This study aims to conduct a comprehensive analysis of switching disinfectants from sodium hypochlorite bleach to chlorine dioxide (ClO2) in the water distribution system of Geyikbayiri, Antalya. For this purpose, bulk decay rates of ClO2 at various water temperatures were determined in laboratory studies. The study revealed ClO2 bulk decay rates of 0.12639 day-1, 0.17848 day-1, and 0.19621 day-1 at temperatures 15°C, 20°C, and 30°C, respectively. The EPANET, a widely employed computer program for simulating the extended-period behavior of hydraulic and water quality in pressurized pipes, was utilized for the analysis of the fate and transport of ClO2. A hydraulic model was first developed, calibrated, and verified using distinct data sets. The Hazen-Williams friction coefficient of the PSA was determined to be 120 by the trial-and-error method with a mean absolute error (MAE) of 0.408 m. A ClO2 model was then integrated with the calibrated and verified hydraulic model, revealing a wall decay rate of 0.01 m/day and an average MAE of 0.034 mg/l. After calibration and verification of the ClO2 model, several management scenarios were developed, and ClO2 dosing rates were determined. The study showed that ClO2 dosing rates of 0.40 mg/l and 0.45 mg/l should be applied to keep ClO2 concentrations within certain limits. PRACTITIONER POINTS: Disinfectants must maintain a sufficient residual in water distribution systems. Chlorine dioxide requires less contact time and is not affected by pH fluctuations. Modeling serves as a decision-making tool for the management of disinfectants. Bulk and wall decay rates of chlorine dioxide are crucial for management strategies. Chlorine dioxide is a good alternative as a disinfectant in such systems.

Pandemics of microorganism are serious problem such as corona virus induced disease 2019(COVID-19), and the infectious diseases rapidly transmitted via airborne or aerosol among community space. To prevent aerosol infections, ozone and chlorine dioxide gases are practical methods in room air. However, ozone requires relatively high concentrations for this purpose, which might be toxic to humans present in the room. On the other hand, the low concentration of chlorine dioxide gas and aqueous solution are sufficiently effective against aerosol infection for the causative microorganism, and it is expected that when it is used in combination with a high-efficiency particulate air filter, it will be highly safe with high prevention effect and cost effectiveness.

UNASSIGNED: Beta-thalassemia major is a blood disorder caused by impaired synthesis of hemoglobin beta chain. Oral manifestations of beta-thalassemia major in pregnancy have rarely been reported.
UNASSIGNED: This study aimed to describe a case of oral manifestations in a pregnant woman with beta-thalassemia major for multidisciplinary management.
UNASSIGNED: A 27-year-old woman, suffering from beta thalassemia major who is undergoing therapy in the form of routine blood transfusions every month and taking anti-chelation drugs but is currently stopping this because she is pregnant, currently 16 weeks pregnant, complains complained of swollen gums, bleeding, and bad breath. Extraoral examination revealed dry, exfoliative lips. Intraoral examination revealed gingival hyperplasia with erythema, soft consistency, dark red rounded gingival margins, bleeding, true pockets and pain throughout the labial, buccal, palatal, and lingual. There was no history of systemic disease in this patient. Patient has never visited a dentist, either before or now, with complaints about her oral cavity. Hematological parameters showed abnormalities, and peripheral blood examination revealed an infection. The oral diagnoses included gingival enlargement and chronic periodontitis associated with pregnancy and β- thalassemia major.
UNASSIGNED: Dental management consisted of spooling with 3% hydrogen peroxide (H2O2) spooling, chlorine dioxide spray mouthwash, antibiotics, calculus removal, and oral hygiene instructions. Blood transfusions were administered once a month, and anti-chelation therapy was stopped during pregnancy. After three months of multidisciplinary management, the results were satisfactory.
UNASSIGNED: Multidisciplinary, collaborative dental and medical management with non-surgical therapy of oral manifestations in pregnant women with beta-thalassemia major showed satisfactory results.

Sanitizer spray and brush roller treatments have been documented as an effective means of reducing Salmonella on the surface of produce. The purpose of this study was to evaluate the efficacy of chlorine (NaOCl), peroxyacetic acid (PAA), and chlorine dioxide (ClO2) sprays to reduce Salmonella populations on the surface of mangoes during washing with brush or polyvinyl chloride (PVC) rollers. Whole mangoes were spot inoculated with 100 µL of a rifampicin-resistant Salmonella (8 log CFU/mL) cocktail at the equator and dried for 1 h. Mangoes were washed with a lab-scale roller system with either ground water (control), or sanitizers (100 ppm NaOCl, 80 ppm PAA, or 5 ppm ClO2) for 0, 5, 15, 30, or 60 s (n = 15 mangoes). Dey/Engley buffer (100 mL) was used to rinse mangoes before plating on media supplemented with rifampicin. NaOCl, PAA, and ClO2 spray (except for ClO2 at 30 s) had significantly higher reduction on Salmonella population than water spray at all treatment times (P ≤ 0.05) when brush rollers were used. All tested sanitizers also achieved a significantly higher reduction than water at 5 s when PVC rollers were used (P ≤ 0.05). Salmonella reductions achieved by brush and PVC rollers was not statistically different (P > 0.05). After a 5 s treatment on brush and PVC rollers, NaOCl, PAA, and ClO2 spray had ca. 3.03 and 3.45 log, 3.96 and 3.28 log, and 2.54 and 2.00 log CFU/mango reductions, respectively, whereas water spray achieved 1.75 and 0.98 log CFU/mango reduction. Addition of sanitizers to spray water used during brush or PVC washing in mango packinghouses can reduce Salmonella on mango surfaces.

The risk of fungal pollution in drinking water has been paid attention. Solar/chlorine dioxide (ClO2) combined system is an environment-friendly, economical and efficient disinfection method, especially for countries and regions that are economically backward and still exposed to unsafe drinking water. In this paper, the kinetics, influencing factors, mechanism and regrowth potential of inactivated Aspergillus niger (A. niger) spores by solar/ClO2 were reported for the first time. The inactivation curve can be divided into three stages: instant inactivation within 1-2 min, slow linear inactivation and finally a tail. The synergistic factors produced by solar/ClO2 in terms of log reduction and maximum inactivation rate were 1.194 and 1.112, respectively. The inhibitory effect on the regrowth of A. niger spores inactivated by solar/ClO2 was also stronger than that by ClO2 alone. Strongly oxidizing reactive species produced by solar/ClO2 accelerated the accumulation of endogenic reactive oxygen species (ROS) caused by oxidation stress of A. niger spores, improving the inactivation ability of the system. The inactivation order of A. niger spores was: loss of culturability, accumulation of intracellular ROS, loss of membrane integrity, leakage of intracellular species and change of morphology. The inactivation performance of solar/ClO2 was better than solar/chlor(am)ine according to the comparison of inactivation efficiency and regrowth potential. Results also suggested that solar/ClO2 process was more suitable for the treatment of ground water sources.

This study investigates the effects of chlorine dioxide (ClO2) disinfection on the community structure, regrowth potential, and metabolic product secretion of disinfection-residual bacteria (DRB) in secondary effluent (SE), denitrification filter effluent (DFE), and ultrafiltration effluent (UE). Results show that ClO2 effectively reduces bacteria in SE and UE, achieving log removal values exceeding 3 at 1 mg/L within 30 min. A salient positive correlation (R2 > 0.95) exists between changes in total fluorescence intensity and disinfection efficacy. Post-treatment, Acinetobacter abundance increased in SE, while Pseudomonas decreased in DFE and UE. At lower ClO2 concentrations, Staphylococcus, Mycobacterium, Aeromonas, and Lactobacillus increased in DFE, but decreased at higher concentrations. After storage, bacterial counts in disinfected samples exceeded those in the control group, surpassing 105 CFU/mL. Despite an initial decline, species richness and evenness partially recovered but remained lower than control levels. Culturing DRB for 72 h showed elevated extracellular polymeric substances (EPS) secretion, quantified as total organic carbon (TOC), ranging from 5 to 27 mg/L, with significantly higher EPS in the disinfection group. Parallel factor analysis with self-organizing maps (PARAFAC-SOM) effectively differentiated water sample types and EPS fluorescent substances, underscoring the potential of three-dimensional fluorescence as an indirect measure of ClO2 disinfection efficacy.

OBJECTIVE: This study aimed to assess the effects of chlorine dioxide (ClO2) in water on whiteleg shrimp Penaeus vannamei, evaluating its impact on the stomach microbiota, gill transcriptome, and pathogens.
RESULTS: ClO2 was added to the aquarium tanks containing the shrimp. The application of ClO2 to rearing water was lethal to shrimp at concentrations above 1.2 ppm. On the other hand, most of the shrimp survived at 1.0 ppm of ClO2. Microbiome analysis showed that ClO2 administration at 1.0 ppm significantly reduced the α-diversity of bacterial community composition in the shrimp stomach, and this condition persisted for at least 7 days. Transcriptome analysis of shrimp gill revealed that ClO2 treatment caused massive change of the gene expression profile, including stress response genes. However, after 7 days of the treatment, the gene expression profile was similar to that of shrimp in the untreated control group, suggesting a recovery to the normal state. This 1.0-ppm ClO2 significantly reduced shrimp mortality in artificial challenges with an acute hepatopancreatic necrosis disease-causing Vibrio parahaemolyticus and white spot syndrome virus, which were added to rearing water.
CONCLUSIONS: The use of ClO2 at appropriate concentrations effectively eliminates a significant portion of the bacteria in the shrimp stomach and pathogens in the water. The results of this study provide fundamental knowledge on the disinfection of pathogens in water using ClO2 and the creation of semi germ-free shrimp, which has significantly decreased microbiome in the stomach.

OBJECTIVE: The disinfection efficiency of disinfectants differs in specific conditions. This study aimed to investigate the disinfection efficiency of commercial hydrogen peroxide, chlorine dioxide, and chlorine disinfectant on real field surfaces and provide data for precise disinfection.
METHODS: Simulated field disinfection and field disinfection methods were conducted to quantitatively evaluate the disinfection efficiency of hydrogen peroxide, chlorine dioxide, and sodium dichloroisocyanurate. The log10 reduction of biological indicators, Escherichia coli (ATCC 8099) and Staphylococcus aureus (ATCC 6538), was calculated. Next, the reduction in natural bacteria on the surfaces of a food production and processing workshop and a biosafety laboratory was determined.
RESULTS: The 3 commercial disinfectants evaluated were effective against E coli and S aureus, with a reduction of more than 3.00 log10 colony-forming units/mL tested for an exposure time of 15 minutes with 3.5% hydrogen peroxide, 100 mg/L chlorine dioxide, and 250 mg/L sodium dichloroisocyanurate. The natural load in the food production and processing workshop decreased by more than 90% using 10.5% hydrogen peroxide with an exposure time of 30 minutes. The same disinfection level in the biosafety level 2 laboratory was achieved by 500 mg/L chlorine dioxide at an exposure time of 60 minutes and 450 mg/L sodium dichloroisocyanurate at 60 minutes.
CONCLUSIONS: This study provides a reference for precise disinfection of surfaces in the food industry and biosafety laboratories.

The increase in vegetable consumption has underlined the importance of minimizing the risks associated with microbiological contamination of fresh produce. The critical stage of the vegetable washing process has proven to be a key point for cross-contamination and the persistence of pathogens. In this context, the agri-food industry has widely adopted the use of disinfectants to reduce the bacterial load in the wash water. Therefore, we conducted laboratory-scale experiments in order to demonstrate the antimicrobial activity of disinfectants used in the wash tank of agro-food industries. Different wash water matrices of shredded lettuce, shredded cabbage, diced onion, and baby spinach were treated with sodium hypochlorite (NaClO), chlorine dioxide (ClO2), and per-oxyacetic acid (PAA) at recommended concentrations. To simulate the presence of pathogenic bacteria, a cocktail of E. coli O157:H7 was inoculated into the process water samples (PWW) to determine whether concentrations of disinfectants inhibit the pathogen or bring it to a viable non-culturable state (VBNC). Hereby, we used quantitative qPCR combined with different photo-reactive dyes such as ethidium monoazide (EMA) and propidium monoazide (PMA). The results indicated that concentrations superior to 20 ppm NaClO inhibit the pathogen E. coli O157:H7 artificially inoculated in the process water. Concentrations between 10-20 ppm ClO2 fail to induce the pathogen to the VBNC state. At concentrations of 80 ppm PAA, levels of culturable bacteria and VBNC of E. coli O157:H7 were detected in all PWWs regardless of the matrix. Subsequently, this indicates that the recommended concentrations of ClO2 and PAA for use in the fresh produce industry wash tank do not inhibit the levels of E. coli O157:H7 present in the wash water.

This prospective work focuses on the use of two different gaseous oxidants (chlorine dioxide and ozone) to remediate soil polluted with methomyl in two different applications: ex-situ and in-situ. In the first, the soil washing is integrated with the bubbling of the oxidant, while in the second, the gas was introduced by a perforated pipe located sub-superficially. Regarding the soil washing treatment, results demonstrate that direct use of ozone is not very efficient, although an important improvement is obtained following activation with hydrogen peroxide or UV light. In contrast, chlorine dioxide exhibited complete methomyl depletion from the soil, although with higher energy consumption and technical complexity compared to ozone. The direct dosing of the gaseous oxidants in perforated pipes is effective, achieving methomyl removals of 7.8 % and 9.2 % using ozone and chlorine dioxide, respectively. In these cases, soil conditions are not significantly modified, which becomes an important advantage of the technology as compared with other electrochemically assisted soil remediation process, in which large regions of the treated soil are affected by important changes in the pH or by depletion of ions. This lower impact makes these novel technologies more promising for further evaluations.