• 상하수도학회지
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• 제23권6호
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• pp.769-778
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• 2009

Performances and internal behaviors of the upflow hybrid anaerobic filters treating a dairy wastewater were analyzed to identify the functions and roles of the modular crossflow media and sludge bed layer and to discover their interrelationship in the filter. The media could perform independent biological and physical separation role without buildup of sludge bed, while the role of sludge bed was dependent on the function of the media. The filter packed with the crossflow media did not necessarily require the formation of sludge bed when treating a dairy wastewater. Biological contribution of the media was controlled by that of biologically active sludge bed complementing mutually each other. The gas-liquid-solid separation capability of the media was indispensible to ensure the active biological role of sludge bed, since sludge bed buildup without the media had no independently effective biological function. It was believed that the filter in itself could also function as a selector for physical gas-liquid-solid separation resulting in selectively concentrating particles with superior settleability in sludge bed. The sludge bed in the filter played a key role in the physical solids capture from influent as well as biological organics removal.

• 한국환경과학회지
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• 제11권10호
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• pp.1089-1096
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• 2002

The objectives of this study were to investigate the desulfurization kinetics of paper sludge and limestone in a fluidized bed reactor according to bed temperature and air velocity. The experimental results were presented as follows ; First, the bed temperature had a great influence on the desulfurization efficiency of limestone and paper sludge. In paper sludge, the optimum condition in desulfurization temperature was at 80$0^{\circ}C$ and in limestone, that was at 850 $^{\circ}C$ or 900 $^{\circ}C$ Second, as air velocity increased, the desulfurization efficiency(or the absorbed amount of sulfur dioxide) by limestone and paper sludge decreased. And the absorbed amount of sulfur dioxide by paper sludge was larger than that of by limestone. Third, as the velocity increased and the optimum desulfurization temperature became, ks and the removal efficiency increased. So, ks, kd highly depended on the air velocity and bed temperature.

• 한국환경보건학회지
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• 제32권2호
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• pp.179-185
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• 2006

Effect of organic loading rate on UASB performance was evaluated under the renditions of some surface area/reactor volume ratio and different reactor diameter. At the low leading rate of 0.4 kg $COD/m^3{\cdot}d$, reactor performance was not affected by reactor diameter. At the organic loading rate of 6 kg $COD/m^3{\cdot}d$, however, volatile acid accumulation and low COD removal efficiency is observed in reactor having 6.4 cm diameter, while volatile acid is not accumulated at all and high COD removal efficiency is observed in reactor having 3 cm diameter. Such a difference of reactor performance depending on reactor diameter can be explained that sludge bed can be fluidized by evolved gas bubble in narrow reactor, while sludge bed ran not be fluidized by evolved gas bubble only in wide reactor. At a high organic loading rate of 20 kg $COD/m^3{\cdot}d$, it can be judged that there is no relation between reactor configuration and reactor performance because all reactors showed very low COD removal efficiencies regardless of reactor diameter. Narrow and tall type reactor is favorable condition for making sludge bed fluidization at a constant surface area/reactor volume ratio. Thus, it can be judged that reactor configuration and sludge bed fluidization have great influence to reactor performance.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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• pp.81-91
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• 1999

Fuel characteristics of sewage sludge as required for the fluidized bed incinerators have been evaluated. Sewage sludge is basically a solid fuel with high percentage of moisture. Moisture content of the fuel directly affects the heating value of the fuel and the exhaust gas composition. When the sludge of transported into the incinerator, sludge cake is subject to the mixing, break-up and heat-up. Fluidization process would enhance these physical processes. The sludge fuel could then undergo the moisture evaporation and devolatilization process. Subsequent oxidation of volatiles as well as the remaining char would then follow. Sludge samples are characterized with high percentage of volatiles out of total combustibles. Quantitative understanding of above listed subprocesses would certainly help in the utilization of fluidized bed incinerators. A limited set of fuel characterization tests including calorimetric analysis, proximate analysis, elemental analysis and thermogravimetric analysis were conducted for the selected sludge samples. The measurement reasults of sludge samples were reported along with some published data. Limited experience in the actual incinerator plant is also presented.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.29-32
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• 2014

The practical route for disposal of sewage sludge becomes energy recovery by combustion after its ocean dumping is banned in 2012 in Korea. Due to the high moisture content, however, sewage sludge is required to be dried before transport and combustion. In this study, pyrolysis and combustion characteristics of dried sewage sludge was investigated in a small-scale fixed bed reactor in order to provide fundamental data for energy recovery of the fuel. As the first step of combustion, the primary products of pyrolysis were analyzed in a fixed bed reactor for the condensable volatiles (tar), non-condensable gases, and char. For the combustion characteristics, another fixed bed reactor was constructed to monitor the weight and temperature of the fuel particles during ignition and combustion under different air flow rates. The test results were used to derive the ignition and burning rates.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.165-172
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• 2004

Co-incineration of coal and wastewater sludge was r;erfonn:rl in a O.lMWth bench scale circulating fluidized bed combustor(CFBC) Sludge was received from a wastewater treatment plant in a dye industrial complex in Busan. Metropolis. Moisture content of received sludge was 80%. Coal and sludge mixture was prepared with weight ratio of 90/10, 85/15 and 80/20. Co-combustion characteristics of the coal and sludge mixture demonstrated stable combustion conditions. Component analysis, incineration characteristics, boiler performance was measured before and after the test and application for commercial 59MWth CFBC boiler. The release of hazardous components such as $SO_2$ and Cl was suppressed by the presence of inherent minerals of Ca, Na, K in coal and sludge mixture. Pre-drying was not essential but it was recommended for the benefits of manageability of sludge.

• Environmental Engineering Research
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• 제20권4호
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• pp.336-341
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• 2015

The industrial-scale biological treatment of Chinese nutgall processing wastewater was conducted with a $200m^3$ expanded granular sludge bed reactor and a $900m^3$ bio-contact oxidation reactor. The temperature of the two reactors was controlled under mesophilic conditions ($32-40^{\circ}C$), through changing the proportion of the dilution water, which was composed of steam condensation water and residual circulating water. The effluent COD, gallic acid, chroma, total nitrogen, total phosphorus levels and pH of both the expanded granular sludge bed and bio-contact oxidation reactors were monitored. In addition, the redox potential in the expanded granular sludge bed was recorded. The total COD removal efficiency was 87.257% when the influent COD concentration was $14\;251{\pm}3\;148mg/L$, and the ratio of wastewater: dilution water was 1:5. The removal efficiencies of gallic acid, chroma, total nitrogen, and total phosphorus were 72.221%, 43.940%, 64.151% and 39.316%, respectively. The effluent pH increased in either the expanded granular sludge bed reactor or the bio-contact oxidation reactor during the operation. The redox potential in the expanded granular sludge bed varied between -367 mV and -435 mV. The results indicate that the combined process was suitable for treating Chinese nutgall processing wastewater.

• 환경위생공학
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• 제12권2호
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• pp.13-21
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• 1997

The effect of upflow velocity on size distribution and activity of granular sludge was studied in laboratory-scale Expended Granular Sludge Bed(EGSB) reactor fed with non-fat dry milk and sucrose as sole carbon and energy source. High upflow velocity advanced size and activity of granular sludge by distribution and floatation of granular sludge. Therefore, the reactor operation of an apt upflow velocity was needed and an apt upflow velocity in this experimental was estimated to 1-10m/hr.

• 유기물자원화
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• 제8권2호
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• pp.102-113
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• 2000

본 연구에서는 지렁이처리기술의 실증실험을 통하여 규모의 확대가능성을 파악하고 아울러 유기성오니 처리에 대한 대책방안을 제시하기 위한 목적으로 실제 현장에 사육상을 설치하여 지렁이의 이식방법에 따른 지렁이의 거동 및 정화조.분뇨오니의 처리효율에 대하여 비닐하우스상과 비교검토하였다. 그 결과, 노지사육상에서의 지렁이의 지렁이사육상의 6개월간 먹이 섭취율은 0.27~0.33톤/$m^2$ 로 나타나고, 분변토 발생량은 사육상 6개월간 단위 면적당 평균 0.15톤/$m^2$이었으며 급이된 분뇨케잊의 약 45.5% (44.1~46.7%)로 나타나 절반 정도가 분변토로 배출되어, 비닐하우스 사육상간의 차이는 보이지 않았다. 노지 사육상에서의 지렁이 서식밀도는 최대밀도가 $7kg/m^2$을 기록한 적도 있으나 평균적으로 약 $6.5kg/m^2$을 나타내었고 계절별로는 봄과 가을에 밀도가 높으나 여름에는 다소 낮아지는 경향을 보였으며, 노지사육상에서의 지렁이의 연령분포도는 성체가 많고 유체가 적게 나타나는 역피라미드 형으로 나타났다. 지렁이를 이용하여 처리하는 당해사업소(하우스시설 1200평, 노지 7000평)에는 매립처리비용 및 운반비로 소요되는 비용의 절감효과와 생산된 분변토를 판매한 수익으로 월간 960만원의 수입이 창출되었을 뿐만 아니라 기존의 매립처리방법에 비하여 환경친화적인 것으로 판단되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.922-926
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• 2002

In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks as heating temperature for NOx removal, we measure NO, $NO_2$ concentration as increasing temperature of sludge pellets and applying high voltage to sludge pellets in a quartz-glass reactor at the same time. NO initial concentration is 100ppm balanced with air gas in a mixing chamber. The gas flow is 5[l/min] and the heating temperature of sludge pellets in a quartz-glass reactor is adjusted from $200[^{\circ}C]$ $400[^{\circ}C]$ to investigate the effect of sludge pellets for removal NOx$(NO+NO_2)$ as increasing temperature. $BaTiO_3$ pellets is filled in a packed-bed reactor for corona discharge to measure how much NOx$(NO+NO_2)$ is removed after generating $NO_2$ from the packed-bed reactor. AC[60Hz] voltage is supplied to the reactor for discharge. In the result, $NO_2$ concentration is decreased by sludge pellets without heating temperature for sludge pellets in case of sludge pellets done heat treatment, however NO concentration is almost the same to be compared NO initial concentration. As increasing heating temperature for sludge pellets, $NO_2$ adsorbed on the sludge surface done heat treatment is converted to NO by the thermal energy, so NO concentration is extremely increased by reduction decomposition of $NO_2$. Finally, We think the sludge is possible to use for reduction catalysts, however we need to study more about the possibility and endurance of sludge as catalysts for NOx removal.