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Journal of Hazardous Materials Oct 2022The disinfection of pathogenic microorganisms in water treatment by peracetic acid (PAA)-based advanced oxidation processes (AOPs) has been gaining increasing concern....
The disinfection of pathogenic microorganisms in water treatment by peracetic acid (PAA)-based advanced oxidation processes (AOPs) has been gaining increasing concern. In this work, the inactivation mechanism, influencing factors and regrowth of two pathogenic Aspergillus species in the system of CuO-activated PAA were studied for the first time. The k values of A. niger and A. flavus inactivated by PAA/CuO system were 3.9 and 2.1-fold higher than those inactivated by PAA alone. PAA concentration and CuO dose were positively correlated with the inactivation efficiency, while humic acid and pH were negatively correlated. The main active species that contributed to the inactivation of fungal spores in PAA/CuO system were •OH, CHC(O)OO• and O. PAA/CuO system had more intense oxidative stimulation and more serious damage to fungal spores according to the analysis of cell membrane integrity and intracellular ROS levels. In addition, the PAA/CuO system was less impacted by the water matrix and kept a good inactivation efficiency in real water samples. The regrowth potential of fungal spores after disinfection was also reduced in PAA/CuO system so as to avoid the risk of biological regrowth. This study provides a feasible PAA-based advanced oxidation method for activating PAA and inactivating fungal spores.
Topics: Copper; Disinfection; Kinetics; Peracetic Acid; Spores, Fungal; Water Purification
PubMed: 35863220
DOI: 10.1016/j.jhazmat.2022.129611 -
Water Research Jun 2024Peracetic acid (PAA) has emerged as a new effective oxidant for various contaminants degradation through advanced oxidation process (AOP). In this study, sulfidated nano...
Peracetic acid (PAA) has emerged as a new effective oxidant for various contaminants degradation through advanced oxidation process (AOP). In this study, sulfidated nano zero-valent iron-copper (S-nZVIC) with low Cu doping and sulfidation was synthesized for PAA activation, resulting in more efficient degradation of sulfamethoxazole (SMX, 20 μM) and other contaminants using a low dose of catalyst (0.05 g/L) and oxidant (100 μM). The characterization results suggested that S-nZVIC presented a more uniform size and distribution with fewer metal oxides, as the agglomeration and oxidation were inhibited. More significantly, doped Cu and sulfidation significantly enhanced the generation and contribution of •OH but decreased that of R-O• in S-nZVIC/PAA/SMX system compared with that of nZVIC and S-nZVI, accounting for the relatively high degradation efficiency of 97.7% in S-nZVIC/PAA/SMX system compared with 85.7% and 78.9% in nZVIC/PAA/SMX and S-nZVI/PAA/SMX system, respectively. The mechanisms underlying these changes were that (i) doped Cu° could promote the regeneration of Fe(Ⅱ) for strengthened PAA activation through mediating Fe(Ⅱ)/Fe(Ⅲ) cycle by Cu(Ⅰ)/Cu(Ⅱ) cycle; (ii) S species might consume part of R-O•, resulting in a decreased contribution of R-O• in SMX degradation; (iii) sulfidation increased the electrical conductivity, thus facilitating the electron transfer from S-nZVIC to PAA. Consequently, the dominant reactive oxygen species transited from R-O• to •OH to degrade SMX more efficiently. The degradation pathways, intermediate products and toxicity were further analyzed through density functional theory (DFT) calculations, liquid chromatography-mass spectrometry (LC-MS) and T.E.S.T software analysis, which proved the environmental friendliness of this process. In addition, S-nZVIC exhibited high stability, recyclability and degradation efficiency over a wide pH range (3.0∼9.0). This work provides a new insight into the rational design and modification of nano zero-valent metals for efficient wastewater treatment through adjusting the dominant reactive oxygen species (ROS) into the more active free radicals.
Topics: Iron; Copper; Peracetic Acid; Oxidation-Reduction; Water Pollutants, Chemical; Catalysis
PubMed: 38642536
DOI: 10.1016/j.watres.2024.121621 -
Journal of Food Protection Apr 2020During poultry slaughter and processing, microbial cross-contamination between individual chickens is possible, as well as from one slaughter animal to the next without...
ABSTRACT
During poultry slaughter and processing, microbial cross-contamination between individual chickens is possible, as well as from one slaughter animal to the next without direct contact. One option for reducing the risk of cross-contamination is to decrease the number of microorganisms on contact surfaces by using disinfectants. The aim is to decontaminate the surfaces coming into direct contact with the carcasses. In the present study, the effectiveness of different disinfectants was investigated in laboratory settings, simulating the conditions in the slaughterhouses and in a chicken slaughterhouse. For this, an artificial residue substance (consisting of yeast extract, albumin, and agar) was developed, tested, and included in the assays. Two disinfectants were tested under laboratory conditions: lactic acid (5 and 6.67%) and peracetic acid (0.33 and 0.5%). At the slaughterhouse, peracetic acid (0.021%) was used. In the laboratory tests, it was found that the peracetic acid solution had the highest disinfection potential with respect to an Escherichia coli strain (reduction >4 log CFU mL-1) at 0.5% without an artificial residue substance. The tested lactic acid solutions also showed the highest disinfection potential against a Pseudomonas aeruginosa strain, without an artificial residue substance. When applying the artificial residue substance, the reduction potential of lactic acid and peracetic acid was decreased to less than 1.4 log CFU mL-1. Application of peracetic acid in the slaughterhouse reduced the number of total aerobic bacteria by more than 4 log CFU mL-1 and the number of Enterobacteriaceae by more than 3 log CFU mL-1, depending on the place of sampling.
Topics: Abattoirs; Animals; Chickens; Colony Count, Microbial; Disinfectants; Food Microbiology; Lactic Acid; Peracetic Acid
PubMed: 32221565
DOI: 10.4315/0362-028X.JFP-19-350 -
Water Research Jan 2022The inactivation of algae by a combined process of peracetic acid and ultraviolet irradiation (UV/PAA) was systematically investigated by choosing Microcystis aeruginosa...
The inactivation of algae by a combined process of peracetic acid and ultraviolet irradiation (UV/PAA) was systematically investigated by choosing Microcystis aeruginosa as the reference algal species. Both hydroxyl (HO) and organic radicals (RO) contributed to the cell integrity loss and RO played the dominant roles. The algae inactivation kinetics can be well fitted by the typical Hom model, showing that the inactivation kinetic curves followed a type of shoulder and exponential reduction. The initial shoulder might be induced by the protection from the cell wall. Although the results from the cell morphology, UV-vis spectra and fluorescence excitation-emission matrices analysis suggested the cell lysis and the release of algal organic matter (AOM) in the UV/PAA process, the AOM could be subsequently degraded. Humic acid (1 - 5 mg/L) inhibited the algal cell inactivation, and the presence of chloride (0.5 - 2 mM) had little effect on the cell viability reduction. However, the addition of bicarbonate (1 - 5 mM) promoted cell integrity loss. The UV/PAA process displayed better performance under the natural water background, demonstrating the extensive potential for the practical application of this approach. This study suggests that the UV/PAA process is an effective strategy for algae inactivation.
Topics: Hydroxyl Radical; Microcystis; Peracetic Acid; Ultraviolet Rays; Water Purification
PubMed: 34794020
DOI: 10.1016/j.watres.2021.117847 -
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 -
Foodborne Pathogens and Disease Oct 2021The objective of this study was to evaluate the inhibitory effect of lactic acid (LA) and peroxyacetic acid (PAA) on the biofilm formation of O157:H7 in beef extract...
The objective of this study was to evaluate the inhibitory effect of lactic acid (LA) and peroxyacetic acid (PAA) on the biofilm formation of O157:H7 in beef extract (BE). BE medium was used as the growth substrate in this study, to make the control effect closer to the situation of the factory. The biofilm inhibitory efficacy of LA and PAA was tested by using a crystal violet staining assay and microscopic examination. And then, extracellular polymeric substance (EPS) production, metabolic activity, and real-time polymerase chain reaction assay were used to reveal the biofilm inhibition mechanism of LA and PAA. The results showed that both LA and PAA significantly inhibited biofilm formation of O157:H7 at minimum inhibitory concentrations (MICs) ( < 0.05). At MIC, LA and PAA showed different effects on the biofilm metabolic activity and the EPS production of O157:H7. Supporting these findings, expression analysis showed that LA significantly suppressed quorum sensing genes ( and ) and adhesion genes (), while PAA downregulated the transcription of extracellular polysaccharide synthesis genes ( and ) and the global regulatory factor . This result revealed that LA and PAA had different biofilm inhibitory mechanisms on O157:H7; LA inhibited the biofilm formation mainly by inhibiting metabolic activity, while PAA inhibited EPS production. This study provided a theoretical basis for the control of O157:H7 biofilm in the actual production process.
Topics: Animals; Biofilms; Cattle; Colony Count, Microbial; Escherichia coli O157; Extracellular Polymeric Substance Matrix; Lactic Acid; Peracetic Acid; Plant Extracts
PubMed: 34197219
DOI: 10.1089/fpd.2021.0012 -
Journal of Applied Microbiology Sep 2021An effective decontamination procedure of personnel wearing personal protective equipment is required by CBRN responders and healthcare workers when dealing with...
Peracetic acid-based disinfectant is the most appropriate solution for a biological decontamination procedure of responders and healthcare workers in the field environment.
AIMS
An effective decontamination procedure of personnel wearing personal protective equipment is required by CBRN responders and healthcare workers when dealing with biological warfare agents or natural outbreaks caused by highly contagious pathogens. This study aimed to identify critical factors affecting the efficacy of peracetic acid (PAA)-based disinfectants and products containing either hydrogen peroxide or sodium hypochlorite under the same conditions.
METHODS AND RESULTS
The influence of concentration, application (contact) time, erroneous human behaviour, interfering substance, technical assets and weather conditions on disinfection efficacy against Bacillus subtilis spores were assessed in 14 experimental groups. Residual contamination of protective suits was measured to provide responders with readily understandable information (up to 100 colony forming units classified a suit as disinfected). Weather conditions, short application time and erroneous human behaviour substantially affected the effectiveness of PAAs (P < 0·05). Non-PAA-based disinfectants (either liquid or foam) did not reach comparable efficacy (P < 0·001).
CONCLUSIONS
Peracetic acid was effective at a concentration of 6400-8200 ppm and an application time of 4 min.
SIGNIFICANCE AND IMPACT OF THE STUDY
The study provides operationally relevant data for the use of PAA-based disinfectants in preparedness planning and management of biological incidents and natural outbreaks.
Topics: Decontamination; Disinfectants; Disinfection; Health Personnel; Humans; Hydrogen Peroxide; Peracetic Acid; Personal Protective Equipment; Spores, Bacterial
PubMed: 33590580
DOI: 10.1111/jam.15041 -
Pathogens (Basel, Switzerland) Feb 2021One source of water contamination is the release of wastewater that has not undergone efficient treatment. The aim of this study was to evaluate the reduction obtained...
One source of water contamination is the release of wastewater that has not undergone efficient treatment. The aim of this study was to evaluate the reduction obtained with sodium hypochlorite (NaClO), UV and peracetic acid disinfection treatment of spp., pathogenic , STEC and bacterial indicators in three full-scale municipal wastewater plants. A general reduction in was observed after disinfection, but these bacteria were detected in one UV-treated sample (culture method) and in 33%, 50% and 17% of samples collected after NaClO, UV and PAA disinfection treatments, respectively (PCR method). A better reduction was also observed under NaClO disinfection for the microbial indicators. Independent of the disinfection treatment, O157:H7 was not detected in the disinfected samples, whereas some samples treated with UV and PAA showed the presence of the gene. No reduction in the presence of genes was verified for any of the disinfection treatments. was not detected in any of the analysed samples. The overall results highlight a better reduction in microbiological parameters with a NaClO disinfection treatment in a full-scale municipal wastewater plant compared with UV and PAA. However, the results indicate that a complete and specific monitoring program is necessary to prevent a possible risk to public health.
PubMed: 33572069
DOI: 10.3390/pathogens10020182 -
Water Research Sep 2020Domestic wastewater (WW) contains a large number of pathogenic viruses that are not significantly reduced in most WW treatment processes and are found in high numbers in...
Domestic wastewater (WW) contains a large number of pathogenic viruses that are not significantly reduced in most WW treatment processes and are found in high numbers in the effluent of conventionally disinfected WW. In this study, secondary WW effluent bench-scale disinfection efficacy experiments with two different peracetic acid (PAA) formulations (15 and 22% peracetic acid) and low-pressure ultraviolet irradiation (LP-UV) were carried out using Coxsackievirus B3 (CVB3) as a clinically relevant surrogate for enteric viruses and Escherichia coli (E. coli) as the disinfection efficacy control. Efficacy experiments were done in a test matrix of medium-pressure UV (MP-UV) decontaminated secondary WW effluent under representative PAA doses and LP-UV fluences used at wastewater treatment plants (WWTP). Membrane filtration technique was used to determine Log CFU reductions of E. coli and a tissue culture infectious dose 50% assay (TCID50) for Log TCID50 reduction of CVB3. The CVB3 proved to be quite resistant to PAA with ≤1 Log TCID50 reduction to concentrations ≤50 mg/L at a contact time of 15 min, and highly susceptible to LP-UV at 20 mJ/cm. Concurrent use of both formulations of 3 mg/L PAA with 20 mJ/cm LP-UV achieved ∼4 Log TCID50 reduction. The E. coli results showed ˃5 Log CFU reductions at a contact time of 15 min with both 3 mg/L PAA formulations, 20 mJ/cm LP-UV treatment alone, and combined with both 1.5 mg/L PAA formulations. The E. coli efficacy data were consistent with that reported in the literature and showed to be comparable to conventional chlorine disinfection. The CVB3 efficacy data has shown that PAA alone may not be suitable for the reduction of enteric viruses in secondary wastewater effluent, but this is also the case for chlorine-based disinfectants. The results from this study showed that the use of PAA with LP-UV at reasonable concentrations (1.5 mg/L) and fluence (20 mJ/cm) can significantly reduce the PAA use and meet wastewater disinfection goals for both E. coli and CVs. However, the concurrent use of PAA with LP-UV did not lead to significant synergy in disinfection efficacy in wastewater.
Topics: Disinfectants; Disinfection; Escherichia coli; Peracetic Acid; Ultraviolet Rays; Wastewater
PubMed: 32668349
DOI: 10.1016/j.watres.2020.116048 -
Chemosphere Jan 2022Activating peroxides to produce active substances is the key to advanced oxidation processes (AOPs), but this usually requires energy or is accompanied by additional...
Activating peroxides to produce active substances is the key to advanced oxidation processes (AOPs), but this usually requires energy or is accompanied by additional contaminants. In this study, diclofenac (DCF) was effectively removed by peracetic acid (PAA) in phosphate buffer (PBS). According to the results of radical scavenging experiments and electron paramagnetic resonance (EPR), hydroxyl radical (•OH) and organic radicals (i.e., CHC(=O)OO• and CHC(=O)O•) generated from PBS-activated PAA might be the dominant reactive species responsible for DCF degradation. At neutral pH, PBS/PAA system exhibited the best degradation efficiency on DCF. Presence of NO, SO and Cl had little effect on the removal of DCF, while HCO and natural organic matter (NOM) significantly inhibited DCF degradation in PBS/PAA system, resulting in the lower degradation efficiency of DCF in natural waters than that in ultrapure water. Finally, four possible degradation pathways, including hydroxylation, formylation, dehydrogenation and dechlorination, were proposed based on the detected reaction products. This study suggests that PBS used to control solution pH should be applied cautiously in PAA-based AOPs.
Topics: Diclofenac; Hydrogen Peroxide; Kinetics; Peracetic Acid; Phosphates; Water Pollutants, Chemical
PubMed: 34597644
DOI: 10.1016/j.chemosphere.2021.132396