연속 회분식 혐기성 공정을 이용한 하수슬러지와 음식물쓰레기의 혼합소화 거동 특성 = performance of high-rate anaerobic sequencing batch reactor treating sewagesludge and food waste

다국어 초록 (Multilingual Abstract)

Temperature-phased anaerobic digestion (TPAD), anaerobic sequencing batch reactor (ASBR), and co-digestion technologies were combined together in order to overcome low efficiencies of conventional anaerobic sewage sludge digestion processes. In the performance, TPAD-ASBR process showed high VS removal efficiency over 60% up to the organic loading rate (OLR) of 2.7 g VS/L/d. The first-stage of TPAD-ASBR and control system played a most significant role in VS destruction and methane production. Methane production rate (0.79 l CH4/L/d) of the system was higher than that (0.59 l CH4/L/d) of the control system. The substrate characteristics of the sewage sludge, such as low VS concentration (1.5%, w/w) and biodegradability, were properly improved by the addition of food waste as a co-substrate, leading to more efficient VS removal and methane production. With several track studies, it was revealed that the independent solid retention time (SRT) of those systems prevented untreated particles from outflowing and also, extended the retention time of the active biomass for further degradation. Consequently, it was confirmed that the sequencing batch operation of the TPAD process using co-substrate was a promising alternative for the recycling of sewage sludge with low VS content.

국문 초록 (Abstract)

혐기성 소화효율의 극대화를 위해 온도상분리 공정과 혐기성 회분식 공정을 음식물 쓰레기와 하수슬러지의 혼합기질에 적용한 온도상분리 혐기성 회분식 소화공정(TPAD-ASBR)의 거동 특성을 유기물부하의 변화에 따라 평가하여 다음과 같은 결론을 얻었다. TPAD-ASBR 과 대조구의 첫 단에서 대부분의 메탄생성과 유기물 제거가 이루어졌으며, 단위부피당 메탄발생량은 유기물부하 2.7 g VS/L/d에서 각각 0.79와 0.59L CH4/L/d 였다. 동일 부하에서 TPAD-ASBR의 유기물 제거효율은 61%이었으며 40%의 효율을 보인 대조구에 비해 고온조를 도입한 본 공정의 우수성을 확인하였다. 국내 하수슬러지는 상대적으로 낮은 VS 농도(1.5%, w/w)와 낮은 생분해 효율을 보이는데, 이러한 부정적 특성을 보완하기 위하여 투입된 음식물쓰레기에 의한 기질 특성의 효과적인 개선으로 인해 높은 유기물 감량과 메탄회수가 가능하였다. 또한, track study를 통해 연속회분식 운전방식에 의한 settling 단계의 도입으로 SRT를 HRT보다 길게 유지하여 미처리 입자와 active biomass의 효율적이고 지속적인 접촉을 도모하여 보다 높은 안정화효율 획득이 가능한 것으로 사료된다. 따라서, 혐기성소화공정에 TPAD-ASBR공정과 함께 음식물쓰레기와의 혼합소화를 도입하는 것은 처분이 까다로운 두 가지의 폐기물을 고효율로 처리함과 동시에 효율적인 에너지회수가 가능하여 경제적 운전이 가능하였다.

참고문헌 (Reference)

• 1 "하수슬러지 관리 및 재활용 방안 (특집/슬러지관리 및 처리기술)" 2000.11
• 2 "생활폐기물, 하수도 및 하수슬러지 발생량 통계" 환경부 2002
• 3 "substrate specificity during phase separation" 716-, 1994
• 4 "Use of the upflow sludge blanket reactor concept for biological wastewater treatment" 699-, 1980
• 5 "Treatmet ofdairy wastewater with two-stage anaerobic sequencing batch reactor systems-thermophilic versus mesophilic operations" 68 : 225-233, 1999
• 6 "Temperature-phased anaerobic digestion of wastewater sludges" 36 : 367-374, 1997
• 7 "Standard Methods for the examination of Water and Wastewater" APHA 1998
• 8 "Laboratory studies on the anaerobic sequencing batch reactor" 67 (67): 294-301, 1995
• 9 "Laboratory studies of the teperature-phased asbr system" 36 : 295-302, 1997
• 10 "Hydrolysis and thermophilic anaerobic digestion of sewage sludge and organic fraction of municipal solid waste" 20 : 553-560, 1999
• 11 "Effect of waste components on performance of acidogenic fermenter" 10 (10): 65-70, 2002
• 12 "Degradation characteristics in anaerobic co-digestion of sewage sludge and food waste" 10 (10): 96-101, 2002
• 13 "Comparative performance of anaerobic filters at mesophilic and thermophilic temperatures" 764-, 1993
• 14 "Biogasification of food residuals" 41 (41): 82-86, 2000
• 15 "Biochemical methane potential and solid waste anaerobic digestion of Korean food waste" 245-253, 1995
• 16 "Anaerobic digestion of organic solid waste" 74 : 3-16, 2000
• 17 "Anaerobic Digestion of Long-Chain Fatty Acids in UASB and Expanded Granular Sludge Bed Reactors" Alphenaar 527-, 1993