• 상하수도학회지
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• 제25권6호
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• pp.971-979
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• 2011

Palm Oil Mill Effluent (POME) is the mixed organic wastewater generated from palm oil industry. In this study, kinetic analysis with treating POME in an anaerobic hybrid reactor (AHR) was performed. Therefore, the AHR was monitored for its performances with respect to the changes of COD concentrations and hydraulic retention time (HRT). Batch tests were performed to find out the substrate removal kinetics by granular sludge from POME. Modified Stover Kincannon, First-order, Monod, Grau second-order kinetic models were used to analyze the performance of reactor. The results from the batch test indicate that the substrate removal kinetics of granular sludge is corresponds to follow Monod's theory. However, Grau second-order model were the most appropriate models for the continuous test in the AHR. The second order kinetic constant, saturation value constant, maximum substrate removal rate, and first-order kinetic constant were 2.60/day, 41.905 g/L-day, 39.683 g/L-day, and 1.25/day respectively. And the most appropriate model was Grau second-order kinetic model comparing the model prediction values and measured COD concentrations of effluent, whereas modified Stover-Kincannon model showed the lowest correlation.

• 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.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.508-511
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• 2000

In situ hybridization with fluorescent oligonucleotides(FISH) was used to detect and localize microorganisms in the granules of lab-scale upflow anaerobic sludge blanket(UASB) reactors. An UASB reactor was seeded with mesophilically-grown($35^{\circ}\;C$) granular sludge, and thermophilically($55^{\circ}\;C$) operated by feeding with a synthetic wastewater. Sections of the granules were hybridized with 16S rRNA-targeted oligonucleotide probes for Eubacteria, Archaeabacteria, and specific phylogenetic groups of methanogens. FISH clearly showed the layed structure of thermophilic granules, which was consisted of outer bacterial cells and inner archaeal cells. Methanoseata-, Methanosarcina-like cells were also found to be localized inside the granules. These results demonstrated FISH was useful in studying the spatial organizations of methanogens and in situ morphologies and metabolic functions in thermophilic granular sludges.

• 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.

• 유기물자원화
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• 제14권4호
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• pp.151-160
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• 2006

침출수의 혐기성 처리시 오염물질 거동과 미생물 특성을 평가하기 위하여 10개월간 실험을 수행하였다. 상향류 혐기성 슬러지 블랭킷 (UASB) 반응조의 경우 최대 유기물 부하 $20kgCOD/m^3.d$까지 약 90%의 COD 제거율을 나타내었다. 높은 유기물 부하 ($18-20kgCOD/m^3.d$)에서는 프로피온산의 농도가 상대적으로 증가하여 프로피온산의 초산으로의 전환이 율속단계로 나타났다. UASB 반응조를 이용한 침출수 처리는 높은 유기물 제거능에도 불구하고 입상슬러지와 반응조 내부 등의 무기물 축적으로 인한 운전상의 문제가 발생하였다. 입상슬러지 내 주된 무기물의 성분은 칼슘화합물로 나타났다. 본 연구에서는 비메탄 활성도의 급격한 감소는 발생되지 않았으나 무기물 축적으로 인한 운전상의 문제를 저감하기 위해서는 무기물 제거를 위한 전처리 공정의 도입이 필요할 것으로 판단된다.

• 한국지반환경공학회 논문집
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• 제12권2호
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• pp.55-61
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• 2011

NDMA(N-Nitrosodimethylamine)는 극저농도(10ng/L)에서도 암을 일으킬 수 있는 물질로 알려져 있지만, 기존의 NDMA 제거율 평가 연구는 고농도의 NDMA를 대상으로 한 것이 대부분이었다. 따라서 극저농도의 NDMA 제거효율 평가가 필요하며 그 기초연구로써 호기성/혐기성 조건에서의 분말활성탄, GS(Granular Sludge), MF(Microfiltration), UF(Ultrafiltration)를 이용한 제거효율과 Silica gel(MCM-41, Diatomite, Spherical silica gel)을 이용한 제거효율을 평가하였다. 그 결과 혐기성 조건에서 GS, PAC를 접촉한 후 UF membrane을 이용한 고액분리가 65%의 제거율로 가장 높았으며, Silica gel(MCM-41)이 6%의 제거율로 가장 낮았다. 본 연구는 극저농도의 NDMA 제거의 기초 연구로서 향후 관련 연구의 기초자료로써 활용을 기대한다.

• 상하수도학회지
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• 제14권2호
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• pp.196-206
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• 2000

Methanogenesis and denitrification in an upflow sludge baffled filter (UBF) reactor were studied using glucose as a fermentative substrate. Experiments were carried out to investigate how to reduce ammonification by changing alkalinity and $COD/NO_3-N$ ratio. Characteristics of granular sludges were examined by specifics methanogenic activity(SMA) and specific denitrification rate(SDR) tests. Microstructures of granules were examined using a scanning electron microscopy(SEM). It was found that COD was removed efficiently owing to the diverse microorganisms. In nitrate conversion, not only $COD/NO_3-N$ ratio but also influent alkalinity played important role in the ratio of denitrification and ammonification of nitrate. This reactor achieved over 95% COD and 99% nitrate removal efficiencies when influent contained 4000 mgCOD/L and $700mgNO_3-N/L$ at the hydraulic retention time of 24 hours. As $COD/NO_3-N$ ratio decreased, granular methanogenic activities using acetate and butyrate as substrates increased while activities using propionate and glucose decreased. There were three types in granules according to the surface color; gray, yellowish gray, and black. Gray or yellowish gray-colored granules were composed two layers, which were composed of black inner side and gray or yellowish gray surface substances. SEM illustrated that both were rod-type and cocci-type microorganisms resembling Methanothrix sp. and Methanococci sp. This study showed that by controlling the influent alkalinity and $COD/NO_3-N$ ratio, ammonification and denitrification could be manipulated.

• 상하수도학회지
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• 제10권4호
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• pp.45-54
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• 1996

Effects of temperature on the efficiency of the Upflow Anaerobic Sludge Blanket(UASB) process for treatment of wastewater from a starch and related products manufacturing industry were investigated using laboratory scale reactors equipped with two types of Gas-Solid Separator(GSS). Both fresh digested sludge and granular sludge stored nearly for one year at room temperature were good as a seeding material. The reactors seeded with aged granular sludge showed slow start-up, however, lowered activity at the initial period was recovered gradually. The GSS with an inner cylinder was proved to be effective in liquid-solid separation compared to the conventional type. Although the rate of organic removal and gas production per unit volatile suspended solids in the reactor reduced significantly as the temperature varied from 35 to $20^{\circ}C$, possibility of operation at low temperatures was shown as a result of gradual buildup of volatile suspended solids in the bed. Stable operation with a reduced efficiency was possible at a COD loading of $5-8kg/m^3/day$ at a temperature as low as $20^{\circ}C$.

• 대한토목학회논문집
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• 제11권2호
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• pp.91-98
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• 1991

본 논문에서는 주정폐액을 처리한 이상 UASB 공법에서 형성된 입상슬러지에 관한 현미경실험 결과를 제시하고자 한다. 기질로 사용한 주정폐액의 SS 및 COD 농도는 각각 3.6~10.6, 17.3~30.4g/l였으며, 12.5 l와 4.7 l의 UASB 반응조가 사용되었다. 입상슬러지의 형태학적 연구에는 SEM과 TEM을 사용하였다. 운전 90일과 120일경에 산형성조와 메탄형성조로부터 다른 색깔과 형상을 가진 두 종류의 입상슬러지가 형성되었다. 산형성조 입상슬러지는 주로 긴 고리로 연결된 큰 rod형 bacteria 짧고 통통한 rod형 bacteria, 그리고 다양한 크기의 coccus형 bacteria로 구성되었다. 반면에 메탄조 입상슬러지는 Methanothrix로 구성된 network내에 다양한 종류의 bacteria가 포획되어 있는 구조를 가졌다.

• 유기물자원화
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• 제29권4호
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• pp.33-40
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• 2021

본 연구에서는 실규모 UASB 소화조에서 높이에 따른 그래뉼 슬러지의 물리화학·생물학적 특성에 대해 조사하였다. 혐기성 그래뉼은 UASB 반응조에서 지상으로부터 1 m 높이별(1 m, 2 m, 3 m)로 채취하였다. 형태학적 분석결과, 그래뉼의 크기는 소화조의 상단부로 갈수록 커졌고 원형율(roundness)은 하단부에서 더 둥근 형태를 나타내었다. ANOVA 검정 결과, 그래뉼의 평균 크기와 원형율은 95% 신뢰수준에서 통계적으로 유의한 차이를 보였고 두 변수 사이에 유의한 음의 상관관계가 있는 것으로 나타났다(r=-0.40, p<0.05). 아세트산, 프로피온산, 부틸산을 기질로 사용한 SMA test 결과에서는 2 m 높이에서 채취한 그래뉼의 비메탄활성도가 가장 높았다. EPS의 경우 높이에 따라 함량이 다양하게 나타났으며 2 m에서 가장 높았다. 본 실험의 결과를 통해 높이별 그래뉼 슬러지의 특성을 이해하고 소화조의 유지관리 및 성능 개선에 기초 자료로 활용할 수 있을 것으로 판단된다.