• 상하수도학회지
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• 제19권4호
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• pp.473-479
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• 2005

Applying enhanced coagulation is not uncommon not only to improve water quality but also to obtain economical advantages in water treatment. In this study, the economical evaluation was investigated with considering dosage of coagulant, produced sludges and usage of activated carbon with two different water sources. To simulate the granular activated carbon(GAC) adsorber mini-column test was adapted. Even if there were some variation according to the source waters, the life time of GAC was extended 60 to 110days with adding 2.5 to 3 times of coagulant in enhanced coagulation. With assumption of changing GAC adsorber at 50% of breakthrough the total treatment cost can be reduced to range from 25% to 44% with adapting the enhanced coagulation. The obtained value can not be generalized because the value can be varied by water quality and cost of the GAC or coagulant. However, the evaluation can be basis starting point to find optimum operation methods for the drinking water treatment which has plan to adapt GAC adsorber.

• 펄프종이기술
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• 제36권4호
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• pp.77-82
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• 2004

Expression-deliquoring tests using three types of paper sludges (tissue, newsprint, and paperboard) as deliquoring agent were carried out in order to investigate the effects of sludge dosage and pressure on the expression-deliquoring of slurry. The addition of deli­quoring agent causes expression-deliquoring of slurry to be faster than would be the case without the deliquoring agent. In case of the tissue sludge, the highest compression rate was achieved when $5\%$ of deliquoring agent was added, while in cases of the news­print and the paperboard sludge, $7\%$. Compression rate was increased as pressure increases. Porosity was decreased as pressure increases. The lowest porosity was observed when $5\%$ of tissue sludge was added. When compared the weight of cake where deliquoring agent was not added and the weight of cake that was fastest expression-deliquoring, there was about $17.5\%$ of the weight reduction

• 전기학회논문지P
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• 제61권3호
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• pp.134-139
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• 2012

The power characteristics of the Mg-Air fuel cell were investigated with regard to variation of load conditions. The types of load current using for the Mg-Air fuel cell with 10% NaCl electrolyte were step type, ramp type and pulse type. It was found that transient phenomena occurred in the step current load, which is due to activate of the oxidation-reduction reaction process. And the transient time increase with the load current increase. In the load current of ramp type, the slop of voltage drop increased with current load slop ${\alpha}$ increase. The load voltage and power decreased according to the pulse period of load current decrease were attributed to the metal sludges.

• 상하수도학회지
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• 제12권3호
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• pp.30-40
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• 1998

Increasing water consumption produced sludge problems of the water treatment plants. The objective of this study is to investigate aluminium coagulants recovery n acidic and alkaline conditions. Water treatment plant sludge produced in Pusan Metropolitan City were tested for the aluminium extraction process. Experiment samples were obtained in summer from water treatment plants of Deoksan and Myongjang. Aluminium coagulants used in these plants during the test period were polyaluminium chloride(PAC), polyaluminium sulfate organic(PSO), polyaluminium sulfate silicate(PASS). Aluminium contents of water treatment sludge were in the range of 7.2~10.9% of the total solids. The recovery percentages for aluminium and iron by acidic extraction method was evaluated to 88% and 42% respectively. Extracted mass variation for other materials such as iron, manganese, total organic carbon was observed during the extraction operation. Alkaline extraction produced more than two times amount of total organic carbon than that in the acidic extraction process.

• 산업기술연구
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• 제36권
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• pp.83-88
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• 2016

In this study, a series of experiment was carried to improve dewaterability of the sludge produced in a treatment plant, located in Hongcheon, Gangwondo, which has been treating municipal wastewater and livestock wastewater. Optimum sludge mixing ratio and the amount of sludge conditioner were determined. As sludge conditioners, alum and ferric salt were selected and tested. For the measurement of sludge dewaterability, capillary suction time(CST) and the specific resistance were measured, The specific resistance was detemined by running a series of Buchner Funnel Test. Mixing the two sludges at a 50:50 ratio with the addition of 20 mL alum gave the best results in terms of dewaterability. The moisture content decreased by 2% at this condition.

• 한국토양비료학회지
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• 제32권1호
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• pp.1-6
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• 1999

To find the latent effect of paper mill sludges (PMS) with and without alum, and alum paper mill sludge compost(PMSC) on aluminum toxicity of crops, the pH buffer capacity and the acidification resistance index (ARI) for PMSs and PMSC were investigated, comparing to upland soil. Buffer capacities of PMS with and without alum, and PMSC were significantly higher than $2.5cmol^+kg^{-1}$ of check soil as 137, 250, and $147cmol^+kg^{-1}$, respectively. Owing to such high buffer capacity of PMS and PMSC, they showed to be well-resisted to acidification.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.133-138
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• 2001

In this paper, we have investigated the drying characteristics of waste sludge in a rotary dryer equipped with disintegration device. The sludge samples($moisture\;contents\;:\;70{\sim}85%\;W.B.$) used in the experiment were mainly a soybean and an alcohol fermentation sludges in food industry, or sewage sludge. It was studied by measuring the change of moisture contents that the shaft speed($operating\;range\;:\;100{\sim}250rpm$) affected on the drying rate and the particle size distribution of the dried solid. The dried granular products of the diameter of 1 to 5mm are obtained from sludge materials. In the results, as the increased of shaft speed, the particle size and the moisture contents of dried solid was decreased, and the retention time was increased.

• 동력기계공학회지
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• 제13권6호
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• pp.76-81
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• 2009

Thermal desorption systems are designed to remove organic compounds from solid matrices such as soils, sludges and filter cakes without thermally destroying them. It is a separation technology, not a destruction technology. Since it is a thermal process, there is a common belief that temperature is the only significant parameter to be monitored. While it is true that better removal efficiencies are usually achieved at higher temperatures, other factors must be considered. Since the process is governed by mass transfer, heating time and the amount of mixing are also key parameters in optimizing removal efficiency. Thermal desorption have been successfully used for just about every organic contaminant found to date. It has also been used to remove mercury. In the present study, the numerical simulation has been performed to investigate the characteristics of heat transfer of LTTD(low temperature thermal desorption). The commercial software, AMESIM was applied for analyzing the heat transfer process in the LTTD.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.335-338
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• 2000

BTX를 분해하는 미생물균주를 개발하기 위해 하수처리장과 VOC배출업소의 하수처리장에서 4종류의 활성슬러지를 채취하여 500 mg/L의 BTX에 3개월간 적응하였다. Benzene, toluene의 분해에는 Y혼합균주, p-, m-, o-xylene의 분해에는 A혼합 균주를 선별하였으며 각각은 단일 및 복합성분의 BTX를 빠르게 분해하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.128-131
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• 2003

The effect of microwave irradiation on waste activated sludge was investigated in order to improve solubilization. a different levels of microwave irradiation time were varied within a range from 1 min to 15 min. When WAS was pretreated at 1, 3, 5, 7, and 15 min, the SCOD concentration increased according to microwave irradiation time. A simple batch procedure was used to measure the VFA potential, i.e. the amount of VFA that can be formed through digestion of organic constituent in sludge. At equilibrium point, TVFA in the case of 1, 3, 5, 7 and 15 min microwaved sludges was 8%, 122%, 243%, 279% and 232% higher than that in the case of raw sludge, respectively.