Oxone Research Articles

Self-assembled perylene diimide decorated g-C3N4 heterojunction catalyst with strong interfacial charge transfer through π-π interaction for efficient boosted photocatalytic degradation of tetracycline

Perylene diimide (PDI) organic material and its derivatives as photocatalysts possesses excellent charge separation efficiency and are renowned as among the top n-type organic semiconductors capable of absorbing visible light owing to their narrow band gap (∼1.69 eV). Heterojunction photocatalysts with efficient electron transfer and excellent photocatalytic performance are of great significance for the degradation of organic compounds in the environment. In this work, a series of heterojunction catalysts (CNPDI) with robust interfacial charge transfer via π-π interaction were prepared using g-C3N4 and different mass ratio of the self-assembled PDI as precursors, subsequently utilized as efficient visible-light-driven photocatalysts for the degradation of organic tetracycline. SEM and TEM results indicated that porous CN was completely wrapped around PDI nanorod structure formed by strong π-π interactions. In the presence of activating potassium peroxymonosulfate (PMS) substances, the kinetic rate constant of the CNPDI photocatalytic system clocked in at 0.026 min−1, marking 2.36 fold increase compared to the original CN (0.011 min−1). The bolstered degradation performance was attributed to the built-in potential formed by the self-assembled PDI and CN, promoting the separation of electron-hole pairs and redistribution of charge density in the interface region. This work presents a useful insight into the crafting of PDI-based heterojunction photocatalysts for degradation environmental pharmaceutical pollutants.

Assessing the Efficacy of Three Hatchery Disinfectants for the Inactivation of a Lake Sturgeon Herpesvirus (Family: Alloherpesviridae).

Infectious diseases are a leading cause of losses in the aquaculture industry and conservation programs globally. Simultaneously, infectious diseases pose a substantial risk to fish being hatchery-reared and released into natural habitats for conservation purposes, including the Great Lakes lake sturgeon (Acipenser fulvescens, i.e., GL-LST). Recently, an alloherpesvirus (lake sturgeon herpesvirus 2, i.e., LSHV-2) capable of inducing disease and/or mortality in adult and juvenile GL-LSTs was detected in two adult GL-LST populations. To begin developing disease prevention and/or control methods, in vitro experiments were designed to determine the susceptibility of LSHV-2 to disinfectants commonly used in hatchery and aquaculture facilities (Virkon®-Aquatic: potassium peroxymonosulfate; Ovadine®: polyvinylpyrrolidone iodine complex; and Perox-Aid®: hydrogen peroxide). Cultured LSHV-2 was exposed to each disinfectant at two concentrations (Virkon®-Aquatic: 0.5% and 1%; Ovadine®: 50 and 100 ppm; and Perox-Aid®: 500 and 1000 ppm) in duplicate for durations of 1, 10, and 30 min. Following exposure, the disinfectant was neutralized, and after a 14-day incubation period on a white sturgeon × lake sturgeon hybrid cell line (WSxLS), percent reduction was calculated by comparing the 50% tissue culture infectious doses (TCID50/mL) of the virus with and without disinfectant exposure. When exposed to Perox-Aid®, LSHV-2 percent reduction ranged from 58.7% to 99.5%. When exposed to Ovadine®, the percent reduction ranged from 99.4% to 100%. Lastly, the percent reduction when exposed to Virkon®-Aquatic was 100% for both concentrations and all timepoints. The results herein provide evidence that both Virkon®-Aquatic and Ovadine® are virucidal to LSHV-2 and may represent a means to reduce virus transmission risk under field settings.

The hidden threat: Comprehensive assessment of antibiotic and disinfectant resistance in commercial pig slaughterhouses

The presence of antibiotic resistance genes (ARGs), disinfectant resistance genes (DRGs), and pathogens in animal food processing environments (FAPE) poses a significant risk to human health. However, knowledge of the contamination and risk profiles of a typical commercial pig slaughterhouse with periodic disinfectant applications is limited. By creating the overall metagenomics-based behavior and risk profiles of ARGs, DRGs, and microbiomes in a nine-section pig slaughterhouse, an important FAPE in China. A total of 454 ARGs and 84 DRGs were detected in the slaughterhouse with resistance genes for aminoglycosides and quaternary ammonium compounds, respectively. The entire slaughtering chain is a hotspot for pathogens, including 83 human pathogenic bacteria (HPB), with 47 core HPB. In addition, 68 high-risk ARGs were significantly correlated with 55 HPB, 30 of which were recognized as potential bacteria co-resistant to antibiotics and disinfectants, confirm a three-fold risk of ARGs, DRGs, and pathogens prevailing throughout the chain. Pre-slaughter pig house (PSPH) was the major risk source for ARGs, DRGs, and HPB. Moreover, 75 Escherichia coli and 47 Proteus mirabilis isolates showed sensitivity to potassium monopersulfate and sodium hypochlorite, suggesting that slaughterhouses should use such related disinfectants. By using whole genome multi-locus sequence typing and single nucleotide polymorphism analyses, genetically closely related bacteria were identified across distinct slaughter sections, suggesting bacterial transmission across the slaughter chain. Overall, this study underscores the critical role of the PSPH section as a major source of HPB, ARGs, and DRGs contamination in commercial pig slaughterhouses. Moreover, it highlights the importance of addressing clonal transmission and cross-contamination of antibiotic- and disinfectant-resistant bacteria within and between slaughter sections. These issues are primarily attributed to the microbial load carried by animals before slaughter, carcass handling, and content exposure during visceral treatment. Our findings provide valuable insights for One Health-oriented slaughterhouse management practices.

Structural Characterization and Electrochemical Studies of Selected Alkaloid N-Oxides.

In this work, we synthesized and confirmed the structure of several alkaloid N-oxides using mass spectrometry and Fourier-transform infrared spectroscopy. We also investigated their reduction mechanisms using voltammetry. For the first time, we obtained alkaloid N-oxides using an oxidation reaction with potassium peroxymonosulfate as an oxidant. The structure was established based on the obtained fragmentation mass spectra recorded by LC-Q-ToF-MS. In the FT-IR spectra of the alkaloid N-oxides, characteristic signals of N-O group vibrations were recorded (bands in the range of 928 cm⁻1 to 971 cm⁻1), confirming the presence of this functional group. Electrochemical reduction studies demonstrated the reduction of alkaloid N-oxides at mercury-based electrodes back to the original form of the alkaloid. For the first time, the products of the electrochemical reduction of alkaloid N-oxides were detected by mass spectrometry. The findings provide insights into the structural characteristics and reduction behaviors of alkaloid N-oxides, offering implications for pharmacological and biochemical applications. This research contributes to a better understanding of alkaloid metabolism and degradation processes, with potential implications for drug development and environmental science.

Effective of different industrial disinfection in subzero cold-chain environment

Effective disinfection methods are crucial in the cold chain transportation process of food due to the specificity of temperature and the diversity of contaminated flora. The objective of this study was to investigate the sanitizing effect of different disinfectants on various fungi at – 20 °C to achieve accurate disinfection of diverse bacterial populations. Peracetic acid, hydrogen peroxide, and potassium bisulfate were selected as low-temperature disinfectants and were combined with antifreeze. The sanitizing effect of these cryogenic disinfectants on pathogens such as Bacillus subtilis black variant spores (ATCC9372), Staphylococcus aureus (ATCC 6538), Candida albicans (ATCC 10231), Escherichia coli (8099), and poliovirus (PV-1) was sequentially verified by bactericidal and virus inactivation experiments. After a specified time of disinfection, a neutralizing agent was used to halt the sanitizing process. The study demonstrates that different disinfectants exhibit selective effects during the low-temperature disinfection process. Peracetic acid, hydrogen peroxide, and potassium monopersulfate are suitable for the low-temperature environmental disinfection of bacterial propagules, viruses, and fungal contaminants. However, for microorganisms with strong resistance to spores, a low-temperature disinfectant based on peracetic acid should be chosen for effective disinfection treatment. Our results provide a valuable reference for selecting appropriate disinfectants to sanitize various potential pathogens in the future.

Optimization of Desulfurization Process via Choline Phosphotungstate Coupled with Persulfate Using Response Surface Methodology

Using a simple acid-base neutralization method, a Ch-PW solid catalyst was synthesized by mixing choline hydroxide (ChOH) and phosphotungstic acid (HPW) at a 2:1 molar ratio in an aqueous solution. This catalyst was combined with a 20 wt.% potassium peroxymonosulfate (PMS) solution, using acetonitrile (ACN) as the extraction solvent to create an extraction catalytic oxidative desulfurization system. The optimal desulfurization conditions were determined through response surface methodology, targeting the highest desulfurization rate: 0.99 g of Ch-PW, 1.07 g of PMS, 2.5 g of extraction solvent, at a temperature of 50.48 °C. The predicted desulfurization rate was 90.79%, compared to an experimental rate of 93.64%, with a deviation of 3.04%. A quadratic model correlating the desulfurization rate with the four conditions was developed and validated using ANOVA, which also quantified the impact of each factor on the desulfurization rate: PMS > ACN > Ch-PW > temperature. GC-MS analysis identified the main oxidation product as DBTO2, and the mechanism of desulfurization in this system was further explored.

Enhanced photocatalytic degradation of diazinon using Ni:ZnO/Fe3O4 nanocomposite under solar light

BackgroundThe increasing photocatalytic activity of Ni:ZnO/Fe3O4 nanocomposite in the diazinon degradation under solar light compared to bare ZnO and Ni:ZnO nanoparticles was examined. MethodsThe synthesized nanoparticles and nanocomposite were characterized by SEM, MAP-EDX, XRD, FTIR, DLS, Zeta Potential and UV–Vis Spectrophotometer methods. The photocatalytic degradation of diazinon was investigated under sunlight illumination while continuously mixing on a stirrer for 180 min. Significant findingsThe highest degradation efficiency was achieved for 1.5 wt% Ni:ZnO nanoparticles and 1.0 wt% Ni:ZnO/Fe3O4 nanocomposite at a diazinon concentration of 10 mg/L for the nanoparticle dose equal to 2 g/L was 95 % and 93 %, respectively. The recycling photocatalysts were investigated. Application of H2O2, potassium peroxymonosulfate (PMS) and S2O82− as chemical oxidants increased the photocatalytic activity of the nanocomposite. The use of 1.0 wt% Ni:ZnO/Fe3O4 nanocomposite along with 0.01 M H2O2 displayed the increasing photocatalytic performance. The simultaneous photocatalytic degradation efficiency of combined H2O2 and 1.0 wt% NZF nanocomposite for 100 mg/l of diazinon increased from 44 to 82 %. The photocatalytic mechanism of diazinon was proposed in three pathways.

Investigation of the Resistance of Some Disinfectant Active Substances in ESBL-Producing Enterobacteriaceae

In this study, a total of 200 samples, including 100 neck skin and 100 cecum samples, were collected and analyzed from various poultry slaughterhouses on different sampling days. ESBL-producing Enterobacteriaceae were isolated and ESBL production was confirmed phenotypically by combined disk diffusion and E-test gradient strips. While ESBL production was confirmed in 10 (10%) of 100 neck skin samples, no significant ESBL production could be confirmed in 100 cecal samples. The broth microdilution method of Clinical and Laboratory Standards Institute (CLSI) was used to determine the resistance profiles against benzalkonium chloride (BC), cetylpyridinium chloride (CPC), N-alkyl dimethyl benzyl ammonium chloride (ADBAC) and potassium peroxymonosulfate (PPMS) disinfectants in 10 neck skin isolates with confirmed ESBL production. In the study, it has been determined that MIC50 and MIC90 values were respectively ADBAC (8 and 16 mg/L), BC (16 and 32 mg/L), CPC (16, and 32 mg/L), PPMS (≥ 1024 mg/L). The impacts of Enterobacteriaceae strains on food safety and public health are significant; Disinfectant resistance can lead to increased transmission of antibiotic-resistant bacteria, leading to serious infections in humans that are difficult to treat. For that reason, it is of great importance to develop effective control methods, including appropriate disinfectant use, hand hygiene and appropriate isolation measures, to prevent the spread of disinfectant resistant Enterobacteriaceae strains in food production systems.

Fabrication of an Fe-Doped ZIF-67 Derived Magnetic Fe/Co/C Composite for Effective Removal of Congo Red.

The dyes in printing and dyeing wastewater are harmful to the human body and the environment. It is essential to develop practical and effective adsorbents to deal with them. In this study, an Fe-doped, ZIF-67 derived Fe/Co/C composite material with strong magnetism was successfully synthesized. The effects of pH, initial concentration, and adsorption time on the properties of the adsorbent were investigated. To further improve the removal efficiency and enhance the practicality, potassium peroxymonosulfate (PMS) was added to the system due to its Fenton-like effect. Then, an Fe/Co/C composite was used with PMS to remove Congo red (CR) with a 98% removal of 250 mg·L-1. Moreover, for its high saturation magnetization of 85.4 emu·g-1, the Fe/Co/C composite can be easily recovered by applying a magnetic field, solving the problem that powdery functional materials are difficult to recover and, thus, avoiding secondary pollution. Furthermore, since the composite material was doped before carbonization, this synthetic strategy is flexible and the required metal elements can be added at will to achieve different purposes. This study demonstrates that this Fe-doped, ZIF-67 derived magnetic material has potential application prospects for dye adsorption.

Efficient removal of size-fractionated antibiotic resistance genes (ARGs) in WWTPs secondary effluent by vacuum ultraviolet (VUV) activated potassium peroxymonosulfate (PMS)

Antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in secondary effluent from wastewater treatment plants (WWTPs) have a size-fractionated character and conventional processes have difficulties in removing ARGs and MGEs. Therefore, this study aimed to explore the removal efficiency, removal mechanism and regeneration potential of size-fractionated ARGs and MGEs by vacuum ultraviolet (VUV)-activated peroxymonosulfate (PMS) and ascertain their potential hosts in secondary effluent. The proportion of particle-associated (PA)-ARGs and PA-MGEs was 85.07 %, followed by free-living (FL) fraction (14.91 %) and cell-free (CF) fraction (0.02 %). More than 95.00 %∼99.99 % of ARGs and MGEs in PA- and CF- fractions were removed by VUV/PMS, but the average removal efficiency of FL-ARGs and FL-MGEs was 66.15 %. Compared to the regeneration potential of PA- and CF-ARGs and MGEs (0.02 < C/C0 < 5.27), the regeneration occurred mainly in FL-ARGs and FL-MGEs (0.08 < C/C0 < 24.06). ·OH was the dominant radical (16.810 × 10-6 mol/L) in VUV/PMS for the removal of size-fractionated ARGs and MGEs from the secondary effluent, while SO4-· (4.478 × 10-6 mol/L) played a supporting role in the system based on the quenching experiment, electron paramagnetic resonance spectrometer and probe experiments. Based on full-scale classification, conditionally rare or abundant taxa (CRAT) were the core potential hosts in PA-, FL- and CF- fractions, while rare taxa (RT) and conditionally rare taxa (CRT) potential hosts were more diverse in the three fractions. This study suggests that VUV/PMS can effectively remove size-fractionated ARGs and MGEs from secondary effluent and thereby obviously reduce their dissemination risk to receiving water bodies, providing technical support for the engineering application of VUV/PMS in full-scale WWTPs.

Evaluation of potassium monopersulfate footbath solution for controlling digital dermatitis in lactating dairy cattle. A randomized clinical trial.

Our objective was to assess potassium monopersulfate as a disinfectant used in footbath to control digital dermatitis (DD) in dairy cows. We hypothesized that a potassium monopersulfate solution would control DD. A 180-day randomized negative controlled trial was conducted in a 265-Holstein free-stall facility. Throughout the trial, foot bathing was performed bi-weekly using a split (left vs. right feet) footbath: one tub filled with 1% potassium monopersulfate (treatment), the other with tap water (control). Digital dermatitis lesions were scored during trimming chute examinations of the unwashed hind heels every 90 days using the modified M-scoring system. Digital dermatitis lesions were re-categorized into four variables: 1) inactive; 2) active; 3) any; 4) inactive or absence of DD lesions. Three longitudinal outcomes were characterized: risks of 1) developing a DD lesion; 2) reactivating an inactive DD lesion; 3) development of an inactive or the absence of the DD lesion. A generalized linear model was used to compare the variables and longitudinal outcomes between treated and control groups. Prevalence of active DD lesions increased from 12.5% to 39.9% between days 0 and 90. This significant increase in prevalence justified the discontinuation of the study on day 90 for ethical reasons. There was no statistical difference between treated and control groups for the first outcome (RR: 1.0; 95% CI: 0.62, 1.7), the second outcome (RR: 1.0; 95% CI: 0.62,–1.7); or the third outcome (RR: 0.88; 95% CI: 0.37, 2.1). A 1% potassium monopersulfate footbath solution appears ineffective to control DD in this study.

Exploring Effective Strategies for ToBRFV Management in Tomato Production: Insights into Seed Transmission Dynamics and Innovative Control Approaches

The tomato brown rugose fruit virus (ToBRFV), a formidable tobamovirus, poses a significant threat to tomato production globally. This comprehensive study is dedicated to establishing an integrated control strategy for ToBRFV, encompassing the entire tomato cultivation process from seed to harvest. Initial investigations revealed a 0.8% seed transmission rate of ToBRFV, with viral presence detected in endosperms but not in seed embryos. Employing a multifaceted approach, infected seeds underwent a meticulous disinfection process. Gradual heating in a rotating thermal machine from 20 °C to 72 °C for 3 days resulted in a remarkable 0.3% contamination rate, rendering the virus non-infectious. Furthermore, ToBRFV-infected seeds underwent UV light treatment at 254 nm for 30 min, resulting in a 50% reduction in contamination rates. Chemical disinfectants, including 1% Tsunami 100 (comprising 30–60% acetic acid, 15.2% peroxyacetic acid, and 11.2% hydrogen peroxide) and 1% Biocon A (a combination of potassium peroxymonosulfate with buffer and organic acid), exhibited notable success. This study not only unravels the intricate dynamics of ToBRFV transmission and inactivation but also underscores the efficacy of integrated control measures. The findings provide valuable insights for the sustainable management of ToBRFV, contributing to the resilience of global tomato cultivation against this viral menace.

Harnessing potassium peroxymonosulfate activation of WO3/diatomite composites for efficient photocatalytic degradation of tetracycline.

The increasing prevalence of pharmaceutical contaminants in aquatic ecosystems poses profound challenges for both environmental sustainability and public health. Addressing this pressing issue requires the development of innovative, cost-effective, and efficient remediation approaches. Here we report the synthesis of WO3/diatomite composites and their photocatalytic degradation in conjunction with potassium peroxymonosulfate (PMS) activation. By leveraging the synergistic effects, we observe a remarkable degradation of tetracycline, a significant pharmaceutical contaminant, under visible light. Analytically, we have elucidated the driving factors for the enhanced performance, emphasizing the optimal amount of WO3 (10%) in the composite and PMS concentration (3 mM). Specifically, the WO3/diatomite catalyst presents a degradation rate of 80.75% tetracycline (40 mg L-1) after 180 min of visible light irradiation. Also, we elucidate the primary roles of ˙SO4 - radicals in driving the photocatalytic reaction using free radical trapping studies. Our approach not only offers a direct solution to controlling pharmaceutical contamination but also opens new possibilities for advancing the design of composite-based photocatalysts by taking advantage of nature-derived materials.

Mononuclear Non-Heme Manganese-Catalyzed Enantioselective cis-Dihydroxylation of Alkenes Modeling Rieske Dioxygenases.

The practical catalytic enantioselective cis-dihydroxylation of olefins that utilize earth-abundant first-row transition metal catalysts under environmentally friendly conditions is an important yet challenging task. Inspired by the cis-dihydroxylation reactions catalyzed by Rieske dioxygenases and non-heme iron models, we report the biologically inspired cis-dihydroxylation catalysis that employs an inexpensive and readily available mononuclear non-heme manganese complex bearing a tetradentate nitrogen-donor ligand and aqueous hydrogen peroxide (H2O2) and potassium peroxymonosulfate (KHSO5) as terminal oxidants. A wide range of olefins are efficiently oxidized to enantioenriched cis-diols in practically useful yields with excellent cis-dihydroxylation selectivity and enantioselectivity (up to 99% ee). Mechanistic studies, such as isotopically 18O-labeled water experiments, and density functional theory (DFT) calculations support that a manganese(V)-oxo-hydroxo (HO-MnV═O) species, which is formed via the water-assisted heterolytic O-O bond cleavage of putative manganese(III)-hydroperoxide and manganese(III)-peroxysulfate precursors, is the active oxidant that effects the cis-dihydroxylation of olefins; this is reminiscent of the frequently postulated iron(V)-oxo-hydroxo (HO-FeV═O) species in the catalytic arene and alkene cis-dihydroxylation reactions by Rieske dioxygenases and synthetic non-heme iron models. Further, DFT calculations for the mechanism of the HO-MnV═O-mediated enantioselective cis-dihydroxylation of olefins reveal that the first oxo attack step controls the enantioselectivity, which exhibits a high preference for cis-dihydroxylation over epoxidation. In this study, we are able to replicate both the catalytic function and the key chemical principles of Rieske dioxygenases in mononuclear non-heme manganese-catalyzed enantioselective cis-dihydroxylation of olefins.

Intensified degradation of reactive blue 222 (RB222) textile dye by a hybrid AOP system of hydrodynamic cavitation coupled with inline UV and PMS oxidant

Treatment of textile wastewater poses a significant problem due to the recalcitrant nature of dyes. The present work aims to evaluate a hybrid advanced oxidation process (AOP) comprising hydrodynamic cavitation (HC), ultraviolet irradiation (UV) and different oxidants. Synthetic wastewater (SW) was prepared by dissolving 50 ppm of reactive blue 222 dye, salt, sodium carbonate and detergent. A venturi, a single-hole orifice plate and multiple-hole orifice plates were compared as cavitating devices for HC. Multiple-hole orifice plate 3 proved to be the most efficient cavitation device. Three different oxidants, namely Fenton, potassium peroxymonosulfate (PMS), and potassium persulfate (KPS), were compared in combination with HC + UV. PMS turned out to be the most effective oxidant at pH 6.5, and HC + UV + PMS was the most effective treatment process as compared to standalone methods. NaCl (salt) in wastewater promotes the degradation of RB222 dye, and sodium carbonate suppresses the degradation of RB222 by scavenging radicals. After 120 min, the TOC reduction for the HC-only, UV-only, HC + UV, UV + PMS (2 g/L), and HC + UV + PMS (2 g/L) process was 3.23 %, 4.17 %, 9.64 %, 32.48 %, 38.51 %, and 75.96 %, respectively. After 180 min of treatment with HC + UV + PMS (2 g/L), the maximum 85.66 % TOC reduction of SW was reached, and the complex intermediates formed are also reported.

Isolating micro/nanoplastics from organic-rich wastewater: Co/PMS outweighs Fenton system

Rapid isolation of microplastics is the prerequisite for correct and in-depth understanding of their environmental impacts and human health threats. And Fenton’s reagent (Fe/H2O2 system, FHS) has been proven to be a viable way to isolate microplastics from wastewater, but it is limited because of harsh reaction conditions, long reaction time and low efficiency. Herein, it's proven that the Fenton-like system, which is using Cobalt (II) salts to decompose potassium peroxymonosulfate (Co/PMS system, CPS) with generation of 1O2, can offer shorter time (within 30 min) in complex sample isolation. The experimental results showed that the isolation time of micro/nanoplastics from pollutants with CPS in only 30 min, while it was at least more than 5 h with FHS. Via a serious of experiments of comparison and characterization between FHS and CPS, whether from the point of view of reaction time or isolation effect, CPS is superior to FHS. On this basis, we validate the applicability of this system (CPS) in different reaction conditions (concentration, pH), different sizes (from microns to nanometers) and types of plastic (PS, PA, PE, PP, PVC). In addition, the CPS can also preserve the integrity of the plastic itself and reduce the impact on the quality of samples evidenced by a variety of characterization of physicochemical structure like UV–vis, TEM, AFM, FTIR and XPS. CPS is proved to be faster, higher, stronger for enhancing the isolation of micro/nanoplastics from complex matrix. In a word, this study provides a promising solution for the efficient isolation of microplastics from wastewater without causing additional harm to the plastics.

Synthesis of Aryl Carboxylic Acids through Ambient Electro-oxidation of Arylacetylenes

AbstractAn efficient and environment-friendly synthesis of aryl carboxylic acids through the ambient electro-oxidation of the arylacetylenes is demonstrated. The reaction proceeds smoothly at certain applied potentials in a mixed solution of acetonitrile and water with potassium peroxymonosulfate (Oxone) as the additive. The isolated yields of the desired products are good up to 90%, and the reaction exhibits excellent functional-group tolerance. In this electrochemical system, transition metal catalysts, extra acids/bases, and high temperature are not required. This method may open up a pathway for the synthesis of carboxylic acids by the electrochemistry strategy.

Peak-like three-dimensional CoFe2O4/carbon nanotube decorated bamboo fabrics for simultaneous solar-thermal evaporation of water and photocatalytic degradation of bisphenol A

Catalytic CoFe2O4 and solar-thermal carbon nanotube decorated bamboo fabrics (CCBF) are fabricated for integrating efficient solar steam generation from wastewater with catalytic degradation of its organic contaminants. Thanks to the numerous porous channels and polar groups of bamboo fabric and the efficient solar-thermal energy conversion of black carbon nanotubes, the porous and hydrophilic CCBF exhibits fast upward transport of water, efficient solar light absorption, and high solar-thermal energy conversion efficiency. The decorated CoFe2O4 not only enhances the solar-thermal energy conversion efficiency of CCBF but also activates potassium peroxymonosulfate to generate abundant highly active species for catalytic degradation of bisphenol A (BPA). Furthermore, folding the CCBF into a peak-like 3D evaporator can enhance solar energy utilization, and gain environmental energy for promoting solar-thermal water evaporation and catalytic degradation performances. The 3D CCBF evaporator achieves a water evaporation rate of 2.72 kg m–2 h–1 under 1-sun irradiation. Meanwhile, 100% of the BPA in the seawater can be degraded within 10 min. An exceptional high purification efficiency of 27.72 kg m–2 h–1 is achieved with the 3D evaporator during a long-term treatment of BPA-containing seawater under 1-sun irradiation. This work demonstrates efficient purification of seawater/wastewater with both metal ions and organic pollutants by simultaneous solar-thermal evaporation of water and catalytic degradation of organic pollutants.

Late-stage diversification strategy for the synthesis of peptide acids and amides using hydrazides

Aim: Modification of the C-terminus of a peptide to improve its properties, particularly after constructing the peptide chain, has great promise in the development of peptide therapeutics. This study discusses the development of a late-stage diversification method for synthesizing peptide acids and amides from hydrazides which can serve as a common precursor. Methods: Peptide hydrazides were synthesized solely by using conventional solid-phase peptide synthesis (SPPS). Hydrazides were subjected to oxidation by potassium peroxymonosulfate (Oxone) to afford carboxylic acids. Azidation of hydrazides using sodium nitrite (NaNO2) under acidic conditions, followed by the addition of β-mercaptoethanol (BME), could also be used to generate carboxylic acids. For the preparation of peptide amides, azides that can be prepared from hydrazides were reacted with ammonium acetate (NH4OAc) or tris(2-carboxyethyl)phosphine (TCEP)∙hydrochloride (HCl) to develop the products through ammonolysis or a Staudinger reaction, which produces iminophosphorane from an azide and a phosphine. The antimicrobial activity of modelin-5 derivatives synthesized from the corresponding hydrazides was evaluated by the colony count of Escherichia coli (E. coli) after treatment with the peptides. Results: Oxone oxidation yielded the corresponding acids rapidly although oxidation-prone amino acids were incompatible. Azidation and subsequent treatment with BME afforded peptide acids an acceptable yield even in sequences containing amino acids that are prone to oxidation. Both methods for conversion of hydrazides to amides were found to afford the desired products in good yield and compatibility. The conditions that were developed were adapted to the synthesis of modelin-5 derivatives from the corresponding hydrazides, yielding late-stage production of the desired peptides. The amides of the resulting peptide showed more potent activity against E. coli than the acid form, and the most potent activity was observed from the hydrazide. Conclusions: The developed protocols allow hydrazides to be converted to acids or amides, enabling late-stage diversification of peptide C-terminal residues.

A parametric study on intensified degradation of textile dye water using hydrodynamic cavitation based hybrid technique

In this paper, a detailed investigation of the treatment of model textile dye wastewater (MTDW) by applying a hybrid approach of hydrodynamic cavitation (HC) coupled with UV light and different oxidants is reported. A distinct hybrid strategy of HC combined with inline UV and different oxidants was employed to treat model textile dye wastewater comprising mixed dyes under neutral to alkaline conditions and in the presence of salt and detergent, which form significant components of textile wastewater. The model textile dye wastewater was made of three dyes: Reactive Yellow 84, Reactive Black 8, and Reactive Violet 5 with 100 ppm of total concentration. Effects of various operating conditions, such as feed pressure at the venturi inlet, initial pH, process time, and different oxidizing agents, on percentage COD reduction were investigated. The extent of dye decolourization using HC combined with different oxidizing agents, viz., hydrogen peroxide (H2O2), sodium persulfate (NaPS), and potassium peroxymonosulfate (PPMS), were studied. HC coupled with UV and potassium peroxymonosulfate (PPMS) oxidant produced maximum decolourization of dyes to the extent of 100 % at pH 7. A maximum COD reduction of 87.7 % was obtained at the optimized operation conditions of hydrodynamic cavitation (HC) coupled with UV and PPMS. The treatment of model dye wastewater utilizing a hybrid strategy of HC+UV+PPMS achieved a synergetic index of 1.92, which was significantly better than standalone treatments. The current work contributes significantly to our understanding of the performance of cavitation-based systems for treating complicated textile effluent.