• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.60-70
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• 2000

The swine wastewater from slurry feedlot has been a social problem in Korea since the proper treatment is very difficult. Therefore, a practical study on the Solid-Liquid separation of swine wastewater from slurry feedlot was carried out as a pan of pretreatment for the successful biological treatment. The appropriate type of coagulant and optimum dosage were proposed for the most efficient Solid-Liquid separation and the best Solid-Liquid separation methods for different size of feedlot were determined through the tests with field-scaled Solid-Liquid separation equipment. The appropriate coagulant for the conditioning of dewatering property was E-851, which is a cationic polyelectrolyte made of polyacrylamide, and the optimum dosage was 0.24~0.6% of unit solids weight. Mesh Screen, Drum Screen, Cyclone Drum Filter, Screw Press, High-speed Screw Decanter, Low-speed Screw Decanter, and Dissolved Air Flotation Process had been investigated in this study. According to the results, the Screw Press was the best dewatering equipment for the small & medium size for feedlot and low-speed Screw Decanter was the best for the large size feedlot & public owned treatment facilities for the primary Solid-Liquid separation, and the most suitable secondary treatment process was DAF. On the other hand, reductions for the requirement of bulking agent and organic loading by Solid-Liquid separation process were 94.8% and 84.7%, respectively Therefore, the Solid-Liquid separation process must be required for the successful treatment of swine wastewater from slurry feedlot.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.57-64
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• 1999

The purpose of this study is to establish effective conditions for controlling $CH_4$, $N_2O$ emission from organic Waste / wastewater treatment processes. Continuous and batch experiments were conducted to treat the micro algae from polluted and eutrophicated lakes through the thermophilic oxic process. The microalgae used were mainly Microcystis sp.(collected from eutrophic lake) and Chlorella sp. (cultured in laboratory) Wasted cooking oil was added by aid-heating source. Physico-chemical components of sludges and microalgae were analyzed. In batch experiments, air supply was changed from 50ml/min to 150ml/min. The temperature. water content and drained water were affected by the air flow rate at initial stage. However, there was almost no influence of air flow rate on them in middle and last stages. At air flow rate of 100ml/min, the degradation rate of organic material was higher than that at other air flow rates. $CO_2$ concentration in exhaust was proportional to the strength of aeration, especially at initial stage when degradation was active. $CH_4$ with low concentration was detected only at starting stage when air diffusion was not enough. $N_2O$ production was not affected by variation of air supply. In continuous experiments no matter what the dewatering methods (with PAC and without PAC) and media (wood chip and reed chip) were changed, $N_2O$ was almost not affected by variation of injected air. Result showed that the reed chips using for lake purification could be used as media for thermophilic oxic process in lake and marshes area. $CO_2$ concentration was not so much affected by the change of dewatering methods and media types. $CH_4$ was not detected in the experimental period. So it can be shown that the thermophilic oxic process had been well operated in wide handling conditions regardless of media and dewatering methods.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.1
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• pp.58-66
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• 2013

This study was conducted in order to develop slaughterhouse rumen content (SRC) as a potential feed additive. The moisture content of SRC can reach 80%, and therefore an appropriate dewatering process is required before it can be used. In this study, the effects of heating temperature, heating time, and filler content during the dewatering process on the activity of various enzymes in SRC were investigated. The Box-Behnken experimental design was employed, involving a total of 45 experimental runs, consisting of three variables (heating time, heating temperature, and filler content) with three levels per variable (12, 30 and 48 hr; 60, 75 and $90^{\circ}C$; 12, 22.5 and 33% for heating time, heating temperature, and filler content, respectively). For enzyme activities, xylanase, cellulase, and amylase were examined, and the results were subjected to an analysis of variance. Heating time, heating temperature and filler content had significant effects on the activity of each enzyme (p<0.05). Cellulase and amylase activities decreased (p<0.05) at elevated heating temperatures, whereas xylanase was reasonably stable around $90^{\circ}C$. The activities of all enzymes decreased (p<0.05) with increased heating time. Optimum filler contents for xylanase, cellulase, and amylase activities were 22.5, 12 and 33%, respectively. However, optimum conditions for all variables that simultaneously maximize the activity of all three enzymes could not be ascertained in this study. Nevertheless, the results from the current study can be useful as basic information for the development of SRC as a feed additive enriched with improved major enzymes for livestock feed digestion.

• Journal of the Korean Institute of Gas
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• v.21 no.2
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• pp.1-9
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• 2017

Enhanced coalbed methane recovery (ECBM), as injecting $CO_2$ or $N_2$ into the coalbed methane (CBM) reservoir for increasing methane recovery, takes center stage in these days. ECBM makes a better recovery than the conventional production method, it called dewatering process. However the characteristics of injection gas affect to methane recovery, thus analysis on the mixed ratio of injection gas should be required. In this study, CBM reservoir model was built to estimate the methane recovery of ECBM method by different mixed ratio of injection gas. Additionally, to consider the characteristics of injection gas such as carbon captured storage, nitrogen re-injection, etc. economic analysis was performed. The results showed that ECBM cases produced methane almost twice as much as dewatering case and $CO_2$ 10% and $N_2$ 90% case resulted in the highest methane recovery among the mixed gas cases. On the other hand, the results of economic analysis showed that $CO_2$ 20% and $N_2$ 80% case made the highest total production profit. Therefore, both the recovery of methane and economical efficiency should be considered to apply ECBM process.

• Journal of the Korean GEO-environmental Society
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• v.6 no.2
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• pp.51-60
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• 2005

The disposal problem of waste lime which is a residual product of lime industry have caused a lots of arguments in the past few years. Further more, waste lime contains a high moisture content which causes the disposal of waste lime is a great difficulty. The purpose of this study is to investigate for the effective dewatering solutions by placing various prefabricated vertical drains. The moisture content and degree of consolidation, pore water pressure, changes of settlement, bearing capacity with various vertical drains in waste lime were analyzed. The laboratory test results indicate that PBD is 2 times higher than circular drain in coefficient of consolidation. Based on the laboratory test results, settlement, pore water pressure, and dewatering measurements are shown in similar tendency. It is considered that PBD can drain primitive pore water much efficiently. The picture of SEM shows that circular drain filter has a serious clogging problem in comparison with PBD. In conclusion, PBD holds a superiority in waste lime's ground improvement and dewatering pore water pressure from the waste lime sludge. Also, circular drain is desired for some modification in its filtering system.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.756-762
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• 2013

The economical feasibility was conducted to find the adequate method to treat the dredged sediments from agricultural reservoirs in a pilot project that had been operated to improve the quality of water and benthic environments by dredging of contaminated sediments. For benefit/cost (B/C) analysis, the net expenses were considered as the costs of project, and the benefits were calculated from the saving of waste-treatment cost through reuse of dredged sediment, the saving of construction cost of settling pond, and the values of retained water by dredging. Although the economic feasibility depended on the sites of operation, the average B/C value of the pilot project was estimated as 1.32, indicating this project is economically feasible. Depending on the treatment methods, the B/C values were in the order of the methods of coagulating sedimentation, machinery dewatering, stabilization through exothermic reaction, and soil improvement and stabilization. The machinery dewatering method is estimated as the most adequate one to treat the dredged sediments because of the minimum riskiness of secondary pollution, the recyclability, and its economic feasibility.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2001.05a
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• pp.173-176
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• 2001

• Journal of Energy Engineering
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• v.10 no.2
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• pp.114-119
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• 2001

TRIGA Mark-II&III 연구로서의 운영과정에서 발생된 방사성 슬러리 함유 폐액에 대하여 음이온, 앙이온, 그리고 비이온 응집제를 첨가하였을 때의 여과 효과를 실험실 규모의 진공여과 장치로 연구하였다. 여과 실험 자료를 이용하여 Darcy’s Law에서 유도된 여과 케익 저항 값을 산출하였다. 응집제 사용으로 응집제를 사용하지 않은 경우롸 비교하여 케익 저항값의 개선은 있었지만, 수분함량은 증가하였다. 각각의 응집제 사용에 따른 침전율, 여과 케익의 수분함량, 그리고 여과 케익 저항 값을 비교한 결과 음이온 응집제 12~16ppm/$\ell$ waste를 사용하였을 경우가 가장 효과적인 것으로 나타났다.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.290-295
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• 2000

Mechanical and physical properties of wood fiber for the reinforcement of thin-sheet cement products were investigated. The slurry-dewatering method followed by pressing was used to manufacture the products. Mechanical and physical properties of wood fiber reinforced cement composites were assessed with flexural strength, density, and water absorption. The results obtained in this study were analyzed statistically using the analysis of variance in order to derive statistically reliable conclusions.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.1
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• pp.90-99
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• 2005

This study was conducted to survey the attitude of Chuncheon citizens on food waste generation. About 50% of the citizens were generating $5{\sim}10{\ell}$ of MSW (municipal solid wastes) a week. These answers were almost from below 35 years old. And the citizens answered that the ratio of FW (food waste) to MSW were 10-30%. They were generating FW enveloped in a standardized vinyl bag after dewatering. About 10% of the answers were generating FW with MSW without any dewatering. The reason for FW generation in large quantities was to cook and buy much more food materials than needed. They thought that malodor and harmful insect were the most severe problems from FW storage. The systematic management was the most needed in individual restaurants. They answered that an individual citizen should make an effort to reduce FW generation. However, in fact, they did not do their best to try to reduce FW generation. They agreed that an individual citizen should try to reform 'present food culture' and to think FW as resources.