• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.725-731
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• 2010

This study was to evaluate the ozone oxidation of dissolved Fe, Mn, $SO{_4}^{2-}$ ions and color in abandoned mining drainage by conducting a bench-scale operation at various reaction times in an ozone reactor. The influent was collected from an abandoned mine drainage (AMD) near the J Mine in Jungsungun, Kangwon Province. The ozone reactor was operated at ozone reaction times of 10, 20 and 30 min with ozone doses of 0.0 and $2.4g\;O_3/hr$. Samples from each effluent from subsequent sand filtration were regularly collected and analyzed for pH, Fe, Mn, Al, Cr, Hg, $SO{_4}^{2-}$, alkalinity, color, ORP, TDS and EC. The effluent concentrations of Fe and Mn from the sand filter were less than 0.1 mg/L, which were below the concentrations on Korean drinking water quality standards (Fe, Mn < 0.30 mg/L). The influent $SO{_4}^{2-}$, concentrations were not noticeably changed during this ozone oxidation. Cr and Hg in the raw wastewater from the abandoned mining drainage were not detected in this study. The experimental result shows that the ozone oxidation of dissolved heavy metals and subsequent sand filtration of metal precipitates are desirable alternative for removing heavy metals in AMD.

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.225-229
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• 2009

The efficacy of ozone water in reducing food-borne pathogenic bacteria on High Density Polyethylene (HDPE) and wooden chopping boards in food industry was investigated in this study. 1-5 log reductions of E. coli O157:H7, S. aureus, S. Typhimurium, and B. cereus were observed with increasing concentrations of ozone water. The immersion treatment evidenced superior capability to inactivate food-borne pathogens than washing treatment. The Gram-negative bacteria, such as E. coli O157:H7 and S. Typhimurium, evidenced lower resistance against ozone water than was seen with the gram-positive bacteria, which included S. aureus and B. cereus. The sterilizing effects of ozone water on HDPE chopping boards was superior to that on wooden boards. This result might be utilized to remove food-borne pathogens from food contact surfaces in the food industry.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.109-115
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• 2018

This study was conducted to solve the water shortage problem by reclaiming urine from homes or public places and using it as cleaning water for toilets. The process used in this experiment is a chemical oxidation process combining ozone, hydrogen peroxide, and UV. We set the key substance that is to be removed as chromaticity and conducted the experiment to remove it. If the quantity or concentration of injected ozone, UV, and hydrogen peroxide is insufficient, then the chromaticity will initially increase due to low oxidizing power, and will later decrease. In addition, the efficiency of removing chromaticity appeared to be higher, depending on the quantity of ozone injected, for medium concentrated urine than highly concentrated urine. However, the absolute quantity of removed chromaticity was about 68% higher for highly concentrated urine, when 16 g/hr of ozone was injected. The higher the pH level, the reaction time and efficiency of removing chromaticity were higher, and in normal conditions, in reference to a pH of 8.55, there was a 6% difference in efficiency between a pH level of 5.05 and a pH level of 10.12. Finally, when processing urine through an ozone-only process, COD decreased steadily over time, but DOC did not decrease. This is because ozone reacts selectively with organic matter.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.419-424
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• 2007

According to increase of consumer's desire for clean tap water, advanced treatment processes include with membrane, ozone, and granular activated carbon(GAC) were introduced. In order to evaluate the effect of advanced treatment processes for residual chlorine decay and trihalomethane(THM) formation in water distribution system, dissolved organic matter(DOC) removal of each advanced treatment process was investigated. The residual chlorine decay and THM formation using bottle tests were also evaluated. $UV_{254}$ removal in all advanced treatment was better than DOC removal. Especially, DOC by ozone treated was removed as 4% in contrast with sand filtered water, but $UV_{254}$ was removed about 17%. This result might be due to convert from hydrophobic DOC to hydrophilic DOC by ozonation. Ozone/GAC process was most effective process for DOC removal. The residual chlorine decay constants in treated water by sand filtration, ozonation, GAC adsorption, and ozone/GAC processes were 0.0230, 0.0307, 0.0117 and 0.0098 $hr^{-1}$, respectively. The sand filtered water was produced 81.8 ${\mu}g/L$ of THM after 190 hours of reaction time, as the treated water by ozone, GAC, and Ozone/GAC was less produced 6.0, 26.2, 30.3% in contrast with sand filtered water, respectively. Consequently, the durability of residual chlorine and reduction of THM formation were improved by advanced treatment processes.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.145-150
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• 2004

This study investigated the effect of chlorine dose and chlorine reaction time for the formation of haloacetic acids (HAAs). According to the results, HAA formation was highly affected by chlorine dose and chlorine reaction time. HAA formation reached a plateau value at 30 mg/L of chlorine dose and 24 hr of chlorine reaction time. For the speciation of formed HAAs in the test water, the concentration of brominated-HAAs was significantly lower than that of chlorinated-HAAs because of low level of bromide ion concentration in the test water. It also investigated the removal efficiency of HAA precursors by several unit processes, such as ozone alone, UV alone, and combined ozone/UV system. Of them, ozone/UV system was proved as the best process to control the HAAs formation. The increase of the brominated-HAAs was observed during ozonation with and without UV irradiation showing the slight increase of total HAA concentrations.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.362-367
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• 2014

This study was performed to test the applicability of the ozone/hydroxy radical reaction system, which applied advanced oxidation processes, to remove total petroleum hydrocarbon (TPH) from the fine soil in washing water of the soil washing process. Removal efficiency was tested on 40 L of washing water in a pilot reaction tank. Fine soil contaminated with $800mg\;kg^{-1}$ TPH was prepared at 5% and 10% suspended solids. Testing conditions included ozone/hydroxy radical flow rates of 40, 80, and $120L\;min^{-1}$, and processing time of 2 to 12 hours. The removal efficiency of petroleum hydrocarbon from water waster by ozone/hydroxy radical was increased with higher flow rates and lower percentages of suspended solids. Optimal efficiency was achieved at $80L\;min^{-1}$ flow rate for 4 hours for the 5% suspended solids, and $120L\;min^{-1}$ for 6 hours for the 10% suspended solids. These results verified the efficiency of hydroxy radical in removing TPH and the applicability of the ozone/hydroxy radical reaction system in the field.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.256-262
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• 2016

Rapid industrialization and a significant population growth has led to an increased use of chemicals, which has limited the biological processes that account for most of the existing water and wastewater treatment methods. Ozone microbubble technology, which is one of advanced oxidation processes, has recently attracted attention as a method to solve these issues. In this paper, we reviewed both the physical and the chemical characteristics of microbubbles, and evaluated microbubble-based ozone oxidation processes focusing on the removal of various toxic contaminants. In addition, we discussed the potential of an ozone microbubble process as water and wastewater treatment processes by combining it with other treatment technologies.

• 연구논문집
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• s.33
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• pp.99-109
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• 2003

Recently the utilization of the ozone dissolved de-ionized water(DIW-$O_3$) in semiconductor wet cleaning process and photoresist stripping process to replace the conventional sulfuric acid and hydro peroxide mixture(SPM) method has been studied. In this paper, we propose the water-electrode type ozone generator which has the characteristics of the high concentration and purity to produce the high concentration DIW-$O_3$ for the photoresist strip process in the semiconductor fabrication. The proposed ozone generator has the dual dielectric tube structure of silent discharge type and the water is both used to electrode and cooling water. Through this study, we obtained the results of the 10.3 wt% of ozone gas concentration at the oxygen gas of 0.5 [liter/min.] and the DIW-$O_3$ concentration of 79.5 ppm.. Through the photoresist stripping test using the produced DIW-$O_3$, we confirmed that the photoresist coated on the silicon wafer was removed effectively in the 12 minutes.

• KSBB Journal
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• v.19 no.2
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• pp.98-103
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• 2004

The aim of the present study was to investigate how the hardness of groundwater affects in the alcohol fermentation. Ozone plays an important role to enhance the water quality, resulting in 85% reduction of hardness, and 30% increase in total glucose produced due to increased conductivity and biodegradability of water. After all, experiments using ozone are presented for the improvement of alcohol productivity. Although initially increased slightly alcohol production, higher than expected ethanol production was observed, with ozone treatment resulting in 20% higher production.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.481-490
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• 2017

Water and wastewater treatment has always been a challenging task due to the continuous increase in amount and the change in characteristics of the poorly biodegradable and highly colored organic matters, as well as harmful micro-organisms. Advanced techniques are therefore required to successfully remove these pollutants from water before reuse or discharge to receiving water bodies. Application of ozone, which is a powerful oxidant and disinfectant, alone or as part of advanced oxidation process depends on the complex kinetic reactions and the mass transfer of ozone involved. Micro- and nano bubbling considerably improves gas dissolution compared to conventional bubbles and hence mass transfer. It can also intensify generation of hydroxyl radical due to collapse of the bubbles, which in turn facilitates oxidation reaction under both alkaline as well as acidic conditions. This review gives the overview of application of micro- and nano bubble ozonation for purification of water and wastewater. The drawbacks of previously considered techniques and the application of the hydrodynamic ozonation to synthetic aqueous solutions and various industrial wastewaters are systematically reviewed.