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Environmental Pollution (Barking, Essex... Sep 2023Light and ultrasound have been tested as physical factors activating peracetic acid (PAA) to oxidize bisphenols (BPs). Based on the chemometric approach of the Taguchi...
Light and ultrasound have been tested as physical factors activating peracetic acid (PAA) to oxidize bisphenols (BPs). Based on the chemometric approach of the Taguchi method, UV irradiation with a wavelength of 254 nm was selected as the optimal type of PAA activator. The effectiveness of the UV/PAA system was also compared with other oxidation methods. Under optimal conditions ([BPs] = 1 mg/L, 1 mM PAA, pH 9, UV 254 nm) the tested bisphenols are completely degraded within 15-60 min. The influence of the matrix on the process of organic micropollutants removal in the UV/PAA system was also investigated. Toxicity assessment leads to the conclusion that the reaction mixture shows limited toxicity towards living organisms.
Topics: Peracetic Acid; Wastewater; Oxidation-Reduction; Ultraviolet Rays; Hydrogen Peroxide; Water Pollutants, Chemical
PubMed: 37336351
DOI: 10.1016/j.envpol.2023.122029 -
Journal of Food Protection Jul 2024Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls...
Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls due to contamination with Salmonella. A study was conducted to determine the fate of Salmonella on apple slices, following immersion in three antimicrobial solutions (viz., ε-polylysine [epsilon-polylysine or EP], sodium bisulfate [SBS], or peracetic acid [PAA]), and subsequent hot air dehydration. Gala apples were aseptically cored and sliced into 0.4 cm thick rings, bisected, and inoculated with a five-strain composite of desiccation-resistant Salmonella, to a population of 8.28 log CFU/slice. Slices were then immersed for 2 min in various concentrations of antimicrobial solutions, including EP (0.005, 0.02, 0.05, and 0.1%), SBS (0.05, 0.1, 0.2, and 0.3%), PAA (18 or 42 ppm), or varying concentrations of PAA + EP, and then dehydrated at 60°C for 5 h. Salmonella populations in positive control samples (inoculated apple slices washed in sterile water) declined by 2.64 log after drying. In the present study, the inactivation of Salmonella, following EP and SBS treatments, increased with increasing concentrations, with maximum reductions of 3.87 and 6.20 log (with 0.1 and 0.3% of the two compounds, respectively). Based on preliminary studies, EP concentrations greater than 0.1% did not result in lower populations of Salmonella. Pretreatment washes with either 18 or 42 ppm of PAA inactivated Salmonella populations by 4.62 and 5.63 log, respectively, following desiccation. Combining PAA with up to 0.1% EP induced no greater population reductions of Salmonella than washing with PAA alone. The addition of EP to PAA solutions appeared to destabilize PAA concentrations, reducing its biocidal efficacy. These results may provide antimicrobial predrying treatment alternatives to promote the reduction of Salmonella during commercial or consumer hot air drying of apple slices.
Topics: Malus; Peracetic Acid; Salmonella; Polylysine; Food Microbiology; Humans; Colony Count, Microbial; Sulfates; Food Preservation; Dose-Response Relationship, Drug; Desiccation; Food Contamination; Food Handling; Consumer Product Safety
PubMed: 38734414
DOI: 10.1016/j.jfp.2024.100297 -
Microscopy Research and Technique Apr 2020The aim was to assess the effects of 1% peracetic acid (PAA) as a single endodontic irrigant on microhardness, roughness, and erosion of root canal dentin, compared with...
The aim was to assess the effects of 1% peracetic acid (PAA) as a single endodontic irrigant on microhardness, roughness, and erosion of root canal dentin, compared with 2.5% sodium hypochlorite (NaOCl) and with 2.5% NaOCl combined with 17% EDTA. Forty human, single-rooted tooth hemisections were submitted to Knoop microhardness test, before and after the following irrigation protocols: PAA = 1% PAA; NaOCl = 2.5% NaOCl; NaOCl-EDTA-NaOCl = 2.5% NaOCl +17% EDTA +2.5% NaOCl; and SS = saline. Another 40 roots were instrumented, irrigated with the same protocols, and sectioned longitudinally. The roughness analysis was performed on the mesial section using a confocal laser scanning microscope, whereas erosion was analyzed on each third of the distal section, using a scanning electron microscope. The data were analyzed using ANOVA and Tukey post-tests, and Kruskal-Wallis and Dunn post-tests (α = .05). The PAA and NaOCl-EDTA-NaOCl groups showed no significant differences (p > .05); both promoted reduction in microhardness and increase in roughness, compared with the NaOCl and SS groups (p < .05). NaOCl-EDTA-NaOCl promoted higher erosion in the cervical and middle thirds than the other groups (p < .05); there was no difference among PAA, NaOCl, and SS (p > .05). There was also no difference among the groups regarding the apical third (p > .05). PAA used as a single endodontic irrigant caused reduction in root canal dentin microhardness and increase in roughness in a similar way to NaOCl-EDTA-NaOCl; however, PAA caused less erosion than NaOCl-EDTA-NaOCl.
Topics: Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Peracetic Acid; Root Canal Irrigants; Root Canal Preparation; Sodium Hypochlorite; Surface Properties; Tooth Erosion; Tooth Root
PubMed: 31833180
DOI: 10.1002/jemt.23424 -
Environmental Science & Technology Nov 2023Peracetic acid (PAA) and performic acid (PFA) are two major peroxyacid (POA) oxidants of growing usage. This study reports the first systematic evaluation of PAA, PFA,...
Peracetic acid (PAA) and performic acid (PFA) are two major peroxyacid (POA) oxidants of growing usage. This study reports the first systematic evaluation of PAA, PFA, and chlorine for their disinfection byproduct (DBP) formation potential in wastewater with or without high halide (i.e., bromide or iodide) concentrations. Compared with chlorine, DBP formation by PAA and PFA was minimal in regular wastewater. However, during 24 h disinfection of saline wastewater, PAA surprisingly produced more brominated and iodinated DBPs than chlorine, while PFA effectively kept all tested DBPs at bay. To understand these phenomena, a kinetic model was developed based on the literature and an additional kinetic investigation of POA decay and DBP (e.g., bromate, iodate, and iodophenol) generation in the POA/halide systems. The results show that PFA not only oxidizes halides 4-5 times faster than PAA to the corresponding HOBr or HOI but also efficiently oxidizes HOI/IO to IO, thereby mitigating iodinated DBP formation. Additionally, PFA's rapid self-decay and slow release of HO limit the HOBr level over the long-term oxidation in bromide-containing water. For saline water, this paper reveals the DBP formation potential of PAA and identifies PFA as an alternative to minimize DBPs. The new kinetic model is useful to optimize oxidant selection and elucidate involved DBP chemistry.
Topics: Peracetic Acid; Disinfection; Hydrogen Peroxide; Wastewater; Chlorine; Bromides; Oxidants; Chlorides; Halogenation; Water Purification; Water Pollutants, Chemical; Disinfectants
PubMed: 37489812
DOI: 10.1021/acs.est.3c00670 -
The Science of the Total Environment Aug 2023Preharvest agricultural water has been recognized as one of the routes of contamination for foodborne pathogens during fruit and vegetable production. Several strategies...
Preharvest agricultural water has been recognized as one of the routes of contamination for foodborne pathogens during fruit and vegetable production. Several strategies have been proposed to reduce the risk of pathogens, including preharvest water chemigation, but literature is lacking with regards to microbiological inactivation of common bacterial foodborne pathogens associated with fresh produce contamination, Salmonella enterica, Shiga-toxigenic Escherichia coli (STEC), and Listeria monocytogenes, in surface irrigation water after exposure to chlorine and peracetic acid (PAA). Surface water supplied by a local irrigation district was collected over the summer of 2019. Water was autoclaved, divided into 100 mL samples, and inoculated with a cocktail of five Salmonella, STEC, or Listeria monocytogenes strains or a single strain non-pathogenic E. coli. Samples were then treated with 3, 5, or 7 ppm of free chlorine or PAA, and surviving populations were evaluated using a time-kill assay. A first-order kinetic model was used to fit the inactivation data and obtain the D-values. A secondary model was used to explain the changes due to the type of water, treatment, and microorganism. At a concentration of 3 ppm, the observed and predicted D-values of free chlorine treatments were higher than that of PAA treatments for ground and surface water. Results indicated that PAA was more effective inactivating bacteria than sodium hypochlorite at concentrations of 3 and 5 ppm for both water sources (surface and ground). However, at 7 ppm, the effectiveness of PAA and sodium hypochlorite showed no statistically significant difference for both surface and groundwater. Findings will provide information regarding efficacy of chemical sanitizers like chlorine and PAA for inactivation of Salmonella, Listeria, and STEC in surface water from which treatments can be derived. Ultimately benefitting growers in the selection of an appropriate method for in-field treatment of irrigation water if deemed necessary.
Topics: Peracetic Acid; Chlorine; Water; Listeria monocytogenes; Disinfectants; Sodium Hypochlorite; Food Microbiology; Colony Count, Microbial; Escherichia coli O157; Salmonella; Chlorides; Shiga-Toxigenic Escherichia coli
PubMed: 37142011
DOI: 10.1016/j.scitotenv.2023.163884 -
Water Research Aug 2023In this study, a novel water treatment process combining permanganate (Mn(VII)) and peracetic acid (PAA, CHC(O)OOH) was employed to degrade sulfamethazine (SMT), a...
In this study, a novel water treatment process combining permanganate (Mn(VII)) and peracetic acid (PAA, CHC(O)OOH) was employed to degrade sulfamethazine (SMT), a typical model contaminant. Simultaneous application of Mn(VII) and a small amount of PAA resulted in much faster oxidation of organics than a single oxidant. Interestingly, coexistent acetic acid played a crucial role in SMT degradation, while background hydrogen peroxide (HO) had a negligible effect. However, compared with acetic acid, PAA could better improve the oxidation performance of Mn(VII) and accelerate the removal of SMT more significantly. The mechanism of SMT degradation by Mn(VII)-PAA process was systematically evaluated. Firstly, based on the quenching experiments, electron spin resonance (EPR) results and UV-visible spectrum, singlet oxygen (O), Mn(III) and MnO colloids were the predominant active substances, while organic radicals (R-O) showed negligible contribution. Then, the decay of Mn(VII) in the presence of PAA and HO was investigated. It was found that the coexisting HO accounted for almost all the decay of Mn(VII), PAA and acetic acid both had low reactivity toward Mn(VII). During the degradation process, acetic acid was able to acidify Mn(VII) and simultaneously acted as a ligand to form reactive complexes, while PAA mainly played a role of spontaneously decomposing to produce O, they jointly promoted the mineralization of SMT. Finally, the degradation intermediates of SMT and their toxicities were analyzed. This paper reported the Mn(VII)-PAA water treatment process for the first time, which provided a promising approach for rapid decontamination of refractory organics-polluted water.
Topics: Oxides; Manganese Compounds; Peracetic Acid; Sulfamethazine; Hydrogen Peroxide; Water Pollutants, Chemical; Oxidation-Reduction; Acetic Acid
PubMed: 37413749
DOI: 10.1016/j.watres.2023.120298 -
BMC Oral Health Apr 2022The main goal of an endodontic treatment is a complete debridement of the root canal system; however, currently mechanical shaping and chemical cleaning procedures for...
BACKGROUND
The main goal of an endodontic treatment is a complete debridement of the root canal system; however, currently mechanical shaping and chemical cleaning procedures for this purpose have deemed non-satisfactory.
METHODS
The efficacy of peracetic acid (PAA; 0.5, 1.0, 2.0%), as a root canal irrigation solution, against Enterococcus faecalis (DSM 20478) and Parvimonas micra (DSM 20468) when compared with the one of sodium hypochlorite (NaOCI; 1.0, 3.0, 5.0%), chlorhexidine digluconate (CHX; 0.12, 0.2, 2.0%) and 0.9% NaCI (as a control solution) was in vitro investigated with the agar diffusion and direct contact methods. The inhibition zone diameters observed with the agar diffusion test were determined. The viable bacterial counts (CFU/ml) were calculated with the direct method.
RESULTS
The agar diffusion test showed that all three root canal irrigation solutions had an efficacy against E. faecalis at all concentrations. The largest inhibition zone diameters against E. faecalis were observed with 5.0% NaOCI. At all three concentrations of PAA, NaOCI, and CHX, the inhibition zone diameter increased with increase in concentration. For P. micra, PAA had a similar inhibition zone diameter despite a concentration increase. In contrast, for NaOCI and CHX, the inhibition zone diameter increased with increasing concentration. 2.0% CHX produced the largest inhibition zone diameter against P. micra. For E. faecalis, only the comparison between 2.0% PAA and 5.0% NaOCI showed statistical significance (p = 0.004). For P. micra the efficacy comparison between the lowest, middle, and highest concentrations of each solution, a statistical significance (p < 0.05) was found for all three solutions. After direct contact with PAA, NaOCI and CHX, no viable bacteria could be determined for either P. micra or E. faecalis.
CONCLUSIONS
PAA had a similar antibacterial efficacy as the one of NaOCl and CHX when in direct contact with E. faecalis and P. micra. In the agar diffusion test, PAA showed a similar antibacterial efficacy as the one of CHX and a lower one as the one of NaOCl for E. faecalis.
Topics: Agar; Anti-Bacterial Agents; Chlorhexidine; Dental Pulp Cavity; Enterococcus faecalis; Firmicutes; Humans; Peracetic Acid; Root Canal Irrigants; Sodium Hypochlorite
PubMed: 35397605
DOI: 10.1186/s12903-022-02148-8 -
Food Microbiology Oct 2019The risk posed by outbreaks associated with strawberries together with the safety issues of by-products from chlorine disinfection in the fruit industry has led to a...
The risk posed by outbreaks associated with strawberries together with the safety issues of by-products from chlorine disinfection in the fruit industry has led to a search for alternative sanitizers. The disinfection capacity of peracetic acid (PA) at three concentrations (20, 40 and 80 ppm) and washing times (1 and 2 min) was compared to sodium hypochlorite (200 ppm) (NaClO) treatments and a water control, and its influence on the physico-chemical, biochemical and nutritional quality of strawberries was also studied. Counts on total aerobic mesophilic microorganisms were comparable between NaClO and PA. For yeasts and molds, only NaClO and 80 ppm PA reduced contamination in washing water, but no differences wereobserved in strawberries. Artificially inoculated L.innocua was reduced by at least 4 log cfu/g in strawberry by all the PA treatments, except at 20 ppm PA for 1 min. Total soluble solids, pH, titratable acidity, antioxidant activity and total phenolic content values were maintained after all treatments. Only anthocyanin content was affected. Treatments of 20 and 40 ppm PA did not significantly affect fruit color, and there were no losses on strawberry firmness. PA, as a GRAS substance that has shown potential to reduce microorganisms present in strawberries without any major physicochemical or sensorial alteration, could be a suitable alternative to chlorine disinfection.
Topics: Colony Count, Microbial; Disinfectants; Disinfection; Food Contamination; Food Microbiology; Food Quality; Fragaria; Fruit; Listeria; Peracetic Acid
PubMed: 31202407
DOI: 10.1016/j.fm.2019.05.004 -
The Science of the Total Environment Oct 2021In recent years, there has been increasing interest in using of advanced oxidation processes in water and wastewater decontamination. As a new oxidants peracids, mainly... (Review)
Review
Peracids - New oxidants in advanced oxidation processes: The use of peracetic acid, peroxymonosulfate, and persulfate salts in the removal of organic micropollutants of emerging concern - A review.
In recent years, there has been increasing interest in using of advanced oxidation processes in water and wastewater decontamination. As a new oxidants peracids, mainly peracetic acid (PAA) and peracid salts, i.e. peroxymonosulfate (PMS) and persulfate (PS) are used. The degradation process of organic compounds takes place with the participation of radicals, including hydroxyl (OH) and sulfate (SO) radicals derived from the peracids activation processes. Peracids can be activated in homogeneous systems (UV radiation, d-electron metal ions, e.g. Fe, Co, Mn, base, ozonolysis, thermolysis, radiolysis), or using heterogeneous activation (metals with zero oxidation state, metal oxides, quinones, activated carbon, semiconductors). As a result of oxidation, products of a lower mass than the parent compounds, less toxic, and more susceptible to biodegradation are formed. An important task is to investigate the effect of the peracid activation method and matrix composition on the efficiency of contamination removal. The article presents the latest information about the application of peracids in the removal of organic micropollutants of emerging concern (mainly focuses on endocrine disrupted compounds). The most important information on peracetic acid, peroxymonosulfate and persulfate salts, and methods of their activation are presented. Current uses of these oxidants in organic micropollutants removal are also described. Information was collected on the factors influencing the oxidation process and the effectiveness of pollutant removal. This paper compares PAA, PMS and PS-based processes for the first time in terms of kinetics and efficiency.
Topics: Oxidants; Oxidation-Reduction; Peracetic Acid; Peroxides; Salts; Water Pollutants, Chemical
PubMed: 34380254
DOI: 10.1016/j.scitotenv.2021.148195 -
Environmental Technology Nov 2021In this study, peracetic acid (PAA) activated by Fe(II) was proposed to remove diclofenac (DCF) in polluted water. It was found that Fe(II)/PAA system could effectively...
In this study, peracetic acid (PAA) activated by Fe(II) was proposed to remove diclofenac (DCF) in polluted water. It was found that Fe(II)/PAA system could effectively remove DCF at neutral condition, which has a significant advantage over classical Fenton process. According to the result of scavenging experiment, both hydroxyl radical and peroxy radical were considered to be responsible for the degradation of DCF. The influence of several operational parameters including initial pH, Fe(II) dosage, PAA concentration and common water matrix on DCF removal were investigated. 80% DCF was removed at mild condition (pH 6-7) within 60 s, and its removal rate could be enhanced with the increase in Fe(II) dosage and PAA concentration. Presence of and natural organic matter (NOM) was proved to have a significantly negative impact on DCF degradation. Four probable degradation pathways of DCF were proposed based on the detected reaction products, including hydroxylation, C-N bond cleavage, decarboxylation and dehydrogenation.
Topics: Diclofenac; Ferrous Compounds; Oxidation-Reduction; Peracetic Acid; Water Pollutants, Chemical
PubMed: 32295490
DOI: 10.1080/09593330.2020.1756926