Search

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.

Background: Inactivation of infectious liquid waste can be performed by different means, including autoclaving or chemical inactivation. Autoclaving is most widely used, but cannot always be implemented, so that chemical inactivation is a possible alternative. However, its efficacy has to be proven by in-house validation. Here, we provide an easy-to-implement validation process adapted from existing standards. Methods: The bactericidal activity of two commercially available disinfectants, containing glucoprotamine or peracetic acid, was tested on two gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pneumoniae (SP). Quantitative suspension tests were adapted from the European standard EN 13727. Membrane filtration was used to remove any trace of the active antiseptic. The stability of working solutions and the effect of different organic loads were also assessed. Further, the aquatic toxicity of glucoprotamine was tested on the viability and behavior of zebrafish larvae. Results: Peracetic acid was highly efficient against both strains, even at a working concentration of 0.25% for 1 minute S. pneumoniae was also highly sensitive to glucoprotamine, whereas MRSA required either higher concentrations (1%) or longer exposure times (30 min) at lower concentrations. Further, the lethal dosis that kills 50% of the embryos (LD50) for glucoprotamine was 3–3.5 mg/L using the zebrafish Embryo Acute Toxicity Test. Conclusion: We could confirm the very high efficacy of glucoprotamine- and peracetic-based disinfectants to inactivate liquid waste containing gram-positive bacteria. Also considering aquatic toxicity, this methodology could help laboratories to establish validated procedures for chemical inactivation of infectious liquid wastes relevant to their institution, balancing efficacy, and environmental issues. [ABSTRACT FROM AUTHOR]

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]

Diethyl phthalate (DEP) is a commonly utilized plasticizer that has gained significant attention due to its widespread occurrence in the environment and its harmful impact on human health. The primary objective of this study was to evaluate and compare several (ultraviolet) UV-(peracetic acid) PAA advanced oxidation processes based on hydroxyl radicals to degrade DEP. The effect of UV-LEDs incorporating PAA at different UV ranges (UV-A, λ = 365 nm; UV-C, λ = 254 nm and VUV, λ = 254 nm) was evaluated. The results demonstrated that DEP was successfully degraded in both the UVC/PAA (removal rate 98.28%) and VUV/PAA (removal rate 97.72%) processes compared to the UVA/PAA process (removal rate of 2.71%). The competitive method evaluated the contribution of R-O•, which were 24.08% and 33.92% in UVC/PAA and VUV/PAA processes, respectively. We also evaluated the effects of peroxymonosulfate (PMS) dosages, UV irradiation, pH and anion coexistence on the removal of DEP. In the UVC/PAA system, DEP degradation was particularly effective (removal rate about 95.52%) over a wider pH range (3–9). As the concentration of HCO3− ions increased, there may have been some inhibition of DEP removal. The inhibitory effect of HA and Cl− ions on DEP removal were negligible. Analysis of the intermediates revealed that DEP degradation primarily occurred via two pathways: hydrolysis and hydroxylation reactions. This study presents a potential mnethod for the removal of phthalates and offers some guidance for the selection of appropriate disinfection technologies in drinking water treatment. [ABSTRACT FROM AUTHOR]

Sustainable bleaching of Juton (a Jute-Cotton blend) fabric with peracetic acid (PAA) and bleach activators was investigated. The whiteness effect of PAA can be enhanced by adding bleach activators such as tetraacetylethylenediamine (TAED) and sodium nonanoyloxybenzenesulfonate (NOBS). This study evaluated six distinct bleaching methods on Juton fabric: using only PAA, using PAA/TAED, using PAA/NOBS, using only H2O2 (HP), using HP/TAED, and using HP/NOBS. The Juton fabric was bleached at different temperatures, in various pHs, and for different durations, using PAA, HP, and their combinations with TAED and NOBS. FT-IR, XPS, and SEM analyses were conducted to examine the chemical structure, bonding, and surface morphology of the Juton fabrics following the bleaching process. Fabrics bleached with PAA in combination with NOBS exhibited enhanced whiteness, oxygen-to-carbon (O/C) ratios, and mechanical properties. [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

In response to the urgent need for efficient degradation of emerging organic contaminants, this study has developed a novel catalytic system based on an original Fe-doped aerogel catalyst (FeCAS) and its carbonization-enhanced variant (FeCAS-400), designed to improve the activation performance of peracetic acid (PAA). The FeCAS/PAA achieves a remarkable 96.1% degradation of sulfamethoxazole (SMX) without external energy input, while the FeCAS-400/PAA further elevates the SMX removal rate to 98.4% (kobs = 0.326 min−¹) and demonstrates effectiveness across a broad pH range of 3–11. Theoretical calculations reveal that carbonization enhances electron transfer between iron–carbon substrates, which contributes to improved catalytic performance. The system also exhibits versatility in removing a wide range of prevalent contaminants and proves effective in real water matrices. This synergistic approach, combining aerogels with metal–carbon electron transfer, holds promise for an extension to other advanced oxidation processes, contributing to the assurance of water quality safety and sustainability. [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.

Mushrooms are traditionally packaged in single‐use retail packaging made of commercially available polyethylene terephthalate. It is now necessary to replace these plastics, which, after use, significantly pollute the environment, with biodegradable alternatives. After the jute fibre is extracted from the jute plant, the jute stick is left behind and can be used to make packing paper. Jute stick was used as a raw material for the development of packaging paper following three pulping methods: (i) alkaline sulfite anthraquinone methanol (ASAM); (ii) kraft; and (iii) peracetic acid (acid) methods. An analysis was conducted on the pulps' yield, chemical composition, crystallinity, whiteness, and cost‐effectiveness. From each pulp, three gram per square metre (GSM) of paper (100, 200, and 300) were produced and their rates of water vapour transfer, swelling, and physical and mechanical absorption were assessed. The acid approach was the most expensive, whereas the ASAM method produced the highest yield (50.2%). The acid pulp paper had the longest folding endurance with three to five hundred double folds. Although kraft paper's water absorption time was just 0.5–1 min, it had a higher tensile index than ASAM paper. For this reason, ASAM200 paper was chosen for making the packing tray. After ten days, there was no discernible difference between the mushrooms packed in the ASAM200 packing paper tray and those in commercially available PET containers kept at 5°C and 65% relative humidity in terms of weight loss, colour, texture, and general acceptability. Therefore, it was discovered that ASAM200 paper might be a sustainable option for packing highly respiring fruits and vegetables. [ABSTRACT FROM AUTHOR]

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]

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]

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]

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]

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]

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.