Úvod: Přítomnost patogenů na površích stomatologických otisků představuje riziko přenosu infekce jak na personál v zubní ordinaci, tak i na pracovníky v zubní laboratoři. Standardní dezinfekce stomatologických otisků se provádí ponořením otisků do dezinfekční lázně nebo použitím dezinfekčního aerosolu. Běžně se používají roztoky na bázi aldehydů, kvarterních amoniových solí, isopropyl alkoholu, hydrogenperoxosíranu draselného, kyseliny vinné a chlóru. Z důvodu rezistence mikroorganismů je nutná pravidelná obměna dezinfekčních účinných látek. Ozon, který vykazuje antibakteriální, antivirové, antimykotické vlastnosti, se nám jeví jako další možný dezinfekční prostředek a představuje slibné řešení. Cíl práce: Cílem naší studie bylo vyhodnotit účinky ozonované vody jako možného dezinfekčního prostředku na stomatologické otisky. Materiál a metody: Devadesáti dobrovolníkům jsme odebrali 180 otisků. První skupina 90 otisků sloužila jako kontrolní vzorky a druhou skupinu 90 otisků jsme vystavili antimikrobiálním účinkům ozonované vody při koncentracích 8, 10, 12 a 13,5 O3 mg/l při časech působení 10, 15 a 20 minut. Vzorky jsme kultivovali na pevných a tekutých růstových půdách. Provedli jsme bakteriologické vyšetření aerobních, mikroaerobních a anaerobních bakterií. Výsledky: Koncentrace 13,5 mg rozpuštěného ozonu v 1 litru vody vykázala eliminaci všech mikrobů u celého souboru vzorků. Závěr: Ozon rozpuštěný ve vodě o koncentraci 13,5 mg/l se jeví jako možný prostředek pro dezinfekci stomatologických otisků.
Introduction: Presence of microbes on the surface of dental impressions poses a risk of spread of infection on dental office staff and also on dental technicians. The standard disinfection of dental impressions is carried out by immersion in disinfective solution or spraying by disinfectant. The commonly used solutions are based on aldehydes, quarter ammonium, isopropyl alcohol, kalium-peroxomonosulphate, tartar acid and chlorine. Regular interchange of disinfective agents is required because of microorganisms’ resistance. We consider ozone, which possesses antimicrobial, antiviral and antimycotic properties, as a promising disinfective agent. Aim: The aim of our study was to evaluate efficacy of ozonated water as a possible disinfective agent for dental impressions. Materials and methods. A total amount of 180 impressions were taken from 90 volunteers. First group of 90 impressions served as control group and second group was treated by antimicrobial ozonated water with concentration of 8, 10, 12, 13.5 mg/l and exposition time of 10, 15 and 20 minutes. Samples were cultivated on hard and fluid growth media. Bacteriologic examination of aerobic, microaerobic and anaerobic bacteria was carried out. Results: Solution of 13.5 mg of ozone in 1 liter of water eliminated all microorganisms in all groups of samples. Conclusion: 13.5 mg/l concentration of ozone in water is thought to be a promising agent for disinfection of dental impressions.
- MeSH
- Disinfection methods standards instrumentation MeSH
- Financing, Organized MeSH
- Ozone pharmacology standards MeSH
- Surface Properties MeSH
- Materials Testing statistics & numerical data MeSH
- Water MeSH
- Dental Disinfectants standards MeSH
- Dental Impression Technique standards MeSH
- Publication type
- Evaluation Study MeSH
Úvod a cíl práce: Ozón se vyznačuje antimikrobiálními vlastnostmi a také širokým spektrem účinků na organismus člověka. Jeho použití ve stomatologii, např. při léčbě poextrakčních zánětů zubního lůžka, může mít značný význam. Cílem této studie bylo porovnání účinků standardní metody léčby poextrakčního zánětu zubního lůžka a léčebných metod s použitím ozónované vody a ověření předpokladu, že terapie alveolitidy po extrakci zubu za použití ozónované vody by mohla vést ke zkrácení doby léčby o dva až tři dny. Metodika: Navrhovaný léčebný postup vycházel z analogie ke standardní léčbě alveolitidy. Studie se uskutečnila v chirurgické ambulanci Stomatologické kliniky 1. LF UK a VFN v Praze. Soubor 100 pacientů byl náhodně rozdělen na dvě podskupiny po 50 subjektech s aplikací ozónované vody o koncentraci ozónu 6 a 10 mg/l. Lokální působení ozónované vody na extrakční ránu pacienta se suchým lůžkem trvalo jednu minutu při každodenní návštěvě. Tento postup se opakoval do odeznění subjektivních obtíží a objektivních příznaků nemoci. Výsledky: Léčba alveolitidy ozónovanou vodou trvala tři až čtyři dny u 98 % pacientů. Po první aplikaci došlo ke zmírnění obtíží. Podání antibiotik a analgetik během léčby nebylo třeba. Všichni pacienti byli práce schopni. Výsledky klinického hodnocení průběhu léčby byly sumarizovány a statisticky zpracovány. Závěry: Léčba poextrakčního zánětu zubního lůžka ozónovanou vodou ve srovnání se standardní metodou terapie se projevila zkrácením doby léčby o šest dní (z průměrných 9,39 dne na 3,37 dne), dále snížením počtu ordinačních návštěv (ze 4,27 na 3,37 návštěv). Zátěž organismu antibiotiky a analgetiky byla nulová. Pracovní neschopnost nebyla vystavena ani v jednom případě, všichni byli práce schopni.
Introduction, aim: Ozone has antimicrobial properties and wide range of effects on human body. That is why its usage in dentistry, e.g. in treatment of dry socket may be of great value. The aim of this study was to compare the effects of standard treatment method of alveolar osteitis and therapeutic modality using ozonated water. In addition the hypothesis that ozonated water in the dry socket therapy may alleviate subjective complaints and reduce treatment time by two or three days was tested. Methods: Suggested therapeutic method originated from standard procedure for alveolar osteitis treatment. The study was conducted at Oral Surgery Unit, Department of Dentistry, General University Hospital and 1st Faculty of Medicine, Charles University in Prague. 100 patients with dry socket were randomly divided in two groups of 50 patients. Ozonated water with two ozone concentrations (6 and 10 mg/l) was applied. Its local action on patient‘s wound lasted for one minute daily. This procedure was repeated daily until subsidence of subjective complaints and objective signs of the disorder. Results: Alveolar osteitis treatment with ozonated water lasted for three to fourth days in 98 % of patients. Symptoms alleviation arouse after its first application. Antibiotics and painkillers were not required. All patients were available to do their jobs. Clinical findings in the course of the therapy were summarized and statistically assessed. Conclusions: Dry socket therapy with ozonated water showed reduction of treatment time by six days comparing with standard method (from average 9.39 to 3.37 days). The amount of patient visits also decreased (from 4.27 to 3.37 visits). Neither antibiotics nor painkillers were administered. Sickness leave did not need to be issued; all patients were fit for work.
Cylindrospermopsin (CYN) is an important cyanobacterial toxin posing a major threat to surface waters during cyanobacterial blooms. Hence, methods for cyanotoxin removal are required to confront seasonal or local incidences to sustain the safety of potable water reservoirs. Non-thermal plasmas provide the possibility for an environmentally benign treatment which can be adapted to specific concentrations and environmental conditions without the need of additional chemicals. We therefore investigated the potential of two different non-thermal plasma approaches for CYN degradation, operated either in a water mist, i.e. in air, or submerged in water. A degradation efficacy of 0.03 ± 0.00 g kWh-1 L-1 was found for a dielectric barrier discharge (DBD) operated in air, while a submerged pulsed corona-like discharge resulted in an efficacy of 0.24 ± 0.02 g kWh-1 L-1. CYN degradation followed a pseudo zeroth order or pseudo first order reaction kinetic, respectively. Treatment efficacy of the corona-like discharge submerged in water increased with pH values of the initial solution changing from 5.0 to 7.5. Notably, a pH-depending residual oxidative effect was observed for the submerged discharge, resulting in ongoing CYN degradation, even without further plasma treatment. In this case hydroxyl radicals were identified as the dominant oxidants of CYN at acidic pH values. In comparison, degradation by the DBD could be related primarily to the generation of ozone.
The ozone treatment for enhancement of biodegradability of persistent organic pollutants in landfill leachates and subsequent biological treatment were studied. Transformation of pollutants was assessed using the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) values. Biological tests were carried out in order to evaluate the potential of biological treatment of ozonated landfill leachates. The potential of biological processes for treatment of ozonated landfill leachates followed from the results of nitrification and denitrification tests.
This article describes and particularly explains a new phenomenon of persistent microbicidal effect of water previously exposed to the low-temperature plasma, which cannot be attributed to the acidification only. The direct microbicidal action of plasma is well documented, being mediated by number of reactive particles with a short lifetime. However, we observed the microbicidal effect also in exposed water stored for a month, where it must be mediated by stable particles. In water and in phosphate-buffered saline, the formation of NO(x) and corresponding acids, H(2)O(2) and O(3) was confirmed after exposition to the low-temperature plasma generated in air by DC negative glow corona and positive streamer discharge. The time course of acidification, H(2)O(2) and O(3) formation were deremined. Except uncertain traces of HCN, SIFT-MS analysis of exposed liquids reveals no additional reactive compounds. The microbicidal effect persists almost unchanged during 4 weeks of storage, although O(3) completely and H(2)O(2) almost disappears. Staphylococcus epidermidis and Escherichia coli were inactivated within 10 min of incubation in exposed liquids, Candida albicans needs at least 1 h. The solutions prepared by artificial mixing of reactive compounds mimic the action of exposed water, but in lesser extent. The acid milieu is the main cause of the microbicidal effect, but the possibility of still unidentified additional compound remains open.
- MeSH
- Anti-Infective Agents chemistry pharmacology MeSH
- Candida albicans drug effects MeSH
- Electric Conductivity MeSH
- Escherichia coli drug effects MeSH
- Mass Spectrometry MeSH
- Hydrogen-Ion Concentration MeSH
- Ozone chemistry MeSH
- Hydrogen Peroxide chemistry MeSH
- Plasma Gases chemistry MeSH
- Staphylococcus epidermidis drug effects MeSH
- Water chemistry pharmacology MeSH
- Air MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Anti-influenza drugs constitute a key component of pandemic preparedness plans against influenza. However, the occurrence of such drugs in water environments, the potential of resistance development in the natural hosts, and the risk for transmission of antiviral resistance to humans call for measures to increase removal in wastewater treatment plants (WWTPs). In this study, removal of three anti-influenza drugs; amantadine (AM), oseltamivir carboxylate (OC) and zanamivir (ZA), and formation/removal of their transformation products during ozonation of wastewater effluents from two Swedish WWTPs in Uppsala and Stockholm were studied. The removal profile of target antivirals and formation/removal of their transformation products were studied by liquid chromatography/high resolution mass spectrometry. 3.5 h of ozone exposure (total dose of ozone 5.95 g) led to complete removal of the three anti-influenza drugs with a degradation in the following order ZA > OC > AM. Two, five and one transformation products were identified and semi-quantified for AM, OC and ZA, respectively. Increasing and later decreasing transformation products concentration followed the decrease in concentration of target compounds. All transformation products detected, except one of AM in wastewater from Stockholm WWTP, were removed at the end of the experiment. The removal efficiency was higher for all studied compounds in wastewater from Uppsala WWTP, which had lower TOC and COD values, less phosphorus, and also higher pH in the water. Ozonation thus offers multiple benefits through its potential to degrade influenza antivirals, hence decrease the risk of environmental resistance development, in addition to degrading other pharmaceuticals and resistant microorganisms.
- MeSH
- Antiviral Agents chemistry MeSH
- Water Pollutants, Chemical chemistry MeSH
- Influenza, Human drug therapy MeSH
- Mass Spectrometry MeSH
- Kinetics MeSH
- Humans MeSH
- Waste Disposal, Fluid methods MeSH
- Wastewater chemistry MeSH
- Ozone chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
With increasing population growth and climate change, de facto reuse practices are predicted to increase globally. We investigated a longitudinal gradient within the Uhlava River, a representative watershed, where de facto reuse is actively occurring, during Fall and Spring seasons when instream flows vary. We observed human pharmaceutical levels in the river to continuously increase from the mountainous areas upstream to downstream locations and a potable intake location, with the highest concentrations found in small tributaries. Significant relationship was identified between mass flow of pharmaceuticals and the size of human populations contributing to wastewater treatment plant discharges. Advanced ozonation and granular activated carbon filtration effectively removed pharmaceuticals from potable source waters. We observed a higher probability of encountering a number of targeted pharmaceuticals during colder Spring months when stream flows were elevated compared to warmer conditions with lower flows in the Fall despite a dilution paradigm routinely applied for surface water quality assessment and management efforts. Such observations translated to greater water quality hazards during these higher Spring flows. Future water monitoring efforts should account for periods when higher chemical uses occur, particularly in the face of climate change for regions experiencing population growth and de facto reuse.
- MeSH
- Water Pollutants, Chemical * analysis MeSH
- Water Purification * MeSH
- Water Quality MeSH
- Pharmaceutical Preparations * MeSH
- Humans MeSH
- Wastewater MeSH
- Seasons MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Mycobacteria are widely present in diverse aquatic habitats, where they can survive for months or years while some species can even proliferate. The resistance of different mycobacterial species to disinfection methods like chlorination or ozonation could result in their presence in the final tap water of consumers. In this study, the culture method, Mycobacterium tuberculosis complex conventional duplex PCR for detection of non-tuberculous mycobacteria (NTM) and quantitative real-time PCR (qPCR) to detect three subspecies of M. avium species (M. a. avium, M. a. hominissuis, and M. a. paratuberculosis) were used to trace their possible path of transmission from the watershed through the reservoir and drinking water plant to raw drinking water and finally to households. A total of 124 samples from four drinking water supply systems in the Czech Republic, 52 dam sediments, 34 water treatment plant sludge samples, and 38 tap water household sediments, were analyzed. NTM of 11 different species were isolated by culture from 42 (33.9 %) samples; the most prevalent were M. gordonae (16.7 %), M. triplex (14.3 %), M. lentiflavum (9.5 %), M. a. avium (7.1 %), M. montefiorenase (7.1 %), and M. nonchromogenicum (7.1 %). NTM DNA was detected in 92 (76.7 %) samples. By qPCR analysis a statistically significant decrease (P < 0.01) was observed along the route from the reservoir (dam sediments), through water treatment sludge and finally to household sediments. The concentrations ranged from 10(0) to 10(4) DNA cells/g. It was confirmed that drinking water supply systems (watershed-reservoir-drinking water treatment plant-household) might be a potential transmission route for mycobacteria.
- MeSH
- Bacteriological Techniques * MeSH
- Nontuberculous Mycobacteria isolation & purification MeSH
- Drinking Water microbiology MeSH
- Polymerase Chain Reaction * MeSH
- Prevalence MeSH
- Water Supply MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
Ozonation pretreatment is typically implemented to improve algal cell coagulation. However, knowledge on the effect of ozonation on the characteristics and coagulation of associated algal organic matter, particularly cellular organic matter (COM), which is extensively released during algal bloom decay, is limited. Hence, this study aimed to elucidate the impact of ozonation applied before the coagulation of dissolved COM from the cyanobacteria Microcystis aeruginosa. Additionally, the degradation of microcystins (MCs) naturally present in the COM matrix was investigated. A range of ozone doses (0.1-1.0 mg O3/mg of dissolved organic carbon - DOC) and ozonation pH values (pH 5, 7 and 9) were tested, while aluminium and ferric sulphate coagulants were used for subsequent coagulation. Despite negligible COM removal, ozonation itself eliminated MCs, and a lower ozone dose was required when performing ozonation at acidic or neutral pH (0.4 mg O3/mg DOC at pH 5 and 7 compared to 0.8 mg O3/mg DOC at pH 9). Enhanced MC degradation and a similar pattern of pH dependence were observed after preozonation-coagulation, whereas coagulation alone did not sufficiently remove MCs. In contrast to the benefits of MC depletion, preozonation using ≥ 0.4 mg O3/mg DOC decreased the coagulation efficiency (from 42%/48% to 28%-38%/41%-44% using Al/Fe-based coagulants), which was more severe with increasing ozone dosage. Coagulation was also influenced by the preozonation pH, where pH 9 caused the lowest reduction in COM removal. The results indicate that ozonation efficiently removes MCs, but its employment before COM coagulation is disputable due to the deterioration of coagulation.
- MeSH
- Water Purification * MeSH
- Microcystis * MeSH
- Ozone * MeSH
- Publication type
- Journal Article MeSH
