• Title/Summary/Keyword: Activated sludge process

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Rapid Detection of Ammonia-oxidizing Bacteria in Activated Sludge Based on 16S-rRNA Gene by Using PCR and Fluorometry

  • Hikuma, Motohiko;Nakajima, Masanori;Hirai, Toshiaki;Matsuoka, Hiroshi
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.5
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    • pp.323-326
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    • 2002
  • To detect whole ammonia-oxidizing bacteria in the activated sludge, group-specific primers targeting the 16S-rRNA gene of ammonia-oxidizing bacteria were used. The electrophoresis pattern of the PCR products seemed to produce a single band of approximately 1.0 k bp for the bacteria in activated sludge and Nitrosomonas europaea. No band was observed for nitrite-oxidizer Nitrobacter winogradskyi and heterotrophs such as Pseudomonas putida. Then direct measurement of the PCR product was made by fluorometry using the reagent Hoechist 33258, so that the fluorescent intensity was in proportional to the cell number of the sample up to 240. Total time required for the test was about 4 h including DNA extraction. The DNA fragments produced were cloned and their sequences showed high similarity to those of Nitrosomonas spp. This study showed the feasibility to detect ammonia-oxidizing bacteria and to esti-mate their population rapidly for the control of the nitrogen elimination process.

A Study on the Development of Activated Carbons from Sewage Sludge (하수슬러지를 이용한 활성탄 개발에 관한 연구)

  • Lee, Taek-Ryong;Chung, Chan-Kyo;Joe, Young-Cheon
    • Clean Technology
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    • v.15 no.1
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    • pp.31-37
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    • 2009
  • This study deals with the production process of activated carbons from the sewage sludge char by chemical activation reaction. KOH and NaOH were used as activating agents, which react well with carbon. From the experiments, it was found that activated carbons made with KOH treatment had better physicochemical properties in terms of iodine number and BET value than those made with NaOH treatment. It was also found that the optimal deposition ratio of an activating agent to the sewage sludge char was 75 wt% of KOH and 50 wt% of NaOH. Activated carbons were washed out by distilled water after neutralization with 5 M hydrochloric acid solution. The activated carbons that were produced from a sewage sludge char at this optimal conditions have BET surface areas of approximately $600m^2/g$.

Sewage Treatment using Moving Media Complete Mixing Activated Sludge/Solid Contact Process (회전매체를 가진 완전혼합 활성슬러지/Solid Contact 공법을 이용한 하수처리에 관한 연구)

  • 김홍태
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.4
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    • pp.67-75
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    • 1993
  • This study was carried out to investigate the applicability of Solid Contact Process for the improvement of Moving Media Complete Mixing Activated Sludge(MMCMAS) effluents. Laboratory MMCMAS Reactor and MMCMAS/Solid Contact were operated at the hydraulic loading of 122~340 L/m$^2$/d. The conclusions from this study were as follows ; The addition of Solid Contact tank to the MMCMAS reactor has increased the SCOD and SBOD removal efficiencies of 4 to 67% and 2 to 41%, respectively. In addition, the increments of nitrification rates were about 13 to 46%. It was also observed that the addition of Solid Contact tank has greatly increased the organic removal efficiencies at the higher hydraulic loading rates and also decrement of sludge production rates was 0.1 gVSS/gBODrem. It was therefore concluded that the addition of Solid Contact tank could have polished the effluent of MMCMAS at the higher hydraulic loading rates.

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Effect of pH on the Degradation of 2, 4-Dinitrophenol in Sequencing Batch Reactor Process (연속회분식(連續回分式) 처리공정(處理工程)에 의한 2, 4-Dinitrophenol분해시(分解時) pH의 영향(影響))

  • Jo, Kwan-Hyung
    • Journal of Korean Society of Water and Wastewater
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    • v.12 no.1
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    • pp.96-101
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    • 1998
  • Substrate inhibition of 2,4-dinitrophenol (DNP) degradation was investigated using activated sludge which had been adapted to mineralize DNP. DNP is a metabolic uncoupler, preventing cells from making energy for growth and it has been suggested that pH may be important in mitigating effects of uncouplers. After acclimation of the activated sludge, the effect of pH on toxicity of DNP at high concentration (75 mg/L) was investigated, over a pH range of 5 to 9. DNP inhibition was found to be strongly dependent on mixed liquor pH. The DNP degradation rate was highest in the pH range of 6.95 to 7.84; at pH 5.94 degradation of 75 mg/L DNP was significantly inhibited; at pH < 5.77, DNP degradation was completely inhibited after approximately 30% of the DNP was degraded. By comparison, no significant effect of pH variation in the same range was seen on glucose uptake by the activated sludge culture.

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A Study on Biodegradability of Various Dyeing Auxiliaries (각종 염색조제의 생분해성에 관한 연구)

  • 류원률;이호경;이영호;신현철;최장승;이기풍;조무환
    • Textile Coloration and Finishing
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    • v.10 no.6
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    • pp.42-48
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    • 1998
  • For the effective operation of complex dyeing wastewater treatment plant, the biodegradability of various dyeing agents were investigated. For experiments in biodegradability, activated sludge from aeration tank of wastewater treatment plant was used. Biodegradability of dyeing agents were compared by measuring the $BOD_5/COD_{Cr}$ ratios and $BOD_5$ removal efficiency. $COD_{Cr}$. removal efficiency of dyeing agents was less than 80% , while $BOD_5$ removal efficiency was less than 60% after of days. Therefore, biodegradation by activated sludge were found very difficult. Judging from this, it is necessary to isolate strains biodegrading dyeing agents in order to operate activated sludge process safely.

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Relationship Between C/N Ratio and Nitrogen Removal in Intermittently Aerated Activated Sludge System (간헐폭기 활성슬러지공정에서 C/N비와 질소제거의 관계)

  • 서인석;김병군;이상일
    • Journal of environmental and Sanitary engineering
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    • v.13 no.2
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    • pp.57-65
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    • 1998
  • In this research, Effect of C/N ratio on nutrient removal in intermittently aerated activated sludge system(IAASS) was investigated with dormitary, building and swine wastewater. Three types (2-stage, 4-stage, modified) of IAASS were operated. Time interval of aeration/nonaeration in IAASS was 1hr/1hr. In treatment of Dormitary wastewater(BOD/T-N ratio : 4.4), Building wastewater (BOD/T-N ratio : 3.14) and swine wastewater(BOD/T-N ratio : 3.84), Nitrogen removal efficiency of 80, 70 and 90.4% was achieved, respectively. Nitrogen removal in IAASS was a great influenced on influent C/N ratio, efficient nitrogen removal was achieved at BOD/T-N ratio over 4. In IAASS operation, $\Delta $BOD mg/L/$\Delta $ nitrogen mg/L ratio was about 4-6. Simultaneous removal of organic, nitrogen and phosphorus in IAASS can achieved. And influent organic was efficiently utilized in denitrification. IAASS could be one of the best alternative process for the retrofit of conventional activated sludge system for the removal of nutrients.

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Removal Characteristics of Cyclic Ethers in Biological Wastewater Treatment System (고리형 에테르의 생물학적 처리 특성)

  • Lee, Sung-Ryul;Jeong, Yeon-Koo
    • Journal of Environmental Science International
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    • v.17 no.3
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    • pp.343-350
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    • 2008
  • The fate of two cyclic ethers, THF(Tetrahydrofuran) and 1,4-Dioxane, in conventional biological wastewater treatment plants was investigated using sequential activated sludge process. Removal efficiency of THF were about 86% in average, which was greater than that of 1,4-Dioxane, 30%. However, it was not clear whether the removal of cyclic ethers in biological system was caused by microbial activity or not. Thus treatability tests were conducted by batch experiments. The effects of mixing, aeration and the addition of activated sludge on the removal of cyclic ethers were investigated in batch experiments. THF was totally removed by mixing and aeration in 24 hours while removal ratio of 1,4-Dioxane was at most 30% for the same period. This results could be ascribed to the differences in Henry's law constants between the two chemicals. In addition, biological degradation including biosorption was not obviously observed in these batch tests.

Tsukamurella sunchonensis sp. nov., aBacterium Associated with Foam in Activated Sludge

  • Seong, Chi-Nam;Kim, Young-Sook;Baik, Yeun-Shik;Park, Sang-Ki;Kim, Min-Bae;Kim, Seung-Bum;Michael Goodfellow
    • Journal of Microbiology
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    • v.41 no.2
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    • pp.83-88
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    • 2003
  • The taxonomic position of actinomycete strain SCNU5$\^$T/, isolated from extensive foam in the aeration basin of an activated sludge process, was clarified by phenotypic, chemotaxonomic and phylogenetic analyses. The strain possesses wall chemotype IV, MK-9(H$\^$0/), as the major menaquinone, and contains saturated, monounsaturated and 10-methyl branched fatty acids. The G+C content of its DNA is 68.1 mol%. Phenotypic data and DNA relatedness to known species indicate that the strain SCNU5$\^$T/ represents a new species within the genus Tsukamurella, for which we propose the name Tsukamurella sunchonensis SP. NOV. The type Strain Of T. sunchonensis is SCNU5$\^$T/ (=KCTC 9827$\^$T/).

제지산업의 지속가능한 처리공정을 위한 제지슬러지 재활용 기술

  • Im, Mi-Hui;Lee, Jong-Gyu;Nam, Seong-Yeong;An, Ji-Hwan
    • Ceramist
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    • v.14 no.2
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    • pp.7-14
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    • 2011
  • This paper has investigated physicochemical properties and conventional and environmental-friendly treatment methods of paper mill sludge to emphasize the importance and necessity of the sludge recycling. The paper mill sludge generally shows high contents of calcium and water, and is mostly discharged by landfill after incineration process rather than being recycled due to technical or economical problems. In recent years, however, several possible methods for recycling the paper mill sludge have been suggested for its sustainable process as follows; compost, raw material for the construction and paper industry, new energy source for reducing fossil fuel use and raw material of activated carbon for treating paper mill wastewater. Thus the authors suggest that practical recycling technologies of the paper mill sludge must be developed for substantiality in the paper industry through comprehending physicochemical compositions and generation status of the sludge and actively performing various related studies. Furthermore, this investigation could be used as preliminary information for the study on recycled paper development using paper mill sludge incineration ash.

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An Experimental Study on Wastewater Treatment by Modified Activated Sludge Process (변형된 활성슬러지공법의 폐수처리에 관한 실험적 연구)

  • 채수권;연기석
    • Water for future
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    • v.22 no.1
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    • pp.117-125
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    • 1989
  • This study deals with the performance of an acivated sludge system which is modified by the researcher to function without any additional chemical or internal recyle in removing organics, nitrogen, and phosphorus from synthetic wastewater. To improve the nutrient removal efficiency, the researcher utilized the anoxic, anaerobic, and aerobic reactor sequences with a single sludge return, whiched to nitrification/denitrification and phosphorus release/overplus accumulation. A bench scale system was operated with a view to investigating the reaction characteristics of each reactor, and to measuring the biological kinetic coefficients(Y, $K_d$, k, $K_s$) for theremoval of COD in relation to the mean cell residence time at five different MLSS concentrations, 5000, 4200, 3300, 2600, and 1900 mg/l. The results of the research showed that organic substance and nutrient were removed simultaneously by this modified activated sludge process. And the process kad 66%-99% ortho-p removal efficiency.

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