• 한국환경과학회지
• /
• 제1권2호
• /
• pp.125-136
• /
• 1992

Digestion of a municipal wastewater sludge by the anaerobic sequencing batch reactor (ASBR) was investigated to evaluate the performance of the ASBR process at a critical condition of high-solids-content fined. The reactors were operated at an HRT of 10 days with an equivalent loading rate of 0.8-1.5 gVS/L/d at 35$^{\circ}C$ The main conclusions drawn from this study were as follows: 1. Digestion of a municipal wastewater sludge was possible using the ASBR in spite of high concentration of settleable solids in the sludge. The ASBRS with 3- and 4-day cycle period showed almost identical high digestion performances. 2. No adverse effect on digestion stability was observed In the ASBRS in spite of withdrawal and replenishment of 30% or 40% of liquid contents. A conventional anaerobic digester could be easily converted to the ASBR without any stability problem. 3. Flotation thickening occurred in thicken step of the ASBRS throughout steady state, and floating bed volume at the end of thicken period occupied about 70% of the working volume of the reactor Efficiency of flotation thickening in the ASBRS could be comparable to that of additional gravity thickening of a completely mixed digester. 4. Solids were accumulated rapidly in the ASBR during start-up period. Solids concentrations in the ASBRS were 2.6 times higher than that in the completely mixed control reactor at steady state. Dehydrogenase activity had a strong correlation with the solids concentration. Dehydrogenase activity of the digested flu형e in the ASBR was 2.9 times higher than that of the flu형e in the control reactor, and about 25 times higher than that of the subnatant in the ASBR. 5. Remarkable increase in equivalent gas production of 52% was observed at the ASBRS compared with the control reactor in spite of similar quality of clarified effluent from the ASBRS and control reactor. The increase in gas production from the ASBRS was believed to be combined results of accumulation of microorganisms, higher driving force applied, and additional long-term degradation of organics continuously accumulated.

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

• 대한토목학회논문집
• /
• 제7권3호
• /
• pp.45-53
• /
• 1987

본(本) 연구(硏究)의 목적(目的)은 충전상(充塡床) 호기성(好氣性) 생물막공법(生物膜工法)의 반응속도론(反應速度論)을 구명(究明)하는 것으로서, 폭기(曝氣)되는 충전상(充塡床) 반응조(反應槽)에 합성폐수(合成廢水)를 주입(注入)함으로써 실험(實驗)이 수행(遂行)되었다. 유리구슬을 매질(媒質)로 채운 반응조(反應槽)의 공칭체류시간(公稱滯留時間)은 5시간(時間)이었으며, 반응조내(反應槽內)에서의 흐름형태는 소금용액을 사용한 추적자(追跡子) 실험(實驗) 결과(結果) 완전혼합형(完全混合形)이었음이 알려졌다. 연구결과(硏究結果)에 따르면 유기물(有機物) 용적부하(容積負荷)가 증가함에 따라 미생물막(微生物膜)의 성장(成長)에 의하여 반응구내(反應構內)에서의 미생물량(微生物量)이 증가함으로 F/M는 거의 일정(一定)한 값으로 유지(維持)되었다. 또한 충전상(充塡床) 호기성(好氣性) 생물막공법(生物膜工法)이 슬러지반송(返送)이 있는 완전혼합(完全混合) 활성(活性)슬러지 공법(工法)의 반응속도론(反應速度論)에 의하여 해석될 수 있음이 구명(究明)되었다.

• 청정기술
• /
• 제3권1호
• /
• pp.106-113
• /
• 1997

본 연구의 목적은 유동층반응기를 이용하여 층온도와 유속에 따른 석회석입자(천연석회석과 제지슬러지)의 소성과 황화반응 특성에 관해 조사하는 것이었으며, 실험결과는 다음과 같다. 첫째, 층온도는 천연석회석과 제지슬러지 입자의 소성과 황화반응에 매우 큰 영항을 미치는 것으로 나타났으며, 천연석회석의 경우 층온도 $850^{\circ}C$ 또는 $900^{\circ}C$가 최적 온도였고 제지슬러지의 경우 층온도 $800^{\circ}C$가 최적 온도로 조사되었다. 둘째, 유속이 증가할수록 입자의 비표면적은 감소하는 현상을 보였으나 큰 차이를 나타내지는 않았으며, 제지슬러지 입자의 비표면적이 천연석회석 입자의 비표면적 보다 훨씬 큰 것으로 나타났다. 셋째, 유속이 증가할수록 입자의 탈황능이 감소되었으며, 제지슬러지 입자에 의한 흡착량이 천연석회석 입자에 의한 흡착량 보다 큰 것으로 나타났다. 따라서 제지슬러지는 우수한 탈황제라는 것을 확인 할 수 있었으며, 유동층에서 소성반응과 황화반응시 층온도는 매우 중요한 변수라는 것을 알 수 있었다.

• 한국환경보건학회지
• /
• 제24권2호
• /
• pp.9-19
• /
• 1998

Laboratory experiments were carried out to investigate the performance of anaerobic sequencing batch reactor(ASBR) for digestion of a municipal sludge. Each cycle of the ASBR comprised feeding, two-or three-day reaction, one-day thickening, and withdrawal. The reactors were operated at an HRT of 10days and 5days with an equivalent organic loading rate of 0.8-1.54 gVS/l/d, 1.81-3.56 gVS/l/d at 35$\circ$C, respectively. Solids accumulation was remarkable in the ASBR during start-up period, and directly affected by settleable solids in the feed sludge. Floatation thickening occured in the ASBRs, and Solids profiles at the end of thickening step dramatically changed at solid-liquid interface. Slight difference in solids concentrations was observed within thickened sludge bed. Efficiencies through floatation thickening were comparable to that of additional thickening of the completely mixed control reactor. Average solids concentrations in the ASBRs were 2.2-2.6 times higher than that in the control throughout the total operation period. The dehydrogenase activity had a strong correlation with the solids concentration. Organics removals based on clarified effluent of the ASBRs were consistently above 86%. Remarkable increase in equivalent gas production of 27-52% was observed at the ASBRs compared with the control though the control and ASBRs showed similiar effluent quality. Thus, digestion of a municipal sludge was possible using the ASBR in spite of high concentration of solids in the sludge.

• 한국환경과학회지
• /
• 제11권6호
• /
• pp.569-576
• /
• 2002

Anaerobic/aerobic reactor system was used to treat a synthetic wastewater with glucose as carbon sources(0.38~2.29 kg COD/m3.day) and Acid Red 14(1.05 "24.00 g Acid Red 141m3.day, color degree of 570 ~ 1710). COD removal efficiency by the anaerobic stage in operation period were above 90 % organic loading rate of 0.38 ~ 2.29 kg COD/m3.day(except, adaptation period) and the removal efficiency of the whole system were above 96 %. The decolorization of the Acid Red 14 was through the alteration of the dye structure(or cleavage of the Azo bond) during the anaerobic treatment. In the A/A system, the anaerobic stage played an essential role in removing both color and COD. In addition it also improves biodegradability of dye f3r further aerobic treatment. After operation, average MLSS concentration of anaerobic sludge reactor, anaerobic fixed-bed reactor and aerobic fixed-bed reactor were 17100mg/L, 20000mg/L, and 10000mg/L, respectively.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• 제1권2호
• /
• pp.125-136
• /
• 1997

Digestion of a municipal wastewater sludge by the anaerobic sequencing batch reactor(ASBR) was investigated to evaluate the performance of the ASBR process at a critical condition of high-solids-content feed. The reactors were operated at an HRT of 10 days with an equivalent loading rate of 0.8-1.5 gVS/L/d at $35^{\circ}C.$ The main conclusions drawn from this study were as follows: 1. Digestion of a municipal wastewater sludge was possible using the ASBR in spite of high concentration of settleable solids in the sludge. The ASBRS with 3- and 4-day cycle period showed almost identical high digestion performances. 2. No adverse effect on digestion stability was observed in the ASBRS in spite of withdrawal and replenishment of $30\%\;or\;40\%$ of liquid contents. A conventional anaerobic digester could be easily converted to the ASBR without any stability problem. 3. Flotation thickening occurred in thicken step of the ASBRS throughout steady state, and floating bed volume at the end of thicken period occupied about $70\%$ of the working volume of the reactor. Efficiency of flotation thickening in the ASBRS could be comparable to that of additional gravity thickening of a completely mixed digester. 4. Solids were accumulated rapidly in the ASBR during start-up period. Solids concentrations in the ASBRS were 2.6 times higher than that in the completely mixed control reactor at steady state. Dehydrogenase activity had a strong correlation with the solids concentration. Dehydrogenase activity of the digested sludge in the ASBR was 2.9 times higher than that of the sludge in the control reactor, and about 25 times higher than that of the subnatant in the ASBR. 5. Remarkable increase in equivalent gas production of $52\%$ was observed at the ASBRS compared with the control reactor in spite of similar Quality of clarified effluent from the ASBRS and control reactor. The increase in gas production from the ASBRS was believed to be combined results of accumulation of microorganisms, higher driving force applied, and additional long-term degradation of organics continuously accumulated.

• 대한환경공학회지
• /
• 제32권5호
• /
• pp.437-442
• /
• 2010

본 연구에서는 반도체 폐수에 함유된 불소 처리 시 유동상 반응기 (FBR)을 이용하여 불소 제거 효율을 극대화 시키는 조건에서 발생하는 슬러지의 함수율을 최소화 시키고 $CaF_2$의 순도를 높이고자 하였다. 이를 위해 최적 pH 및 $Ca^{2+}$ 주입몰 비 ($[Ca^{2+}]/[F^-]$)가 도출되었다. 연구 결과 pH 및 $Ca^{2+}$ 주입 몰비가 증가함에 따라 불소 제거효율은 증가하였으며, 최적조건에서 79.8%의 불소제거효율이 관찰되었다. 불소 제거 효율이 최적인 조건에서 인 제거 효율은 약 9.3% 로서 불소 제거시 $Ca^{2+}$과 ${PO_4}^{3-}$-P의 부 반응이 거의 발생하지 않아 높은 순도의 $CaF_2$이 침전 슬러지로 발생하는 것으로 나타났다. 또한 이때 슬러지 함수율은 약 19.3%로 매우 낮은 것으로 나타나 불소 제거, 슬러지 순도 및 함수율 측면에서 FBR은 매우 효과적인 불소 제거 공정인 것으로 나타났다.

• 청정기술
• /
• 제23권1호
• /
• pp.80-89
• /
• 2017

하수슬러지 고형연료 및 우드펠렛의 전소 및 혼소 실험을 위해 내경 0.1 m, 높이가 1.2 m인 기포 유동층 반응기를 적용하였으며, 장치는 유동층 반응기, 연료 공급장치, 사이클론, 냉각기, 그리고 가스분석기로 구성되었다. 층 물질의 평균입자크기는 $460{\mu}m$이며, 최소 유동화 속도는 $0.21ms^{-1}$이다. 실험에 사용된 연료는 국내산 하수슬러지 고형연료 및 캐나다산 우드펠렛을 적용하였으며, 우드펠렛 기준 혼합율 20, 50, 80%로 고위발열량을 기준으로 산정하였다. 실험 고정변수는 당량비 1.65, 산화제 $100Lmin^{-1}$, 반응기 온도 $800^{\circ}C$, 유동화수 4로 설정하였다. TGA 분석 결과, 하수슬러지의 고형 연료의 연소성이 우드펠렛이 비해 상대적으로 좋지 않았다. 연소시 반응기 온도는 $800{\sim}900^{\circ}C$ 사이로 유지되었으며, 유동층 반응기에서 하수 슬러지 고형연료의 낮은 연소성으로 인해 CO가 상대적으로 높게 측정되었다. 뿐만 아니라 $NO_X$와 $SO_X$는 하수슬러지 고형연료 내의 질소함량으로 인해 우드펠렛에 비해 높게 측정되었으며, 혼소율이 증가될수록 CO, $NO_X$, 그리고 $SO_X$의 배출이 감소하였다. 혼소에 따른 회분의 거동 및 퇴적 경향에서 모든 조건에 대해 슬래깅/파일링의 가능성이 높은 것으로 분석되었다.

• 대한환경공학회지
• /
• 제30권4호
• /
• pp.371-376
• /
• 2008