• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.172-181
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• 2001

Upflow anaerobic sludge blanket (UASB) system employs granular sludge to treat various wastewaters including landfill leachate. CH$_4$ production of the granules determines overall performance of a UASB reactor. Sludge granules are developed by self-granulation of microorganisms and dynamic balance between granule growth and decay results in coexistence of granules with different sizes in the reactor. In this study, granules taken from a laboratory-scale UASB reactor were classified into 4 groups based on their diameters and their Physicochemical characteristics we were investigated. Each group was analyzed for settling ability, specific methanogenic activity (SMA), and elemental content. Settling ability was proportional to granule diameter. suggesting effective detainment of larger granules in the reactor. When acetate or glucose was used as a substrate, all groups showed relatively slight difference in SMA. However SMA with a volatile fatty acid mixture showed significant increase with granule diameter, suggesting better establishment of syntrophic relationship in larger granules. Larger granules showed higher value of SMA upon environmental changes (i.e., PH, temperature, or toxicant concentration). Comparative analysis of elemental contents showed that content (dry weight %) of most tested elements (iron, calcium, phosphorus, zinc, nickel. and manganese) deceased with granule diameter, suggesting importance of these elements for initial granulation. Taken together, this study verified experimentally that Physicochemical Properties of granules are related to granule size distributions. Overall results of physicochemical characterization supports that larger.

• 한국물환경학회지
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• 제23권3호
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• pp.397-402
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• 2007

Anammox reactor seeded with sewage sludge from RBC reactor and anaerobic granule from full-scale UASB reactor treating distillery wastewater was operated. Mixed granule and suspended sludge in the ammonium oxidizing process were taken and analyzed to investigate microbial community structure by molecular methods such as gene cloning and phylogenetic tree analysis after 250 days of continuous cultivation. The average nitrogen removal rate showed $0.9kg\;N/m^3-day$ after 250 days of continuous operation, then the maximum nitrogen removal rate showd $1.9kg\;N/m^3-day$ when $2.1kg\;N/m^3-day$ of nitrogen loading rate was applied. As results of gene cloning and phylogenetic tree analysis, Three kinds of phylum were found to be Proteobacteria, Acidobacteria and Planctomycetes (anammox bacteria) in mixed granule. Five kinds of phylum were found to be Proteobacteria, Chlorobi, Planctomycetes, Nitrospirae and Verrucomicrobia in suspended sludge. We found planctomycete KSU-1 and putative new anammox bacteria in the reactor. Microbial structure represented different consortia depending on the types of sludge in the anammox reactor.

• 유기물자원화
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• 제15권2호
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• pp.136-146
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• 2007

상향류 혐기성 블랭킷 반응조를 이용한 매립지 침출수 처리시 입상슬러지 첨가 유무에 상관없이 성공적인 처리가 가능하였다. 입상슬러지의 첨가는 초기 운전기간를 현저히 단축할 수 있었다. 수리학적 체류시간 1일과 $4-8kgCOD/m^3.d$ 의 유기물 부하율에서 Control 반응조와 Granule 반응조의 COD 제거율은 90% 이상을 유지하였다. 실험기간 동안 입상슬러지 첨가 유무에 상관없이 슬러지 표면과 반응조 벽면에 무기 침전물이 축적되었다. 비메탄 활성도는 미생물의 기질에 대한 적응도와 유기물 부하량이 증가함에 따라 증가하였다. Granule 반응조의 최대 비메탄 활성도의 값은 $0.57gCOD/g{\cdot}VSS{\cdot}.d$로 나타났다. 비록 본 연구에서는 과도한 무기물 축적으로 인한 비메탄 활성도의 저감은 발생하지 않았으나 무기물의 제거를 위하여 유입수의 전처리 공정이 필요할 것으로 판단된다.

• 유기물자원화
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• 제16권4호
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• pp.91-97
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• 2008

본 연구에서는 상향류 혐기성 블랭킷 반응조를 이용한 침출수 처리시 입상활성탄과 입상슬러지의 첨가가 반응조의 성능에 미치는 영향을 평가하였다. Control 반응조의 경우 식종물질로 혐기성 소화슬러지를 이용하였으며 GAC 반응조와 Granule 반응조의 경우 Control 반응조와 동일 방식으로 식종하였으며 단지 GAC와 입상슬러지를 소량 첨가하였다. Granule 반응조가 초기 운전기간 동안 가장 짧은 순응기간을 보였으며 GAC 반응조의 경우에도 운전초기에 만족할 만한 성능을 보였다. 그러나 활성탄의 흡착능이 소모됨에 따라 유출수 COD 농도가 점차 증가하는 경향을 보였다. 반응조가 안정화된 후 GAC 반응조가 다른 반응조에 비해 약간 우수한 결과를 보였으며 모든 반응조의 COD 제거율은 수리학적 체류시간 1일에서 90% 이상을 나타내었다. 특히 GAC 반응조의 경우 COD 제거율의 변화 없이 유기물 부하 $4.0{\sim}8.2kg\;COD/m^3.d$에서 95%를 유지하였다. 소량의 입상슬러지 첨가에 의해 초기 운전기간을 단축시킬 수 있었으며 처리효율은 GAC 첨가에 의해 향상되는 것으로 나타났다.

• 한국환경과학회지
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• 제4권2호
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• pp.201-214
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• 1995

Design approach of upflow Anaerobic Sludge Blanket(UASB) process based on the biological kinetic parameters are known to be very difficult since the characteristics of the granular slut비e depends on the type of wastewater and size distribution of the granular sludge also depends on the upflow velocity in the UASB reactors. Furthermore, industrial wastewater containing toxic substances has been treated by UASB process without the clear knowledge of toxic effects on the granular slut형e. Hence, the present research was aimed on the intensive evaluation of biological kinetic parameters of the granular sludge in UASB reactor with and without toxic substance of 2, 4-dichlorophenol in order to present the basic design measures for UASB process design. The results could be summarized as follows. The biological kinetic parameters(k and Ks) considerably varied with the granular size of the sludge. Generally, 연e k and ks values of the granular sludge increased with the particle size of the granule. The biological kinetic parameters(k and Ks) of the granular sludge obtained from batch test were not applicable to design purpose of UASB process due to substrate diffusional limitation into the granular sludge in the completely mixed UASB reactors. The toxic effects on k and Ks greatly varied with the granular sixte. And as the toxicant concentration increased, the k value decreased while the Ks value increased. Inhibition constant(hi) for k with the toxicant of 2, 4-dichlorophenol varied from 0.5 to 2.3 depending on the granular sizes while the inhibition constant(Ki) for Ks varied from 20.7 to 80.1, showing the mixed inhibition.

• 대한환경공학회지
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• 제28권10호
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• pp.1055-1064
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• 2006

본 연구소에서는 혐기성 입상슬러지를 충진한 UASB 반응기와 탄소섬유를 충진한 배양기를 조합하여 아주 느린 성장특성을 가진 혐기성 암모늄 산화균의 배양을 시도하였다. 연속배양 180일 이후, 유입질소부하가 0.6 kg $N/m^3-d$였을 때, 평균 질소전환율은 0.54 kg $N/m^3-d$로 나타났다. 검은 혐기성 입상슬러지는 연속배양시간이 지남에 따라 갈색과 붉은 색으로 변화되었으며, anammox 반응기는 붉은색 입상슬러지가 많을수록 높은 활성도를 나타내었다. 따라서, 붉은색 입상슬러지를 채취하여 분자생물학적 방법을 이용하여 미생물 군집구조를 분석하였다. 클로닝 및 계통분류학적 분지도 작성 결과, anammox UASB 반응조의 붉은색 입상슬러지에서 발견된 미생물 종류는 anammox 미생물과 더불어 문단위의 4가지 다른 미생물, Proteobacteria, Acidobacteria, Chlorobi와 Chloroflexi로 나타났다. Anammox UASB 반응조내의 붉은색 입상슬러지에서는 clone의 개수를 기준으로 anammox 미생물이 약 25%가 존재하였고 $\beta$-proteobacteria가 우점하고 있는 양상을 보여주었으며, 본 연구의 클로닝 정보와 AMX368 FISH 탐침자를 이용해 in silico 실험을 수행한 결과 AMX368과 정확히 들어맞는 anammox 미생물 clone 하나와 하나의 염기서열이 변이를 일으킨 11개의 anammox 미생물 clone을 확인할 수 있었다. 사상균 형태의 Chloroflexi는 혐기조건 입상 슬러지의 형성과 관련이 있는 것으로 판단되었다. FISH 수행결과, anammox 미생물은 붉은색 입상 슬러지에 우점하고 있는 것으로 나타났다.

• 상하수도학회지
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• 제22권6호
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• pp.673-679
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• 2008

The representative microorganism of autotrophic denitrification using sulfur granule, oxidizes the reduction from S and performs denitrification by reducing $NO_3{^-}-N$ to $N_2$ gas. The sampling of autotrophic denitrification microorganisms has been performed from foreshore sludge, condensed sludge, and active sludge, but the analysis of autotrophic denitrification microbial community characteristics has been lacking. Based on the separation and identification of each sample using the PCR and DGGE methodologies, many types of sulfuric microorganisms and autotrophic denitrification microorganisms were found.

• 한국물환경학회지
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• 제23권6호
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• pp.993-997
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• 2007

The upflow anaerobic sludge blanket (UASB) reactor can be effective for treating simple organic compounds containing high concentration of ammonia nitrogen. The chemical oxygen demand (COD) removal efficiency was about 80% at ammonia nitrogen concentration up to 6,000 mg-N/L. This result also showed that it would be possible to treat propionate effectively at free ammonia nitrogen concentration up to 724 mg-N/L if sufficient time was allowed for adaptation. However the specific methanogenic activity (SMA) of granule was lower than that of granule in the reactor with lower ammonia nitrogen concentration. At 8,000 mg-N/L, the inhibition of high ammonia concentration was observed with evidence of increase of the volatile suspended solids (VSS) concentration in the effluent. It might be ascribed to the decrease in the content of extracellular polymer (ECP), which resulted to the sloughing off of obligated proton-reducing acetogens and heterogenotrophic methanogens from the exterior of granular sludge. This caused a great portion of the finely sludge to be easily washed out. Therefore, failure to maintain the balance between these two groups of microorganism cause accumulation of the hydrogen partial pressure in the reactor, which could have inhibited the growth of acetate utilizing methanogens.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.378-384
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• 2003

Mesophilically-grown granular sludge seeded in thermophilic UASB reactor was monitored to better understand the start-up process of the reactor. The reactor was fed with a synthetic wastewater containing glucose. As COD loading rate increased stepwise, methane production rate increased. Maximum values of COD removal efficiency (95%) and methane production rate (5.3 l/day) were achieved by approximately day-80 and remained constant afterward. However, physicochemical and microbial properties of granules kept changing even after day-80. Specific methanogenic activity (SMA) was initially negligible, and increased continuously until day-153 and remained constant afterward, showing the maximum value of $1.51{\pm}0.13\;g\;CH_4-COD/g$ VSS/day. Deteriorated settling ability of granules recovered the initial value by day-98 and was maintained afterward, as determined by sludge volume index. Initially reduced granule size increased until day-126, reaching a plateau of 1.1 mm. Combined use of fluorescence in situ hybridization and confocal laser scanning microscopy (CLSM) allowed to localize families of Methanosaetaceae and Merhanosarcinaceae in granules with time Quantitative analyses of CLSM images of granule sections showed abundance patterns of the methanogens and numerical dominance of Methanosaeta spp. throughout the start-up period. The trend of SMA agreed well with abundance patterns of the methanogens.

• Membrane and Water Treatment
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• 제15권1호
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• pp.1-9
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• 2024

Biological nutrient removal is gaining increasing attention in wastewater treatment plants; however, it is adversely affected by low temperatures. This study examined temperature effects on nutrient removal and morphological stability of the granular and denitrifying phosphorus accumulating organisms (PAO and DPAO, respectively) using sequencing batch reactors (SBRs) at 5, 10, and 20 ℃. Lab-scale SBRs were continuously operated using anaerobic-anoxic and anaerobic-oxic cycles to develop the PAO and DPAO granules for 230 d. Sludge granulation in the two SBRs was observed after approximately 200 d. The average removal efficiency of soluble chemical oxygen demand (SCOD) and PO₄^3--P remained >90% throughout, even when the temperature dropped to 5 ℃. The average removal efficiency of NO₃^--N remained >80% consistently in DPAO SBR. However, nitrification drastically decreased at 10 ℃. Hence, the removal efficiency of NH₄⁺-N was decreased from 99.1% to 54.5% in PAO SBR. Owing to the increased oxygen penetration depth at low temperatures, the influence on nitrification rates was limited. The granule in DPAO and PAO SBR was observed to be unstable and disintegrated at 10 ℃. In conclusion, morphological characteristics showed that changed conversion rates at low temperatures in aerobic granular sludge altered both nutrient removal efficiencies and granule formation.