혐기성 연속 회분식 공정에 의한 도시하수슬러지 소화시 고액분리 특성에 따른 처리효율평가

• 영문명: Performances of Anaerobic Sequencing Batch Reactor for Digestion of Municipal Sludge at the Conditions of Critical Solid-liquid Separation
• 발행기관: 한국환경보건학회
• 저자명: 허준무(Hur JoonMoo) 박종안9Park JongAn)
• 간행물 정보: 『1. 한국환경보건학회지』제28권 제5호, 77~85쪽, 전체 9쪽
• 주제분류: 공학 > 환경공학
• 파일형태: PDF
• 발행일자: 2002.12.31

국문 초록

중용과 고온의 혐기성 연속회분식 공정(anaerobic sequencing batch reactor; ASBR)에서 소화슬러지의 고액분리특성이 처리효율에 미치는 영향을 규명하고자 하였다. 연구결과 침전가능 고형물농도가 높은 도시하수슬러지 처리시 고액분리특성 및 고액분리형태가 전체처리의 안정성 및 처리효율에 상당한 영향을 미쳤다. 중온 ASBR 에 서는 부상농축현상이 일어났으나, 고온 ASBR 에서는 중력농축에 의한 고액분리가 일어났으며, 상대적으로 고온 ASBR 의 처리효율이 우수하였다. 그리고 수리학적 체류시간, cycle period 및 고액분리형태는 소화슬러지의 농축 특성과 임계 고형물농축을 지배하는 중요한 인자였다. 중온 ASBR 에서 고액분리 후 농축슬러지베드용적 (thickened sludge bed volume) 은 매우 중요한 운전 요소이며, 소화슬러지의 중력농축특성은 배출시 농축고형물의 유실현상과 침전시 계속적으로 발생하는 소화가스에 의한 슬러지계면의 파괴현상 및 슬러지베드의 불안정성을 야기시켜 처리효율을 감소시켰다. 중력농축의 경우 소화가스와 슬러지농축용적간의 상호작용 (cyclic mutual effect) 이 주기적으로 일어났으나, 부상농축에서는 이러한 현상이 일어나지 않았다.

영문 초록

The objective of this study was to evaluate the performances of the ASBR under critical conditions of solid-liquid separation, caused by extremely high solids concentration, for wider application of the ASBR to various wastes. The ASBRs and completely-mixed daily-fed control runs were operated using a municipal mixed sludge at 35°C and 55°C. Conversion of completely-mixed daily-fed reactor to sequencing batch mode and changes in HRT of all ASBRs were easily achieved without adverse effect, regardless of digestion temperature. Solids accumulation was remarkable in the ASBRs, and directly affected by settleable solids concentration of the feed sludge. Noticeable difference in solids-liquid separation wa~ that flotation thickening occurred in the mesophilic ASBRs, while gravity thickening was a predominant solid-liquid separation process in the thermophilic ASBRs. Solids profiles at the end of thickening step dramatically changed at solidliquid interface, and slight difference in solids concentrations was observed within thickened sludge bed. Organics removals based on supernatant or supernatant after thickening always exceeded 80% in all reactors. Thickened sludge volume and gas production of the ASBRs affected mutually. Gas production increased as thickened sludge accumulated, and continuous gas evolution during thickening could cause thickened sludge to expand or resuspend. Thickened sludge volume exceeding a predetermined withdrawal level resulted in loss of organic solids as well as biomass during withdrawal step, leading to decrease in gas production and SRT. Such an adverse mutual effect was significant in gravity thickening, while it was not sensitive in flotation thickening. Changes in organic loading had no significant effect on organic removals and gas production after build-up of solids in the ASBRs.

목차

ABSTRACT

요약

Ⅰ.Introduetion

Ⅱ.Materials and Methods

Ⅲ.Results and Discussion

Ⅳ.Conelusions

Aeknowledgment

References