• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.4
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• pp.97-105
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• 2012

This study examined for possibility of the food wastewater incineration treatment method as one of overland treatment method by incineration through liquefied spray of food wastewater when incinerating domestic wastes under operation and for the relationship, etc of air discharge material discharged in incineration, and the results of study are as follow: The food wastewater as one of overland treatment method was analysed 94-96% of moisture contents. Temperature of incinerator outduct during mixed incineration of food wastewater with MSW was average $897^{\circ}C$ and incineration of only MSW was $925^{\circ}C$. Temperature of the mixed incineration of food wastewater was dropped about $28^{\circ}C$ by incineration of only MSW. Concentration of nitrogen oxides(NOx) among air discharge gases was studied by 50ppm, 46ppm when inputting $200{\ell}/hr$, $300{\ell}/hr$ into the incinerator as the quantity of food wastewater. In the mixed incineration of food wastewater, generation speed of scales in the inside of a tubular exhaust gas boiler became rapid and the scale generation quantity became large but the exhaust gas boiler normally operated since scales were removed in cleaning of the tube with a compressive air cleaning facility and there was no opening clogging phenomena in a filter cloth of the filtering dust collector. The overland treatment method, not ocean dumping of food wastewater can be proposed as a technology since mixed incineration of food wastewater with MSW in the existing domestic waste incineration plant is possible, and operation costs of the incineration facility were reduced since use of chemicals such as ammonia and urinary hydrogen ion excretion, etc used in incineration facilities for removing nitrogen oxides(NOx).

• Journal of the Society of Naval Architects of Korea
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• v.55 no.4
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• pp.330-340
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• 2018

In the present works, the High-speed Cavitation Tunnel (HCT) has been designed and manufactured to have the large test section to conduct various supercavitation experiments. The large amount of air ventilated behind a cavitator produces lots of tiny bubbles, which prevent clear observation of supercavitation at the test section. To collect small bubbles effectively, a bubble collecting section of large volume is equipped upstream of the test section. HCT has the test section dimension of $0.3^H{\times}0.3^W{\times}3.0^L\;m^3$ and provides maximum flow speed of 20.4 m/s at the test section. The blockage and Froude effects on the ventilated supercavitation are investigated successfully at the test section. The basic studies such as the supercavitation evolution, drag measurements and cavity shape extraction with air flow rate are also carried out in HCT.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.668-676
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• 2018

Most reservoirs in Korea have a low water depth and are small in size. Water pollution of the reservoir is serious because of the organic matter flowing from livestock wastewater, domestic sewage, and farmland. In this study, an attempt was made to improve the water purification effect by replacing the secondary dam installed in the depression area of the agricultural reservoir with the riprap dam. To evaluate the long-term performance, a riprap dam was installed in a reservoir in Gyeonggi province and water purification effect for 36 months was measured. The field test results showed that COD was 14.6%, SS 38.6%, T-N 9.5%, and T-P 11.2%. The concentrations in the influent water exhibited a significant change according to season, and the water purification effect increased with increasing concentration of influent water. The pollutant flowing into the lake from the depression area can be blocked effectively if the secondary riprap dam for water purification is installed in the agricultural reservoir.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.197-206
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• 2006

This study evaluated the effect of ultrasonic irradiation on improving the flux and cleaning efficiency in membrane process which is widely applied for the treatment of landfill leachate. The experiments on improvement of membrane flux according to the types of membranes(hallowfiber microfiltration, MF and tubular ultrafiltration, UF) were performed with changing frequency($40{\sim}120$ kHz), intensity ($200{\sim}500$ W) and irradiation time of ultrasound as well us operation pressure($0.1{\sim}2.3kg/cm^2$). Membrane was fouled for the first 50 min with primary treated leachate and then the change in flux according to ultrasonic irradiation period was observed for 70 min. Parameters influenced to the recovery ratio corresponding the net flux on pure water and to the enhancement ratio applied after ultrasonic irradiation on the flux were analyzed. In same condition, the flux was improved in proportion to ultrasonic intensity while the improvement of flux was inversely proportional to ultrasonic frequency. The cleaning effect of membrane was delayed and reduced when operation pressure of membrane was high. The recovery ratio and enhancement ratio for $0.1{\mu}m$ MF membrane were 10% and 500%, respectively while those were maximized at $75{\sim}98%\;and\;40{\sim}50%$ for UF membrane for 10,000 and 100,000 MWCO, respectively. In conclusion, it was confirmed that ultrasonic cleaning using mechanical vibration is alternative to water or chemical cleaning for improving membrane flux.

• Journal of Navigation and Port Research
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• v.30 no.3 s.109
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• pp.241-245
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• 2006

Displayed result that handle particle contaminant and hydrospace organism included a number of ballast that is happened in ship using automatic back washing filter. Reason that removes first contaminant that is included in number of ballast is that heighten processing effectof after processing processof the filter. Another advantage is to drop off the solids with controlling revolution of drum screen in pretreatment filtration process. The fact that it is easy to attach and detach a several type of screen for getting the expected water quality is another advantage. Filter rotation speed of filtration filter could be expose by 35mmHg more than 60 rpm and filter consecutively filtration pressure is 40.5mmHg in 20 rpm and 40 rpm are 36.6mmHg. Filtration system removal aquatic organism over $70{\mu}min$ ballast water. This study shows that the filtration treatment system has a potential for the treatment of ballast water.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.414-418
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• 2008

하천유지유량에 대한 인식과 개념은 시대와 사회, 경제의 발전에 따라 변화되어 새로운 물 배분 패러다임에 입각한 하천유지유량이 정립되고 있다. 우리나라에서 하천유지유량의 필요성이 제기되기 시작한 것은 댐 건설 이후부터이며, 하구의 염수침입을 방지하기 위해 하천에서 기본적으로 유지되어야 할 필요수량을 정하면서 부터이다. 실제적인 하천유역의 관리에서 댐 건설 이전에는 하천의 유량을 조절할 수 있는 능력이 거의 없었기 때문에 하천유지유량의 설정 자체가 크게 의미를 갖지 못하였다. 우리나라 하천유지유량의 주요 기능은 1960년대 이전에는 하천의 주운기능, 1970년대는 하구의 염수침입방지 기능, 1980년대는 수질보전을 위한 희석용수의 기능으로 인식되었으며, 1990년대 이후 환경에 대한 인식 변화로 수질과 함께 하천생태계 보전의 필요성이 증가하여 이에 대한 연구가 활발히 진행되어 왔고, 2000년대에 들어서는 자연환경을 중심으로 하는 하천유지유량과는 별도의 용수개념인 사회환경 개선을 위한 환경개선용수의 도입의 필요성이 제기되고 있다. 하천유지유량에서 고려하는 항목은 갈수량을 기준으로 하고 하천기능 유지에 필요한 하천생태 및 하천수질 보전을 기본항목으로 하여 고려하도록 하며, 현실적으로 하천유지유량 산정 검토시 부수적인 미미한 비중을 차지하고 있는 하천경관, 하구막힘 방지, 지하수위 유지, 하천시설물 보호, 염수침입 방지 등의 항목은 필요항목으로 구분하되 하천 상황에 따라 추가적인 항목에 대한 검토가 필요한 경우 감안할 수 있도록 하였다. 갈수량의 산정은 반드시 유역 개발과 각종 유수사용, 수공구조물에 의한 유량 조절 효과가 없는 자연상태를 기준으로 산정하도록 하고 어류생태를 고려한 필요유량 산정 시 대표어종은 하천의 특성을 고려하고 지역사회의 의견을 수렴하여 단일어종보다는 생태적 군(Guild, 군(群))을 고려하여 선정하고 최소유량의 개념보다는 계절별 유량변동성을 고려하도록 하였다. 수질보전에 필요한 필요유량 산정 목표는 생태계 서식 및 생육 환경의 보전과 인간의 물 이용 측면에서 요구되는 목표수질을 구분하여 적용하도록 하였다. 하천유지유량 이외에 친수공간 확보, 물놀이, 관광, 하천문화행사 등 사회환경 개선을 위해 하천의 일부구간 또는 일부지역에 필요한 수량은 이를 이용하고자 하는 수혜대상 집단(지자체, 특정 기관 또는 개인 등)의 요구에 의해 발생되는 수량이므로 환경개선용수로 분류하여 별도로 산정하도록 하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.181-185
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• 2005

The treated ballast water from previous treatment contains microorganisms and pathogenic organisms in an filtration treatment system. The advantage of this process can be filtrated to minimize the demage to screen clogging of drum filter with sweeping the solids off rotating the surface of the filter. Another advantage is to drop off the solids with controlling revolution of drum screen in pretreatment filtration process. Also the fact that it is easy to attach and detach a several type of screen for getting the expected water quality is another advantage, too. Filter rotation speed at 20rpmis 40.5cmHg and 40rpm is 36.6cmHg. Filter out impurities from ballast water over 60rpm is 35cmHg. Filtration system removal aquatic organism over $80{\mu}m$ in ballast water. This study shows that the filtration treatment system has a potential for the removal of ballast water.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.221-227
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• 2010

The solidification methods for powder wastes dried at CWDS(Concentrate Waste Drying System) in PWR have been studied in a variety of ways both at home and abroad. The solidification for these wastes has been performed using stabilization agents such as cement, paraffin and polymer. The applicability studies to maximize the reduction ratio of wastes and operational effectiveness for wastes treatment have been carried out, recently. It is necessary to pretreat the powder wastes before feeding wastes to vitrification facility because the fines flying brings about clogging of feeding pipes and off-gas treatment system or workers' exposure to radiation during maintenance. This paper describes an effective method for treatment of powder wastes to improve safety and stability of vitrification facilities.

• Membrane Journal
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• v.30 no.2
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• pp.131-137
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• 2020

In this study, effect of inorganic particles on organic fouling was investigated by a laboratory-scaled pressurized membrane filtration. In order to cause organic fouling, sodium alginate (SA) was used as a feed solution. Regardless of the presence of inorganic SiO₂ particles, the complete pore blocking played an important role in determining the fouling rate during the initial period of membrane filtration. However, the formation of cake layer resulted in the membrane fouling more dominantly as filtration time progressed. In the presence of inorganic particles, both specific cake resistance and compressibility associated with the membrane fouling formed were relatively lower than that without SiO₂ particles. Membrane fouling was more severe at constant flux mode of filtration than that observed at constant pressure mode probably due to the concomitant increase of compressibility of fouling layer with transmembrane pressure (TMP). It was found that the presence of SA and SiO₂ particles in feed solution provided the synergistic effect on the hydraulic backwashing to reduce membrane fouling as compared to the SA solution alone without the inorganic particles.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.59-64
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• 2011

Clogging in drainage pipe is one of the important problems, so it needs a remedy urgently. Recently, scale in drainage pipe is removed by water jet cleaning and other treatment. But these treatments need much cost and regular management. The principal component of scale in drainage pipe is $CaCO_{3}$. It was observed the setting of $CaCO_{3}$ by some kind of analysis such as SEM, XRD, visual and weight measuring analysis to solve these problems and prevent setting formation in drainage pipe. As a result, in case of magnetic, particle shape of $CaCO_{3}$ is changed Aragonite from Calcite. Also in case of Quantum Stick, the amount of scale is reduced by expert inspector's result. As a whole, Magnetic treatment and Quantum Stick have the effect for protecting of scale precipitation.