over Cerium-Doped MIL88-A/g-C3N4: Catalytic Performance and Mechanism.

Since enormous amounts of antibiotics are consumed daily by millions of patients all over the world, tons of pharmaceutical residuals reach aquatic bodies. Accordingly, our study adopted the Fenton catalytic degradation approach to conquer such detrimental pollutants. (Ce0.33Fe) MIL-88A was fabricated by the hydrothermal method; then, it was supported on the surface of g-C3N4 sheets using the post-synthetic approach to yield a heterogeneous Fenton-like (Ce0.33Fe) MIL-88A/10%g-C3N4 catalyst for degrading the tetracycline hydrochloride drug. The physicochemical characteristics of the catalyst were analyzed using FT-IR, SEM-EDX, XRD, BET, SEM, and XPS. The pH level, the H2O2 concentration, the reaction temperature, the catalyst dose, and the initial TC concentration were all examined as influencing factors of TC degradation efficiency. Approximately 92.44% of the TC was degraded within 100 min under optimal conditions: pH = 7, catalyst dosage = 0.01 g, H2O2 concentration = 100 mg/L, temperature = 25 °C, and TC concentration = 50 mg/L. It is noteworthy that the practical outcomes revealed how the Fenton-like process and adsorption work together. The degradation data were well-inspected by first-order and second-order models to define the reaction rate. The synergistic interaction between the (Ce0.33Fe) MIL-88A/10%g-C3N4 components produces a continuous redox cycle of two active metal species and the electron-rich source of g-C3N4. The quenching test demonstrates that •OH is the primary active species for degrading TC in the H2O2-(Ce0.33Fe) MIL-88A/10%g-C3N4 system. The GC-MS spectrum elucidates the yielded intermediates from degrading the TC molecules.

Novel Fe2O3/Bi2O3/CeO2 heterojunction photocatalyst for wastewater treatment: Characterization, photocatalytic performance and mechanism study

A novel ternary Fe2O3/Bi2O3/CeO2 (FeB/CeO2) heterojunction nanocomposite with different Fe2O3/Bi2O3 amounts on CeO2 (5, 10, 20, 30 and 40 wt%) was synthesized through a simple wet impregnation process. The properties of the synthesized nanocomposite were validated thorough XPS, XRD, FE-SEM, TEM, and EDS-Mapping analyses. This photocatalyst exhibited exceptional efficiency in the of Tetracycline’s (TC) photodegradation in comparison to individual Fe2O3, Bi2O3, and CeO2. The effect of Fe2O3/Bi2O3 loading on CeO2 and the influence of operational factors on TC decomposition including photocatalyst dosage (0.05–0.2 g/L), TC concentration (10–40 mg/L), and pH (1–11) were examined with the optimal conditions yielding an experimental degradation efficiency of 99.35 %. Moreover, scavenger tests showed that O2− and OH radicals served as the main oxidative radical species. The study further delved into proposing potential degradation pathways of TC in accordance with liquid chromatography tandem-mass spectrometry analysis. Notably, the stability of the synthesized photocatalyst was assessed through five degradation cycles, affirming its sustained effectiveness.

Assessing the Impact of Pomegranate Juice on Liver Tissue in Male Rats Exposed to a Commercial Energy Drink

The current study was designed to investigate the effect of pomegranate juice on some biochemical and histological variables resulting from dosing male rats with the energy drink Red Bull. In this study, 28 white male rats were used, divided into four groups, each involving seven animals, according to the following: G1 was given a physiological solution (5 ml/kg) and a standard diet for 120 days; G2 was given a dose of the energy drink Red Bull (volume 1 ml per 100 g); G3 was given pomegranate juice (5 ml/kg) first; then Red Bull; and G4 was given Red Bull first; and after six weeks, he was given pomegranate juice. The results showed that Red Bull consumption significantly elevated RBS, AST, ALT, TC, and TG levels. Pomegranate juice has the ability to reduce the concentration of RBS, AST, ALT, TC, and TG. Histological changes in the liver of animals that were given the Red Bull energy drink were represented by congestion of the central vein, degeneration, and necrosis of liver cells, with severe infiltration of inflammatory cells and a thick wall of the central vein (TW), as well as amyloid (AM) deposition, compared to the negative control group. The results of the histological examination showed that pomegranate juice could repair cellular tissue in the liver and make it similar to the tissue of a control normal group, denoting the possibility of using it in the diet and in treating atherosclerosis and heart disease. Keywords: Pomegranate juice, liver, rats, energy drink, rat model, atherosclerosis, heart disease.

Purple Sweet Potato Extract and Aerobic Exercise Reduce Lipid Profiles in Hyperlipidemic Rats Model

Obesity and dyslipidemia are the major risk factors for cardiovascular disease. It has been shown that dietary supplementation combined with exercise at appropriate intensity improves lipid profile and reduces the risk of cardiovascular disease. This study investigates the effect of purple sweet potato extract and swimming training on the lipid profile of a hyperlipidemic rat model. Twenty-five male Wistar rats were grouped into standard diet and high-fat diet and given their respective diet for two weeks. Afterward, they were randomly divided into five weight-matched groups; normal control (C; n=5), high-fat diet (HF; n=5), exercise (E; n=5), purple sweet potato extract (PSP; n=5), and exercise combined with purple sweet potato extract (EPSP; n=5). Purple sweet potato extract was given 100 mg/day through oral gavage for three weeks. Swimming exercise was performed for 30 minutes/day, five days a week, for three weeks at an intensity of 6% of body weight. At the end of the experimental period, intracardiac blood samples were drawn to measure lipid profiles. Data analysis technique using a one-way ANOVA test with a significant level of 5%. The findings revealed that the concentration of TC and LDL was highest in HF. The combination of exercise and purple sweet potato extract significantly reduced LDL and increased HDL levels compared to exercise or PSP alone (p ≤ 0.05). It indicates that purple sweet potato extract combined with swimming exercise is shown to be effective in improving lipid profiles in hyperlipidemic rat models. Keyword: Aerobic exercise, hyperlipidemia, lipid profile, purple sweet potato.

Simultaneous removal of U(VI) and tetracycline from aqueous solution by biochar-supported nano-hydroxyapatite: New insights into the role of biochar and interactions between pollutants

U(VI) and tetracycline (TC) in hospital wastewater pose serious threats to human health and the environment. In this study, agricultural corn straw residue was utilized as a precursor for biochar, and biochar-supported nano-hydroxyapatite (nHAP) adsorbents (CSPCs) were synthesized at various ratios. These CSPCs were employed for the removal of U(VI) and TC in both one-component and two-component systems. In the one-component system, the adsorption capacity of the material was related to the ratio of nHAP to biomass, and the maximum adsorption capacities of CSPC-1 (nHAP/biomass = 1/1) for U(VI) and TC were 724.63 mg g−1 and 15.06 mg g−1, respectively. The XPS and XRD results confirmed that biochar promoted the dissolution and precipitation of U(VI) by nHAP, which stabilized the adsorption of U(VI) by CSPC-1. In the two-component system, the complexation strength of U(VI) and TC had a significant effect on the adsorption of both. At pH < 3.0, U(VI) inhibited the adsorption of TC, whereas TC enhanced the adsorption of U(VI). However, at pH > 4.0, the adsorption of U(VI) and TC were mutually reinforcing. At pH = 5.0, TC inhibited the adsorption of U(VI) only when the concentration of TC was significantly greater than that of U(VI). Combined with the systematic analysis of the FTIR, XPS and Raman spectroscopic results, these results suggest that these phenomena can be attributed to the complexation-bridging interactions between U(VI) and TC and their competition for adsorption sites.

Noncovalent hybridization of Fe single-atom with biochar for highly efficient peroxymonosulfate activation: Built-in electric field-driven radical and non-radical processes

A non-covalent hybridisation method was used to manipulate the electron transfer from BC to an iron monoatomic catalyst (SA Fe-N-C) using biochar (BC) as a dopant. By optimizing the mass proportion of BC to SA Fe-N-C during co-pyrolysis, the stack structure of two componants was successfully fabricated. The built-in electric field (BIEF) is induced by the defect position of graphite carbon structure in BC and the electron-withdrawing nitrogen atom in SA Fe-N-C. The electron transport road from BC to SA Fe-N-C was established by using the BIEF between the interfaces. As a result, the non-covalent stack of BC/SA Fe-N-C rendered a promising way in activating peroxymonosulfate (PMS), and meanwhile exhibited superior stability concerning their robust geometric skeleton. The degradation experiments showed that the degradation efficiency of the composite was increased to 91% compared with that of the pristine SA Fe-N-C (69%) at a extremely higher concentration of TC (20 mg/L). Based on theoretical calculations and in-situ detections, it was found that the PMS activation follows the route of generating radicals (SO4•–,•OH) and non-radical (1O2, Fe(V)=O). The presence of the BIEF accelerated the electron delocalization, driving the electrons transfer for Fe(III)/Fe(II) and Fe(V)=O/Fe(III) recycle. The present study offer a new pathway for the synergistic PMS activation by combing single atom catalysts and biochar.

Preparation of a Carbon paste electrode with Active materials for the detection of Tetracycline

The Electrochemical sensor based on carbon-clay paste electrode (CCPE) was constructed for sensitive determination of Tetracycline (Tc). The mineralogical composition, morphology, structure and performance of CCPE were characterized using X-ray diffraction powder, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Cyclic Voltammetry analysis. The CCPE is constituted of two types of clay having the ratio 1/1 and 2/1 characteristic of kaolinite and montmorillonite clay respectively. Its porous structure is ascribed to the presence of graphite. The CCPE exhibited a good electrocatalytic activity towards the oxidation of Tc. The electrochemical kinetics and mechanism of Tc were proposed, showing that Tc electrocatalytic oxidation reaction was controlled by diffusion process and took place in three steps. A low concentration of Tc was detected by amperometry with the linear ranges of 0.5μM–0.8 μM (R2 = 0.98), the sensitivity was 8.01 μA/μM.cm2, the limit of detection and quantification were 5.16x10−3μM(S/N = 3) and 1.72x10−2μM respectively. Thus, the proposed electrode provides a promising and prospective CCPE sensing platform for the detection of Tc in the environment.

Synthesis and Magnetic Resonance of Lanthanum Manganites Doped with Potassium Ions

Manganites doped with potassium ions La1 – xKxMnO3, where х = 0.0, 0.1, and 0.15, have been obtained by extraction-pyrolytic method at low temperature. The compounds have been studied by X-ray powder diffraction, electronic paramagnetic and ferromagnetic resonances. Unit cell parameters of La1 – xKxMnO3 samples have been calculated. According to magnetic resonance spectroscopy, La1 – xKxMnO3 exhibits phase delamination into paramagnetic and ferromagnetic phases. The fraction of the latter phase increases when temperature decreases. The temperature of transition from paramagnetic into ferromagnetic phase (Curie temperature, TC) for La1 – xKxMnO3 is –17.4, –13.7, and –4.8°С at х = 0.0, 0.1, and 0.15, respectively. The reason of symbate change in TC and potassium ion concentration in La1 – xKxMnO3 is supposed to be the change in the content of ferromagnetic pairs Mn3+–О2––Mn4+ in the manganites.

Construction of CuMoO4/MnO2/tourmaline composite for efficient organic wastewater decontamination via photo-Fenton-like processes

A CuMoO4/MnO2/tourmaline (CMT) heterogeneous photocatalyst was successfully constructed by hydrothermal method followed by calcination and applied to activate peroxymonosulfate (PMS) for organic contaminant degradation over a wide pH range under visible light illumination. The CMT catalyst exhibited impressive degradation efficiencies of tetracycline hydrochloride (TC, 93.48%), safranine T (SaT, 100%), acridine orange (AO, 99.46%), methyl orange (MO, 97.47%), neutral red (NR, 94.10%), trypan blue (TB, 93.67%), methylene blue (MB, 90.36%) and rhodamine B (RhB, 89.85%) within 50 min. The influence of related parameters including catalyst dosage, PMS concentration, initial pH value, TC concentration, coexisting ions, humic acid (HA) and different water matrices on TC degradation were systematically investigated. According to quenching experiments and electron paramagnetic resonance (EPR) tests, e−, SO4•−, •OH, •O2− and 1O2 all contributed to TC degradation, and •O2− played a predominant role in the photo-Fenton-like process. The reusability of CMT was evaluated by consecutive experiments, and comparable removal efficiencies could be maintained after five cycles. The degradation pathways of TC were deduced and the toxicity of degradation intermediates based on HPLC−MS detection was estimated by Toxicity Estimation Software (T.E.S.T.). Moreover, the catalytic degradation mechanisms of TC in CMT/PMS/Vis system were further proposed and the role of tourmaline was illustrated. This work opens an avenue for the construction of heterogeneous catalysts based on natural minerals in PMS/Vis coupling system for wastewater decontamination.

Alteration of the migration trajectory of antibiotic resistance genes by microplastics in a leachate activated sludge system

The environmental behavior of emerging contaminants of microplastics (MPs), antibiotics and antibiotic resistance genes (ARGs) in the leachate activated sludge system has been monitored and analyzed comprehensively. The results suggested that MPs could effectively alter the migration trajectory of tetracycline resistance genes (tet genes) in the leachate activated sludge system under intermittent and continuous influent conditions. After adding MPs, the total average abundance of tet genes in leachate increased from 0.74 ± 0.07 to 0.78 ± 0.07 (log10tet genes/log10 16S rRNA) and that in sludge increased from 0.65 ± 0.08 to 0.70 ± 0.06 (log10tet genes/log10 16S rRNA). Except for tetA, the abundance of tetB, tetO, tetM and tetQ on MPs increased with increasing TC concentration under both aerobic and anaerobic conditions. MPs not only significantly affect the abundance level and migration trajectory of ARGs in the leachate activated sludge system, but also remarkably improve the level of heavy metals in the ambient environment, indirectly promoting the selective effect of antibiotic-resistant bacteria (ARB) and promoting the development of antibiotic resistance (AR). In addition, MPs changed their physicochemical properties and released hazardous substances with aging to force tet genes to migrate from the leachate activated sludge system to the MPs, making AR more difficult to eliminate and persisted in wastewater treatment plants. Meanwhile, microorganisms played a driving role, making MPs serve as a niche for ARGs and ARB colonization. The co-occurrence network analysis indicated the specific distribution pattern of tet genes and microorganisms in different media, and the potential host was speculated. This study improves the understanding of the environmental behavior of emerging contaminants in leachate activated sludge system and lays a theoretical for protecting the ecological environment.

Optical sensing of tetracycline concentration using a liquid crystal-based platform targeting the chelating properties of tetracycline

In this study, a liquid crystal (LC)-based assay for the real-time detection of tetracycline (Tc) was developed. The sensor was constructed by implementing an LC-based platform that utilized the chelating properties of Tc to target Tc metal ions. This design enabled Tc-dependent induction of changes in the optical image of the LC; these modifications could then be observed in real-time with the naked eye. The performance of the sensor in detecting Tc was investigated with various metal ions to identify the most effective metal ion for Tc detection. In addition, the selectivity of the sensor was evaluated using different antibiotics. A correlation between Tc concentration and the optical intensity of the LC optical images was established, which enabled the quantification of Tc concentrations. The proposed method can detect Tc concentrations with a detection limit as low as 2.67 pM. Tests were conducted on milk, honey, and serum samples, which demonstrated that the proposed assay is highly accurate and reliable. The high sensitivity and selectivity of the proposed method make it a promising tool for real-time Tc detection, with potential applications in fields ranging from biomedical research to agriculture.

Serum per- and polyfluoroalkyl substances and abnormal lipid metabolism: A nationally representative cross-sectional study

BackgroundThe associations of legacy per- and polyfluoroalkyl substances (PFAS) with lipid metabolism are controversial, and there is little information about the impact of emerging PFAS (6:2 Cl-PFESA) on lipid metabolism in China. ObjectivesWe aimed to explore the associations of legacy and emerging PFAS with lipid profiles and dyslipidemia in Chinese adults. MethodsWe included 10,855 Chinese participants aged 18 years and above in the China National Human Biomonitoring. The associations of 8 PFAS with 5 lipid profiles and 4 dyslipidemia were investigated using weighted multiple linear regression or weighted logistic regression, and the dose–response associations were investigated using restricted cubic spline model. ResultsAmong the 8 PFAS, the concentration of PFOS was the highest, with a geometric mean of 5.15 ng/mL, followed by PFOA and 6:2 Cl-PFESA, which were 4.26 and 1.63 ng/mL, respectively. Legacy (PFOA, PFOS, PFUnDA) or emerging (6:2 Cl-PFESA) PFAS were associated with lipid profiles (TC, LDL-C, HDL-C, non HDL-C) and dyslipidemia (high LDL-C, high TC, low HDL-C), and their effects on TC were most obvious. TC concentration increased by 0.595 mmol/L in the highest quartile (Q4) of PFOS when compared with the lowest quartile (Q1), (95 % CI:0.396, 0.794). Restricted cubic spline models showed that PFAS are nonlinearly associated with TC, non HDL-C, LDL-C and HDL-C, and that the lipid concentrations tend to be stable when PFOS and PFOA were > 20 ng/mL well as when the 6:2 Cl-PFESA level was > 10 ng/mL. The positive associations between PFAS mixtures and lipid profiles were also significant. ConclusionsSingle and mixed exposure to PFAS were positively associated with lipid profiles, and China's unique legacy PFAS substitutes (6:2 Cl-PFESA) contributed less to lipid profiles than legacy PFAS. In the future, cohort studies will be needed to confirm our findings.

Activation of peroxymonosulfate by S-scheme Bi2S3/doped gCN heterostructure photocatalyst for highly efficient visible light driven tetracycline degradation: Insights into reaction mechanisms

A solid state microwave (MW) assisted hydrothermal method was used to prepare S-scheme heterojunction composite Bi2S3@doped gCN (BS@CN). TC was degraded upto 99.9 % under 20 min visible light, with synergistic action of 0.2 g/L catalyst having 10 wt% Bi2S3 (BS(10)@CN) and 1.5 g/L PMS, for initial TC concentration of 50 mg/L, exhibiting first order rate constant (kapp): 0.215 min−1. The modulation of band-structure due to the generation of heterojunction, coupled with different surface-bound redox cycles, i.e.,Co2 +/Co3 +surf.,Ce3 +/Ce4 +surf. andBi3 +/Bi4 +surf., helped the charge migration, separation of excited e-/h+ and production of reactive species, like,SO4∙-,∙OH,O2∙-,O21, etc., that played important roles towards TC degradation. Band-structure determination, XPS analysis and other characterizations revealed the formation of S-scheme configuration and corresponding surface-bound metastable complexes towards self-regeneration and excellent catalytic activity of the composite, even in the contaminated real-life surface water sources. Extensive intermediate analysis was carried out to develop a detailed TC degradation pathway. The BS@CN photocatalyst can be recycled multiple times, without significant loss of photocatalytic activity (∼88 % TC degradation after 5 cycles). This study demonstrated the design and fabrication of metal oxide doped gCN/metal chalcogenide-based heterojunction photocatalysts that have potential applications towards the removal of refractory contaminants in aqueous medium.

Bimetallic MOFs loaded cellulose as an environment friendly bioadsorbent for highly efficient tetracycline removal

Due to the increasingly serious antibiotic-related pollution, it is crucial to develop novel green bioadsorbents to effectively remove antibiotics from aqueous solutions. In this study, Fe doped zeolitic imidazolate frameworks-8 loaded cellulose (Fe/ZIF-8@cellulose) aerogels were prepared. The synthesized Fe/ZIF-8@cellulose aerogels were characterized experimentally including morphology observation and chemical compositions determination. The effects of bioadsorbent dosage, solution pH, adsorption time, initial TC concentration and adsorption temperature on the TC adsorption behaviors were systematically studied. Due to the introduction of Fe in the ZIF-8, the maximum adsorption capacity of Fe/ZIF-8@cellulose for TC could reach as high as 1359.2 mg/g, which is higher than the reported ZIF-8 loaded polysaccharide based adsorbents. The adsorption kinetics and isotherm of TC adsorption were also determined. With the cellulose as the matrix to load Fe/ZIF-8, the obtained Fe/ZIF-8@cellulose aerogels exhibited good reusability. Most importantly, the TC adsorption mechanism was proposed. The results of our finding suggest that the Fe doping into MOFs is an effective strategy to improve the antibiotics adsorption performance and the application of cellulose as the matrix is a valuable method to increase the cyclic utilization. This study highlights the potentials of applying the Fe/ZIF-8@cellulose aerogels in the antibiotics removal for practical wastewater.

A novel intelligently integrated MOF-based ratio fluorescence sensor for ultra-sensitive monitoring of TC in water and food samples

In this work, a high-precision visual and point-of-care testing (POCT) ratiometric fluorescent nanosensor for TC was constructed by embedding fluorescein (FL) into l-histidine modified ZIF-8 (LZIF-8) and chelating with rare earth citrate complex. Upon exposure to TC, the coordination and energy transfer between Eu3+ and TC make Eu3+ sensitized emission characteristic red fluorescence, while without prejudice to the emission peak intensity of FL. This ratiometric fluorescent probe with stable reference signal had the characteristics of high sensitivity (ultralow LOD = 5.99 nM) and selectivity and fast response kinetics (within 20 s). The high-bright fluorescence emission was beneficial to human eye recognition and it can realize semi-quantitative detection of TC in eggs, meeting the requirements of household use. In addition, the color can be read and analyzed quickly with the help of smart phone color analysis APP, and the semi-quantitative concentration of TC can be determined more conveniently.