• Title/Summary/Keyword: sludge bed

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Role of Crossflow Module Media in Gas-liquid-solid Separation and Biomass Retention in Hybrid Anaerobic Filter (교차흐름식 모듈 충전 hybrid 혐기성여상의 기·액·고 분리능 및 슬러지보유능)

  • Chang, Duk;Chae, Hee-Wang;Bae, Hyung-Suk;Chung, In;Han, Sang-Bae;Hur, Joon-Moo;Hong, Ki-Ho
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.6
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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.

Desulfurization kinetics of waste paper-sludge and limestone in a fluidized bed reactor (유동층반응기에서 폐제지슬러지와 석회석의 탈황 동역학)

  • 조상원;오광중
    • Journal of Environmental Science International
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    • v.11 no.10
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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.

Performance of Upflow Anaerobic Sludge Blanket (UASB) Reactor Depending on Reactor Configuration and Sludge Bed Fluidization (반응조 형태 및 슬러지층 유동화 특성에 따른 Upflow Anaerobic Sludge Blanket (UASB) 반응조의 운전효율)

  • Jeong Byung-Gon
    • Journal of Environmental Health Sciences
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    • v.32 no.2 s.89
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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.

Fuel Characteristics of Sewage Sludge in a Fluidized Bed Incinerator (유동상 소각로에서 하수 슬러지 연료 특성)

  • Choi, Jin-Hwan;Choi, Sang-Min
    • 한국연소학회:학술대회논문집
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    • 1999.10a
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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.

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Pyrolysis and combustion characteristics of dried sewage sludge in a fixed bed reactor (건조 하수 슬러지의 열분해 및 고정층 연소 특성 연구)

  • Kim, Minsu;Lee, Yongwoon;Park, Jinje;Ryu, Changkook
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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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.

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Incineration of Waste Water Sludge and Coal In a Circulating Fluidized Bed Combustor (순환유동층에서 폐수슬러지와 석탄의 혼소 특성)

  • Bae, Dal-Hee;Shun, Do-Won;Park, Jae-Hyeon;Ryu, Ho-Jung;Park, Do-Hyun
    • 한국연소학회:학술대회논문집
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    • 2004.06a
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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.

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Industrial-scale biological treatment of Chinese nutgall processing wastewater by combined expanded granular sludge bed and bio-contact oxidation

  • Wu, Yundong;Zhou, Kanggen;Dong, Shuyu;Yu, Wei;Liang, Chunsheng
    • Environmental Engineering Research
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    • v.20 no.4
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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.

Effect of upflow liquid velocity on size and activity of granular sludge in Expended Granular Sludge Bed(EGSB) reactor (EGSB 반응조 운전시 상향유속이 입상슬러지의 크기 및 활성도에 미치는 영향)

  • 이헌모;정병곤
    • Journal of environmental and Sanitary engineering
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    • v.12 no.2
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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.

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Investigation on management conditions for vermicomposting of night soil in Field at N Sewage Water plant (N하수처리장 정화조.분뇨케익의 재활용을 위한 지렁이 사육 조건검토)

  • Kim, K.Y.;Lee, C.B.;Choi, H.G.;Phae, C.G.
    • Journal of the Korea Organic Resources Recycling Association
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    • v.8 no.2
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    • pp.102-113
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    • 2000
  • This study was conducted to investigate the expandibility of sludge treatment by earthworm through real scale experiment and the optimum counter-plan for organic sludge treatment. For the purposes, sludge removal efficienciesof night-soil using earthworm and it's behavior according to the transplanting methods of the earthworm on non-cover worm bed or in the green house worm bed were compared. Sludge uptake rates on non-cover worm bed for 6 months were $0.27{\sim}0.33ton/m^2$ and the excrement of earthworm yields $0.15ton/m^2$(44.1~46.7% of raw night soil sludge dosage). These results were not much different from the worm bed in the green house. The average and maximum earthworm density were about $6.5kg/m^2$ and $7kg/m^2$ respectively on the non-cover worm bed. The density of the worm bed was comparatively higher in spring and fall terms but lower in summer. The amount of old earthworm was much plenty than young earthworm on the non-cover worm bed, resulting in reverse distribution type of pyramid. From the experiments on non-cover worm bed(7,000 pyeong)and in the green house worm bed(1,200 pyeong), it was concluded that landfill and transporting cost could be reduced when the earthworm was applied for the night-soil sludge treatment. Profits from the excrement sale of earthworm was 9,600,000 won. Through this study, it was founded that earthworm treatment method for organic sludge are much more environmentally sound than landfill treatment.

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Co-firing Characteristics and Slagging Behavior of Sewage Sludge with Coal and Wood Pellet in a Bubbling Fluidized Bed (기포 유동층 반응기를 이용한 하수 슬러지와 석탄 및 우드 펠렛의 혼소 특성 및 슬래깅 성향 연구)

  • Ahn, Hyungjun;Kim, Donghee;Lee, Youngjae
    • Clean Technology
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    • v.24 no.4
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    • pp.323-331
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    • 2018
  • The results of an experimental investigation on the co-firing characteristics and slagging behavior of dried and hydrothermal carbonization sewage sludge, sub-bituminous coal, and wood pellet in a fluidized bed were presented. Combustion tests were conducted in a lab-scale bubbling fluidized bed system at the uniform fuel-air equivalence ratio, air flow rate, and initial bed temperature to measure bed temperature distribution and combustion gas composition. 4 different fuel blending cases were prepared by mixing sewage sludge fuels with coal and wood pellet with the ratio of 50 : 50 by the heating value. $NO_x$ was mostly NO than $NO_2$ and measured in the range of 400 to 600 ppm in all cases. $SO_2$ was considered to be affected mostly by the sulfur content of the sewage sludge fuels. The cases of hydrothermal carbonization sewage sludge mixture showed slightly less $SO_2$ emission but higher fuel-N conversion than the dried sewage sludge mixing cases. The result of fly ash composition analysis implied that the sewage sludge fuels would increase the possibility of slagging/fouling considering the contents of alkali species, such as Na, K, P. Between the two different sewage sludge fuels, dried sewage sludge fuel was expected to have the more severe impact on slagging/fouling behavior than hydrothermal carbonization sewage sludge fuel.