• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.641-650
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• 2008

This paper reviews the infrastructure of the water supply and sewerage system in North Korea. North Korean has similar legal protection to preserve water environment that can be seen in Republic of Korea, but North Korean regulations seemed lack of detailed measures. The critical pollution problems of rivers and lakes in the northern part of peninsula is mainly due to the lack of sewage collection system and poor treatment works. It has been estimated that less than 20% of sewers are connected to the wastewater treatment plants. Although the availability of water resources seemed sufficient, North Koreans suffer the lack of the drinking water supply which needs an urgent attention. Based on the analysis, it has been suggested that the reconstruction of North Korean water and sewage infrastructure needs at least 17.5 trillion Korean Won.

• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.505-510
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• 2005

The objective of this study was to remove non-biodegradable matters and ammonia ion in livestock wastewater using Fenton oxidation and Zeolite adsorption process. After coagulation process as 1st treatment, non-biodegradable matters remained after 1st treatment were removed by using OH radical produced in Fenton oxidation process. Zeolite as cation adsoption process was used to remove ammonia ion in 2nd treatment water. As a result of treatment using these processes, NBDCOD removal efficiency was over 90% and ammonia ion was almost removed. Most aromatics or polynuclear aromatics like benzene, phenol and scatol in livestock wastewater wasn't detected after Fenton oxidation process.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.610-614
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• 2004

The objective of this study was to remove organics and color in livestock wastewater using coagulation and Fenton oxidation process. After coagulation process as $1^{st}$ treatment, organics in $1^{st}$ treatment water were removed by using OH radical produced in Fenton oxidation process. Removal efficiencies of $COD_{Mn}$ and color were 87.2% and 95.7% separately. At that time, the ratio of $Fe^{2+}/H_2O_2$ was 0.8~1.0, and range of reaction pH was effective at the pH of 3.5~3.8. The Reaction time of 120min more than 60min or 90min was sufficient in Fenton process. Removal efficiency of organics was higher two- or multi-stage treatment than one-stage treatment.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.131-137
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• 2007

Industrial wastewater management guideline and evaluation model of Best Available Technologies for the leather tanning and finishing industry was developed as an economical evaluation model using evaluation of BAT including economical evaluation combined with cost analysis model and cost annualization model in considering of economical factors and non-water environmental factors. It was verified that approximately 10% will be increased annually to modify conventional treatment process ($3,700m^3/d$) of J leather wastewater treatment plant to advanced process of K leather wastewater treatment plant.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.3
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• pp.373-382
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• 2013

In this study, a biological odor treatment system was proposed to remove odor(foul smell) materials causing several problems in the closed sewage treatment plant. This odor treatment system was composed of a two-step biofilter system in one reactor. The two-step biofilter reactor was constructed with natural purification layer in upper part and artificial purification layer in lower part. The reed grasses of water purification plants were planted in the surface area and mixed porous ceramic media were filled with the lower part of biofilter reactor. By using the above experimental apparatus, the ammonia gas removal efficiency was attained to 98.3 % and the hydrogen sulfide gas removal efficiency was appeared more than 97.7 % which shows more effective than the conventional odor removal process.

• KSBB Journal
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• v.27 no.1
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• pp.16-20
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• 2012

In this study, novel nano silver sand filtration method was compared with UV treatment and normal sand filtration method through filtering treated water from sewage treatment plant. As a result, $BOD_5$ removal rate of nano silver sand filtration showed higher approximately 31% and 23%, comparing with UV treatment and sand filtration. Moreover, $KMnO_4$ removal rate of nano silver sand was about 6.6 and 2.8 times higher than other two methods. In addition, it showed better for removing SS and total coliform, comparing with others. Also, there is no bacteria on nano silver sand after experiments. Therefore, nano silver sand filtration will be effective for advanced water treatment.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.2
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• pp.99-106
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• 2002

This study is performed to examine pH reduction by neutralization treatment and curing condition of porous concrete using rice straw ash for planting. Test results show that pH of porous concrete without neutralization treatment in the dry and water curing is 10.34 ∼ 10.57 and 9.42 ∼ 9.72, respectively. pH of porous concrete by neutralization treatment in the dry and water curing is 9.72 ∼ 10.03 and 9.00 ∼ 9.37, respectively. Accordingly, the best method for pH reduction of porous concrete for planting is to use water curing and neutralization treatment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.138-143
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• 2006

This research emphasis the commercialize and experiment in the quality of water treatment by making water treatment reactor. The hybrid water plasma torch used this research is excellent in tans of economical efficiency because of using existent neon transformer. Further more, It has excellent energy efficiency because it is manufactured by low electric power. Especially hybrid water plasma torch used this research has two filed of water plasma and inputs each strong point into the water. Following The data such as dissolved ozone(2.8[ppm]), hydrogen peroxide(100[ppm]), 2[PH], are very affordable data and immensely useful in sterilization. Those data have excellent result: perfect eradication of a colon bacillus within maximum 10 minute applying to sterilization processing of a colon bacillus.

• Membrane and Water Treatment
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• v.8 no.5
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• pp.449-462
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• 2017

Direct treatment of municipal wastewater by forward osmosis (FO) process was evaluated in terms of water flux decline, reverse salt diffusion, pollutants rejection and concentration efficiency by using synthetic seawater as the draw solution. It was found that when operating in PRO mode (active layer facing the draw solution), although the FO membrane exhibited higher osmotic water flux, more severe flux decline and reverse salt diffusion was also observed due to the more severe fouling of pollutants in the membrane support layer and accompanied fouling enhanced concentration polarization. In addition, although the water flux decline was shown to be lower for the FO mode (active layer facing the feed solution), irreversible membrane fouling was identified in both PRO and FO modes as the water flux cannot be restored to the initial value by physical flushing, highlighting the necessity of chemical cleaning in long-term operation. During the 7 cycles of filtration conducted in the experiments, the FO membrane exhibited considerably high rejection for TOC, COD, TP and $NH_4{^+}-N$ present in the wastewater. By optimizing the volume ratio of seawater draw solution/wastewater feed solution, a concentration factor of 3.1 and 3.7 was obtained for the FO and PRO modes, respectively. The results demonstrated the validity of the FO process for direct treatment of municipal wastewater by using seawater as the draw solution, while facilitating the subsequent utilization of concentrated wastewater for bioenergy production, which may have special implications for the coastline areas.

• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.432-436
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• 2004

The principle and methodology of risk assessment was applied to establish the quality standard of potential impurities of drinking water treatment chemicals. The impurities(arsenic, lead, cadmium, chromium, mercury, etc.) are regulated as the contained quantity of chemicals in Korea while they are regulated as the quality standard with the idea of 10% of the national safety drinking water standard in U.S.A(NSF) and Japan(JWWA). According to risk assessment of the current standard implemented in Korea, the excess cancer risk of arsenic and lead were determined in around $10^{-5}$ and the hazard quotient(HQ) of cadmium and chromium were below $10^{-2}$, respectively. And the standard concentration of the impurities are regulated as much as 2%~6% of the national drinking water quality standard. The values are more enforced rather than the standards in U.S.A(NSF) and Japan(JWWA) regulating the concentration of impurities the 10% of the national drinking water quality standard. We conclude that the impurities standard of drinking water treatment chemicals should be reconsidered comprehensively concerning the national safety drinking water quality standard and risk assessment.