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Akaiwa, Japan

Hiragaki K.,Ohnit Co. | Ishimaru T.,Ohnit Co. | Nakanishi M.,Ohnit Co. | Muraki R.,Ohnit Co. | And 3 more authors.
EPJ Applied Physics | Year: 2015

Generated ozone foam was applied to the disinfection of Pseudomonas fluorescens. The effect of disinfection has been confirmed experimentally and new equipment for the disinfection of hands using this ozone foam has been put on the market for the practical use. The ozone foam was produced in the foam generator after mixing the water including surfactant (30 mL/min) and air including ozone (1000 ppm = 2.14 g/m3 ∼ 1600 ppm = 3.4 g/m3, 300 mL/min). The liquid-to-gas ratio is 100 L/m3. The concentration of dissolved ozone in the thin liquid films of the bubbles was about 3 mg/L which was measured by the chemical method of the KI absorption and titration of sodium thiosulfate solution. The disinfection test samples were prepared using the PET disk on which Pseudomonas fluorescens of its number of more than 108 were attached. Test sample was inserted into ozone foam set on the glass plate for one to 6 min. The survival rate log (N/N0 decreased with time and its value of about-2.6 (i.e., ∼1/400) was obtained at 6 min (2 min × 3 times repeated). It was also confirmed that the ozone foam was useful for the disinfection of hands. For more effective disinfection (in case of taking a long time for foam melting), the ozone foam was broken by force and changed into ozone water by which the survival rate decreased ×4 (i.e., N/N0 = 1/10 000) at 4 ∼ 6 min. © 2015 EDP Sciences. Source


Kwiatkowski M.P.,Saga University | Satoh S.,Saga University | Yamabe C.,Saga University | Ihara S.,Saga University | Nieda M.,Ohnit Co.
IEEJ Transactions on Fundamentals and Materials | Year: 2012

The purpose of this study was to investigate the electrical energy for the environmental applications using AOPs (advanced oxidation processes) combined with ozonation and sonication to remove the FOG (fats, oils and greases) from wastewater of the sewage system. This study focused on FOG removal from a grease trap using the hybrid AOPs. Fatty acids (linoleic, oleic, stearic and palmitic acids) were used as representative standards of FOG. The studies were conducted experimentally in a glass reactor under various operational conditions. The oxidation efficiency using the combination of the ozonation and sonication was determined by the KI dosimetry method and the calorimetry method. Fatty acids concentration were measured by GC/MS. The local reaction field of the high temperature and high pressure, so-called hot spot, was generated by the quasi-adiabatic collapse of bubbles produced in the water under sonication, which is called cavitation phenomenon. Mixing the ozone bubbles into the water under acoustic cavitation, the formation of OH radicals increased. The mechanical effect of acoustic cavitation such as microstreaming and shock waves have an influence on the probability of reactions of ozone and radicals with fatty acids. © 2012 The Institute of Electrical Engineers of Japan. Source


Kwiatkowski M.P.,Saga University | Satoh S.,Saga University | Fukuda S.,Saga University | Yamabe C.,Saga University | And 3 more authors.
EPJ Applied Physics | Year: 2013

The oil and fat were treated at first by only ozone bubbling and it was confirmed that the collection efficiency of them became 98.4% when the aeration was used. It showed that the aeration method in a grease trap cleared the standard value of 90% and there was no worry on the oil and fat outflow from a grease trap. The characteristics of sonication process were studied for free fatty acids degradation. The free saturated fatty acids are the most hard-degradable compounds of the fats, oils and greases (FOGs) in the grease trap. The influence of various parameters such as immersion level of an ultrasound probe in the liquid and bubbling of various gases (Ar, O2, air, O3) on the sonochemical and energy efficiency of the sonication process was investigated. The most effective degradation treatment method for saturated free fatty acids was the combination of sonication and low flow rate argon bubbling. © 2013 EDP Sciences. Source


Kwiatkowski M.P.,Saga University | Satoh S.,Saga University | Yamabe C.,Saga University | Yamabe C.,Ohnit Co. | And 2 more authors.
Ozone: Science and Engineering | Year: 2015

In the present work, study of the sonication process was investigated for saturated fatty acids degradation. Saturated fatty acids are the most hard-degradable compounds of FOG (fats, oils, and greases) wastewater contaminants. The influence of various conditions (probe immersion level into the liquid, simultaneous ultrasound irradiation and bubbling of Ar, O2, air, and O3) on the sonochemical and energy efficiency of the sonication process were studied. According to our experimental data and the state of the art, the most appropriate conditions were selected on purpose to decompose hydrophobic compounds, such as saturated free fatty acids. The most effective degradation treatment method for saturated free fatty acids was the simultaneous sonication (with high probe immersion level into the liquid) and argon bubbling (at low flow rate) under controlled temperature. © 2015, Copyright © 2015 International Ozone Association. Source

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