• Proceedings of the Membrane Society of Korea Conference
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• 1996.10a
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• pp.60-61
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• 1996

염색폐수를 처리하기 위하여, 일반적으로 물리.화학적 공정과 호기성 생물학적 공정을 조합한 방법들을 사용하고 있다. 하지만 호기성 생물학적 공정은 난분해성 물질의 제거능력이 낮고, 염색폐수의 주된 오염원인 염료분자가 호기성 미생물에 대한 에너지원으로 적합하지 않아 분해되기 어려우며, 물리.화학적 공정을 이용한 처리방법으로도 높은 처리효율을 얻을 수가 없다. 이러한 문제점을 극복하기 위하여 염색폐수 처리에 혐기-호기공정을 이용하며, 혐기성 공정에서 생물학적으로 분해되기 어려운 고분자 물질들을 가수분해하여 생물학적으로 분해가능한 저분자물질로 전환시키고, 호기성 공정에서 저분자 물질을 효과적으로 처라할 수 있기때문에 기존의 염색폐수 처리공정에 비하여 훨씬 높은 처리효율을 얻을 수 있다. 특히, 혐기성 미생물은 호기성 미생물에 비하여 난분해성 물질에 대한 분해력이 높고, 생물독성 물질에 대한 내성이 강하기 때문에 수중생물에 유해한 염료를 함유한 염색폐수의 색도제거에 효과적인 것으로 기대된다. 또한, 막분리 공정은 유기물 및 미생물이 막표면에 축적, 증식함으로써 막세공에 막힘현상을 초래하여 역세척 등의 물리적인 방법이나 화학약품을 이용한 화학적 세척 방법으로도 투과플럭스의 회복이 불가능한 상태를 유발함으로 막의 수명을 단축시키는 원인이 된다. 따라서, 혐기-호기공정과 조합하면 색도성분 제거 및 막 오염의 원인이 되는 유기물 및 용존성 고형물을 제거하고, 막 오염의 억제를 통한 후 수염의 연장은 물론, 처리수의 수질향상에 활용될 수 있을 것으로 사료된다.1로 강구와 함께 공구강 vial에 장입 후, Spex mixer/mill을 이용하여 기계적 합금화 하였다. 기계적 합금화 공정으로 제조한 분말에 대한 X-선 회절분석과 시차 열분석으로 합금화 정도를 분석하였다. (Bi1-xSbx)2Te3 및 Bi2(Te1-ySey)3 합금분말을 10-5 torr의 진공중에서 300℃∼550℃의 온도로 30분간 가압소결하였다. 가압소결체의 파단면에서의 미세구조를 주사전자현미경으로 관찰하였으며, 상온에서 가압소결체의 열전특성을 측정하였다. (Bi1-xSbx)2Te3의 기계적 합금화에 요구되는 공정시간은 Sb2Te3 함량에 따라 증가하여 x=0.5 조성에서는 4 시간 45분, x=0.75 조성에서는 5 시간, x=1 조성에서는 6 시간 45분의 vibro 밀링이 요구되었다. n형 Bi2(Te1-ySey)3 합금분말의 제조에 요구되는 밀링시간 역시 Bi2Se3 함량 증가에 따라 증가하였으며 Bi2(Te0.95Se0.05)3 합금분말의 제조에는 2시간, Bi2(Te0.9Se0.1)3 및 Bi2(Te0.85Se0.15)3 합금분말의 형성에는 3시간의 bivro 밀링이 요구되었다. 기계적 합금화로 제조한 p형 (Bi0.2Sb0.8)2Te3 및 n형 Bi2(Te0.9Se0.1)3 가압 소결체는 각기 2.9x10-3/K 및 2.1x10-3/K 의 우수한 성능지수를 나타내었다.ering)가 필수적이다. 그러나 침전법에서 얻게 되는 분말은 매우 미세하여 colloid를 형성하게 되며, 이러한 colloid 상태의 미세한 침전입자가 filte

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.258-270
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• 2016

This study was conducted to test the green-tide mitigation technique in the lower part of the Sook Stream (Chusori) of Daecheong Reservoir from June 27 to August 24, 2014. And the effects were compared with weekly monitoring result of the watching station of the algae alert system (AAS) as well as test beds reach. The green-tide in a test bed was begun from the upstream, and it was gradually transferred and spread toward the downstream by the hydrological factors. The total amount of algae removed by algae removal device during the test period was 33,920 kg, and solids dewatered by natural gravity was 8,480 kg. Also chlorophyll-a content was 2.83 kg, the number of blue-green algae cells was equivalent to $78.6{\times}10^{14}$ cells. Compared with the results of the watching station of AAS, the pre-concentrate removal work in the outbreak waters was able to suggest the possibility of green-tide mitigation. In addition, an effective management of the green-tide was required spatial and temporal occurrence information and practical device technology. Particularly, the optimal timing of algae removal in the river-reservoir hybrid system was recommended at times before the monsoon rainy season and reached the lowest water level.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.908-914
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• 2017

In this study, we developed a system that automatically removes the scale in the piping by using electrolysis principle in order to solve the cooling performance of the refrigeration and air conditioning system by acting as heat resistance in the heat transfer process by forming the scale in the heat exchanger for refrigeration air conditioning. We want to check the performance through experiments. Therefore, by circulating the treated water using the principle of electrolysis without stopping the system, Ca, Mg and $SiO_2$ are precipitated in the form of solids and discharged to the outside of the pipe system, thereby preventing scale formation in the pipe and removing the scale. Thereby maintaining the heat transfer performance of the pipe. As a result of the experiment, the heat transfer rate of the scaled pipe was 86.66% when the heat transfer rate of the new pipe was 100, and the heat transfer rate was recovered to 90.5% when the scaled pipe was operated for 1 month. The heat transfer rate recovered to 97.86% when driving for two months and to 98.72% for three months. It was confirmed that the scaling effect of the scale formed in the piping was understood in a relatively short experiment period, and the heat transfer performance was also influenced.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.2
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• pp.67-74
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• 2016

This study was purposed to evaluate the characteristic changes of the solidified livestock manure fuel(SLMF) through the application of compression treatment process. The compression process led to an increase of VS/TS ratio (Volatile solids/Total solids ratio) and moisture removal effect of SLMF. The amount of leachate withdrawn from dairy cattle manure and Hanwoo manure by compression were 21~26%(w/w) and 15~20%(w/w), respectively. The specific gravity of the leachate of dairy cattle manure and Hanwoo manure were 1.01 and 0.99, respectively. The dehydrated cow manure was easily processed into ball-shaped solidified fuel. The drying time of the SLMF was proportional to the diameter of the solidified fuel. The highest heating value was observed in diameter range of 10~15mm SLMF. It is concluded that the higher heating value of 10~15mm SLMF was related with the amount of fibrous matter contained in the SLMF.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.318-323
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• 1995

To improve wastewater treatment in a confectionery factory and to optimize chemical coagulation process, this study was performed. $COD_{Mn}$ and total solid of untreated wastewater were $200{\sim}820ppm\;and\;860{\sim}1350ppm$, respectively. Composition of total solid was sugar 40%, protein 10%, hexane-soluble 20%, and ash 30%. Turbidity at 650 nm and the amount of suspended solid (SS) showed correlation, thus turbidity could be used for the on-line measurement of SS. The most effective combination of coagulants for the removal of $COD_{Mn}$ and SS was that of $Al_2(SO_4)_3\;and\;Ca(OH)_2$. The optimal concentration of $Al_2(SO_4)_3\;and\;Ca(OH)_2$ was 480 ppm and 200 ppm, respectively. Optimal retention time of wastewater for $Al_2(SO_4)_3$ addition $Ca(OH)_2$ addition : flocculation was 2 : 2 : 10 min. Multiple treatment of $Al_2(SO_4)_3:Ca(OH)_2$ overcame coagulation inhibition by gelatin and detergent, and addition of microbial sludge reduced it.

• KSBB Journal
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• v.18 no.4
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• pp.318-323
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• 2003

This study was carried out to investigate the possibility of reusing newspaper or paperbox waste by methane fermentation. When 15 g of newspaper and box wastes were digested separately for 24 days by batch fermentation, the amount of total organic acids produced were 2461 and 4978 mg/L, respectively. The tCOD removal rates were found to be 60.9 and 62.4%, respectively. In addition, the removal efficiencies of total solid were 34.8 and 33.4%, and those of volatile solid were 40.0 and 39.2%, respectively. During this period, the amounts of biogas produced were 6.95 and 6.43 L. In a semicontinuous reaction, tCOD removal efficiencies for newspaper and box wastes were 64.7 and 65.0%, respectively, after 14 days of digestion. After 25 days, which were needed to stabilize the methane fermentation, the amounts of biogas produced daily were 0.31 and 0.30 L/g.dry wt, respectively. Methane contents were 57.3 and 56.2%, respectively, and the pHs in the anaerobic acidogenic and methanogenic fermenters were 5.0 and 7.5, respectively.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.652-660
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• 2002

To develop natural food preservatives for extending the shelf-life of jeotkal (salted and fermented seafood), antimicrobial substances were extracted from 32 types of medicinal herbs and edible plants using 95% ethanol. Among the extracts, Glycyrrhizae radix, Curcumae domestica, Galla rhois, and Resina pini showed relatively high inhibitory effects on the growth of the microorganisms isolated from the deteriorated jeotkal. We selected and tested the extract from Recina pini as a natural jeotkal preservative. This ethanol extract was purified partially by adding equal quantity of water, through which 77% of insoluble materials were removed as impurities. In manufacturing modified jeotkal using squid, sucrose and starch syrup were substituted with sorbitol, $glucono-{\delta}-lactone$ was added instead of vitamin C and lactic acid, and sterilized hot pepper was used instead of natural one. The shelf-life of modified jeotkal was prolonged by 4 days compared with the control jeotkal when stored at $20^{\circ}C$, while that of modified jeotkal containing 1.0% partially purified Recina pini extract was prolonged by 6 days compared to the control. The same tests were conducted for the changran (stomach and intestine of Alaska pollack) jeotkal preservation. The shelf-life of the control jeotkal was 24 days, whereas the modified jeotkal and the Resina pini extract-containing modified jeotkal maintained their qualities without changes in microbial and chemical characteristics for 90 days at $20^{\circ}C$ storage.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.136-141
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• 2005

A bench-scale feasibility study was conducted with solid farming feed to evaluate a treatment process for microbiological removal of nitrogen (N) and phosphorus (P). Strains, Bacillus sp. CK-10 and Bacillus sp. CK-13, were originally isolated from water samples of shrimp farming pond. Simultaneous removal of N/P in marine media was monitored in the co-cultures, CK-10 and CK-13. As the results, $400\;{\mu}M\;NH^{+}_4$ and $400\;{\mu}M\;NO^{-}_2$ were eliminated within 12 hours and $NO^{-}_3$ within 36 hours, and $500\;{\mu}M\;PO^{-3}_4$ was completely disappeared within 36 hours from the media. Cultures of CK-10 and CK-13 were applied for removal of N/P leached from shrimp farming fred. HPAEC-PAD system was used to analyze sugars in farming feed, resulting in resolution of various sugars including glucose, galactose, galatosamine, mannose, and fucose. $0.2\%$ (w/v) Pulp densities of the farming feed contained approximately $33.3\;{\mu}M\;NH^{+}_4,\;12.9\;{\mu}M\;NO^{-}_2.\;81.5\;{\mu}M\;NO^{-}_3\;and\;248\;{\mu}M\;PO^{-3}_4$ which could dissolved within 72 hours of leaching in aqueous solution followed by bacterial removal. Complete bacterial removal of N/P was achieved within 84 hours at $0.2\%$ of the feed in co-cultures, whereas single cultures removed to incompletion of N/P during the incubation period. This work demonstrated that test cultures, CK-10 and CK-13 showed effective removal of N/P derived from shrimp farming feed.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.221-227
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• 2012

In Korea, ocean dumping has been widely used as the ultimate disposal of sewage sludge. However, ocean dumping of food wasted and sewage sludge from 2013 is expected to legally restricted as London convention on marine pollution prevention has been effective in 2009. This research aims to examine the effect of HEAS in treating the environmental pollution load caused by organic high concentrated sludge. Thus, onsite laboratory scale treatability test using HEAS was adopted to treat the high concentrated organic sludge from sewage and industrial wastewater treatment plant. The research results showed that the HEAS is useful to reduce the environmental pollution caused by organic high concentrated sludge. Specific results are as follows. 1. The organic removal after the sludge digestion using the high efficiency aeration system was 55.2-85.8%. Although these results were lower than those from the general sewage treatment, the high efficiency aeration system could be evaluated as efficient, considering the object sludge contained the industrial waster water. 2. The average removal efficiency was about 25.2%. 3. It was revealed that sludge digestion by the high efficiency aeration system could effectively contribute to the sludge treatment cost. Especially, the high efficiency aeration system is more applicable to the onsite treatment of small sewage and wastewater treatment plant that contains high solid content sludge, industrial wastewater sludge, high fixed solid sludge.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.895-902
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• 2011

Objective of this research was to investigate the characteristics of biogas production in anaerobic digestion reactor with different mixing ratio of food waste and swine manure. It was observed that the highest removal efficiency of organic material was 80% at 60 : 40 of mixing ratio (livestock manure : food waste). And also biogas yield was varied due to different mixing ratio of them. The cumulative biogas yield was highest at 60 : 40 of mixing rate (livestock manure : food waste). For use of the liquefied fertilizer as effluent from anaerobic digester, it was the limited ratio for 30% of co-digested food waste based on its salt content.