• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.3
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• pp.83-90
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• 2008

The ultrasonic pre-treatment of sewage sludge (SS) was investigated to increase soluble organic material and to improve anaerobic biodegradability. Ultrasonic disintegration of SS increased the amount of soluble chemical oxygen demand (SCOD), protein and carbohydrate concentrations whereas particle size decreased due to the break-up of cell walls. In terms of anaerobic biodegradability, ultrasonic pre-treatment enhanced the anaerobic biodegradation of SS, leading to the methane gas production improvement. Biochemical methane potential (BMP) of SS was 211.3 ml $CH_4/gVS$ whereas BMP after ultrasonic pre-treatment was 294.3 ml $CH_4/gVS$. The improvement in BMP for SS treated with ultrasonic disintegration was as high as 40 %. This result indicated that disintegration of SS was efficient for enhancing anaerobic biodegradability.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1186-1192
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• 2005

The relationship between bacteria and anaerobic archaea, sludge yield coefficient and nitrogen removal rate were investigated in intermittent aeration systems(I/A) with added archaea, I/A and conventional activated sludge system. As the archaea solution was added to the I/A reactor, organic removal rate as well as nitrogen removal rate increased. Also, sludge production rate in I/A system added the archaea was maintained lower than other systems because sludge yield coefficient was decreased due to the role of anaerobic archaea such as anaerobic degradation of organics. The experimental data supported the possibility of symbiotic activated sludge system with anaerobic archaea under intermittent aeration, leading to the enhanced nitrogen removal. Crucial results to be presented are: 1) specific oxygen utilization rate(SOUR) of the I/A-arch system was $2.9\;mg-O_2/(g-VSS{\cdot}min)$. SOUR and nitrification rate of the sludge from the I/A-arch system was higher than those from the I/A and A/S reactors. 2) Removal efficiencies of $TCOD_{Cr}$ in the I/A-arch, I/A and A/S reactors were 93, 90 and 87%, respectively. 3) Nitrification occurred successfully in each reactor, while denitrification rate was much higher in the I/A-arch reactor. Efficiencies of TN removal in the I/A-arch, I/A and A/S reactors were 75, 63 and 33%, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.3
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• pp.97-105
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• 2007

This study was conducted to compare the performances of acidogenic fermentation and hydrogen fermentation using bench-scale leaching-bed reactors for organic solid waste. Acidogenic fermenters were operated with dilution rates (D) of 2.0, 3.0 and $4.0d^{-1}$ after employing anaerobic sludge and hydrogen fermenters were operated with D of 2.0, 4.0 and $6.0d^{-1}$ after employing heat-treated anaerobic sludge. The highest chemical oxygen demand (COD) conversion efficiency (56.2%) was obtained in acidogenic fermentation with D of $3.0d^{-1}$. Only volatile fatty acid (VFA) was produced as a metabolite. On the other hand, hydrogen fermentation did not show higher COD conversion efficiency (49.3%) than acidogenic fermentation, but it produced hydrogen gas (5.1% of total COD) which was a clean and environmentally friendly fuel with a high energy yield. Therefore, either acidogenic fermentation or hydrogen fermentation could be applied to organic solid waste depending on the purpose of treatment, which could maximize the economics of anaerobic treatment.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.601-606
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• 2014

Lab scale experiment study was carried out for biological treatment process development in shipboard. SBR(Sequence Batch Reactor) process with BM(Beneficial Microorganisms) was investigated for practical application on shipboard sewage treatment. From the results it was suggested that SBR process with BM might be a suitable process in terms of harmful materials removal. By adding BM to SBR system, the useful species of microorganisms and EPS(Extracellar Polymetric Substances) in sludge was increased. It was found that the biodegrability and harmful organic compounds like VOCs and harmful inorganic compounds like heavy metals. was reduced over 70%. As far as reclamation water is considered, this process is very advantageous to special environments such as cruise ships, because the method of adding BM makes it unnecessary to add other facilities on the SBR system.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.13-24
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• 2013

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.763-766
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• 2007

국내에서 발생되는 고형폐기물 중 자원으로 재활용 가능한 유기성폐기물은 하수슬러지, 음식물류폐기물, 축산분뇨 등을 대표 할 수 있다. 이들 유기성폐기물은 환경적인 측면에서 볼 때 다른 유기성 폐수 및 폐기물에 비하여 오염부하량이 상대적으로 높지만, 이를 생물자원 (Biomass)으로 인식하고 이용 할 경우 지구온난화와 같은 환경문제 뿐만아니라 향후 자원고갈문제를 동시에 해결할 수 있는 대체에너지 자원이다. 유기성폐기물을 대체에너지 자원으로 효율적으로 이용하기 위해서는 우선적으로 국제적 환경규제와 에너지 정책에 능동적으로 대응할 수 있는 자원순환형 폐기물관리 시스템 구축이 필요하며, 이를 위한 체계적인 정책적 지원책과 기술 개발이 뒷받침 되어야 할 것이다. 자원 재활용과 에너지회수 기술에 있어 혐기성소화(anaerobic digestion)는 유기성폐기물의 효과적인 감량화, 재이용화, 안정화를 만족시키는 동시에 유용 에너지원인 메탄가스를 회수할 수 있는 바이오가스 전환기술로 최근에 주목을 받는 biotechnology 중의 하나로 자리매김 하고 있다. 특히, 소비자원의 대부분이 해외에 의존하는 국내현실과 최근 고유가에 따른 국가 에너지 정책을 제고해야하는 현 시점에서 유기성폐기물을 이용한 바이오가스화 기술을 널리 보급하기 위해서는 요소기술 개발과 정부의 적극적인 정책적 지원 방안이 마련되어야 할 것이다.

• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.2
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• pp.237-258
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• 1993

Objectives in this study are to stabilize the organic sludges which were produced from papermill wastewater, nightsoil treatment facilities and utilized as foods for earthworm, to find the method for using the cast which was orginated by earthworm as fertilizer, and ultimately to develop the practical technique to solve the environmental problems by optimization of wastes treatment. The results of this study were summarized as follows. In the investigation for fertilizer effect of cast, germination rates of cucumber, tomato, and cabbage were investigated. The germination status of 3 types of plants was excellent as over 90% in the combination case of 30-45% cast. In the investigation for fertilizer effect of cast derived from nightsoil sludge, the growing status of cucumber, tomato, and cabbage was excellent in the combination case of 30-45% cast. In the experiment for fertilizer effect investigation of cast derived from papermill sludge, the growing status of cucumber, tomato, and cabbage was excellent in the combination case of 30-45% cast. Also, in the combination case of 60% cast, plants growth was not disturbed.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.180-186
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• 2005

This paper discusses the development of mixtures for silica fume as a stabilization/solidification agent and a binder for industrial wastewater residue containing organic and heavy metal contaminants. The UCS (unconfined compressive strength) gradually increased to 66.7% as the silica fume content increased to 15%. The leaching of TOC (total organic carbon) and chromium decreased as more OPC (Ordinary Portland Cement) was substituted with the silica fume. When a mixture had 5% silica fume, it retained about 85% TOC, and chromium leached out 0.76 mg-Cr/g-Cr in acidic solution. Also, microstructural studies of the solidified analysis showed that the silica fume caused an inhibition to the ettringite formation which did not contrilbute to setting but coated the cement particles and retarded the setting reactions. The results indicated that the incorporation of silica fume into the cement matrix minimized the detrimental effects of organic materials on the cement hydration reaction and the contaminant leachability.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.3
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• pp.35-43
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• 2011

In this study, anaerobic biological decomposition were attempted after solubilization treatment of sewage sludge with the complex pre-treatment (acid/base treatment with ultrasonic radiation). Solubilization ratios were compared for ultrasonic treatment at acid or base condition. Solubilization effect of the complex pre-treatment was more effective at higher pH. Biological decomposition of complex pre-treated sludge was faster than non treated (raw) sludge, showing 10 times higher total gas production. Biological digestion of the sludge shows more biogas production. B/A ratio. which indicates hydrogen production potential, was 50% higher with complex pre-treated sludge than raw sludge but lactic acid or propionic acid were also detected during anaerobic decomposition process.

• Journal of the Korea Concrete Institute
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• v.27 no.1
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• pp.65-73
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• 2015

This study discussed the pozzolanic properties of calcined sewage sludge (CSS) according to calcination and fineness conditions. The chemical and mineralogical analysis of CSS according to calcination temperature and time were carried out and compared with that of the existing pozzolanic materials such as fly-ash, blast furnance slag and meta-kaolin. Various mortars were made by mixing those CSS and $Ca(OH)_2$ (1:1 wt. %), and their compressive strength and hydrates according to experimental factors such as fineness of CSS and curing age were also investigated in detail. The results show clearly the potentiality of calcined sewage sludge (CSS) as an admixture materials in concrete, but the CSS should be controlled by calcination temperature and time, and fineness etc. In this experimental condition, the calcination temperature of $800^{\circ}C$, calcination time of 2 hours and fineness of $5,000cm^2/g$ were optimum conditions in consideration of the mechanical properties and economic efficiency of CSS. The compressive strength of CSS mortars was higher than that of fly-ash mortars and blast furnace slag mortars, especially at the early ages. Then, the utilization of CSS in construction fields was greatly expected.