• 상하수도학회지
• /
• 제19권6호
• /
• pp.791-799
• /
• 2005

The phased isolation intra-clarifier ditch system used in this study is a simplified novel process enhancing simultaneous removal of biological nitrogen and phosphorus in municipal wastewater in terms of elimination of additional pre-anaerobic reactor, external clarifier, recycle of sludge, and nitrified effluent recirculation by employing intrachannel clarifier. Laboratory-scale phased isolation ditch system was used to assess the treatability on municipal wastewater. When the system was operated at the HRTs of 6~12hours, SRTs of 9~31days, and cycle times of 2~8hours, the system showed removals of BOD, TN, and TP as high as 88~97%, 70~84%, and 65~90%, respectively. The rainfall in Korea is generally concentrated in summer because of site-specific characteristics. Especially, the wet season has set in on June to August. In combined sewers, seasonal variations are primarily a function of the amount of stormwater that enters the system. In order to investigate the effect of hydraulic shock loading on system performance, the laboratory-scale system was operated at an HRT of 6hours (two times of influent flowrate) during two cycles (8hours). The system performance slightly decreased by increasing of influent flowrate and decreasing of system HRT. Nitrification efficiency and TN removal were slightly decreased by increasing of influent flowrate (decreasing of system HRT), whereas, the denitrification was not affected by hydraulic shock loading. However, the higher system performance could be achieved again after four cycles. Thus, the phased isolation technology for enhanced biological nutrient removal in medium- and small-scale wastewater treatment plants suffering fluctuation of influent quality and flowrate.

• 한국콘텐츠학회논문지
• /
• 제20권8호
• /
• pp.674-684
• /
• 2020

하수의 종류(생활하수, 축산폐수) 및 다양한 처리 공정에 따른 미생물군집구조를 비교하기 위해 A2O공법으로 운영되는 생활하수처리시설(안심·서부·신천)의 10개 생물학적 반응조와 축산폐수처리시설의 활성슬러지를 채취해 DNA 유전체를 추출한 후 세균은 프라이머 27F/518R, 고세균의 경우, 프라이머 Arch519F/A958R를 이용해 유전체를 증폭시켰고 그 염기서열을 Roche 454 GS-FLX Titanium을 이용한 pyrosequencing 법으로 분석하였다. 그 결과, 생활하수와 축산폐수에 따른 미생물 군집구조의 차이는 컸지만 A2O공법에 따른 산소 유무 등의 환경 변화와 관련된 군집구조의 변화는 크지 않았다. 혐기조 및 무산소조 반응조들에서만 분석한 고세균 군집 결과에서는 동일 하수처리시설의 반응조들의 고세군군집들끼리만 모이는 하수처리시설별 집괴현상을 나타냈다. 세균다양성 및 종 풍부도가 높은 서부처리시설이 다른 시설보다 더 높은 질소 및 인 제거율을 나타냈다.

• 한국지반환경공학회 논문집
• /
• 제15권9호
• /
• pp.5-12
• /
• 2014

슬러지의 안정화, 휘발성 고형물 감소, 바이오가스 생산을 위해 혐기성 소화공정이 슬러지의 처리 방안으로 연구됐다. 본 연구에서는 하 폐수 슬러지(MWS, IWS), 혼합슬러지(Mix), 탈수슬러지(MWSC)를 대상으로 바이오가스 생산 가능성을 살펴보기 위해 Total solids, Volatile solids, 원소분석, BMP 실험을 하였다. Total solids 함량은 11.2~20.6 %의 값을 가지며 Volatile solids의 함량은 TS의 62.1~83.1 %의 값을 가지고 있다. C/N비는 4.96~8.33의 값을 나타났다. BMP test를 한 결과 혼합슬러지의 경우 약 20일, 하 폐수 슬러지의 경우 약 16~17일에 메탄발생이 종료되었다. 탈수케이크는 약 10일까지 메탄이 발생하였으며 가장 빨리 메탄발생이 종료되었다. 누적 메탄발생량의 경우 혼합슬러지가 395.50 mL $CH_4/g$ VS으로 가장 높은 누적 메탄 발생량을 가진다. 누적 이산화탄소 발생량은 탈수케이크를 제외하고 비슷한 값을 보이고 있다.

• 상하수도학회지
• /
• 제24권5호
• /
• pp.561-572
• /
• 2010

The efficiency of biological hydrolysis at $80^{\circ}C$ on municipal solid waste mixed with anaerobic digestion sludge was investigated in 100L batch reactors. The hydrolysis effect was observed within a day, when the hydrolysis reactor used for a pre-treatment reactor for methanogenesis, and the effect was observed during two days, When the reactor used for post-treatment reactor. For both configurations, methane production rate decreased, when hydrolysis was carried out more than a day. Gaseous ammonia in the hydrolysis reactors was successtully removed by the ammonia stripping system. Microbial diversity analysis on the hydrolysis reactors indicated dependency of microbial diversity on the configuration of the hydrolysis reactors. Carbohydrate and lactate degrading microbes dominated in the hydrolysis reactor, when the hydrolysis reactor used for a pre-treatment reactor for methanogenesis, while protein degrading microbes dominated in the post-treatment reactor.

• 대한환경공학회지
• /
• 제32권4호
• /
• pp.333-340
• /
• 2010

하수나 폐수를 이용해서 조류를 배양하고 이를 통해서 획득된 조류 생체로부터 바이오디젤을 생산한다는 것은 친생태적이면서 신재생에너지 생산이라는 점에서 최근 각광받는 녹색성장기술이다. 바이오디젤 생산에 필요한 지질의 함량이 높은 조류 종에 대한 연구가 최적 인공배양액 조건에서 연구된 사례들이 있다. 하지만 실제 하수의 조건에서 고지질 함량 조류의 생체생성과 하수처리능에 대한 정보 제공이 미흡한 것이 현황이다. 본 연구에서는 바이오디젤 전구물질인 지질함량이 높다고 알려진 조류 종들을 선별해서 국내 하수조건에서 생체생성능과 하수처리능을 분석하였다. 이를 위해서 실제 하수에서 토착조류를 제거한 후 지질함량이 높다고 알려진 조류 4종(Chlorella vulgaris AG10032, Ankistrodesmus gracilis SAG278-2, Scenedesmus quadricauda, Botryococcus braunii UTEX 572)을 각각 하수에 식종한 후에 조류의 성장률과 유기물, 질소 및 인의 제거를 실험실 규모의 회분식반응조에서 분석하였다. 일정한 광반응 조건 (80 ${\mu}E$, 24시간)에서 9일간 배양하면서 시간 별로 조류의 건조 생체량과 COD, 질소 및 인을 각기 측정하였다. 그 결과 C. vulgaris, A. gracilis와 S.quadricauda는 하수의 토착조류 보다 하수에서 더 우월하게 성장하는 것을 알 수 있었다. 반면 B. braunii는 하수조건에서 성장을 할 수 없는 것으로 나타났다. 하수에서 배양가능한 조류들에 의한 질소 (Total-N, ${NH_4}^+$-N)와 인(Total-P, ${PO_4}^{3-}$-P)의 제거능이 우수하였고, 하수처리 방류수질 기준을 만족하였다. 하수에서 배양가능한 조류들에 의한 용존 COD의 제거 분석 결과, A. gracilis와 S. quadricauda는 효과적인 COD제거를 지속하였지만, C. vulgaris는 초기의 COD 제거가 지속되지 않는 불안정성을 보였다. 이러한 결과들을 종합적으로 고려해서 본 연구에서는 A. gracilis와 S. quadricauda를 실제 하수에 적응성과 처리능이 우수한 조류자원으로 선정하였다.

• 한국환경보건학회지
• /
• 제30권1호
• /
• pp.50-58
• /
• 2004

The present study was designed to evaluate primary production organic matter in basin of lake around by execution of total maximum daily loading. BOD influent loading of Uiam lake was 2,819 kg/day, which was less then 28.3 percent, total effuluent loading as 3,619 kg/day, in comparision with BOD, total nitrogen influent loading was 4,681 kg/day, which was less then 10.0 percent, total effuluent loading as 5,150 kg/day. But in case of total phosphors influent loading was 73.3 kg/day, which was more then 34.2 percent, total run off loading as 48.3 kg/day. The result of survey reduction plan of primary production organic matter in basin of lake around which objectives of abstract is as follows. First plan was reduction of primary production organic matter by moving the outlet of municipal wastewater treatment center from present place to lake downstream. Secondary plan was improvement by diffusion type of outlet municipal wastewater treatment center. The third plan was reduction of environmental impact by passing and storing of municipal wastewater. Finally plan was decline water surface level which was present hydrouric retention time was reduction from 7.6 day to 6.0 day per meter.

• KIEAE Journal
• /
• 제11권6호
• /
• pp.133-138
• /
• 2011

This paper presents energy self-sufficiency simulated in municipal wastewater treatment plants (WWTPs) by adopting solar energy production systems that were simulated by varying azimuth and super-hydrophilic coating on the surface of photovoltaic (PV). Relative to the national average energy consumption in WWTPs, the employment of 100 kW PV system was simulated to achieve 2.75% of energy self-sufficiency. The simulated results suggested that the installation of PVs toward South or Southwest would produce the highest energy self-sufficiency in WWTPs. When super-hydrophilic coating was employed in the conventional PV, 5% of additional solar energy production was achievable as compared to uncoated conventional PV. When 100 kW of PV system was installed in a future test-bed site, Kihyeung Respia WWTP located in Yongin, South Korea, the energy self-sufficiency by solar power was simulated to be 1.77%. The simulated solar power production by azimuth and super-hydrophilic coating will be useful reference for practitioners in designing the solar PV systems in the WWTPs.

• 한국물환경학회지
• /
• 제21권2호
• /
• pp.158-168
• /
• 2005

In this study, the discharging effluents from have been 9 municipal wastewater treatment plants surveyed for 1 year-period. Statistics including probability distribution, cumulative occurrence concentration and other statistical parameters were presented. In addition, treatment performance and its stability were also discussed. Most of the plants, have an operational problem of high soluble organic content in the secondary effluent which may be associated with the integrated treatment of human and livestock manures. Nitrogen concentration in the effluents were usually higher during the period of summer and winter. It was found that this is mainly due to lack of the proper C/N ratio during the summer, or/and the effects of low temperature and less dilution by dry weather during the winter. Phosphorus concentration is sharply increased in June. Discussion with plant operators told that it is due to the dissolution of phosphate from the sludge accumulated in the primary settling tanks from the early spring to june. During this period, usually, sludge treatment line is highly overloaded with flush-outs of the sediments also stored in the bottom of combined sewer due to the low flow during winter season. Most of the plants can meet new effluent discharge limits of the nitrogen and phosphorus, and total coliform without further treatment.

• 산업기술연구
• /
• 제36권
• /
• pp.83-88
• /
• 2016

In this study, a series of experiment was carried to improve dewaterability of the sludge produced in a treatment plant, located in Hongcheon, Gangwondo, which has been treating municipal wastewater and livestock wastewater. Optimum sludge mixing ratio and the amount of sludge conditioner were determined. As sludge conditioners, alum and ferric salt were selected and tested. For the measurement of sludge dewaterability, capillary suction time(CST) and the specific resistance were measured, The specific resistance was detemined by running a series of Buchner Funnel Test. Mixing the two sludges at a 50:50 ratio with the addition of 20 mL alum gave the best results in terms of dewaterability. The moisture content decreased by 2% at this condition.

• 상하수도학회지
• /
• 제14권1호
• /
• pp.62-75
• /
• 2000

Most of biological treatment to remove contaminants in municipal wastewater have been conducted by activated sludge process. But, the process have several probIems such as enormous site needed for construction of treatment facilities, unstable treatment due to limited ability to control load fluctuation, frequent sludge bulking and appearance of lots of surplus sludge. In this study, the experiments were performed through submerging biofilm of PEPP media in existing aeration tank with raw water from municipal wastewater treatment plant and then submerging PVDC and PEPP media, different from shape and chemical peculiarity in anoxic reactor. Throughout the experience, nutrient removal efficiency according to HRT, nitrogen phosphorous removal efficiency, behavior of nitrogen and dewatering efficiency have been compared and analysed with those of activated sludge process. As the results, BOD removal efficiency according to BOD volumetric load and F/M ratio was not found any differency in two processes, but was decreased below 90% as going along the condition of high load in activated sludge process. Kinetic coefficient was $K_{max}=1.162day^{-1}$, $K_s=53.77mg/L$, $Y=0.166mgVSS/mgBOD_{rem}$. and $K_d=0.019day^{-1}$. It was found that the removal efficiency, even though in aerobic condition, in biofilm process equipped anoxic reactor was higher than the one in activated sludge process within the range of 70~80%, and became better as HRT increased. Phosphorous removal efficiency was not found any differency in two processes. In biofilm process, treament efficiency even in conditions of high load was not decreased, because the biomass concentration could be maintained in high condition compared with activated sludge process. As HRT increased, suspended and attached biomass was increased and the other hand, F/M ratio was decreased as biomass' increasing. Biomass thickness was increased. from $10.43{\mu}m$ to $10.55{\mu}m$ as HRT increased and density of biomass within $40.79{\sim}41.16mg/cm^2$. The results also present that the dewatering efficiency of sludge generated in biofilm process was higher than in activated sludge process, and became better as HRT increased.