• Environmental Engineering Research
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• 제20권3호
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• pp.277-284
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• 2015

Experiments for highly concentrated contaminants in pig waste slurry were carried out for the feasibility test of a pilot-scale innovative process scheme of engaging autothermal thermophilic aerobic digestion (ATAD) and expended granular sludge bed (EGSB) followed by sequencing batch reactor (SBR) system. Contaminants in pig waste slurry such as organic substance, total nitrogen (TN), ammonia nitrogen and total phosphorus (TP) contents were successfully reduced in the system. Total volatile solids (TVS) and chemical oxygen demands (COD) for organic matter in the feed were 32.92 g/L and 42.55 g/L respectively, and they were reduced by about 98.7% and 99.2%, respectively in the system. The overall removal efficiencies for TN and ammonium nitrogen were found to be 98.1 and 98.5%, respectively. The overall removal efficiency for total phosphorus was also found to be 92.5%. Faecal coliform density was reduced to <$1.2{\times}10^4CFU/g$ total solids. Biogas and $CH_4$ were produced in the range of 0.39-0.85 and $0.25-0.62m^3/kg$ [VS removed], respectively. The biogas produced in the system comprised of $295{\pm}26ppm$ (v/v) [$H_2S$].

• 한국물환경학회지
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• 제27권6호
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• pp.754-759
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• 2011

A sequencing batch reactor (SBR) was operated under different pH conditions to better understand the influence of pH to granulation in enhanced biological phosphorus removal systems. Granules from the SBR were also investigated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Considerable decreases in the amount of phosphorus released per substrate provided under anaerobic conditions and the content of biomass polyphosphate under aerobic conditions were observed when pH was changed from 7.5 to 7.0, followed by 6.5. Aerobic granulation was also observed at pH 7.0. A number of bacteria with the typical morphological traits of tetrad-forming organisms (TFOs) were observed at pH 7.0, including large members of cluster. Filamentous bacteria were also there in large numbers. The occurrence and growth of granules were further enhanced at pH 6.5. A SEM analysis showed that the aerobic granules had a compact microbial structure with shaperical shape and morphologically consisted of aggregates of small coccoid bacteria and filamentous bacteria encapsulated by extracellular polymeric substance. The main material ions identified by EDX moreover revealed that the structural materials for polyphosphate in the granules include phosphorus, potassium and calcium. Therefore, these results strongly suggested that PAOs are a dominant population in the microbial community of the aerobic granules.

• 대한환경공학회지
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• 제30권2호
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• pp.175-180
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• 2008

본 연구는 Fill-Contact-Settle-Decant-Idle의 공정으로 구성된 활성슬러지 공정인 SBR(Sequencing bach reactor)공정에서 수리학적 체류시간을 24시간으로 하여 운전하였으며, 세포외 폴리머의 생성량, 흡착량, 제거율 등과 SRT와의 상관관계에 대한 특성을 조사하였다. 본 실험의 목적은 활성슬러지 시스템에서 다양한 SRT를 통한 생물흡착 특성을 결정하기 위한 것이다. 연구 결과 SRT(Sludge retention time)가 증가함에 따라 단위 미생물당 유기물 흡착율 및 제거율이 감소하는 것으로 나타났으며 단위 미생물당 생성되는 세포외 폴리머 양도 감소하는 것으로 나타났다. 생물흡착효율은 SRT가 증가할수록 높았고 SRT 30일에서 그 값은 53.2%였다. 하지만 단위 미생물당 생물흡착량은 SRT 2일에서(48.6 mg COD/gVSS) 가장 높게 관찰되었다. SRT에 따른 EPS량은 TSS, TCOD$_{Cr}$ 그리고 TKN에 의해 정량적으로 분석하였다. 상기의 결과로 인하여 슬러지의 플록 형성을 방해하여 슬러지의 침강성을 저해하며, COD 제거효율을 감소시키는 결과를 초래하는 것으로 사료된다. 따라서 미생물을 이용한 생물학적 공정 운영시 EPS의 특성을 고려하여 SRT, MLSS 유지, 유기물 부하량 등의 설계 인자를 적정히 선정하여 운영하는 것이 필요할 것으로 판단된다.

• 한국물환경학회지
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• 제34권1호
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• pp.109-120
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• 2018

Sidestream in domestic wastewater treatment plants contains high concentration of ammonium, which increases nitrogen loading rate in the mainstream. The process for deammonification consisting of partial nitritation-anaerobic ammonium oxidation (ANAMMOX) and heterotrophic denitrification is an economical method of solving this problem. Currently, about 130 full-scale deammonification plants are fully operating around the world, but none is in Korea. In order to transfer the principal information about sidestream deammonification processes to researchers and operators, we summarized basic concepts, processes type, and key influence factors (e.g., concentration of nitrogen compounds, dissolved oxygen (DO), temperature, and pH). This review emphasis on the processes of single-stage sequencing batch reactor (SBR) deammonification, which are widely used as full-scale plants. Since simultaneous processes of partial nitritation, ANAMMOX and heterotrophic denitrification occur in a single reactor, the single-stage SBR deammonification requires appropriate control/monitoring strategies for several operating factors (DO and pH mostly) to achieve efficient and stable operation. In future, AB-process consisting of A-stage (energy harvesting from organics) and B-stage (ammonium removal without organics) will be applied to the wastewater treatment process. Thus, we suggest mainstream deammonification for B-stage connected with the sidestream deammonification as seeding source of ANAMMOX. We expect that many researchers will become more interested in the sidestream deammonification.

• 대한환경공학회지
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• 제31권2호
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• pp.102-108
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• 2009

연속회분식반응기에서 측정되는 기초상용계측기의 프로파일은 공정 내에서 수행되는 유기오염물질 및 영양염류 제거반응의 진행 정도에 대한 정보를 제공할 수 있다. 특히 호기성 반응구간에 측정되는 pH나 DO, ORP의 변곡점 등의 정보를 이용한 반응 종료 감지는 널리 알려진 응용사례라고 할 수 있다. 그러나 이러한 정보들은 반응의 종료 여부에 대한 정보를 제공할 뿐, 현재 공정에 가해지는 부하에 대한 정보를 제공하지는 못한다. 본 논문에서는 운전자에게 공정 유입수 내의 호기적 반응을 요하는 부하, 즉 암모니아 부하 및 유기물 부하의 고/중/저에 관한 정보를 제공할 수 있는 기초상용계측기의 정보를 활용한 진단 알고리즘을 개발하였다. 본 알고리즘으로 인해, 연속회분식반응기를 운전할 시에 수시로 변화하는 유입수의 부하를 습식분석 없이 자동 계측기 프로파일로부터 얻어낼 수 있을 것으로 사료된다.

• 한국환경보건학회지
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• 제35권2호
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• pp.116-123
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• 2009

Laboratory scale experiments were conducted to investigate the removal characteristics of nitrogen and phosphorus by the variation of aeration time in four sequencing batch reactors (SBRs). In R1 which has the shortest aeration time as 1 h, MLVSS concentration in reactor decreased by the wash-out of biomass because of the poor sedimentation. The TOC removal efficiencies were almost similar in 3 reactors except R1. At the low aeration time as 1 h, the nitrification was severely inhibited by the deficiency of oxygen. ${NH_4}^+$-N removal efficiency was decreased by the decrease of aeration time. At the aeration time over 2 h, the phosphorus removal efficiency was not affected by the variation of aeration time. The nitrification was inhibited but the phosphorus release and uptake was not inhibited by the decrease of low aeration time. Therefore, we can see that the phosphorus removal microorganisms are superior to nitrification microorganisms in oxygen utilization.

• 대한환경공학회지
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• 제29권8호
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• pp.944-949
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• 2007

연속 회분식 반응기에서 측정되는 기초 상용계측기의 프로파일은 공정 내에서 행해지는 제거반응의 진행 정도에 대한 정보를 제공할 수 있다. 특히 ORP(산화환원전위, Oxidation-Reduntion Potential, ORP) 프로파일에서 관찰되는 탈질 완료를 알리는 굴곡점(nitrate knee point, NKP)을 이용한 탈질 반응의 완료 감지는 널리 알려진 응용사례라고 할 수 있다. 그러나 ORP 굴국점의 재현성이 부족하고, ORP 신호 자체가 가지는 잡음 등의 문제로 탈질 반응의 완료를 감지한 공정 제어의 현장 적용은 미비한 상태이다. 본 논문에서는 이러한 기존의 문제점을 극복할 수 있는 대안으로 ORP 프로파일의 패턴을 인지하여 탈질의 종료 여부를 진단할 수 있는 알고리즘을 제안하였다. 동적 시간 와핑 방법을 사용하여 패턴인지를 수행한 결과, ORP 굴곡점의 출현 여부와 상관없이 공정의 탈질 완료 여부를 감지할 수 있었다.

• 유기물자원화
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• 제21권2호
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• pp.63-70
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• 2013

현장 실규모의 다단공정으로 ATAD, EGSB 및 SBR을 조합한 HMUS 공정을 이용하여 돼지 축분 처리가능성을 시험하였다. 실험결과 고농도 유기물, 질소와 인의 제거에 효과적이었다. 각 오염항목의 시스템 공정별 처리효율이 ATAD 공정에서는 CODcr이 43.3%로 제일 높게 나타났다. 다음 단계인 응집침전 공정에서는 TS의 제거효율이 96.5%로 가장 높게 나타났다. 운전조건 중 OLR은 3-6Kg $COD/m^3{\cdot}day$ 및 선속도는 1.5-4 m/h의 범위일 때 평균 CODcr 제거 효율은 HRT 3일에서 가장 높게 나타났다. 유입수의 성상이 영향을 미치는 고온호기성 산화반응은 TS가 50,000 mg/L 이상 되어야 고온발열효과를 얻어 병원균을 사멸할 수 있는 온도를 얻었다. EGSB 공정을 거치는 동안 유기물제거량 당 발생된 가스발생량은 $2.3{\sim}8.5m^3/kgTS{\cdot}d$ (평균 $5.2m^3/kgTS{\cdot}d$)로 나타났다. 후처리단계인 간헐포기공정에서 전체운전기간 중 평균제거효율은 CODcr 71.7%, TS 64.1%, TN 45.9%, 및 TP 50.4% 로 나타났다.

• 한국환경과학회지
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• 제24권11호
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• pp.1485-1491
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• 2015

There are two treatment processes that are currently applied to ships are the biological treatment process using the activated sludge and the electrochemical treatment. However, neither of them are able to remove both nitrogen and phosphorus due to their limited ability to remove organic matters, which are main causes of the red tide. This study was conducted to identify the characteristics of nitrogen removal factors from manure wastewater by replacing the final settling tank in SBR (Sequencing Batch Reactor) process and applying immersion type hollow fiber membrane. SBR process is known to have an advantage of the least land requirement in special environment such as in ship and the immersion type hollow fiber membrane is more stable in water quality change. As the result, the average in the cases of DO (Dissolved Oxygen) is 2.9(0. 6~3.9) mg/L which was determined to be the denitrifying microorganism activity in anaerobic conditions. The average in the cases of ORP (Oxidation Reduction Potential) is 98.4~237.3 mV which was determined to be the termination of nitrification since the inflection point was formed on the ORP curve due to decrease in the stirring treatment after the aeration, same as in the cases of DO. Little or no variation in the pH was determined to have positive effect on the nitrification. T-N (Total Nitrigen) removal efficiencies of the finally treated water were 71.4%, 72.3% and 66.5% in relatively average figures, thus was not a distinct prominence. In being applied in ships in the future, the operating conditions and structure improvements are deemed necessary since the MEPC (Marine Environment Protection Committee). 227(64) ship sewage nitrogen is less than the standard of 20 Qi/Qe mg/L or the removal rate of 70%.

• 한국물환경학회지
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• 제30권2호
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• pp.220-225
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• 2014

A sequencing batch reactor (SBR) was operated to obtain thiosulfate-utilizing denitrifier cultivated with two types of electron accepter (nitrate and nitrite). Using the microbial biomass obtained from the SBR, batch tests were conducted with different nitrite concentrations (50 and 100 mg-N/L) at pH 7.0, 7.5 and 7.9 to see how free nitrous acid (FNA) negatively works on the thiosulfate-utilizing denitrification of nitrate. The specific denitrification rate (SDR) of nitrate was significantly influenced by pH and FNA. The presence of nitrite caused a remarked decrease of the SDR under low pH conditions, because of the microbiological inhibitory effect of FNA. The minimum SDR was observed when initial nitrite concentration was 100 mg-N/L at pH 7.0. Moreover. the SDR was influenced by the type of electron acceptor used during the SBR operation. Thiosulfate-utilizing denitrifier cultivated with nitrite showed smaller SDR on the thiosulfate-utilizing denitrification of nitrate than those cultivated with nitrate.