• 대한환경공학회지
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• 제38권10호
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• pp.574-579
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• 2016

생활하수슬러지만 소각하는 시설에서 발생되는 비산재를 비료 제조시 주원료 또는 부원료로 활용하기 위해 비산재를 원료로 비료를 제조하고 구성성분을 분석하였다. 비산재를 포함해 제작된 비료의 구성 및 물성, 강도, 중금속에 대한 위해성 등을 분석하였다. 비산재는 충분한 인을 함유하여 비료의 원료로 사용될 수 있으나, 비산재를 주원료(40% 이상 포함)로 비료를 제작할 경우 조립화율(2-4 mm 입자 형성율)을 80% 이상 달성할 수 없었다. 비산재를 보조원료로 첨가하여 비료를 제조할 경우, 비산재 함유량을 15%이하로 유지하면 조립화율을 80% 이상 달성할 수 있었다. 비산재를 보조원료로 조립화된 비료의 중금속 분석결과, 폐기물공정시험기준인 용출실험에서는 위해성이 없는 것으로 나타났다. 그러나 토양오염공정시험의 함량분석 상으로는 비산재 함유량이 높아짐에 따라 카드뮴 등 중금속 위해성을 초과하는 항목이 발생되었다. 따라서 비료제작시 비산재를 보조원료로 투입할 경우 중금속을 제거하기 위한 전처리를 하지 않는다면 비료원료의 비산재 함유량을 7% 이하로 유지하는 것이 바람직하다.

• 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.

• Journal of Microbiology and Biotechnology
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• 제29권4호
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• pp.633-644
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• 2019

An advanced anaerobic expanded granular sludge bed (AnaEG) and an internal circulation (IC) reactor, which were adopted to treat starch processing wastewater (SPW) and ethanol processing wastewater (EPW), were comprehensively analyzed to determine the key factors that affected the granules and microbial communities in the bioreactors. The granule size of $900{\mu}m$ in the AnaEG reactor was smaller than that in the IC reactor, and the internal and external morphological structures of the granular sludge were also significantly different between the two types of reactors. The biodiversity, which was higher in the AnaEG reactor, was mainly affected by reactor type. However, the specific microbial community structure was determined by the type of wastewater. Furthermore, the dominant methanogens of EPW were mainly Methanosaeta and Methanobacterium, but only Methanosaeta was a major constituent in SPW. Compared with the IC reactor, characteristics common to the AnaEG reactor were smaller granules, higher biodiversity and larger proportion of unknown species. The comparison of characteristics between these two reactors not only aids in understanding the novel AnaEG reactor type, but also elucidates the effects of reactor type and wastewater type on the microbial community and sludge structure. This information would be helpful in the application of the novel AnaEG reactor.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.417-420
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• 2008

Recently, the interest in NDMA(N-nitrosodimethylamine) has increased due to its recognition as a pollutant by Ontario Ministry of Environment and Energy and California Department of Health Sciences. It is, in fact, one of the DBPs(Disinfection By-products) which appears due to chlorination and is reported to be fatal if exposed continuously to human body. Due to uncertainty in mechanism to remove it, its treatment is not yet carried out. In this experiment, treatment of biological NDMA is carried out by letting it adsorbed on Granular Sludge and then filtering the medium through MF(Microfiltration) and UF(Ultrafiltration) membranes. Granular Sludge is adapted to aerobic and anaerobic conditions for 7 days and the experimental conditions are MLSS of 8000mg/L, COD of 250mg/L, TN of 12.5mg/L, and TP of 2.5mg/L. Several batch tests were carried out and samples were collected with the interval of 1 hour. Samples were measured by LSC(Liquid scintillation counter) after filtering by MF and UF. In batch test with granular sludge the permeate concentrations(removal efficiencies) of NDMA by MF and UF were 71.7ng/L(32.0%) and 62.0ng/L(43.7%) at aerobic state, and 52.0ng/L(49.2%) and 47.6ng/L(58.9%) at anaerobic state, respectively. Hence, UF membrane showed about 10% more removal efficiency than MF and removal efficiency at anaerobic condition was 15% more than that at aerobic condition.

• 한국환경과학회지
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• 제28권8호
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• pp.677-687
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• 2019

This study evaluated the biosorption properties of calcium ion using Aerobic Granular Sludge (AGS). A sequencing batch reactor was used to induce the production of Extracellular Polymeric Substances (EPS) through salinity injection, and the calcium ion adsorption efficiency was analyzed by a batch test. The EPS contents showed significant changes (104-136 mg/g MLVSS) at different salinity concentrations. The calcium ion adsorption efficiency was highest for AGS collected at 5.0% salinity, and it was confirmed that the biosorption efficiency of AGS was increased owing to the increase in EPS content. The results of the Freundlich isotherms showed that the ion binding strength (1/n) was 0.3941-0.7242 and the adsorption capacity ($K_f$) was 2.4082-3.3312. The specific surface area and the pore size of the AGS were $586.1m^2/g$ and 0.7547 nm, respectively, which were not significantly different from each other. It was confirmed that the influence of biological properties, such as EPS content, was relatively large among the factors affecting calcium ion adsorption.

• 한국환경과학회지
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• 제28권7호
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• pp.629-637
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• 2019

The purpose of this study was to evaluate the effect of high-salinity wastewater on the microbial activity of Aerobic Granule Sludge (AGS). Laboratory-scale experiments were performed using a sequencing batch reactor, and the Chemical Oxygen Demand (COD), nitrogen removal efficiency, sludge precipitability, and microbial activity were evaluated under various salinity injection. The COD removal efficiency was found to decrease gradually to 3.0% salinity injection, and it tended to recover slightly from 4.0%. The specific nitrification rate was 0.043 - 0.139 mg $NH_4{^+}-N/mg$ $MLVSS{\cdot}day$. The specific denitrification rate was 0.069 - 0.108 mg $NO_3{^-}-N/mg$ $MLVSS{\cdot}day$. The sludge volume index ($SVI_{30}$) ultimately decreased to 46 mL/g. The specific oxygen uptake rate decreased from an initial value 120.3 to a final value 70.7 mg $O_2/g$ $MLVSS{\cdot}hr$. Therefore, salinity injection affects the activity of AGS, causing degradation of the COD and nitrogen removal efficiency. It can be used as an indicator to objectively determine the effect of salinity on microbial activity.

• 한국환경과학회지
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• 제27권4호
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• pp.233-240
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• 2018

The purpose of this study was to confirm the applicability of aerobic granular sludge (AGS) in the advanced sewage treatment process. Simulated influent was used in the operation of a laboratory scale reactor. The operation time of one cycle was 4 h and the reactor was operated for six cycles per day. The volume exchange ratio was 50%. The influent was injected in divisions of 25% to increase the removal efficiency of nitrogen in every cycle. As a result, the removal efficiencies of $COD_{Cr}$ and TN in this reactor were 98.2% and 76.7% respectively. During the operation period, the AGS/MLVSS concentration ratio increased from 70.0% to 86.7%, and the average $SVI_{30}$ was 67 mL/g. The SNR and SDNR were 0.073-0.161 kg $NH_4{^+}$-N/kg MLVSS/day and 0.071-0.196 kg $NO_3{^-}$-N/kg MLVSS/day respectively. These values were higher or similar to those reported in other studies. The operation time of the process using AGS is shorter than that of the conventional activated sludge process. Hence, this process can replace the activated sludge process.

• 한국물환경학회지
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• 제37권1호
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• pp.47-54
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• 2021

Aerobic granular sludge (AGS) can be classified as a type of self-immobilized microbial aggregates measuring more than 0.2 mm. It offers the option to simultaneously remove COD, N, and P that occur in different zones inside a granule. Also, AGS is characterized by high precipitability, treatability with high organic loading, and high tolerance to low temperature. In this study, a sequencing batch reactor inoculated with AGS (AGS-SBR) is a new advanced wastewater treatment process that was proven to grow AGS with integrated nutrient removal and low C/N ratio. A pilot plant, AGS-SBR with a capacity of 225 ㎥/d was installed at an S sewage treatment plant in Gyeonggi-do. The results of the operation showed that the water quality of the effluent indicated that the value of BOD5 was 1.5 mg/L, CODMn was 11.4 mg/L, SS was 6.2 mg/L, T-N was 13.2 mg/L, and T-P was 0.197 mg/L, and all of these values reliably satisfied an effluent standard (I Area). In winter, the T-N treatment efficiency at a lower temperature of less than 11℃ also showed reliability to meet the effluent standard of the I Area (20 mg/L or less). Analysis of microbial community in AGS showed a higher preponderance of beneficial microorganisms involved in denitrification and phosphorus accumulation compared with activated sludge. The power consumption and sludge disposal cost were reduced by 34.7% and 54.9%, respectively, compared to the domestic SBR type sewage treatment plant with a processing capacity of 1,000 ㎥/d or less.

• 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.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권5호
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• pp.345-351
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• 2004

We investigated the anaerobic ammonium oxidation (anammox) reaction in a lab-stale upflow anaerobic sludge blanket (UASB) reactor. Our aim was to detect and enrich the organisms responsible for the anammox reaction using a synthetic medium that contained low concentrations of substrates (ammonium and nitrite). The reactor was inoculated with granular sludge collected from a full-scale anaerobic digestor used for treating brewery wastewater The experiment was performed during 260 days under conditions of constant ammonium concentration ($50\;mg\;NH_4^+-N/L$) and different nitrite concentrations ($50{\~}150\;mg\;NO_2-N/L$). After 200 days, anammox activity was observed in the system. The microorganisms involved in this anammox reaction were identified as Candidatus B. Anammoxidans and K. Stuttgartiensis using fluorescence in situ hybridization (FISH ) method.