Peracetic Acid Research Articles

Antimicrobial Effectiveness of Clove Oil in Decontamination of Ready-to-Eat Spinach (Spinacia oleracea L.)

Due to an increased demand for natural food additives, clove oil was assessed as a natural alternative to chemical disinfectants in produce washing. This study assessed the antimicrobial activity of 5 and 10% (v/v) clove oil-amended wash liquid (CO) using a zone of inhibition (ZIB) test and determined the time required to completely inactivate pathogenic bacteria using bacterial death curve analysis. A washing experiment was used to evaluate CO’s ability to inhibit bacterial growth on inoculated RTE spinach and in the wash water. The findings showed that Shigella flexneri, Salmonella Typhimurium, and Salmonella enterica recovery were completely inhibited within 5 min. Escherichia coli and Staphylococcus aureus recovery were completely inhibited at 10 and 30 min, respectively. The ZIB test showed that 5% CO had the highest inhibitory effect on both Salmonella strains and E. coli with approximately 10 mm ZIB diameter. Additionally, 5% CO completely inactivated all bacterial strains on spinach samples and in the wash water except for S. aureus. A total of 80 mg/L peracetic acid (PAA) resulted in >2log CFU/mL recovery on experimental washed samples. These findings suggest that 5% CO was highly effective in inhibiting microbial growth on RTE spinach, potentially contributing to sustainable food safety and shelf-life extension strategies.

Experimental study of extracellular vesicle-small intestine submucosa novel biological composite for urethral stricture repair and reconstruction

Background Urethral stricture (US) is a common condition that considerably affects patients’ quality of life. Objectives This study aimed to explore the adoption value of the extracellular vesicle (EV)- small intestinal submucosa (SIS) complex in the repair of USs. Methods EVs were extracted from healthy male New Zealand white rabbits, and SIS was prepared using peracetic acid (PAA) oxidation and decellularization. The morphology and particle size of the prepared EV-SIS complex were evaluated using electron microscopy and qNano nanoparticle analyzer, and the labeled proteins of EVs were detected using Western blot method. EV-SIS the complex was implanted in a rabbit model of US, and urodynamic parameters were assessed. Results The EV-SIS complex displayed a full morphology, intact membrane structure, and uniform particle size. The protein concentration of EVs in the complex was approximately 0.351 µg/µL, with a yield of approximately 1.86 µg/106 cells. The complex exhibited remarkable repair effects in the rabbit model of US, with bladder capacity, maximal urethral pressure, and minimal urethral pressure all markedly superior to those in the US group ( P < 0.05). Conclusion The EV-SIS complex demonstrates potential clinical value in the repair of USs, improving urodynamic parameters, and offering a promising therapeutic option for patients with US.

Emerging biofilm formation and disinfectant susceptibility of ESBL-producing Klebsiella pneumoniae

Klebsiella pneumoniae is an opportunistic pathogen responsible for various infections in humans and animals. It is known for its resistance to multiple antibiotics, particularly through the production of Extended-Spectrum Beta-Lactamases (ESBLs), and its ability to form biofilms that further complicate treatment. This study aimed to isolate and identify K. pneumoniae from animal and environmental samples and assess commercial disinfectants’ effectiveness against K. pneumoniae isolates exhibiting ESBL-mediated resistance and biofilm-forming ability in poultry and equine farms in Giza Governorate, Egypt. A total of 320 samples, including nasal swabs from equine (n = 60) and broiler chickens (n = 90), environmental samples (n = 140), and human hand swabs (n = 30), were collected. K. pneumoniae was isolated using lactose broth enrichment and MacConkey agar, with molecular confirmation via PCR targeting the gyrA and magA genes. PCR also identified ESBL genes (blaTEM, blaSHV, blaCTX-M, blaOXA-1) and biofilm genes (luxS, Uge, mrkD). Antimicrobial susceptibility was assessed, and the efficacy of five commercial disinfectants was evaluated by measuring inhibition zones. Klebsiella pneumoniae was isolated from poultry (13.3%), equine (8.3%), wild birds (15%), water (10%), feed (2%), and human hand swabs (6.6%). ESBL and biofilm genes were detected in the majority of the isolates, with significant phenotypic resistance to multiple antibiotics. The disinfectants containing peracetic acid and hydrogen peroxide were the most effective, producing the largest inhibition zones, while disinfectants based on sodium hypochlorite and isopropanol showed lower efficacy. Statistical analysis revealed significant differences in the effectiveness of disinfectants against K. pneumoniae isolates across various sample origins (P < 0.05). The presence of K. pneumoniae in animal and environmental sources, along with the high prevalence of ESBL-mediated resistance and biofilm-associated virulence genes, underscores the zoonotic potential of this pathogen. The study demonstrated that disinfectants containing peracetic acid and hydrogen peroxide are highly effective against ESBL-producing K. pneumoniae. Implementing appropriate biosecurity measures, including the use of effective disinfectants, is essential for controlling the spread of resistant pathogens in farm environments.

Odorant production surges induced by exogenous oxidative stress: An overlooked risk in PAA-based moderate preoxidation for algal-laden water.

Moderate preoxidation is feasible for odor-producing algae treatments, usually requiring trade-offs in algal removal and integrity maintenance. However, dosing oxidants may cause internal oxidative homeostasis imbalances and secondary odorous metabolite responses, adding new trade-offs for moderate treatments. Peracetic acid (PAA)/Fe processes are promising strategies in moderate treatments and thus were applied to examine how to achieve the following three trade-offs: good algal removal, no odorant increases and no releases. For algal removal, the highest removal efficiency was 71.1 %, 87.0 % and 98.1 %, respectively, in PAA/Fe(Ⅲ) separate, PAA/Fe(Ⅱ) separate and PAA/Fe(Ⅱ) simultaneous process. Odorant responses always followed a pattern of "promotion-low dosages, inhibition-high dosages", with the highest production reaching 3.91-fold of the control without PAA addition, well above odorant threshold concentrations (500 ng/L). Instant releases did not occur, yet with delayed releases observed during sludge retention in sedimentation tanks (5, 16 h). It was verified that exogenous oxidative stress stimulated odorant generation with multiple reactive species. Among them, PAA oxidant was crucial in algal removal and odorant promotion; R-O· and ·OH caused odorant generation and degradation, respectively. Overall, PAA/Fe(Ⅱ) processes were more suitable for moderate treatments, simultaneously avoiding odorant increases and allowing sludge retention. This work provides a novel perspective for moderate preoxidation, highlighting instant odorant generation and delayed releases triggered by exogenous PAA stressors.

Detection of Viable but Nonculturable E. coli Induced by Low-Level Antimicrobials Using AI-Enabled Hyperspectral Microscopy.

Rapid detection of bacterial pathogens is essential for food safety and public health, yet bacteria can evade detection by entering a viable but nonculturable (VBNC) state under sublethal stress, such as antimicrobial residues. These bacteria remain active but undetectable by standard culture-based methods without extensive enrichment, necessitating advanced detection methods. This study developed an AI-enabled hyperspectral microscope imaging (HMI) framework for rapid VBNC detection under low-level antimicrobials. The objectives were to (i) induce the VBNC state in Escherichia coli K-12 by exposure to selected antimicrobial stressors, (ii) obtain HMI data capturing physiological changes in VBNC cells, and (iii) automate the classification of normal and VBNC cells using deep learning image classification. The VBNC state was induced by low-level oxidative (0.01% hydrogen peroxide) and acidic (0.001% peracetic acid) stressors for 3days, confirmed by live-dead staining and plate counting. HMI provided spatial and spectral data, extracted into pseudo-RGB images using three characteristic spectral wavelengths. An EfficientNetV2-based convolutional neural network architecture was trained on these pseudo-RGB images, achieving 97.1% accuracy of VBNC classification (n=200), outperforming the model trained on RGB images at 83.3%. The results highlight the potential for rapid, automated VBNC detection using AI-enabled hyperspectral microscopy, contributing to timely intervention to prevent foodborne illnesses and outbreaks.

Control of rotavirus by sequential stress of disinfectants and gamma irradiation in leafy vegetable industry.

Rotavirus (RV) causes severe gastroenteritis in infants and young children worldwide. Fresh produce has been reported as a source of RV infection during production and harvesting, leading to foodborne illness. Cases of contamination from contact surfaces have also been reported. Therefore, this study applied chemical methods (chlorine dioxide [ClO2], peracetic acid [PAA]), physical methods (gamma irradiation), and a combination of methods (disinfectants+gamma irradiation) to inactivate RV on food contact surfaces (stainless steel) and food (lettuce). Furthermore, the changes in food quality after the combined treatments were assessed. The results of the chemical treatment showed that RV was reduced below the detection limit after treatment for 1min with 20ppm ClO2 or 120ppm PAA in RV suspension. On stainless steel, treatment with 200ppm ClO2 or 2,000ppm PAA reduced contaminated RV by more than 4 log. A 5min treatment with 50ppm ClO2 or 80ppm PAA on lettuce reduced the RV by 1.79 and 0.75 log, respectively. Treatment with 4kGy of gamma irradiation resulted in more than 5 log reduction in suspensions and 3.27 log reduction on food. The sequential treatments, including 30ppm ClO2 followed by 1.5kGy gamma irradiation and 80ppm PAA followed by 1.5kGy gamma irradiation, showed additional inactivation effects (p<0.05) compared to each single treatment. No changes in food quality (color difference and texture) were observed after any treatments, suggesting that the combined treatment of both ClO2 and gamma irradiation and PAA and gamma irradiation can be applied in the fresh food industry to reduce RV contamination.

Effect of Pimenta Essential Oil and Peracetic Acid as Pre-Grind Dip Treatments on Emerging Salmonella, Spoilage Bacteria, and Quality Attributes of Ground Turkey during Chilled Storage

Effect of Pimenta Essential Oil and Peracetic Acid as Pre-Grind Dip Treatments on Emerging Salmonella, Spoilage Bacteria, and Quality Attributes of Ground Turkey during Chilled Storage

Differences in Salmonella Serovars Response to Lactic Acid and Peracetic Acid Treatment Applied to Pork.

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 400ppm. Pork samples were assigned to each serovar, inoculated with 6.0 Log CFU/cm2Salmonella (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 400ppm 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<0.05) compared with the control, indicating that these three serovars are more susceptible to PAA treatments than the rest. The behavior of different Salmonella serovars under stress conditions can give us an insight into how these pathogens survive processing.

Self-enhanced degradation of tetramethylphosphonate by the micron-scale iron-copper (Fe/Cu) bimetals activated peracetic acid

Self-enhanced degradation of tetramethylphosphonate by the micron-scale iron-copper (Fe/Cu) bimetals activated peracetic acid

Ultraviolet-Shielded Transparent Wood with Improved Interface for Insulating Windows.

Recently, transparent wood (TW) has been considered for many energy-efficient building products, such as windows and decorations. However, the existing TW still faces issues with size and thickness, as well as problems with functional fillers affecting the optical and mechanical properties of TW, which limits its wide application in the window products. In this study, a wood composite material (WCM) with good optical, mechanical, and thermal insulation and UV-shielding properties was prepared by using delignified wood (DW), methyl methacrylate (MMA), and 4-vinylphenylboric acid (VPBA). Compared with NaClO2 delignification, peracetic acid (PAA) preserves hemicellulose and a more stable pore structure, which facilitates the filling of polymers into the DW template, resulting in the preparation of more extensive and thicker TW. VPBA, as a functional raw material for UV shielding, on the one hand, improves the interfacial compatibility of the TW, thus improving the optical properties (transmittance of about 90%, haze of about 55%) and mechanical properties (64.5 MPa). On the other hand, WCM was found to effectively block UV-C, UV-B (about 100%), and UV-A (about 90%) radiation while maintaining sufficient visible light transmittance. In addition, as an insulating window, WCM has low thermal conductivity and can maintain a high temperature for a long time after the loss of solar radiation, which is an ideal thermal insulation material and is expected to become a potential substitute for conventional glass.

Optimized Ultrasound-Assisted Peracetic acid pretreatment approach for enhanced sugars and decreased inhibitors for bio-ethanol production from OPEFB

The Oil palm empty fruit bunch (OPEFB) constitutes the primary solid waste produced by the palm oil sector. This study aims to identify the best pretreatment conditions for increasing the sugars yield and lowering that of inhibitors in ultrasonic-treated OPEFB biomass using PAA. To study the individual and combined effects of pretreatment independent process variables, such as PAA concentration, sonication time, and temperature on the response variables glucose, xylose, arabinose, furfural, and HMF response surface approach, the central composite design (CCD) model was used. According to the findings from response surface analysis, the optimal conditions to obtain the highest sugar yield with the least amount of inhibitors were PAA concentration (10%), sonication time (120 min), and temperature (60ºC) for pretreatment, which produced 32.19, 15.83, and 5.92 g/L of glucose, xylose, and arabinose sugars, respectively, and about 1.86 and 3.2 g/L of furfural and HMF, respectively. The strong agreement observed between the experimental and predicted results. Detoxification with activated carbon, results in decreasing the inhibitory compounds in the hydrolysate. Subsequent fermentation studies demonstrated that hydrolysate with higher sugar content resulted in achieving a greater ethanol yield (67.5 g/L) than low ultrasonicated OPEFB (56.7 g/L).

Bicarbonate ions promote rapid degradation of pollutants in Co(II)Fe(II)/peroxyacetic acid systems.

Peroxyacetic acid (PAA), as an oxidizing agent, has gained significant attention in the field of advanced oxidation because of its low toxicity and high degradation capacity. In this study, cobalt-iron-based Prussian blue analogs (Co-PBAs) were utilized for the first time to activate PAA for tetracycline degradation. In the Co-PBAs/PAA system, organic radicals (RO•) and high-valent metal oxides are mainly produced. TC is efficiently removed in a wide pH range (5-9) and a variety of interferences (Cl-, SO42-, bicarbonate ions (HCO3-), humic acid, and the actual water bodies) in water bodies due to the specificity of RO•. Interestingly, the catalytic rate of the Co-PBAs/PAA system was significantly accelerated in the presence of HCO3- (kobs increasing from 0.171 min-1 to 0.534 min-1). This enhancement is attributed to the reaction between HCO3- and PAA, and carbonate radicals (•CO3-) and acetyl peroxyl radicals (CH3C(O)OO•) are generated and then react with the phenolic hydroxyl group of TC. In this study, the mechanism of PAA activation by Co-PBAs was revealed, and PAA-based advanced oxidation process enhanced by HCO3- was provided for the removal of pollutants from wastewater.

Mechanistic Insights into Sulfamethazine Degradation by Defect-Rich MnO2-Activated Peracetic Acid

Mechanistic Insights into Sulfamethazine Degradation by Defect-Rich MnO₂-Activated Peracetic Acid

Comparison of UV/PAA and VUV/PAA Processes for Eliminating Diethyl Phthalate in Water

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.

Evaluation of aqueous chlorine and peracetic acid sanitizers to inactivate protozoa and bacteria of concern in agricultural water.

This research is critical to inform decisions regarding the application and use of sanitizers in pre-harvest agricultural water settings to enhance food safety. Understanding the effectiveness of chlorine (Cl) and peracetic acid (PAA) on bacteria and protozoa will allow for the more efficient and practical use of these sanitizers, thus improving agricultural practices in ways that are beneficial to both growers and consumers.

Intensive electron transfer of a single-atom Fe-based catalytic ceramic membrane for municipal wastewater treatment: The synergistic effects of nitrogen vacancy defect and ultrathin nanostructure.

The integration of membrane separation with heterogeneous advanced oxidation processes is a prospective strategy for the elimination of contaminants during wastewater treatment. Fe-based catalysts and the green oxidant peracetic acid (PAA) are desirable candidates for the development of catalytic membranes because they are environmentally friendly. However, the construction of catalytic ceramic membranes (CMs) modified with efficient Fe-based catalysts that generate increased amounts of high-valent Fe-O species during PAA activation for the degradation of specific pollutants, especially during instantaneous membrane filtration, remains challenging. Herein, a single-atom Fe-based catalytic CM was fabricated and further optimized via the "electron enrichment + electron-transfer enhancement" method, which specifically refers to the simultaneous introduction of nitrogen vacancy (Nv) defects and the construction of ultrathin nanostructures. The CM-UCNv-Fe/PAA system exhibited outstanding bisphenol A (BPA) removal performance, with a first-order rate constant of 0.078 ms-1 (4680 min-1), which was 37 times greater than that of CM-BCN-Fe/PAA system (126 min-1). In addition, the remarkable environmental adaptability, stability and low Fe leakage underscored its practical application potential. Mechanistic investigations revealed that Fe(V)=O was the predominant reactive oxygen species. Multi-scaled characterization and theoretical calculations confirmed that engineered Nv defects facilitated the construction of electron-rich single-atom Fe sites, which had the potential to supply more electrons. Porous ultrathin nanosheets exposed more Fe active sites, and many microinterfaces within the catalytic layers of the CM increased the possibility of contact between the Fe sites and PAA. The synergy of them enabled intensive electron transfer from Fe sites to PAA, which was the driving force for Fe(V)=O conversion during transient membrane filtration. In addition, the efficacy of the catalytic CM in municipal wastewater treatment and membrane fouling control were investigated. This work expands the research on the intensive electron transfer of a single-atom Fe-based catalytic CM for increased Fe(V)=O conversion via Nv defect introduction and ultrathin nanostructure construction.

Substituent structure variances alter degradation pathways of sulfonamides in UV/PAA system: Insights from intermediates, ROS, and DFT calculations.

Sulfonamides (SAs) are one of the major emerging contaminants of concern, but comparative studies on the degradation of different types of SAs are still limited. This work comprehensively compared the degradation of sulfadiazine (SDZ), sulfamethoxazole (SMX) and sulfathiazole (STZ) under UV light in peracetic acid (PAA) from both experimental and theoretical aspects, as they represent two structural classes based on substituent differences. The two SAs with five-membered heterocyclic substituents (SMX, STZ) generally decomposed at faster rates, with SMX degrading up to 10 times faster than SDZ (pH = 3; PAA dosage = 80 mg/L). For all three SAs, the degradation efficiency stayed high across pH levels, peaking at pH 9 for SDZ and STZ, and at pH 3 for SMX. Free radical scavenging experiments and EPR tests proved that the degradation of SAs involved various free radicals, among which 3SA*s and •OH played a major role. Fukui functions indicated N(7) in aniline groups of SDZ and SMX had the highest reactivity, while in STZ, S(23) in the thiazole moiety was the most active site. The degradation pathways were proposed and compared and the cleavage of S-C bond was observed in all three SAs and hydroxylation was the most common reaction. This study elucidated the impacts of different substituent structures on the degradation of three sulfonamide drugs in the UV/PAA system, contributing to a better understanding of the degradation behavior of various types of sulfonamide drugs in water treatment.

Waste manganese sand activated peracetic acid for efficient degradation of emerging contaminants: Resource utilization and dual-phase mechanism

Waste manganese sand activated peracetic acid for efficient degradation of emerging contaminants: Resource utilization and dual-phase mechanism

Enhanced Mn(II)/peracetic acid by nitrilotriacetic acid to degrade organic contaminants: Role of Mn(V) and organic radicals

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.

Synergistic iron enhanced aerogel and peracetic acid for degradation of emerging organic contaminants

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.