• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.401-408
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• 2012

High-voltage dielectric discharges are an emerging technique in environmental pollutant degradation, which that are characterized by the production of hydroxyl radicals as the primary degradation species. The initiation and propagation of the electrical discharges depends on several physical, chemical, and electrical parameters such as 1st and 2nd voltage of power, gas supply, conductivity and pH. These parameters also influence the physical and chemical characteristics of the discharges, including the production of reactive species such as OH, $H_2O_2$ and $O_3$. The experimental results showed that the optimum 1st voltage and air flow rate for RNO (N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical) degradation were 160 V (2nd voltage of is 15 kV) and 4 L/min, respectively. As the increased of the 2nd voltage (4 kV to 15 kV), RNO degradation, $H_2O_2$ and $O_3$ generation were increased. The conductivity of the solution was not influencing the RNO degradation and $H_2O_2$ and $O_3$ generation. The effects pH was not high on RNO degradation. However, the lower pH and the conductivity, the higher $H_2O_2$ and $O_3$ generation were observed.

• Journal of Microbiology
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• v.42 no.2
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• pp.94-98
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• 2004

Phenanthrene is a three-ring polycyclic aromatic hydrocarbon and commonly found as a pollutant in various environments. Degradation of phenanthrene by white rot fungus Trametes versicolor 951022 and its laccase, isolated in Korea, was investigated. After 36 h of incubation, about 46％ and 65％ of 100 mg/l of phenanthrene added in shaken and static fungal cultures were removed, respectively. Phenanthrene degradation was maximal at pH 6 and the optimal temperature for phenanthrene removal was 30$^{\circ}C$. Although the removal percentage of phenanthrene was highest (76.7％) at 10 mg/1 of phenanthrene concentration, the transformation rate was maximal (0.82 mg/h) at 100 mg/L of phenanthrene concentration in the fungal culture. When the purified laccase of T. versicolor 951022 reacted with phenanthrene, phenanthrene was not transformed. The addition of redox mediator, 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) or 1-hydroxybenzotriazole (HBT) to the reac-tion mixture increased oxidation of phenanthrene by laccase about 40％ and 30％, respectively.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.221-228
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• 2015

In this research traditional Buddhist dietary life style was studied as an alternative for both saving water and decreasing water pollution from household. A traditional dietary life style for the Buddhist monks, called Balwoo Gongyang, and its modernized one for citizens, called Dish Gongyang were examined with water use amount, wastewater quality and pollutant loading rate, and were compared with the kitchen wastewater from household. And several types of natural detergent were also examined to compare their effect on the wastewater quality and pollutant loading rate. This research was carried out using the wastewater from Balwoo and Dish Gongyang in J building located in Seoul. Wastewater generation from Balwoo Gongyang that was about $1.0{\ell}$/capita/day was very low compare to that from dish washing in normal household($32.6{\ell}$/capita/day). In case of Dish Gongyang, water generation was 1.8 times higher than that from Balwoo Gongyang, but it was just 1/19.2 of normal household. When the wastewater quality of Balwoo Gongyang was compared with the kitchen wastewater of normal household, SS was 1/16($15mg/{\ell}$), COD was 1/7($22.1mg/{\ell}$), BOD was 1/9($24.1mg/{\ell}$) and T-N was 1/16($1.7mg/{\ell}$). Pollutant loading rate from Balwoo Gongyang was very low, COD 18.0 mg/capita/day, SS 12.3 mg/capita/day and it was 1/290, 1/639 of that from dish washing wastewater from normal household, respectively. Pollutant loading rate from Dish Gongyang was also low 1/13(SS)~1/144(TN) compared to dish washing wastewater from normal household. As a natural detergent, used water from washing rice showed very low pollutant loading rate. It was concluded that Dish Gongyang that was a modernized and simplified dietary life style of Balwoo Gongyang, was very eco-friendly. Especially when it was combined with natural detergents using by-product from cooking process, its effect on the water pollution was very low.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.79-87
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• 2013

An unstable yet efficient phenanthrene-degrading bacterium strain Ph-3 was isolated from a petroleum-contaminated site at the Mathura Oil Refinery, India. The strain was identified as Pseudomonas sp. using a polyphasic approach. An analysis of the intermediates and assays of the degradative enzymes from a crude extract of phenanthrene-grown cells showed a novel and previously unreported pattern of 1, 2-dihydroxy naphthalene and salicylic acid production. While strain Ph-3 lost its phenanthrene- degrading potential during successive transfers on a rich medium, it maintained this trait in oligotrophic soil conditions under the stress of the pollutant and degraded phenanthrene efficiently in soil microcosms. Although the maintenance and in vitro study of unstable phenotypes are difficult and such strains are often missed during isolation, purification, and screening, these bacteria constitute a substantial fraction of the microbial community at contaminated sites and play an important role in pollutant degradation during biostimulation or monitored natural attenuation.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.39-44
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• 2019

LID facilities do not consider environmental factors, and due to inappropriate vegetation planting causing degradation in efficiency due to plant damage and difficulty in maintenance. Therefore, in this study, assessment of impact environmental factor by seasonal variation of chlorophyll and growth of vegetation planted in LID technologies and change of pollutant reduction were conducted. In the case of B-SJ and B-RI, growth rate decreased after summer (August), and B-MG showed steady growth until autumn (September). Chlorophyll was found to increase during spring season while it decreased during autumn season. The chlorophyll concentration was found to affect the plant growth pattern. TN reduction efficiency was highest with greater than 80% efficiency in summer, and it was analyzed that plants were identified as the main factor affecting the seasonal reduction efficiency of TN. Also, temperature and relative humidity were analyzed to affect plant growth, activity and pollutant removal efficiency. Plant type and growth pattern are considered as factors to be considered in selection of appropriate plant types in LID technologies.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.7
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• pp.67-75
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• 2005

It has been well-known that the Nonpoint Source (NPS) pollutions are the primary contributors to water quality degradation in the receiving water bodies as well as the Point Source (PS) pollutions. To develop an effective management practice for water quality improvement, pollutant loads must be first estimated. In many studies, the Numeric Integration (NI) method has been used because of its ease of application, irrespective of the total number of samples collected for each storm event. Thus, there have been needs for more accurate pollutant load estimation with a limited number of water quality samples. In this study, NI method and regression method using the USGS ESTIMATOR model were comparatively used to calculate the pollutant loads for the Wolgokri watershed, Gangwon Province. The $NO_{3}$-N, T-N, and T-P loads using NI method and ESTIMATOR model were 13.85 kg/ha, 45.92 kg/ha, and 1.887 kg/ha, and 11.93 kg/ha,43.20 kg/ha, and 1.650 kg/ha, respectively. The estimated loads using ESTIMATOR model were lower than those using NI method by $86\%$, $94\%$, and $87\%$. These discrepancies in the estimated loads using a different load estimation method could be explained in that the total number of samples were not sufficient enough for NI method. Thus, ESTIMATOR model is recommended for the frequently stream discharge and less frequently measured water quality data.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.747-753
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• 2010

A series of experiments with a laboratory scale ultrasound treatment system for MTBE polluted groundwater was performed to increase the efficiency of MTBE degradation in groundwater. This study evaluated several factors to increase the efficiency of MTBE treatment for artificial and natural groundwater. The treated volume of groundwater, ultrasound frequency and power, and pollutant concentrations have been changed to evaluate its effects on the degradation efficiency of MTBE in batch and continuous flow reactor. For the specific experimental conditions on this paper, MTBE degradations are more efficient at 580 kHz than those at 1 MHz. The efficiency of MTBE degradation is proportional to the intensity of ultrasound power per unit volume of MTBE polluted groundwater. The concentration of ions in groundwater does not much affect the efficiency of MTBE degradation. The $1^{st}$ order degradation constant of MTBE for different power per unit volume at 580 kHz shows linear relationship at same concentration. The $1^{st}$ order degradation constant for 0.1 mM MTBE solution is higher than that for 1 mM MTBE solution. These experimental results could be helpful to seek optimal conditions for relatively large volume of polluted groundwater treatment.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.203-206
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• 2004

Many types for environmental pollutant of endocrine disruptors have been reported on abnormal sexual development and abnormal feminizing responses of animals in a number of literatures [1]. Conventional biological methods for the removal of pollutants in wastewater require long times, and chemical oxiation methods in general cannot completely eliminate.(omitted)

• Journal of environmental and Sanitary engineering
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• v.20 no.4 s.58
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• pp.51-58
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• 2005

Photocatalytic degradation using $TiO_2$ Particles suspended in a reactor was experimentally performed to degrade the formaldehyde of indoor pollutants. Exponential increase of degradation appears to prove light availability due to the scattering of W light by particles themselves. Comparative removal studies of formaldehyde were done in both cases of dipping and spraying immobilized techniques of $TiO_2$ Particles suspended in solution. Experiments were performed under several different experimental conditions such as initial concentration of formaldehyde, UV intensity and concentration of photocatalysts. Optimal conditions to degrade formaldehyde were obtained under the conditions of $30\;mg/cm^2$ concentration of catalyst and UV intensity of 30 Watt at the distance of 30 cm using immobilized technique by dipping coating.

• Journal of Electrochemical Science and Technology
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• v.3 no.1
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• pp.44-49
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• 2012

Electrochemical and photochemical techniques have been proved to be effective for the removal of organic pollutants in textile wastewater. The present study deals with degradation of synthetic textile effluents containing reactive dyes and assisting chemicals, using electro oxidation and photo catalytic treatment. The influence of various operating parameters such as dye concentration, current density, supporting electrolyte concentration and lamp intensity on TOC removal has been determined. From the present investigation it has been observed that nearly 70% of TOC removal has been recorded for electrooxidation treatment with current density 5 mA/$dm^2$, supporting electrolyte concentration of 3 g/L and in photocatalytic treatment with 250 V as optimum lamp intensity nearly 67% of TOC removal was observed. The result indicates that electro oxidation treatment is more efficient than photocatalytic treatment for dye degradation.