Ozone Concentration In Water Research Articles

DIELECTRIC BARRIER DISCHARGE BASED PLASMA DEVICE FOR COLD STERILIZATION IN WATER WITH ADDITIONAL ULTRASONIC CAVITATION

A prototype of plasma sterilizer based on dielectric barrier discharge (DBD) with additional ultrasonic cavitation for cold sterilization has been developed. It provides sterilization of reusable small dental instruments, and components made from corrosion-resistant metals and alloys (stainless steel, titanium, etc.), as well as surgical instruments, implants, small drills, plastic sundries, ozone resistant medical rubbers (silicone, etc.), polymers, epoxy resins and glass. The sterilizer is well suited for dentistry and can be used in medical, sanatorium, outpatient and other medical institutions, as well as in military field surgery. The volume of the sterilization bath is 2.5 l. The ozone concentration at the output of the ozone generator is 35…52 mg/l, the ozone concentration in the sterilizer chamber is 6.5…8 mg/l, depending on the water temperature and its volume in the bath. The dependence of the increase of ozone concentration in water on time at different oxygen flow rates is monitored.

Potassium ferrate enhances ozone treatment of pharmaceutical wastewaters: Oxidation and catalysis

This work verified the ability of potassium ferrate to catalyse ozone-driven oxidation of refractory organic matter in a secondary effluent of a wastewater treatment plant at a local pharmaceutical factory. The effect of potassium ferrate reduction products on ozone decomposition was investigated by evaluating the variation in ozone concentration in water. The mechanisms were revealed by separating residual potassium ferrate reduction products from solutions and analysing the dissolved organic carbon (DOC), ultraviolet absorption (UV254), and fluorescent organics. The results showed that (1) the decomposition rate of aqueous ozone was higher with the potassium ferrate reduction products than without them, implying the catalytic ability on ozone decomposition. (2) The reduction products of potassium ferrate during ozone treatment resulted in an increase of 14.9 % in the DOC removal rate and 29.03 % in the UV254 removal rate compared with the results of treatment with potassium ferrate alone. These results show that the reduction products of potassium ferrate can promote ozone oxidation of refractory organic compounds in secondary effluents, and a multistage oxidation system in which potassium ferrate combined with ozone is technically feasible. To the best of our knowledge, this is the first study to verify that the synergistic effect of ferrate (VI)–ozone is due to the catalytic effect of reduction products on ozone oxidation.

Ozonated Water Preparation in Dental Offices: Estimation of Ozone Gas Solubility Ratio – Optimum Configurations and Practical Guidelines

ABSTRACT Dentists wish to prepare enough volume to meet the dental office ozonated water consumption and to reach the desired concentration in the least amount of ozonation time. Several factors affect ozone gas mass transfer in water and the corresponding ozonated water concentration can be measured with analytical or direct in-line monitoring methods. An alternative, ozone gas solubility ratio (SR) may be used as a reference to predict ozonated water concentration. SR of 0.25 is often cited in the literature, but it can vary between 0.2 and 0.4 according to different ozonation configurations and parameters. A total of 70 tests were performed using different ozonation configurations which are commonly used in dental practice. Ozone concentration in water was measured and the SR was calculated. SR varied between 0.13 and 0.4. To our knowledge, this study has never been carried out before and aims to propose practical guidelines on selecting the optimum water ozonation configurations in dental practice, as well as to calculate their corresponding dissolved ozone concentration.

Development of an Experimental Setup for Real-Time In-Line Dissolved Ozone Measurement for Medical Therapy

ABSTRACT Ozone therapy is established in clinical applications since many decades, such as treatment of infections or herniated discs. However, in-line monitoring of ozone concentrations is challenging and therefore not performed by default. We developed an experimental setup to measure the in-line ozone concentration in water in real-time with a spectroscopic sensor. Thereby, the experimental setup enables the calibration and evaluation of newly evolved ozone sensors. The results for ozone concentration measurement with the spectroscopic sensor and the colorimetric photometer show a very good correlation. Furthermore, the ozone decay curves measured with our experimental setup highly correlate with those of previous research.

Time dependence of the concentration of dissolved ozone in water generated by dielectric barrier discharge (DBD) plasma using atmospheric air

Ozone is one of the reactive oxygen species that can be produced from plasma. In this study, the ozone was generated by using a dielectric barrier discharge (DBD) plasma technology. DBD plasma was generated using two electrodes separated by a glass dielectric isolator and an alternating current (AC) voltage source of 5 kV with an airflow rate of 1 L/min at room temperature and atmospheric pressure. In this study, the ozone concentration was determined using the titration method. The ozone concentration was measured by varying the titration time between 0-10 minutes. The time dependence of ozone concentration in water tends to follow the polynomial trendline. The longer plasma treatment was performed, the higher ozone concentration was measured. The ozone significantly increased when the treatment was conducted for more than 6 min.

Removal of metal ions from water using oxygen plasma

Zinc ion dissolved in water is attempted to be removed by generating the oxides of zinc using the oxygen gas in dielectric barrier discharge (DBD) plasma system. The removal rate of zinc oxides’ production (ZnO and Zn(OH)2) are measured at different treatment periods by the oxygen plasma penetration in water. The removal rate of the deposit increases initially and then decreases with the treatment period. The maximum removal rate (29%) of zinc ion from water is achieved at the treatment period of 10 min, where pH is lower (7.4). From FTIR the generation properties of zinc oxide can be recognized. Initially the amount of the deposit increases with the ozone treatment period due to production of both ZnO and Zn(OH)2. After that, the production of Zn(OH)42- increases even when the total removal rate of the deposit decreases. Therefore, to remove zinc ion from water forming metal oxide deposit, the penetration amount of the active oxygens to the water must be controlled to keep the pH lower than around 7.5. Because with increasing pH amount of removal rate of zinc oxides’ deposit decreases. The pH of the zinc dissolved water treated by ozone depends on both zinc ion and ozone concentration in water.

Assessing the Effect of Ozonated Water on Microbial Load and Quality of Nocellara Etnea Table Olives

ABSTRACT The effect of ozonated water on quality and peel microbial load reduction of Nocellara Etnea (NE) olives was evaluated. Different ozone concentrations in water and different time of contact were tested. Moreover, two different ozonated water washing methods, dipping, and continuous shower, were compared. Color, texture, chemical, and microbiological analyses were performed before and after treatments and after 20 days of fermentation in brine with and without Lactiplantibacillus plantarum starter culture at 108 CFU/mL. The continuous shower with 6.5 ppm ozonated water for 10 min led to a reduction of 1 logarithmic unit for mesophilic aerobic bacteria and 1.47 log unit for yeasts and mold population compared to water washing. Olive firmness and color were affected differently.

Multifunctional DBD-Based Ozone Sterilizer with Ultrasonic Cavitation for Low-Temperature Treatment of Medical Tools

The development of a dielectric barrier discharge (DBD) sterilizer for cleaning, disinfection, and low-temperature sterilization in water saturated with ozone is described. The sterilizer consists of an ozone generator based on glow barrier dielectric discharge with flat electrodes covered with dielectric operated at a high-voltage power supply of 250 W. The 2.5-L sterilization bath is equipped with a 100-W ultrasound source to provide additional cleaning of complexly shaped objects. High ozone concentrations in water (up to 10 mg/L) are necessary for effective and complete sterilization of tools and is achieved by dissolving ozone in cooled water (∼ 10–15°C). The ozone concentration at the output of the ozone generator is 25 mg/L. The main characteristics of the ozone sterilizer with ultrasonic cavitation are given, and the effectiveness of this sterilizer in inactivating a number of microbiological objects is shown.

Portable ozone sterilization device with mechanical and ultrasonic cleaning units for dentistry.

A portable device for cleaning and ozone sterilization of small-sized delicate dental instruments that cannot withstand the high heat and humidity of standard autoclaving has been developed. The device contains a remote unit for magnetic mechanical washing, an ultrasonic bath for pre-cleaning treatment, and a container for ozone sterilization with a reactor based on dielectric barrier discharge. The maximum ozone concentration in water reached 8.5 mg/l for 10 min of operation at a water temperature of 19 °C. The results of inactivation of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus are presented. Distilled water with such seeded micro-organisms was bubbled with an ozone-air mixture at an ozone concentration of 5.8 mg/l at 17 °C for 5 min, 10 min, 20 min, and 30 min. The maximum bactericidal effect was manifested for Pseudomonas aeruginosa cells with their total elimination within 10 min. Inactivation of Escherichia coli bacteria was monitored after 20 min of treatment, and Staphylococcus aureus-after 30 min of treatment.

Degradation of prometryn in Ruditapes philippinarum using ozonation: Influencing factors, degradation mechanism, pathway and toxicity assessment

In recent years, prometryn was utilized as watergrass remover in the aquaculture industry, resulting in the accumulated residual in the aquatic products. The present study focuses on the ozone degradation of prometryn in the Ruditapes philippinarum. The ozone concentration in water increased along with the injection time (60min). The contents of hydroxyl (·OH) and superoxide (O2·-) radicals increased along with the ozone injection time. The effects of temperature, pH, prometryn initial concentration and ozone concentration on the removal efficiency of prometryn were evaluated. The maximum removal efficiency of 86.12% was obtained under the conditions of pH 7, prometryn initial concentration 0.05 mg/kg and the ozone concentration 4.2 mg/L at 28 °C for 30 min. Ion chromatography (IC) and Fourier transform infrared (FT-IR) spectroscopy results show that the S and N atoms in the outer layer of the triazine ring during the prometryn degradation process were oxidized and removed. A total of 30 intermediate compounds were identified using the gas chromatography-mass spectrometry (GC-MS) method. Combined with the IC and FT-IR results, three possible degradation pathways of prometryn were proposed. The prometryn was finally degraded into some small molecules with reduced toxicity by 63.16% for 120 min ozonization treatment. Overall, our work provides a novel approach for prometryn degradation in Ruditapes philippinarum, which can be extended for removing the residues of agricultural and veterinary drugs in other aquatic products.

Remediation of heavy-metal-contaminated sediments in USA using ultrasound and ozone nanobubbles

The lower 12·875 km of the Passaic River (NJ, USA) is heavily contaminated due to industrial activities – specifically heavy metal extraction from chromium (Cr)-ore-processing plants and production of pesticides and herbicides. Conventional methods for remediating contaminated sediments have limited application due to the tidal action and urban development of the contaminated section of the Passaic River. Hence, this study proposes an in situ technology using ultrasound and ozone (O3) nanobubbles to remediate the sediments. Ultrasound is capable of desorbing heavy metals from soil, and ozone can oxidise the released heavy metals to a form that is mobile for ease of extraction. Nanobubbles are used as an effective ozone delivery method for the oxidation of heavy metals. Bench-scale tests were performed to evaluate the feasibility of the proposed technology. Ozone nanobubbles increased the solubility of ozone in water and reduced wastage. Also, due to the high ozone concentrations in water, chromium oxidation increased. A synthetic soil with a grain size distribution similar to that of actual river sediments was artificially contaminated with chromium and used in this research. Test results showed a 97·54% chromium removal efficiency, suggesting the feasibility of the proposed technology for pilot-scale studies.

Advanced oxidation process for the removal of ibuprofen from aqueous solution: A non-catalytic and catalytic ozonation study in a semi-batch reactor

The Concern on the availability of clean and safe fresh water and the quality of recycled wastewater are important issues, which require a suitable technology to restore the water quality. Pharmaceuticals in waste water are not easily degraded by conventional water treatment technology. Advanced oxidation processes have been applied to eliminate traces of these compounds from aquatic environments. This study was focused on the degradation of ibuprofen (IBU) in aqueous solutions by catalytic and non-catalytic ozonation. Preliminary experiments were conducted to optimize the ozone concentration in water and to investigate other operation parameters. The operation parameters were: temperature, stirring rate, gas flow rate, pH, and use of Spinchem stirrer to reach higher concentrations of dissolved ozone. In general, the initial concentration of IBU was 10 mg/L, and about 93% of IBU was degraded after 4 h of ozonation under optimal conditions. Additional experiments were carried out to investigate the benefit of applying a solid catalyst. H-Beta and Fe-H-Beta type catalysts were immobilized in the Spinchem rotating bed device. The catalytic experiments illustrated a significant improvement in the degradation rate of IBU. The catalysts were characterized by nitrogen adsorption- desorption, scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction and FTIR.

Investigation on influence of dimensions of ice containing ozone micro-bubbles on characteristics of ozone concentration

Addition of sterilization and deodorization capabilities to ice is effective for a cold storage of food. Therefore, authors clarified the characteristics of ozone micro-bubbles (MBs) concentration fixed in the ice and ozone gas concentration released due to melting. In this paper, ice with different dimensions are prepared by cutting and crushing the formed ice containing ozone MBs, after which influences of dimensions of cut and crushed ice on the above characteristics are examined. Furthermore, using ice slurry is more effective to cool fresh food; therefore, a pseudo ice slurry formed by mixing crushed ice containing MBs with pure water is investigated. Cut ice and original uncut ice mixed with pure water, respectively, are also investigated as a reference. And validities of above ice mixed with pure water, respectively, are shown by measuring ozone concentration in water. Finally, oxidation characteristics due to ozone gas released into fish oil are also clarified.

Electrochemical Properties of Boron-Doped Diamond Thin Film Synthesized by MPCVD on Titanium Substrate to Use as an Ozone Generator

Boron doped diamond is an excellent electrode material with a large potential window in aqueous solution and low background current. The wider potential window and lower background currents make the BDD material very attractive for electrochemical analysis experiments.Furthermore, BDD exhibits high chemical and electrochemical stability, which makes the material a suitable electrode material for various applications such as bioelectrochemical applications and water disinfection.In this paper, we had succeeded to generate ozone by using the BDD electrode with high efficiency compared to traditional lead oxide (PbO2) and other BDD electrods.Firstly, a Titanium substrate had been seeded by ultra sonic agitation with diamond powder(30nm ~ 40nm) for an hour, which was used as a nucleation of diamond. After that BDD film was deposited on the substrate by microwave plasma chemical vapor deposition.The morphology of samples was observed by Scanning Electron Microscopy (SEM) and the structural-chemical properties of synthesized diamond layer was investigated by Raman Spectroscopy. Conductivity, carrier concentration and Hall mobility was then determined by a Hall-effect measurement unit, based on the van der Pauw method. The ozone concentration in water, which was measured by Ozone Colorimeter.

Electrochemical Properties of Boron-Doped Diamond Thin Film Synthesized by MPCVD on Titanium Substrate to Use as an Ozone Generator

Boron-doped diamond (BDD) has been attracting special attentions as a suitable electrode material for water disinfection due to its high chemical and electrochemical stability. In this paper, we had succeeded to generate ozone by using the BDD electrode with high efficiency and more safely compared to traditional lead oxide (PbO2) electrode. The BDD film was deposited on the Ti substrate by microwave plasma chemical vapor deposition to use as an anode for ozone kit. The morphology of samples were observed by Scanning Electron Microscopy (SEM) and the structural-chemical properties of synthesized diamond layer was investigated by Raman Spectroscopy. Conductivity, carrier concentration and Hall mobility was determined by a Hall-effect measurement unit, based on the van der Pauw method. The Ozone concentration in water, which was measured by Ozone Colorimeter.

Experimental Investigation on Ozone Mass Transfer Coefficient Enhanced by Electric Field in Liquid Phase

In order to improve the efficiency of ozone mass transfer in liquid phase, the method enhanced by electric field was put forward. The effect on ozone mass transfer was investigated from voltage, electrode spacing and gas flow rate. The result showed that ozone concentration in water and the total mass transfer coefficient increased correspondingly with the increase of the voltage, and ozone concentration in water and the total mass transfer coefficient increased correspondingly with increase of the electrode spacing in the range from 1 to 3 cm, and ozone concentration in water increased correspondingly with increase of the gas flow rate, but the total mass transfer coefficient reduced correspondingly.

오존발생기와 저온 유전체장벽 플라즈마를 이용한 오존 발생 및 살균력

Ozone concentrations in water and air, and resulting disinfective properties, were measured following generation by either an ozone generator or a low-temperature dielectric barrier discharge plasma generator. In freshwater, ozone concentrations of 0.81 and 0.48 mg/L were observed after the ozone and plasma generators had been operated for five minutes, respectively. Higher levels of dissolved were attained more easily with the ozone generator. In seawater, both systems were capable of creating concentrations greater than 3.00 mg/L after 5minutes of operation. Higher ozone levels were attained more easily in seawater than in freshwater. Rates of bacterial sterilization in seawater after three minutes were 96% and 88%, using the plasma and ozone generators, respectively. In freshwater, higher concentrations of ozone were released into the atmosphere by the ozone generator than by the plasma generator. In creating equivalent levels of dissolved ozone in freshwater, the plasma generator released 4.5 times more ozone into the atmosphere than did the ozone generator. This shows that ozone generators are more effective than plasma generators for creating ozonated water. For the same concentration of dissolved ozone in seawater, more ozone was released into the atmosphere using the ozone generator than using the plasma generator. Therefore, with regard to air pollution, plasma generators seem to be less expensive than ozone generators.

마이크로버블 오존 산화제와 공압파쇄 장치를 연계 적용한 지중 화학적 산화법의 정화효율 평가

ABSTRACT A new type of chemical oxidation technology utilizing micro bubble ozone oxidizer and a pneumatic fracturing equipmentwas developed to enhance field applicability of a traditional chemical oxidation technology using hydrogen peroxide as anoxidizer for in-situ soil remediation. To find an efficient way to dissolve gaseous ozone into hydrogen peroxide, ozone wasinjected into water as micro bubble form then dissolved ozone concentration and its duration time were measured comparedto those of simple aeration of gaseous ozone. As a result, dissolved ozone concentration in water increased by 31%(1.6 ppm → 2.1 ppm) and elapsed time for which maximum ozone concentration decreased by half lengthened from 9 min to33 min. When the developed pneumatic fracturing technology was applied in sandy loam, cracks were developed and grownin soil for 5~30 seconds so that the radius of influence got longer by 71% from 392 cm to 671 cm. The remediation systemusing the micro bubble ozone oxidizer and the pneumatic fracturing equipment for field application was made anddemonstrated its remediation efficiency at petroleum contaminated site. The system showed enhanced remediation capacitythan the traditional chemical oxidation technology using hydrogen peroxide with reduced remediation time by about 33%.Key words :Micro bubble ozone oxidizer, Pneumatic fracturing, In-situ chemical oxidation, Field demonstration,Radius of influence

Theoretical analysis of physicochemical processes occurring during water treatment by ozone and ultraviolet radiation

The paper presents a kinetic model developed for ozone dissolution in water and taking into account convective and diffusion processes occurring in the vicinity of floating bubbles that contain an ozone-air mixture. It was shown that the gradient of ozone concentration in a convective-diffusion layer and consequently the rate of ozone transfer from bubbles to the solution depended on the rate of ozone decomposition both in its reaction with organic admixtures and in the conditions of exposure to ultraviolet radiation. The obtained kinetic curves of destruction of organic compounds and changes of ozone concentration in water and ozone-air mixture are compared with experimental data for humic acids. The paper also analyzes additional factors affecting the kinetics of ozone dissolution and the rate of resultant reactions.

Identifying useful real-time control parameters in ozonation process

Industrial wastewaters that contain phenolic compounds are resistant to biodegradation and need preoxidation to improve their biodegradabilities. Preoxidation of these wastewaters by using ozone as the chemical oxidant has been found previously to be quite effective in promoting their biodegradability. In combined ozonation and biological processes, if we want to stop ozonation at the optimum condition (i.e. the maximum biodegradability), a biodegradation test is required. Since biodegradation tests such as BOD/TOC and oxygen uptake would take a long time, we could not know the time to stop ozonation immediately. This study was undertaken to identify process parameters (pH, ORP, ozone concentration in water, ozone gas concentration at the reactor outlet) that could be useful for monitoring and real-time control purposes in ozonation processes. We want to correlate these parameters with biodegradability and intermediates formed in ozonation processes. Results showed that the rapid increase of dissolved ozone and the first plateau termination of off-gas ozone concentrations are good indicators for the depletion of p-nitrophenol, the maximum of biodegradability and the elimination of toxicity. From the mean oxidation state curve, ozonation of p-nitrophenol could be divided into three stages, and a similar pattern could also be observed in ORP profiles. From the results of this research, the application of ozone concentration and ORP profiles as real-time control parameters seems promising.