• Journal of Korean Society of Water and Wastewater
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• v.28 no.4
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• pp.367-376
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• 2014

This study assessed the removal efficiency of NOM which is known as the precursors of DBPs in advanced water treatment using the ceramic membrane filtration, introduced the first in the nation at the Y water treatment plant (WTP). It is generally well-known that the removal of NOM by MF Membrane is very low in water treatment process. But, the result of investigation on removal efficiency of NOM in advanced water treatment using the ceramic membrane was different as follows. The removal rate of organic contaminant by the ceramic membrane advanced water treatment was determined to be 65.5% for the DOC, 85.8% for UV254, and 77 to 86% for DBPFP. The removal rate of pre-ozonation was found to be 6 to 15% more effective compared with the pre-chlorination. The removal rate of DOC and $UV_{254}$ in biological activated carbon(BAC) process was over 50% and 75%, respectively although the rate was decreased 10 ~ 20% according to analysis items in converting from GAC to BAC.

• Journal of the Korean GEO-environmental Society
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• v.8 no.3
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• pp.5-10
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• 2007

The paper presents results of qualitative analysis of non-regulated organic pollutants in municipal wastewater and treated municipal wastewater with flocculation, ozone and UV process using GC-MS. The majority of the pollutants in the influent of the municipal wastewater treatment facility were either food related or due to the diffuse discharge from products used both in households and in industry. In the case of biological treatment process removed some organic pollutants effectively. But some organic pollutants were not removed with biological treatment. Thus, additional steps to improve the quality of effluent municipal wastewater will require a more rigorous control of consumer products used in household and municipal wastewater process using advanced treatment processs. The obtained data contributed to the evaluation of pollutants discharges to the ecosystem as well as to the characterization of pollution sources in the basin.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.442-450
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• 2014

Concern has grown over a presence of micropollutants in natural water since sulfonamide antibiotic substances such as sulfamethazine, sulfamethoxazole, sulfathiazole have been frequently detected in Nakdong River, Korea. The current work investigates the degradation of the three sulfonamide substances by using quantum chemistry calculations of density functional theory (DFT) and experimental measurement techniques of Fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrophotometer (UV-VIS). DFT calculations demonstrate that the lowest energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbitals (LUMO) lies in sulfanilamide functional group of sulfonamide, implying that the sulfanilamide functional group would be the most active site for ozone oxidation. Also, UV-VIS spectra and FT-IR analysis reveal that 260 nm band originated from sulfanilamide group was absent after ozone oxidation, indicating that a functional group of amine (N-H) was removed from sulfanilamide. Both theoretical and experimental observations agree well with each other, demonstrating the DFT calculation tool can be an alternative tool for the prediction of chemical reactions in purification treatment processes.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1134-1140
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• 2010

Ozonation is a promising process that can effectively reduce the occurrence of micropollutants and pathogen in water. This study investigated the performance of ozonation for the removal of pharmaceuticals and personal care products (PPCPs) in secondary effluent from wastewater treatment plant. Moreover, the disinfection potential of ozonation applied for PPCPs removal was discussed. Secondary effluent filtered by sand filter was used for tested water, and ozonation was performed under 2, 4 and 6 mg/L of ozone doses. As a result, 6 mg/L of ozone dose (ozone consumption : 4.4 mg/L) was essential for the effective removal of 37 PPCPs in tested water. Several previous studies showed that the operation condition could achieve approximately 3 log inactivation of total coliform and enteroviruses. On the other hand, dissolved ozone concentration in tested water increased by 1.8 mg/L under 6 mg/L of ozone dose, probably resulting in the increase of bromate formation potential. This result implies that as alternatives to suppress the bromate formation potential during the oxidation of PPCPs by ozone, investigations on advanced oxidation processes are required.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.47-52
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• 2008

In this study, GAC adsorption, ozonation and $O_3/GAC$ hybrid processes were investigated for treatment of humic acid. The degradation characteristics and efficiencies of humic acid in each process were evaluated through pH variation, $UV_{254}$ decrease, DOC removal, change of molecular size distribution and by-products formation. DOC removal rate in $O_3/GAC$ hybrid process (80%) was higher than arithmetic sum of ozonation (38%) and GAC adsorption process (19%) by synergism. $UV_{254}$ decrease rate of humic acid was also the highest than any other processes when treated in $O_3/GAC$ hybrid process. Molecular size distribution was not significantly changed in the GAC adsorption process. Main distribution of molecular size of humic acid was converted from 3 k~30 kDa into 0.5 k~3 kDa in ozonation. But the most of large molecular sizes of humic acid converted into small molecules(smaller than 0.5 kDa) in $O_3/GAC$ hybrid process. Quantities of formaldehyde and glyoxal formed in $O_3/GAC$ hybrid process were less than the ones in ozonation.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.127-131
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• 1998

Ethane was measured to know whether active oxyzens may induce phytoxicity in stressedcucumber plant.The time course of the increase in ethane evolution was the same as that of the increase of visible injury in all treatments except $SO_2$ treatment.This result showed that air pollutants-induced plant damages were closely related to ethane evolution.And evolution of ethane was more increased in combined stress than singly one,suggesting that phytotoxicity was more severe in complex sterss.Also, evolution of ethane was enhanced in the light condition and scavengers of active oxygen were inhibited,showing that plant damage that plant damage were cause by active oxygens.

• Ecology and Resilient Infrastructure
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• v.3 no.3
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• pp.182-188
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• 2016

This study evaluated structural alternatives for managing water quality problems by reinterpreting and then applying the robustness-cost index (RCI) for urban flood problems. Cases of endogenous hormone pollution in treated sewage and proliferation of protozoa in intake-water were chosen as representative examples because they have different types of regulation standards for the treatment. Current facilities and structural alternatives with robustness indices (RIs) greater than unity were determined to be robust. The RI was combined with the cost index (CI) to obtain the RCI values. For the endogenous hormone pollution in treated sewage, a human-oriented estrogen $17{\beta}$-estradiol was selected as a target pollutant. The RI and RCI values for a structural alternative, extension of the current sewage treatment facility for advanced treatment, were greater than the values for the current practice of conventional activated sludge process. For the intake-water pollution by protozoa, UV and ozone disinfection facilities were evaluated for inactivation of Cryptosporidium parvum. The RCI values for ozone disinfection were greater than those for UV disinfection. Based on the results and the logics involved in the calculation of RCI for water quality issues we studied, we proposed procedures for establishing and implementing structural alternatives for the restoration from and prevention of outbreaks of water quality problems.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.541-548
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• 2014

The pickling brine generated from the salting process of kimchi production is difficult to treat biologically due to very high content of salt. When pickling brine is treated and discharged, it cannot satisfy the criteria for effluent water quality in clean areas, while resources such as the salt to be recycled and the industrial water are wasted. However, sterilization by ozone, UV and photocatalyst is expensive installation costs and operating costs when considering the small kimchi manufacturers. Therefore there is a need to develop economical process. The study was conducted on the sterilization efficiency of the pickling brine using electrochemical processing. The electrochemical treatment of organic matters has advantages over conventional methods such as active carbon absorption process, chemical oxidation, and biological treatment because the response speed is faster and it does not require expensive, harmful oxidizing agents. This study were performed to examine the possibility of electrochemical treatment for the efficient processing of pickling brine and evaluated the performance of residual chlorine for the microbial sterilization.

• Transactions of the Society of Information Storage Systems
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• v.9 no.2
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• pp.42-47
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• 2013

In this study, we have experimentally analyzed how the surface properties of transparent electrode layer influence the photovoltaic performance of bulk heterojunction organic solar cell by the contact angle measurement and X-ray photoelectron spectroscopy(XPS) observation. As a result, the power conversion efficiency of test devices improved from 0.64% to 1.83% and 2.15% by UV-ozone exposure and $O_2$ plasma treatment, respectively. Thus, we conclude that the surface activation process is very important for better performance and stability in addition to the cleaning process of carbonate residue on the surface.

• Journal of Industrial Technology
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• v.17
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• pp.297-303
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• 1997

This study investigates the characteristics of humic acid before and after ozonation. The results were comapred in such terms as CODCr, CODMn, TOC(total organic carbon) and molecular size distribution. As a result of ozonation (with the dose of 3mgO3/mgHumic Acid), UV NIS absorbance, CODCr, CODMn and TOC were decreased with similar tendency. The mole fraction of high molecular size was rapidly decreased and the fraction ratio of low molecular size was increased through ozone treatment. This fact can be correlated with the change in the difference and the ratio of CODCr and CODMn (the value of CODCr-CODMn and CODMn/CODCr). From this result, it can be inferred that the molecular size and the degree of chemical oxidative degradation of humic acid after ozonation were changed.