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The reaction of peracetic acid (PAA) and Fe(II) has recently gained attention due to its utility in wastewater treatment and its role in cloud chemistry. Aerosol-cloud interactions, partly mediated by aqueous hydroxyl radical (OH) chemistry, represent one of the largest uncertainties in the climate system. Ambiguities remain regarding the sources of OH in the cloud droplets. Our research group recently proposed that the dark and light-driven reaction of Fe(II) with peracids may be a key contributor to OH formation, producing a large burst of OH when aerosol particles take up water as they grow to become cloud droplets, in which reactants are consumed within 2 min. In this work, we quantify the OH production from the reaction of Fe(II) and PAA across a range of physical and chemical conditions. We show a strong dependence of OH formation on ultraviolet (UV) wavelength, with maximum OH formation at λ = 304 ± 5 nm, and demonstrate that the OH burst phenomenon is unique to Fe(II) and peracids. Using kinetics modeling and density functional theory calculations, we suggest the reaction proceeds through the formation of an [Fe(II)-(PAA)2(H2O)2] complex, followed by the formation of a Fe(IV) complex, which can also be photoactivated to produce additional OH. Determining the characteristics of OH production from this reaction advances our knowledge of the sources of OH in cloudwater and provides a framework to optimize this reaction for OH output for wastewater treatment purposes.

Summary: In this research, the effects of washing treatments (potassium carbonate (PC), potassium hydroxide (PH), peracetic acid (PA), alkaline hydrogen peroxide (AHP)), ultrasound (US) and high‐intensity pulsed light (HIPL) technologies on the removal of ochratoxin A (OTA) residues in raisins were investigated. PC at 5 min (66.60%), PH at 10 min (65.25%), alkaline hydrogen peroxide at 5 min (63.30%) and HIPL at 12 J cm−2 (62.50%) were found to be the most successful applications in OTA degradation, respectively. Although the OTA degradation rate was high after chemical washing for 10 min, the raisins had a chemical odour. The results show that HIPL effectively reduces OTA levels in raisins without causing any quality loss. [ABSTRACT FROM AUTHOR]

Sink drains in hospitals are notorious reservoirs of bacteria, hosting both planktonic micro-organisms and biofilms within the siphon. Disinfectants based on peracetic acid are both non-corrosive and effective in eliminating biofilm and planktonic micro-organisms, presenting a potential solution for decontaminating sink drains. To examine the effectiveness of Clinell Drain Disinfectant, a peracetic-acid-based disinfectant, in the intensive care unit (ICU) of UZ Brussel. All 10 sinks in one of the ICU subunits known to be heavily contaminated were treated with Clinell Drain Disinfectant for one month. Throughout the treatment period, bacterial growth in the P-traps was systematically monitored qualitatively (using eSwab) and quantitatively (employing a sterile catheter and syringe) on various selective agar plates, processed and incubated in the WASPLab system. Matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy was used to identify all morphologically distinct colonies. At baseline, most of the sink drains were colonized by high concentrations of multidrug-resistant micro-organisms, primarily VIM-producing P. aeruginosa. The cultures taken immediately after decontamination yielded negative results, with only a very few exceptions. Nonetheless, it was observed that the biofilm in the upper section of the drain system remained unaffected, and within two days it was capable of recolonizing the liquid in the P-traps at a concentration >100,000 cfu/mL. After one month, this disinfecting protocol did not result in a lasting decontamination of the sink drains. This study demonstrated the disinfectant's efficacy in decontaminating the P-trap liquid. [ABSTRACT FROM AUTHOR]

Practical Application Spent coffee grounds (SCG) are the waste byproducts of coffee brewing. While SCG can be valorized to produce functional biopolymers due to their valuable structural components, the lignocellulosic structure of SCG is resistant to degradation because of the tightly bound lignin. Therefore, a pretreatment step is required before pulping with peracetic acid (PAA), an eco‐friendlier alternative to traditional pulping methods, to facilitate the extraction of these desired cellulosic materials. Formic acid:acetic acid:deionized water (FA:AA:W = 30:50:20) or 60% (v/v) ethanol pretreatments were applied to SCG to compare the characteristics of the resulting cellulosic materials after PAA pulping. Lignocellulose analysis showed that the lignin content (7.06%) of ethanol pretreated SCG was significantly lower (p < 0.05), and the cellulose content (29.52%) was significantly higher (p < 0.05) than the untreated SCG (15.50% and 11.50%, respectively), indicating that an adequate amount of lignin was removed to obtain the cellulosic materials after the pretreatment process. Morphological and structural changes in the lignin and hemicellulose were observed in all the pretreated SCG, which further confirmed that these components were degraded with pretreatments and pulping. Ethanol pretreated SCG showed the most optimal results based on the greatest lignin decrease seen from its lignocellulose composition, appearance, and structure. This study exemplified a conversion process to extract cellulosic materials from SCG more efficiently to utilize for cellulose‐based products and verify its potential to be valorized as a waste byproduct.Coffee companies can provide the spent coffee grounds (SCG) they produce to develop cellulose‐based materials to make biodegradable packaging products rather than throwing them out or burning them. Using SCG for producing cellulose‐based materials can help promote sustainability and reduce food waste worldwide. SCG can be utilized as an alternative source based on their abundance and desired biopolymeric properties, providing innovative solutions to industries and increasing consumer awareness of this cause. [ABSTRACT FROM AUTHOR]

Herein, we report a general and green protocol for the anti-dihydroxylation of unactivated alkenes. Combining H2O2 and acetic acid at 50 °C results in the formation of peroxyacetic acid, which enables the efficient synthesis of a wide range of anti 1,2-diols in moderate to good yields without the need for hazardous solvents or expensive transition metals as catalysts. [ABSTRACT FROM AUTHOR]

Partial delignification of alder wood specimens was performed with alkaline sulfite and peracetic acid (PAA) methods, and subsequently the delignified samples were saturated with furfuryl alcohol, as an eco-friendly chemical. The aim of delignification before furfurylation was to facilitate the penetration of furfuryl alcohol into the cell wall, in order to overcome the weak mechanical properties and hydrophilicity of alder wood as a fast growing species. The results showed that alkaline delignification removed a lower percentage of lignin despite more significant mass loss as compared to peracetic acid delignification method, which indicates more carbohydrates degradation in alkaline delignification. Infrared spectroscopy also confirmed more retention of carbohydrates in the sample delignified with peracetic acid. The polymerization of furfuryl alcohol in the cell cavities decreased the access of water molecules to the hydroxyl groups of the cell wall, increased the contact angle, and decreasing surface wettability. This effect was more noticeable in the PAAdelignified samples. Mechanical tests revealed that the delignified samples with peracetic acid had higher mechanical strength and modulus, compared to the alkaline sulfite delignified samples. This was attributable to the maintenance of carbohydrates during the delignification process. [ABSTRACT FROM AUTHOR]

The influence of pre-treating Kappa number of 18.0 industrial birch kraft pulp with peracetic acid (Paa) before oxygen delignification (OD) was studied relative to the pulps' level of delignification, yield, brightness, intrinsic viscosity (IV), FS-number, tear index (TI), and the consumption of chlorine dioxide (ClO2) in its subsequent Elemental Chlorine Free (ECF) bleaching. The study showed that such pretreatment is a way to extend the delignification of such pulp quite selectively in OD based on values of IV, FS-number, and TI, and to reduce significantly the consumption of ClO2 required to bleach this pulp to a brightness of 87%. This reduction depended on the amount of Paa used for pulp pretreatment. For example, when 0.33% and 0.66% as active oxygen (A.O.) of Paa were used, ClO2 consumption to bleach the pulp to 87% was lowered by 15.4% and 42.3%, respectively. As high as a 61.5% reduction in ClO2 consumption in its bleaching could be obtained using 0.66% as A.O. on pulp and change of time of OD. This result allows for a significant decrease in the chlorine passing to the filtrates from washing the pulp after the D0 and E stages to the pulp mill wastewater treatment plant. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the antimicrobial efficacy of peroxyacetic acid (PAA) for beef in processing facilities. Inactivation of a wildtype Escherichia coli strain by up to 400 ppm PAA in solutions with different organic loads was determined. The microbial efficacy of PAA was assessed at two commercial beef plants for carcasses and cuts during routine production. The wild type E. coli strain was reduced by >7 log CFU upon exposing to PAA for 15 s at >100 and 200 ppm in low and high organic load solutions, respectively. PAA spray significantly reduced coliforms and E. coli by 1.7–2.0 log units on carcasses artificially inoculated with fecal slurry at one plant, and reduced aerobes and coliforms by 1.7 and 1.0 log units on naturally contaminated carcasses at the other plant. The reduction by PAA spray of aerobes (p < 0.05) on artificially inoculated carcasses was <0.5 log. Significant and consistent reduction of aerobes and coliforms on cuts by PAA was observed for fat surface at both beef plants, but not for lean cut surface. However, fewer cuts sprayed with PAA were positive for E. coli, regardless of cut type, compared with those that were not sprayed. Taken together, PAA can be effective for reducing microbial contamination of beef carcasses and cuts in commercial practice. [ABSTRACT FROM AUTHOR]

The role of MA in FAMA mixed perovskite remains far from being fully understood, due to the intricate chemical evolutions in the precursor solutions. Adjusting the content of MA in FAMA mixed perovskite arbitrarily remains a great challenge. This study elucidates a synergistic effect between H+ and I− oxidation which helps to reduce the content of MA in FA‐dominated perovskite. Briefly, excessive H+ boosts the balanced and rapid assembly of MA and FA components in FA‐dominated perovskite and hampers unfavorable chemical evolution induced by nucleophilic reaction between MA and FA in the precursor solution, while I− oxidation accelerates the in situ crystallization of perovskite. Leveraging this synergistic effect, centimeter‐scaled FAxMA(1‐x)PbI3 single crystals with arbitrarily adjustable values of x are successfully fabricated. In addition, peroxyacetic acid is introduced as the additive, enabling the blade‐coated FA0.9MA0.1PbI3 perovskite solar cells (PSCs) to achieve an impressive efficiency of 23.7%. The efficiency achieved here is among the highest values for blade‐coated PSCs with FA content exceeding 90% so far. The optimized solution developed in this study achieved exceptional stability, allowing it to be stored under air conditions for over 2 months without significant degradation in cell efficiency. This outcome satisfies the requirements for commercialization. [ABSTRACT FROM AUTHOR]

This study innovated cobalt-based catalytic nanocomposites (CCNs) for the heterogeneous activation of peracetic acid (PAA), a green and efficient advanced oxidation process for removing antibiotics from water. Commercial Co3O4 catalysts exhibit limited activity due to stable electronic structures. To overcome this, CCNs were synthesized using a one-step condensation method, incorporating a size control strategy that anchors Co3O4 nanoclusters within 4–5 nm onto six-fold cavity of g-C3N4, simultaneously modifying the coordination environment of Co. This alteration significantly enhances the adsorption energy of PAA and catalytic activity compared to commercial Co3O4. The improved performance of CCN2, in particular, is attributed to a shift in the cobalt d band center towards the Fermi level, facilitating electron delocalization and transfer, enhancing Co–O bonding, and accelerating PAA decomposition. CCN2's superior activity, with a cefapirin (CFP) degradation kinetic rate constant (k1 = 0.760 min−1) ~11 times that of PAA direct oxidation (k1 = 0.070 min−1) and ~5 times that of commercial Co3O4/PAA system (k1 = 0.164 min−1), is due to its ability to generate dominant reactive species for antibiotic degradation, including alkoxy radicals (CH3C(=O)OO•), high valence metal (CoIV(=O)2+), and singlet oxygen (1O2), with the latter two being crucial for the degradation process. The degradation of CFP involved three mechanisms, including direct oxidation by PAA, decarboxylation, and open-ring reactions at nitrogen sites. This research provides insights into developing high-activity catalysts for efficient PAA activation and antibiotic removal, leveraging the strategy of shifting the transition metal d band center. [ABSTRACT FROM AUTHOR]

Abstract In this work, it was found that the presence of nitrilotriacetic acid (NTA) could enhance the elimination of sulfamethoxazole (SMX) significantly in Mn(II)/peracetic acid (PAA) process. NTA firstly complexed with Mn(II) to produce Mn(II)-NTA complex, which could activate PAA producing CH3C(O)O· and Mn(III)-NTA complex. Subsequently, Mn(V) was generated via two-electron transfer between Mn(III)-NTA complex and PAA. According to the results of UV–vis spectrum analysis, scavenging experiments and chemical probe method, organic radicals and Mn(V) were proved to participate in SMX abatement and Mn(V) was the predominant reactive oxidant. Four possible degradation pathways of SMX in Mn(II)/PAA/NTA process including hydroxylation, amino oxidation, bond cleavage and coupling reaction were proposed based on six identified degradation products. Mn(II)/PAA/NTA process worked only in acidic and neutral conditions and the increase in PAA, Mn(II) or NTA concentration could accelerate SMX removal. This study provides a strategy for improving PAA activation by Mn(II) and an insight into SMX degradation mechanism by Mn(II)/PAA/NTA process.

Abstract This study aimed to assess the in vitro and in vivo disinfectant potential of peracetic acid (PAA) (1 mg/L) and hydrogen peroxide (H2O2) (20 mg/L) on the physicochemical and microbiological water quality parameters of fish aquaria, the microbial density of Nile tilapia muscular tissue, fish hepatic cortisol levels, and antioxidant biomarkers. In vitro, PAA and H2O2 reduced A. hydrophila colony viability by 5 log units after 30 and 5 min of contact time, respectively. PAA and H2O2 were added to aquaria water twice a week for the three-week experiment. Increased fish escape reflexes were observed only in the PAA group, which returned to normal within 10 min. No mortalities were reported in either the PAA or H2O2 groups. An in vivo experimental challenge with a pathogenic strain of A. hydrophila revealed a 20% reduction in mortality in the PAA group, with no mortalities in the H2O2 group. Cortisol levels and antioxidant markers were measured to assess the impact of PAA and H2O2 on fish health. Cortisol levels in the PAA and H2O2 groups were significantly higher than in the control group after disinfectant exposure, but they progressively returned to normal. A significant reduction in superoxide dismutase (SOD) and catalase (CAT) activity, along with considerably higher glutathione peroxidase (GPx) and malondialdehyde (MDA) enzymatic activity, was observed in the PAA and H2O2 groups compared to the control group. A substantial increase in total antioxidant capacity (TAC) was recorded in the PAA group. Physicochemical analyses revealed reduced pH and increased dissolved oxygen levels in the PAA and H2O2 groups. Microbiological analyses showed a significant reduction in bacterial density in water by 64% and 76% after 30 min of exposure to PAA and H2O2, respectively, with a non-significant increase in microbial count after bacterial challenge. Additionally, aerobic bacterial count, Aeromonas spp., and psychotropic bacterial count in fish muscle showed a significant reduction in the H2O2 group compared to the PAA and control groups before and after infection. The study concludes that regular application of PAA and H2O2 can temporarily reduce bacterial load in aquaria and fish muscle, regulate stress responses, and improve fish health by reducing A. hydrophila-induced infections and improving survival.

The P450 enzyme CYP121 from Mycobacterium tuberculosis catalyzes a carbon-carbon (C-C) bond coupling cyclization of the dityrosine substrate containing a diketopiperazine ring, cyclo(l-tyrosine-l-tyrosine) (cYY). An unusual high-spin (S = 5/2) ferric intermediate maximizes its population in less than 5 ms in the rapid freeze-quenching study of CYP121 during the shunt reaction with peracetic acid or hydrogen peroxide in acetic acid solution. We show that this intermediate can also be observed in the crystalline state by EPR spectroscopy. By developing an on-demand-rapid-mixing method for time-resolved serial femtosecond crystallography with X-ray free-electron laser (tr-SFX-XFEL) technology covering the millisecond time domain and without freezing, we structurally monitored the reaction in situ at room temperature. After a 200 ms peracetic acid reaction with the cocrystallized enzyme-substrate microcrystal slurry, a ferric-hydroperoxo intermediate is observed, and its structure is determined at 1.85 Å resolution. The structure shows a hydroperoxyl ligand between the heme and the native substrate, cYY. The oxygen atoms of the hydroperoxo are 2.5 and 3.2 Å from the iron ion. The end-on binding ligand adopts a near-side-on geometry and is weakly associated with the iron ion, causing the unusual high-spin state. This compound 0 intermediate, spectroscopically and structurally observed during the catalytic shunt pathway, reveals a unique binding mode that deviates from the end-on compound 0 intermediates in other heme enzymes. The hydroperoxyl ligand is only 2.9 Å from the bound cYY, suggesting an active oxidant role of the intermediate for direct substrate oxidation in the nonhydroxylation C-C bond coupling chemistry.

Peracetic acid (PAA) is efficient for disinfection processes in environmental sanitation and in the presence of transition metals its oxidative performance is enhanced. Thus, the present study aim evaluated the influence of Fe3+ ions during the inactivation process of Escherichia coli and Total Coliforms (TC). The process PAA + Fe3+ ions were also evaluated in relation to the disinfection kinetics, the participation of H2O2 and the influence of the organic load of the treated water. The tests showed an inactivation efficient of 0.5 to 0.9 log in relation to E. coli and 1.3 to 1.5 logs for TC in the concentrations evaluated and complete inactivation of E. coli was achieved within 15 min for both PAA and PAA/Fe3+ There is no damage to the disinfection process in the presence of Fe3+ ions, however, the decomposition of PAA is favored. In this sense, the formation of radicals can justify the maintenance of disinfection efficiency. The decay constants were close both microorganisms: for E. coli with PAA and PAA/Fe3+were 0.0323 and 0.0476 and for TC were 0.0637 and 0.0667. The values of R2 were above 0.95. Computer simulations of peptidoglycans that make up the bacterial cell wall showed that radicals preferentially attacked the carbons from the rings that composes the cell wall peptidoglycan of gram-negative bacteria allowing to break the structure during the disinfection process. [ABSTRACT FROM AUTHOR]

Cellulose obtained from oat hulls by bleaching with peracetic acid was modified, employing an ultrasound method that resulted in an esterification reaction with different vegetable oils (soybean, sunflower, and coconut) to produce modified cellulose (MC) with increased hydrophobicity. MC samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, scanning electron microscopy, and their wettability and oil and water absorption capacities. FTIR indicated that the reaction occurred with all oils, which was observed by forming a new band associated with ester carbonyl groups at 1747 cm−1. The modification did not affect the crystalline structure or surface morphology of the cellulose. MC samples modified with all oil sources showed a 6 to 9-fold decrease in water absorption capacity, a 3-fold increase in oil absorption capacity, and a higher affinity for nonpolar solvents. The modified samples adsorbed lower amounts of water at a slower rate. Different oil sources did not affect the main properties of MC. The ultrasonication-assisted process was not only effective in modifying cellulose by esterification with vegetable oils but was also an eco-friendly and simple strategy that does not require toxic reagents, providing reassurance of its sustainability. [ABSTRACT FROM AUTHOR]

Peracetic acid (PAA) has a long history as an efficacious and eco‐friendly disinfectant. It was first synthesised in 1902, and since then a wide range of applications has been developed in various industries. Aquaculture is a more recent industry wherein the potential of PAA is significant. As the global demand for sustainable development increases, there has likewise been growing interest in using PAA in aquaculture as an alternative to less environmentally friendly practices. PAA has no carcinogenic risk to humans (unlike formalin), has negligible harmful by‐products (unlike chlorine‐based disinfectants) and with appropriate precautions, the risks of causing severe human health damage is easier to control than ozone. Fish show strong physiological recovery and adaptation to PAA, whereas susceptible life stages of pathogens are highly vulnerable, enabling a safe and efficacious disinfection of the entire culture water and not the flow‐restricted disinfection by such processes as ultraviolet radiation or ozone. The effective concentration of PAA against many fish pathogens is usually below 2 mg L−1, which is tolerable for most fish, and it has very low environmental risk due to rapid degradation. However, such degradation and the hydrodynamics in production‐scale aquaculture systems complicate the practical use of PAA. In this review, we summarise key results of safe concentrations of PAA and its effectiveness specifically for fish farmers. We also outline major difficulties and possible solutions for practical uses of PAA. We intend to bring global attention to this compound and inspire future possibilities for its sustainable use as a water disinfectant in aquaculture. [ABSTRACT FROM AUTHOR]

Peracetic acid (PAA) has attracted increasing attention in wastewater decontamination for yielding reactive oxygen species (ROS). In this study, mackinawite (FeS) was synthesized and applied as the heterogeneous catalyst for PAA activation. Using sulfamethoxazole (SMX) as the target pollutant, the influences of FeS dosage, PAA dosage and initial pH values on SMX degradation by the FeS/PAA process were investigated. Under optimal conditions, SMX could be completely removed within 5 min with the apparent first-order rate constant (kobs) of 7.71 × 10−4 s−1. Electron spin resonance spectroscopy (ESR) analysis and radical scavenging experiments were modulated to detect the active species. During the activation process of PAA, various active components were evidenced to be hydroxyl radicals (HO•), singlet oxygen (1O2), superoxide radicals (O2•−) and organic radicals (R-O•, e.g., CH3C(O)O• and CH3C(O)OO•), whereas HO• and R-O• were demonstrated as the dominant active species responsible for SMX abatement. Both dissolved Fe(II) ions and active sites on the surface of FeS were proven to be activators for PAA, and SMX abatement was highly promoted as a result. Furthermore, the acidic pH displayed superior efficiency in SMX decomposition compared with alkaline and neutral conditions. Five degradation pathways of SMX were put forward and the toxicity of byproducts was further evaluated. Overall, this study provided an efficient and environmentally friendly PAA activation approach using FeS, which might broaden its applicability in the remediation of micropollutants. [ABSTRACT FROM AUTHOR]

An increase in foodborne illnesses associated with fruits and vegetables has been observed in recent years, with several outbreaks linked to contaminated agricultural water. The effectiveness of peroxyacetic acid (PAA) and chlorine (Cl) at reducing Escherichia coli in rain barrel and creek water was evaluated in this study. Rain barrel and creek water (12 and 32°C overnight) were inoculated with ~5 log CFU/ml of an E. coli cocktail, reequilibrated to 12 and 32°C (30 min), and treated with 25 ± 2 ppm of Cl, 75 ± 5 ppm of PPA, or a water control (W). Samples were collected 0, 5, 10, 60, 1,440, and 2,880 min after treatment, neutralized in Dey-Engley broth, and enumerated using the Food and Drug Administrationapproved IDEXX Colilert method, as well as E. coli/coliform (EC) Petrifilm, and enriched for the presence or absence of E. coli. E. coli was not detected in 12 and 32°C creek and rain barrel water 0 min after treatment with PAA and 60 min after treatment with Cl using Colilert. E. coli was not detected in samples treated with PAA or Cl at any time point using EC Petrifilm. These data allow growers and extension educators to explore the use of these treatments in surface water sources for postharvest uses in produce. [ABSTRACT FROM AUTHOR]

One of the main threats to aquaculture is represented by microbial pathogens, causing mass mortality episodes in hatcheries, which result in huge economic losses. Among the many disinfection methods applied to reduce this issue, the use of chemicals and beneficial microorganisms (probiotics) seems to be the most efficient. The aim of this study is to test the efficacy of two of them: a chemical, peracetic acid (PAA), and a probiotic, Phaeobacter inhibens. Tests were run on microalgae of the species Isochrysis galbana (var T-ISO). For both remedies, the microalgae survival rate and final cell concentration (cell/mL) were monitored. PAA analysis tested six different concentrations of the chemical: 7.5 µg, 10 µg/L, 20 µg/L, 30 µg/L, 40 µg/L, and 60 µg/L. Meanwhile, P. inhibens was tested with a concentration of 104 CFU/mL. Analysis for both the remedies was conducted on a laboratory scale using glass flasks, and on an industrial scale inside photobioreactors (PBRs). Among all the treatments, the one with PAA dosed with a concentration of 60 µg/L gave the best results, as the culture reached a final density of 8.61 × 106 cell/mL. However, none of the remedies involved in the experiment harmed microalgae or their growth. The results match perfectly with the condition requested for the tested remedies: to obtain an optimal breakdown of pathogens without interfering with culture growth. These features make PAA and P. inhibens good candidates for disinfection methods in aquaculture facilities. [ABSTRACT FROM AUTHOR]

The persistence of Listeria monocytogenes biofilms on equipment surfaces poses a significant risk of cross-contamination, necessitating effective surface decontamination strategies. This study assessed the effectiveness of hurdle treatments combining peroxyacetic acid (PAA) and saturated steam against 7-day-old L. innocua (a non-pathogenic surrogate for L. monocytogenes) biofilms on stainless steel (SS), polyester (PET), and rubber surfaces. Results demonstrated >6 log10 CFU/coupon L. innocua reductions on SS and PET surfaces after PAA (40 ppm, 1 min) followed by steam treatment (100 °C, 6 s). On rubber surfaces, PAA (80 ppm, 1 min) followed by steam treatment (100 °C, 6 s) resulted in ~5 log10 CFU/coupon L. innocua reduction. The presence of apple juice soil reduced the efficacy of hurdle treatments, with PAA (40 ppm, 1 min) and steam exposure (6 s) resulting in 5.6, 5.8, and 4.2 log10 CFU/coupon reductions of L. innocua on SS, PET, and rubber, respectively. The efficacy of this antimicrobial combination was further reduced by surface defects, especially in the presence of organic matter. Nevertheless, the treatment still achieved >5 log10 CFU/coupon reductions of L. innocua on worn SS and PET soiled with apple juice and ~4.5 log10 CFU/coupon reduction on worn, soiled rubber surfaces. These findings highlight that PAA treatments followed by a brief steam exposure are effective strategies for controlling Listeria on food-contact surfaces. [ABSTRACT FROM AUTHOR]

A homogeneous catalyst system consisting of Mn(OAc)2 and 2‐picolinic acid was studied for alcohol oxidation using peracetic acid as the oxidant. Catalyst loadings as low as 0.01 mol% could be utilized and the system compared well to other peroxide based methods. The utilization of continuous flow allowed the fast, exothermic reactions to be carried out in a safe and scalable manner. [ABSTRACT FROM AUTHOR]

The tolerance of 17 isolates of enterobacteria isolated from raw goat milk was evaluated against three sanitisers. All isolates were tolerant to sodium hypochlorite (1250 to >5000 ppm) and eight isolates were tolerant to peracetic acid (up to 1000 ppm). Two isolates were tolerant to all tested concentrations of quaternary ammonium with biguanide (>150/100 ppm). Although not all isolates are considered pathogens, they exert an important influence on the milk production chain. Sanitisers based on quaternary ammonium and biguanide seem to be more suitable for sanitisation in goat milk chain than sodium hypochlorite. [ABSTRACT FROM AUTHOR]

Peracetic acid (PAA) shows potential for use in drinking water treatment as an alternative to prechlorination, such as for mussel control and disinfection by-product precursor destruction, though its impact as a preoxidant during cyanobacterial blooms remains underexplored. Here, Microcystis aeruginosa inactivation and microcystin-LR and -RR release and degradation using PAA were explored. The toxin degradation rates were found to be higher in alkaline conditions than in neutral and acidic conditions. However, all rates were significantly smaller than comparable rates when using free chlorine. The inactivation of M. aeruginosa cells using PAA was faster at acidic pH, showing immediate cell damage and subsequent cell death after 15–60 min of exposure to 10 mg/L PAA. In neutral and alkaline conditions, cell death occurred after a longer lag phase (3–6 h). During cell inactivation, microcystin-LR was released slowly, with <35% of the initial intracellular toxins measured in solution after 12 h of exposure to 10 mg/L PAA. Overall, PAA appears impractically slow for M. aeruginosa cell inactivation or microcystin-LR and -RR destruction in drinking water treatment, but this slow reactivity may also allow it to continue to be applied as a preoxidant for other purposes during cyanobacterial blooms without the risk of toxin release. [ABSTRACT FROM AUTHOR]

Foodborne pathogens pose a persistent threat in broiler chicken production, particularly during the slaughter process, where contamination with zoonotic pathogens remains a concern. This study focuses on the potential of organic acids, such as formic and lactic acid, and the oxidizing agent peracetic acid, to decontaminate scalding water and enhance the hygiene of chicken carcasses. We conducted suspension tests introducing various organic loads to mirror the conditions of practical scalding water. Additionally, the surface tests were performed on chicken skin. Both methods were further tested in an experimental slaughtering facility. In suspension tests, the organic acids achieved impressive decontamination, with a 5‐log10 reduction of the test organisms Enterococcus hirae, Salmonella Typhimurium and Campylobacter jejuni at minimal concentrations (between 0.04% and 2% for formic acid; between 0.1% and 4.5% for lactic acid). Peracetic acid also effectively sanitized model water and chicken skin, even when used in low concentrations (between 0.001% and 0.1%), both in the laboratory‐based testing and in the experimental slaughtering facility. These results suggest that the tested disinfectants can effectively sanitize process water, even under conditions mimicking practical scalding water with organic matter. Peracetic acid, in particular, proved highly effective in improving chicken skin hygiene even at low concentrations. [ABSTRACT FROM AUTHOR]

The present work aimed to examine the association between the changes in the surface hydrophobicity and surface activity of soybean protein isolate (SPI) following structural alterations. To this end, the effects of heating, pH modification, ultrasonication, surfactant (SDS, sodium dodecyl sulphate) treatment, alkaline protease hydrolysis, peracetic acid treatment, and acylation on the surface activity and surface hydrophobicity of SPI were investigated. The results demonstrated that the changes in the surface hydrophobicity of SPI could accurately reflect the changes in its surface activity. A strong correlation between surface hydrophobicity and surface activity alterations was noted after the SPI molecules underwent structural modifications. The higher the surface hydrophobicity of the treated SPI, the greater its surface activity. Given that the surface hydrophobicity of SPI reflects the actual distribution of hydrophobic residues on its surface, this parameter can serve as a key indicator for evaluating and predicting changes in the surface activity of SPI. [ABSTRACT FROM AUTHOR]

The activated sludge process plays a crucial role in modern wastewater treatment plants. During the treatment of daily sewage, a large amount of residual sludge is generated, which, if improperly managed, can pose burdens on the environment and human health. Additionally, the highly hydrated colloidal structure of biopolymers limits the rate and degree of dewatering, making mechanical dewatering challenging. This study investigates the impact and mechanism of microwave irradiation (MW) in conjunction with peracetic acid (PAA) on the dewatering efficiency of sludge. Sludge dewatering effectiveness was assessed through capillary suction time (CST) and specific resistance to filtration (SRF). Examination of the impact of MW-PAA treatment on sludge dewatering performance involved assessing the levels of extracellular polymeric substances (EPS), employing three-dimensional excitation-emission matrix (3D-EEM), Fourier transform–infrared spectroscopy (FT-IR), and scanning electron microscopy. Findings reveal that optimal dewatering performance, with respective reductions of 91.22% for SRF and 84.22% for CST, was attained under the following conditions: microwave power of 600 W, reaction time of 120 s, and PAA dosage of 0.25 g/g MLSS. Additionally, alterations in both sludge EPS composition and floc morphology pre- and post-MW-PAA treatment underwent examination. The findings demonstrate that microwaves additionally boost the breakdown of PAA into •OH radicals, suggesting a synergistic effect upon combining MW-PAA treatment. These pertinent research findings offer insights into employing MW-PAA technology for residual sludge treatment. [ABSTRACT FROM AUTHOR]

The pulp bleaching process is mainly responsible for the generation of toxic substances in the whole paper making process. The modification of conventional ECF (elemental chlorine free) bleaching was studied using an oxygen stage, a peracetic acid stage and an oxygen followed by peracetic acid stage in the following bleaching sequences: OD0EOPD, PaaD0EOPD, OPaaD0EOPD and QOPaaD0EOPD. The PaaD0EOPD sequence reduced the COD, BOD, color, TDS and AOX by 36.8, 37.0, 52.4, 39.8 and 53.9%, respectively, in comparison with D0EOPD. Moreover, PaaD0EOPD has better optical effluent properties, compared to the OD0EOPD sequence. OPaaD0EOPD reduced the chlorophenols, chloroguaiacols by 73.3 and 89.3%, and improved the brightness and whiteness by 1.7 and 3.1 units, respectively, in comparison with the D0EOPD bleaching sequence. The QOPaaD0EOPD sequence improved the pulp viscosity by 0.8 units in comparison with OPaaD0EOPD. The amendment of the conventional bleaching sequence was found to be effective for achieving an improvement in optical properties and effluent quality at reduced dose of chlorine dioxide. [ABSTRACT FROM AUTHOR]

During field conditions and storage, onion bulbs are often severely affected by Aspergillus niger L., which leads to substantial yield and quality loss due to black mold. In the El-Minia region of Egypt, we isolated several strains of A. niger from different onion bulbs. To combat the black mold rot disease caused by A. niger, we tested the individual and combined effects of acetic acid and hydrogen peroxide against the most virulent strain under both in vitro and storage (180 days) conditions. Additionally, we measured the levels of antioxidant compounds such as phenolic acids, polyphenols, and ascorbic acid. Our pathogenicity tests helped us identify the most virulent isolate. We found that the environmentally friendly compound peroxyacetic acid, derived from the combination of hydrogen peroxide and acetic acid, reduced black mold infection in both, in vitro and storage conditions. Treating postharvest onion bulbs with 0.2 g L−1 acetic acid and 0.4 g L−1 hydrogen peroxide promised to mitigate the development of black mold rot for 180 days of storage. Furthermore, our results indicated that these treatments increased bioactive antioxidant compounds such as ascorbic acid, phenolic compounds, and polyphenols. These compounds, as secondary metabolites, served as the first line of defense against onion rot disease during storage. In conclusion, applying peroxyacetic acid proved a practical approach to controlling black mold rot disease development in onion bulbs during storage. [ABSTRACT FROM AUTHOR]

Chick performance and hatchability are adversely affected by microbial contamination of hatching eggs. Egg disinfection is therefore crucial to limiting bacterial numbers and optimizing production. The present study was applied to detect the effect of hatching eggs spraying (nest and floor) with two commercial disinfectants: A (H2O2, peracetic and acetic acid) and B (glutraldehyde and Benzalkonium chloride) on hatching parameters and eggshell microbial counts. Hatching eggs were collected from broiler breeder flocks at different ages (37, 47 and 57 weeks). The obtained results indicated that both disinfectants reduced the levels of bacteria in similar ways, but there were no significant differences between them. Concerning the hatching parameters; hatchability percentages (total and true) were lower than standard in both nest and floor eggs, and higher hatchability percentages were found in eggs sanitized with disinfectant A. However, the lowest values were reported in eggs of 57 weeks old breeders with both disinfectants. Conclusively, disinfectants A and B reduced the microbial load of hatching eggs of different ages, and some hatchability parameters were affected with flock age and the used disinfectants. [ABSTRACT FROM AUTHOR]

Copper-containing materials are attracting attention as self-disinfecting surfaces, suitable for helping healthcare settings in reducing healthcare-associated infections. However, the impact of repeated exposure to disinfectants frequently used in biocleaning protocols on their antibacterial activity remains insufficiently characterized. This study aimed at evaluating the antibacterial efficiency of copper (positive control), a brass alloy (AB+®) and stainless steel (negative control) after repeated exposure to a quaternary ammonium compound and/or a mix of peracetic acid/hydrogen peroxide routinely used in healthcare settings. A panel of six antibiotic-resistant strains (clinical isolates) was selected for this assessment. After a short (5 min) exposure time, the copper and brass materials retained significantly better antibacterial efficiencies than stainless steel, regardless of the bacterial strain or disinfectant treatment considered. Moreover, post treatment with both disinfectant products, copper-containing materials still reached similar levels of antibacterial efficiency to those obtained before treatment. Antibiotic resistance mechanisms such as efflux pump overexpression did not impair the antibacterial efficiency of copper-containing materials, nor did the presence of one or several genes related to copper homeostasis/resistance. In light of these results, surfaces made out of copper and brass remain interesting tools in the fight against the dissemination of antibiotic-resistant strains that might cause healthcare-associated infections. [ABSTRACT FROM AUTHOR]

Objective: The antiparasitic effect of peracetic acid (PAA) was evaluated against an infestation of the protozoan Trichodina spp. in naturally infected juvenile domestic seventh‐generation (F7) Striped Bass Morone saxatilis. Methods: Replicated treatments (n = 3) consisted of 1 and 2 mg/L PAA and a control; treatments were applied every other day for three treatments (30‐min static exposure). Infestation intensity was enumerated 20–24 h after each treatment by counting the number of Trichodina present in a wet mount of excised gill tissue. Result: Neither treatment rate was able to completely eradicate the parasite; however, 2 mg/L PAA resulted in a statistically significant reduction, which equated to 75% reduction of observed parasites. Conclusion: The 2‐mg/L PAA treatment regimen in the present study is proposed as a safe, environmentally friendly, and effective method for reducing the intensity of Trichodina infestations in Striped Bass. Impact statementDefining new treatment regimens for common aquaculture parasites is beneficial to the industry. Emphasis on environmentally friendly chemicals is also good for the industry. Improving animal welfare can be achieved by reducing parasites in fish. [ABSTRACT FROM AUTHOR]

Effective methods for decontamination of Shiga toxin-producing Escherichia coli (STEC) on beef were evaluated by 48 mL spraying, 100 mL, and 500 mL flushing with ethanol, hydrogen peroxide, peracetic acid, acidified sodium chlorite, and sodium hypochlorite in this study. The flushing with 500 mL of 1,000 ppm peracetic acid was most effective, reducing pathogens by 2.8 log CFU/cm2, followed by 1,200 ppm acidified sodium chlorite. The spraying with 1,000 ppm peracetic acid reduced pathogens by 1.6 log CFU/cm2. The flushing with 500 mL of 200 and 500 ppm acidified sodium chlorite, and 50, 100, 200, and 500 ppm peracetic acid significantly reduced the STEC population compared with those treated with distilled water (p 0.05). The flushing with 500 mL of 200 and 500 ppm acidified sodium chlorite and 200 and 500 ppm peracetic acid significantly changed the odor of beef samples compared with those treated with distilled water (p

Abstract Having been successfully bred in semi-intensive and intensive aquaculture systems, oval squids of the Sepioteuthis lessoniana species complex are emerging as promising candidates for research and industry. Nevertheless, information about pathogens and diseases that may affect squid aquaculture remains sparse. In this study, we identify new parasitic copepod species that causes squid mortality and decreases squid hatching rates, and we also offer a solution to eliminate the pathogen during incubation of squid eggs. The newly discovered copepod Ikanecator primus gen. et sp. nov. was identified on oval squid eggs for the first time using both morphological and molecular diagnostic markers. In the genomes of the copepod and associated microbiome, we identified multiple genes for enzymes involved in cephalopod eggshell degradation in genomes of the copepod and associated microbiome. Furthermore, we conducted experiments to assess efficacy of peracetic acid in inhibiting the I. primus gen. et sp. nov. both in vitro and in vivo using immersion treatment. We established that a 2-min exposure to a concentration of 250 μl/L of peracetic acid containing product (PAA-product; 35 mg/L PAA and 15 mg/L H2O2) inhibited the development of nauplii in vitro. All parasites exposed to a concentration of 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) were eliminated within two minutes. On top of this, the immersion treatment with 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) improved survival of squid embryos and increased size of squid hatchlings compared with control and the immersion treatment with 125 μl/L of PAA-product (17.5 mg/L PAA and 7.5 mg/L H2O2) and the immersion treatment with 250 μl/L of PAA-product (35 mg/L PAA and 15 mg/L H2O2). These findings suggest that PAA holds a great potential as inhibitor and controller of parasitic copepod infections and for overall health management in cephalopod culture.

Reasonable regulation of electronic structures of heterogeneous composite catalysts can enhance the charge separation and transfer at the interface of materials, thus further promoting the catalytic performance of catalysts. Recently, peracetic acid〔CH3C(O)OOH, PAA〕 based on heterogeneous advanced oxidation process with biochar(BC) materials has attacked much interests due to various reactive oxygen species(ROS) generated in the process. In this study, biochar modified with Co(OH)2 nanoparticles(h-Co/BC) was successfully synthesized by a simple co-precipitation method, which was applied to activate PAA for tetracycline(TC) degradation. The results showed that h-Co/BC could completely degrade TC with an initial concentration of 10 µmol/L within 7 min at pH 7. The scavenger quenching tests and electron paramagnetic resonance(EPR) analysis further indicated that the produced primary ROS were alkoxy radical, which mainly including CH3COO·, CH3COOO·, ·OH and 1O2. In addition, materials characterizations combined with density functional theory calculation showed that biochar was successfully modified with Co(OH)2 nanoparticles. Thus, the Co 3d-band in h-Co/BC was closer to Fermi level compared with that in pure Co(OH)2, benefiting to directional electron transfer, which could then be easily captured by PAA for cleavage to ROS. This study provided a new method for synthesis of functional materials applied in PAA-based AOPs.

Metronidazole(MNZ), prone to accumulate in the environment, is a nitroimidazole antibiotic and its metabolites have potential carcinogenicity and mutagenicity. In this paper, the degradation characteristics of MNZ by coupled ferrate/peroxyacetic acid〔Fe(Ⅵ)/PAA〕technology, as well as the simulation of MNZ degradation and reaction mechanism, were investigated. When the dosages of Fe(Ⅵ) as 500 μmol/L and PAA as 100 μmol/L, the degradation of MNZ reached 94.85% at pH of 8 in 60 min, and the degradation process followed pseudo-first-order kinetics. Variable experiments showed that the degradation of MNZ was positively correlated with the dosage of Fe(Ⅵ) and PAA, and the best effect was achieved at pH=8. Chloride (Cl-) and nitrate (NO3-) in the water matrix had little effect on the degradation of MNZ. Ammonium salt (NH4+) could promote the degradation of MNZ,while bicarbonate (HCO3-) and humic acid (HA) inhibited the degradation. The removal of MNZ in simulated medical wastewater by Fe(Ⅳ)/PAA was similar to that in ultra-pure water, which could achieve better removal effect. Probe experiments and quenching experiments showed that PAA accelerated the removal of MNZ from active species. H2O2 coexisting with PAA was the main activator of Fe(Ⅵ) while the main active species of Fe(Ⅵ)/PAA system were Fe(V) and Fe(Ⅳ). The results were expected to provide theoretical reference and data support for the application of Fe(Ⅵ)/PAA system in the deep treatment of MNZ in medical wastewater.

Peracetic acid (PAA), a strong oxidizing agent, has been widely used as a disinfectant in food processing settings as it does not produce harmful chlorinated by-products. In the present study, the transcriptional response of Listeria monocytogenes to a sub-lethal concentration of PAA (2.5 ppm) was assessed using RNA-sequencing (RNA-seq). Our analysis revealed 12 differentially expressed protein-coding genes, of which nine were upregulated (ohrR, ohrA, rpsN, lmo0637, lmo1973, fur, lmo2492, zurM, and lmo1007), and three were down-regulated (argG, lmo0604 and lmo2156) in PAA-treated samples compared to the control samples. A non-coding small RNA gene (rli32) was also found to be down-regulated. In detail, the organic peroxide toxicity protection (OhrA-OhrR) system, the metal homeostasis genes fur and zurM, the SbrE-regulated lmo0636-lmo0637 operon and a carbohydrate phosphotransferase system (PTS) operon component were induced under exposure of L. monocytogenes to PAA. Hence, this study identified key elements involved in the primary response of L. monocytogenes to oxidative stress caused by PAA, including the expression of the peroxide detoxification system and fine-tuning the levels of redox-active metals in the cell. The investigation of the molecular mechanism of PAA response in L. monocytogenes is of utmost importance for the food industry, as residual PAA can lead to stress tolerance in pathogens.

Pathogen control in the meat industry relies on the effectiveness of postharvest interventions in reducing microbial populations. This study investigated differences in the survival of Salmonella serovars when exposed to organic acids used as antimicrobials on raw pork meat. Seven serovars were included in this study (S. Newport, S. Kentucky, S. Typhimurium, S. Dublin, S. Heidelberg, S. Infantis, and S. Enteritidis). Multistrain serovar cocktails were prepared and tested against lactic acid (LA) and peracetic acid PAA at two concentrations, LA 2 and 4% and PAA 200 and 400 ppm. Pork samples were assigned to each serovar, inoculated with 6.0 Log CFU/cm2 Salmonella (one serovar at a time), and treated with the corresponding antimicrobials. A two-way analysis of variance was conducted to examine the effects of serovar and antimicrobial concentrations on Salmonella survival. A significant main effect of serovar was identified, indicating that Salmonella concentration and reduction rate were significantly affected by serovar. Similarly, a significant main effect of antimicrobials was observed, suggesting that the treatment types impacted Salmonella concentration and reduction rate. However, the interaction effect between serovar and antimicrobial was not significant. Posthoc comparisons indicate that PAA 400 ppm is more effective at reducing Salmonella concentrations and that S. Dublin may be more susceptible than S. Newport to antimicrobial sprays. Additionally, under PAA exposure, only S. Dublin, S. Kentucky, and S. Heidelberg showed statistically significant differences (P

Having been successfully bred in semi-intensive and intensive aquaculture systems, oval squids of the Sepioteuthis lessoniana species complex are emerging as promising candidates for research and industry. Nevertheless, information about pathogens and diseases that may affect squid aquaculture remains sparse. In this study, we identify new parasitic copepod species that causes squid mortality and decreases squid hatching rates, and we also offer a solution to eliminate the pathogen during incubation of squid eggs. The newly discovered copepod Ikanecator primus gen. et sp. nov. was identified on oval squid eggs for the first time using both morphological and molecular diagnostic markers. In the genomes of the copepod and associated microbiome, we identified multiple genes for enzymes involved in cephalopod eggshell degradation in genomes of the copepod and associated microbiome. Furthermore, we conducted experiments to assess efficacy of peracetic acid in inhibiting the I. primus gen. et sp. nov. both in vitro and in vivo using immersion treatment. We established that a 2-min exposure to a concentration of 250 μl/L of peracetic acid containing product (PAA-product; 35 mg/L PAA and 15 mg/L H2O2) inhibited the development of nauplii in vitro. All parasites exposed to a concentration of 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) were eliminated within two minutes. On top of this, the immersion treatment with 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) improved survival of squid embryos and increased size of squid hatchlings compared with control and the immersion treatment with 125 μl/L of PAA-product (17.5 mg/L PAA and 7.5 mg/L H2O2) and the immersion treatment with 250 μl/L of PAA-product (35 mg/L PAA and 15 mg/L H2O2). These findings suggest that PAA holds a great potential as inhibitor and controller of parasitic copepod infections and for overall health management in cephalopod culture. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing demand for environmentally friendly epoxides made from vegetable oils, including castor oil. This study aims to produce epoxidized castor oil derived ricinoleic acid (ECORA) with applied synergistic sulfate-impregnated zeolite ZM-5 as catalyst. To date, there is no published work on production of ECORA by peracetic acids mechanism using hybrid homogenous–heterogenous catalyst. Peracetic acid produced in situ was used to produce ECORA. By combining acetic acid, which acts as an oxygen carrier, with hydrogen peroxide, which acts as an oxygen donor, peracetic acid was formed. The ratio of ricinoleic acid to acetic acid was used at a ratio of 1:1, while a 1:1 molar ratio of hydrogen peroxide to castor oil was introduced. The epoxidation process has been conducted at a temperature of 55 °C. The mixture was then stirred continuously at a fixed speed of 200 rpm. The maximum conversion to oxirane was achieved at 58%. Overall, ECORA was successfully produced via in situ epoxidation of castor oil with applied hybrid catalyst. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Peracetic acid (PAA) is emerging as a versatile agent for generating long-lived and selectively oxidative organic radicals (R-O•). Currently, the conventional transition metal-based activation strategies still suffer from metal ion leaching, undesirable by-products formation, and uncontrolled reactive species production. To address these challenges, we present a method employing BiOI with a unique electron structure as a PAA activator, thereby predominantly generating CH3C(O)O• radicals. The specificity of CH3C(O) O• generation ensured the superior performance of the BiOI/PAA system across a wide pH range (2.0 to 11.0), even in the presence of complex interfering substances such as humic acids, chloride ions, bicarbonate ions, and real-world water matrices. Unlike conventional catalytic oxidative methods, the BiOI/PAA system degrades sulfonamides without producing any toxic by-products. Our findings demonstrate the advantages of CH3C(O)O• in water decontamination and pave the way for the development of eco-friendly water decontaminations based on organic peroxides. [ABSTRACT FROM AUTHOR]

Canola oil can serve as a substitute for polyol in the production of eco-friendly polyurethane. The aim of this study is to investigate the optimal conditions for the epoxidation of canola oil via the Taguchi optimization method. To date, there is no published work on optimization of process parameters for epoxidized canola oil production using the Taguchi method. In this study, the epoxidation of canola oil was performed using in situ-generated peracetic acid. Peracetic acid was formed by the reaction between acetic acid and hydrogen peroxide in the presence of a catalyst. The highest conversion to oxirane of 85% was achieved at a ratio of 2:1 of hydrogen peroxide to canola oil, a temperature of 65°C, and a stirring speed of 400 rpm. The Fourier-transform infrared spectroscopy (FTIR) characterization reveals the presence of the oxirane ring group, identified at a wavenumber of 1150 cm−1. Employing particle swarm numerical simulations, the results exhibit excellent agreement with the experimental data, thereby confirming the accuracy and validity of the kinetic model. [ABSTRACT FROM AUTHOR]

Background Peracetic acid and irradiation are common sterilization methods for allograft tendons; however, under some conditions, both methods adversely affect the fiber arrangement and ultimate load of the tendon. An in vitro study showed that low-dose peracetic acid combined with irradiation may be less detrimental to allograft tendon structure and properties, possibly because the breakdown of peracetic acid can lead to an enlargement of the interstitial spaces and an increase in porosity. Questions/purposes Using a rabbit Achilles tendon model, we asked: What is the effect of peracetic acid-ethanol combined irradiation on (1) the histopathology and fiber diameter of the allograft tendon, (2) tensile creep and load-to-failure biomechanical properties of allograft tendons, and (3) healing of the treated tendon in vivo compared with fresh-frozen allograft and peracetic acid-ethanol sterilization at 4 and 8 weeks? Methods The Achilles tendons used in this study were sourced from euthanized 10-week-old male New Zealand White rabbits previously used for ophthalmic experiments. All allografts were divided into three groups: fresh-frozen group (control group, n = 20), peracetic acid-ethanol sterilization group (n =20), and peracetic acid-ethanol combined irradiation group (n = 20). The sterilization protocols were performed per a predetermined plan. In the peracetic acid-ethanol sterilization group, the tendon tissues were covered with the peracetic acid-ethanol sterilization solution (1% peracetic acid for 30 minutes). In the peracetic acid-ethanol combined irradiation group, the tendon tissues were covered with the peracetic acid-ethanol sterilization solution (0.2% peracetic acid for 30 minutes) and were subjected to 15 kGy gamma irradiation. Thirty 10-week-old male New Zealand White rabbits received bilateral Achilles tendon allografts surgically. Tendon samples from each group were harvested at 4 weeks (n = 30) and 8 weeks (n = 30) postoperatively. For each timepoint, eight tissues were used for histologic staining and electron microscopy, 15 tissues were used for biomechanical testing, and seven tissues were used for hydroxyproline assay and quantitative polymerase chain reaction. Histopathology was determined qualitatively by hematoxylin and eosin and Masson staining, while fiber diameter was measured quantitatively by transmission electron microscopy. Biomechanical properties were measured using cyclic loading tests and load-to-failure tests. The healing outcome was quantitatively judged through healing-related genes and proteins. Results At 4 weeks and 8 weeks postoperatively, the peracetic acid-ethanol combined irradiation group visually demonstrated the best continuity and minimal peripheral adhesions. Histologic staining showed that tendon fibers in the peracetic acid-ethanol combined irradiation group maintained consistent alignment without notable disruptions or discontinuities, and there was a qualitatively observed increase in the number of infiltrating cells compared with the control group at the 4-week timepoint (444 ± 49 /mm² versus 256 ± 43 /mm², mean difference 188 /mm² [95% confidence interval 96 to 281]; p < 0.001). At 8 weeks postoperatively, the tendon fiber diameter in the peracetic acid-ethanol combined irradiation groups was similar to that of the control group (0.23 ± 0.04 μm versus 0.21 ± 0.03 μm, mean difference 0.02 μm [95% CI -0.04 to 0.08]; p = 0.56). At 8 weeks postoperatively, the peracetic acid-ethanol combined irradiation group exhibited better properties in terms of both ultimate load (129 ± 15 N versus 89 ± 20 N, mean difference 40 N [95% CI 7 to 73]; p = 0.02) and energy absorption density (17 ± 6 kJ/m² versus 8 ± 4 kJ/m², mean difference 8 kJ/m² [95% CI 0.7 to 16]; p = 0.004) compared with the control group. Gene expression analysis revealed higher expression levels of COL1A1 (2.1 ± 0.8 versus 1.0 ± 0, mean difference 1.1 [95% CI 0.1 to 2.1]; p = 0.003) and MMP13 (2.0 ± 0.8 versus 1.0 ± 0, mean difference 1.0 [95% CI 0.4 to 1.6]; p = 0.03) in the peracetic acid-ethanol combined irradiation group than in the control group. There was a higher amount of collagen Type I in tendons treated with peracetic acid-ethanol combined irradiation than in the control group (0.36 ± 0.03 versus 0.31 ± 0.04, mean difference 0.05 [95% CI 0.01 to 0.09]; p = 0.02). Conclusion Treatment with peracetic acid-ethanol combined irradiation did not have any discernible adverse effect on the histology, fiber diameter, enzymatic resistance, collagen content, or biomechanical strength of the allograft tendons compared with the control group. Peracetic acid-ethanol combined irradiation treatment had a positive impact on remodeling of the extracellular matrix and realignment of collagen fibers. Clinical Relevance This sterilization method could be helpful to expand the scope and frequency with which allogeneic materials are applied. The long-term healing effect and strength of allograft tendons must be tested before clinical use, and it is necessary to conduct comparative studies on autografts and synthetic materials that are currently widely used clinically. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate whether 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) combined with n-hydroxysuccinimide (NHS) can repair tendon damage caused by peracetic acid–ethanol and gamma irradiation sterilization. The semitendinosus tendons of 15 New Zealand white rabbits were selected as experimental materials, and the tendons were sterilized in a solution containing 1% (v/w) peracetic acid and 24% (v/w) ethanol. After 15 kGy gamma irradiation sterilization, the tendons were randomly divided into three groups (n = 10). The tendons were repaired with EDCs of 0, 2.5 and 5 mM combined with 5 mM NHS for 6 h, the tendons were temporarily stored at − 80 ± °C. The arrangement and spatial structure of collagen fibers were observed by light microscopy and scanning electron microscopy, the collagen type and collagen crimp period were observed under a polarizing microscope, and the collagen fibril diameter and its distribution were measured by transmission electron microscopy, from which the collagen fibril index and mass average diameter were calculated. The resistance of collagen to enzymolysis was detected by the free hydroxyproline test, and tensile fracture and cyclic loading tests of each group of tendons were carried out, from which the elastic modulus, maximum stress, maximum strain, strain energy density and cyclic creep strain were calculated. The obtained results showed that the gap between loose collagen fibers in the 0 mM control group was wider, the parallel arrangement of tendons in the 2.5 and 5 mM groups was more uniform and regular and the fiber space decreased, the crimp period in the 5 mM group was lower than that in the 0 mM group (P < 0.05), and the concentration of hydroxyproline in the 5 mM group (711.64 ± 77.95 μg/g) was better than that in the control group (1150.57 ± 158.75 μg/g). The elastic modulus of the 5 mM group (424.73 ± 150.96 MPa) was better than that of the 0 mM group (179.09 ± 37.14 MPa). Our results show that EDC combined with NHS can repair damaged tendons after peracetic acid–ethanol and gamma radiation treatment, and 5 mM EDC has better morphological performance, anti-enzymolysis ability and biomechanical properties than 2.5 mM EDC. [ABSTRACT FROM AUTHOR]

Holocellulose fibers exhibit excellent recycling performance and are increasingly gaining attention for addressing the hornification effect that occurs during the recycling of waste paper products. However, the mechanism by which hemicellulose components in holocellulose fibers impact fiber reuse remains unknown. In this study, birch holocellulose was prepared through peracetic acid delignification. The hemicellulose content was adjusted using alkali treatment and xylanase treatment, both based on holocellulose. The removal of hemicellulose resulted in an increase in hornification and porosity growth rate during the recycling process due to these pretreatments. Consequently, fibers subjected to alkali treatment and xylanase treatment exhibited diminished mechanical performance with each recycling cycle. In particular, after five recycling runs, alkali treatment paper experienced a significant reduction in ultimate strength, dropping from 48 to 11 MPa, representing a 77% decrease. In contrast, hemicellulose-rich holocellulose paper retained an ultimate strength as high as 56 MPa (reduced from 81 MPa), marking a 33% decrease. The high hemicellulose content in holocellulose fibers proved advantageous for preserving the network structure of fibers and impeding the co-crystallization and aggregation of fibers during the recycling process, ultimately ensuring the maintenance of mechanical performance, including tensile, tearing, and bursting strength. [ABSTRACT FROM AUTHOR]

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Natural fiber composites have been extensively studied for structural applications, with recent exploration into their potential for various uses. This study investigates the impact of chemical treatments on the properties of Brazilian jute woven fabric/polyester resin composites. Sodium hydroxide, hydrogen peroxide, and peracetic acid were utilized to treat the jute fabrics, followed by resin transfer molding (RTM) to form the composites. Evaluation included water absorption, flexural strength, tensile strength, and short-beam strength. The alkaline treatment induced changes in the chemical composition of the fibers' surface. Chemical treatments resulted in increased flexural and short-beam strength of the composites, with no significant alterations in tensile properties. The hydrogen peroxide treatment exhibited lower water absorption, suggesting its potential as a viable option for enhancing the performance of these composites. [ABSTRACT FROM AUTHOR]