혐기성 유동상 반응기의 수리학적 특성

석종혁(Jong-Hyuk Seok) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.2

기성 유동상 반응기(AFBR)의 수리학적 특성을 고찰하기 위해 “무담체 모드”와 “담체 충진 모드”의 두 가지 모드에서 추적자 실험을 수행하였다. 각 모드에서 동일한 실험조건으로 실험을 수행하여 수리학적 수치들이 유도되었고 실제 반응기의 수리학적 특성파악에 필요한 데이터를 얻어 해석하였다. 두 가지모드에서의 수리학적 해석을 위해 담체는 비 반응성이고 분산계수가 상수라는 가정으로 비 반응성 추적자의 일차원-비 정상상태 농도분포의 분산모델을 사용하였다. 실험결과 담체는 반응기 내부에서의 혼합효과를 크게 증가시켰다. 담체를 충진하지 않은 경우 충진한 경우에 비해 분산계수는 최소 1자리수 이상 작게 나타났다. 담체가 없는 경우 실험영역(Pe⦤83cm/s)에서 이류흐름이 지배적 흐름이었고 반응기의 흐름형태는 마개흐름형 반응기(PFR)에 근접하였다. 이 때 분산계수는 0.82cm/s까지 겉보기유속에 비례적으로 중가하였다. 그러나 담체가 충진된 경우, 흐름형태는 마개흐름형 반응기(PFR)과 완전혼합형 반응기(CMFR)사이에 있음을 나타내었으며 분산계수는 겉보기유속이 0.41cm/s에서 거의 최대치에 도달한 후 0.82cm/s까지 유사한 수치를 나타내었다. 본 실험조건에서 분산계수는 액체 레이놀즈수(Re) 또는 입자 레이놀즈수(Rep)에 비례하였다. Tracer experiments were carried out on two laboratory modes, “without media mode” and “with media mode”, to examine the hydraulic characteristics of the anaerobic fluidized bed bioreactor (AFBR). For both configurations, a formula was derived for the hydraulics and data interpretation to obtain the actual characteristics of the reactor. The dispersion model is based on the assumption that carriers are non-reacting and the dispersion coefficient is constant. The model represents the one-dimensional unsteady-state concentration distribution of the non-reacting tracer in the reactors. The experimental results showed that the media increased the mixing conditions in the reactor considerably. For the reactor without media, in the range tested, the dispersion coefficient was at least an order of magnitude smaller than that of the reactor with media. Advective transport dominates and the flow pattern approaches the plug flow reactor (PFR) regime. The dispersion coefficient increased significantly as us, the superficial liquid velocity, was increased proportionally to 0.82cm/s. On the other hand, for the reactor with media, the flow pattern was in between a PFR and a completely mixed flow reactor (CMFR) regime, and the dispersion coefficient was saturated at us=0.41cm/s, remaining relatively constant, even at us=0.82cm/s. The dispersion coefficient depends strongly on the liquid Reynolds number (Re) or the particle Reynolds number (Rep) over the range tested.

과산화수소와 황토를 이용한 적조생물의 제어

석종혁 ( Jong Hyuk Seok ),전세진 ( Se Jin Jun ) 대한상하수도학회 2009 상하수도학회지 Vol.23 No.4

혐기성 혼합배양 조건에서 프로필렌 글라이콜의 초기 분해기전

석종혁 ( Jong Hyuk Seok ) 한국수처리학회(구 한국수처리기술연구회) 2021 한국수처리학회지 Vol.29 No.1

This study was conducted to identify intermediate products and a possible pathway of propylene glycol degradation under anaerobic conditions. In a 60-day continuous run of two chemostat in series, suspended growth was inoculated with a detached biofilm from the anaerobic fluidized bed bioreactor(AFBR) carriers. The influent was made up of 9.0g COD/L of propylene glycol with an essential nutrient supplement for anaerobes. The fermentative bacteria were dominant in the reactor. Propionaldehyde, propionate, propanol and acetate were detected and identified in the anaerobic propylene glycol degradation. Propionate and propanol were produced at equal concentrations in the intermediate products. No significant growth of microorganisms was observed in the reactor under the imposed experimental conditions. A considerable amount hydrogen was observed at about 1.08~1.10×10^-3atm, indicating that hydrogen plays a key role in the anaerobic propylene glycol degradation. This suggests a possible pathway, where propionaldehyde is an intermediate via a dehydration reaction in the initial diol cleavage. This result leads to a hypothesis of a possible pathway that has propionaldehyde as a transient intermediate product in the very initial degradation stages of propylene glycol. Propionaldehyde would then be disproportionated into an equal molar amount of propionate and n-propanol, which would be further converted to acetate and hydrogen. Propionate would be subsequently degraded to acetate, carbon dioxide and hydrogen. Lastly, methane would be produced both from acetate by acetoclastic methanogens and from hydrogen and carbon dioxide by hydrogenotrophic methanogens.

펄스충격 관형 생물반응기를 이용한 에틸렌 글라이콜의 혐기성 처리

석종혁 ( Jong Hyuk Seok ) 한국수처리학회(구 한국수처리기술연구회) 2020 한국수처리학회지 Vol.28 No.1

This study was performed to test ethylene glycol treatment in an impulsive plug flow type bioreactor under anaerobic conditions. The bioreactor, which was originally designed for the study, induces a rise in fluid level for 10 minutes followed by an abrupt decrease in fluid level. This change in fluid level increases mass transfer efficiency by creating strong fluid movement in the reactor. Industrial ethylene glycol was used as an artificial wastewater source in the bioreactor under anaerobic conditions. The experimental period lasted approximately 130 days. The organic removal and gas production rates decreased significantly after 6.36 days of hydraulic retention time (HRT) and 29.41 kg COD/㎥-day of organic loading rate (OLR). The rates showed optimal performance after 8.17 days of HRT and 22.90 kg COD/㎥-day of OLR, presenting the maximum OLR and minimum HRT. Acetic acid and ethanol were major intermediate products in anaerobic ethylene glycol degradation and produced 56% and 40% of the total COD, respectively, during overload conditions. Accumulation of acetic acid and ethanol was shown to be used as an indicator of an overload condition during the anaerobic degradation of ethylene glycol. Gas production was an excellent operating factor due to its coincidence with the theoretical prediction. In this study, the impulsive plug flow type bioreactor resulted in an efficient treatment of the ethylene glycol under anaerobic conditions, which suggests the potential for applying this method to any anaerobic organic wastewater treatment.

제빙액의 혐기성 분해 기전 및 특성

석종혁(Jong-Hyuk Seok) 한국환경관리학회 2007 環境管理學會誌 Vol.13 No.4

제빙액의 혐기성 분해기전과 특성을 연구하였다. 연속식 반응기의 조작을 위한 초기단계의 연구로서 2개의 serum bottle을 사용하였다. BMP 실험결과 12일간의 실험기간 동안 프로필렌 글리콜의 94.4%와 96.0%가 메탄으로 전환되 었으며 1㎎의 COD 당 0.38~0.39mL의 메탄이 발생하였다. 중간생성물로서 프로판올과 프로피온산 및 아세트산이 관찰되었는데, 초기 반응으로 먼저 프로필렌 글리콜은 프로판올과 프로피온산으로 분해된 다음 프로판올은 프로피온산으로 전환된다. 프로피온산은 아세트산을 거쳐 메탄과 이산화탄소로 최종 분해된다. 프로필렌 글리콜의 메탄화 공정의 반응속도 상수는 0.116~0.121 ㎎ COD/㎎ SS-day으로 나타났다. Mechanism and characteristics of anaerobic de-icing wastewater degradation are studied. For this study, serum bottle testing was conducted in parallel to obtain general information that would be utilized in operating continuous type of reactor. Biochemical methane potential(BMP) test results indicated that 94.4% and 96.0% of propylene glycol was transformed to methane during the test period(12days) and 0.38~0.39mL methane was produced with the degradation of 1㎎ COD. Intermediates study suggested that propylene glycol is degraded to propanol and propionic acid as a primary breakage. The propanol is instantly transformed into propionic acid and the propionic acid is further degraded to acetic acid. Finally, the acetic acid is transformed into methane and carbon dioxide as end products in anaerobic degradation of propylene glycol. The reaction constant of propylene glycol methanization was 0.116~0.121 ㎎ COD/㎎ SS-day.

APEG 공정에 의한 유기염소계 유해폐기물의 탈염소화

석종혁,선용호,황경엽 ( Jong Hyuk Seok,Yong Ho Seon,Kyung Yub Hwang ) 한국폐기물자원순환학회 1993 한국폐기물자원순환학회지 Vol.10 No.1

화학-기계적 연마 공정의 물질제거 메커니즘 해석 Part I: 연성 통합 모델링

석종원,오승희,석종혁,Seok, Jong-Won,Oh, Seung-Hee,Seok, Jong-Hyuk 한국반도체디스플레이기술학회 2007 반도체디스플레이기술학회지 Vol.6 No.2

An integrated material removal model considering thermal, chemical and contact mechanical effects in CMP process is proposed. These effects are highly coupled together in the current modeling effort. The contact mechanics is employed in the model incorporated with the heat transfer and chemical reaction mechanisms. The mechanical abrasion actions happening due to the mechanical contacts between the wafer and abrasive particles in the slurry and between the wafer and pad asperities cause friction and consequently generate heats, which mainly acts as the heat source accelerating chemical reaction(s) between the wafer and slurry chemical(s). The proposed model may be a help in understanding multi-physical interactions in CMP process occurring among the wafer, pad and various consumables such as slurry.

단신 : 납 중금속 검출을 위한 탄소나노튜브 전극 및 네모파 양극 벗김 전압전류법 이용

최장군 ( Chang Kun Choi ),석종혁 ( Jong Hyuk Seok ),권용재 ( Yong Hai Kwon ) 한국공업화학회 2012 공업화학 Vol.23 No.5

본 연구에서는 사람의 뇌와 신경계통에 나쁜 영향을 주는 납 중금속의 식용 수에서 검출을 쉽게 하기 위해 새로운 탄소나노튜브전극의 사용을 제안하였다. 이를 위해 제작된 탄소나노튜브 전극을 작동전극으로 사용하여 증류수와 수돗물 상태에서의 납이온의 민감도 및 검출한계농도를 네모파 양극 벗김 전압전류법을 이용하여 측정하였다. 실험결과, 납 이온의 농도 25∼150 ppb의 범위에서 탄소나노튜브전극에 의한 납이온의 민감도 및 이론적으로 계산된 검출한계농도는 이온수에 근거한 0.1 M 황산전해질에서 12.85uA/uM 및 26 ppb, 수돗물에 근거한 황산전해질에서 10.36uA/uM 및 38 ppb이었다. 실험적으로 납의 검출한계 농도를 측정하였을 때, 증류수 및 수돗물에 근거한 전해질에서 그 값은 4 ppb 및 10 ppb를 나타내었다. 또한, 납의 벗김 반응은 순환 전압 전류법 분석에 의해 표면반응에 의해 진행됨을 알 수 있었다. 이러한 납 민감도는 다른 참고문헌들에 의한 값들과 비교되었고 그 결과 본 연구에 의한 납 분석결과가 더 우수함을 알 수 있었다. In this study, we investigate the use of new carbon nanotube paste electrode (CNPE) for promoting the detection of lead (Pb) heavy metal in the a drinkable water, which negatively affects human brain and nerve system. For the evaluations, CNPE is served as a working electrode, while sensitivity and limit of detection (LOD) of Pb are measured in DI and tap water based electrolytes using squarewave anodic stripping voltammetry (SWASV). As a result of that, in the 25∼150 ppb range of Pb2+ ions, its sensitivity and calculated LOD are 12.85uA/uM and 26 ppb in DI water based 0.1 M H2SO4 electrolyte while they are 10.36uA/uM and 38 ppb electrolytes respectively. In addition, experimentally measured LOD values of Pb are 4 ppb and 10 ppb in the two water electrolytes. The stripping of Pb2+ ion is also controlled by surface reaction. Our experimental data are then compared with those of other already published references. With the comparison, it is proved that our electrode outperforms other electrodes in terms of the sensitivity and LOD of trace Pb metal.

지속가능한 순환경제실현 및 폐기물 감량을 위한 인천시 재활용가능자원의 고부가가치화 방안

송연민 ( Yun Min Song ),석종혁 ( Jong Hyuk Seok ) 한국폐기물자원순환학회(구 한국폐기물학회) 2021 한국폐기물자원순환학회지 Vol.38 No.1

The purpose of this study is to figure out the waste production and characteristics of Incheon Metropolitan City (IMC) for a sustainable cyclic economy and waste reduction, and thus propose a policy direction for recyclable resources as high value-added wastes. In 2017 in IMC, the production and emission unit of domestic (domestic and business) wastes were 2,290 tons/day and 0.76 kg/cap.-day, respectively. Comparing the recycling of domestic wastes in 2017 vs. in 2012, papers (18.8%→36.0%) and plastics (19.9%→11.6) increased, while glass bottles (13.8%→10.0%) and synthetic resins (19.9%→17.3%) decreased. At the time of this study, the number of industry sectors in IMC were 6,308 in the metal processing field, 955 in wood processing, and 1,091 in clothing and textile, for the production and utilization of up-cyclable waste materials. Based on the research data, supply and demand forecasting in related industries is required for the establishment of stable and high value-added recyclable materials. Subsequently, it is necessary for the recycling markets to revitalize the establishment of pretreatment facilities for upcyclable materials, material classification and development, and material banks.

신기술 및 특허 : Gas holdup을 이용한 CSTRs in series형태의 호기성 생물반응기의 특성에 관한 연구

박주형 ( Ju Hyung Park ),최홍복 ( Hong Bok Choi ),지덕기 ( Duk Gi Ji ),최은주 ( Eun Ju Choi ),박진아 ( Jin Ah Park ),류수현 ( Soo Hyun Soo ),석종혁 ( Jong Hyuk Seok ) 한국물환경학회 ( 구 한국수질보전학회 ) 2004 공동 추계학술발표회 Vol.2004 No.-