• 한국농공학회논문집
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• 제47권3호
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• pp.69-76
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• 2005

An Absorbent Biofilter System (ABS) combined with the recirculation process was investigated for the feasible application in additional removing of organics (BOD, SS) as well as nutrients (TN, TP) from small Community wastewater in Korea. Polyurethane biofilter media with high porosity and large surface area were /used for the aerobic system. A part of treated wastewater was recirculated into the anoxic septic tank to promote removal of nutrients. The concentrations of BOD and SS of treated wastewater satisfied the regulations for small on-site wastewater treatment facility (10 mg/L) during the overall experimental period. The effluent concentrations of BOD and SS were decreased with enhancement of removal efficiencies of 95.7 and $96.7\%$. The nitrogen and phosphorus removal efficiencies by the recirculation increased to $52.9\%\;and\;43.2\%$ in average during the overall experimental period, respectively. With the improvement, these values were increased as much as additional 42 and $18\%$ compared with those of non-recirculation. The rates of nitrification and denitrification were enhanced showing $65\~77\%\;and\;42\~92\%$, respectively. The described process modification is a low cost and effective method of enhancing nitrogen and phosphorus removal, especially on existing systems without changing major design components of a treatment facility.

• 상하수도학회지
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• 제21권1호
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• pp.83-89
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• 2007

A biological anoxic-aerobic reactor filled with porous media was operated in lab scale for the advanced wastewater treatment. The experiments were conducted for 6 months with three HRTs (4, 6, 8hr) and temperature of $23{\sim}25^{\circ}C$. Some other experimental conditions were as follows; nitrification reactor (MLSS 4,500mg/L, DO 3.3mg/L, $23{\sim}28^{\circ}C$), denitrification reactor(MLSS 8,000mg/L, ORP -100mV, Temp.$19{\sim}23^{\circ}C$). Average removal efficiencies of SS, $BOD_5$, $COD_{Cr}$, T-N, and T-P were 97.8%, 95.5%, 94.5%, 80.2%, and 60.6%, respectively. The reactor filled with porosity media showed stable removal capacity for organics and nutrients. Fast and complete nitrification and denitrification were accomplished. Maintaining high MLSS with porous media in the nitrification and denitrification reactor appears to enhance the nitrogen removal process. For the higher T-P removal, some coagulant addition process will be needed.

• 한국환경보건학회지
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• 제24권1호
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• pp.132-140
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• 1998

회전원판공정(rotating biological contactorRBC)과 화학적 처리공정을 결합한 처리시스템을 이용하여 도시하수내 포함된 유기물과 영양염류를 제거할 경우에 수리학적 부하 (hydraulic loading)와 처리수 반송율 (recirculation rate)의 시스템 처리효율에 미치는 영향을 알아보고자 하였다. 각각의 수리학적 부하 0.031, 0.0535 및 0.076 $m^3/m^2/d에서 반송율을 100%, 200%, 300%로 변화시켰고, 질산화에 필요한 알카리도의 보충 및 화학적 처리를 위하여 lime(CaCO$_3$)을 가하여 유입수의 pH를 10.4-11.0으로 유지시켰다. 실험결과 수리학적 부하 0.0535 $m^3/m^2/d에서 BOD, COD의 제거효율이 가장 높게 나타났으며, 질산화 효율 및 질소 제거효율에서는 수리학작 부하 0.035 $m^3/m^2/d, 반송율 300%에서 가장 높았으며, 반송율별에서는 수리학적 부하를 고려할 때 300% 반송하는 것이 가장 높은 유기물 제거효율을 보였다. 반송율과 수리학적 부하를 증가시킬 경우에 발생되는 슬러지내 유기물 함량은 점점 증가하였고, 수리학적 부하 0.076 $m^3/m^2/d, 반송율 300%일 경우에는 유기물 함량이 47%로 매우 높았다. 이는 부하증가에 따른 미생물 성장의 증가와 더불어 수리학적 부하 증가에 따른 전단력의 증가가 영향을 미쳤기 때문이다. 인을 제거하기 위하여 pH를 10.4-11.0으로 유지시킨 경우에 인을 90%이상 제거할 수 있었으며, 유출수내 평균 SS농도는 40 mg/l를 상회하였다.

• 한국환경보건학회지
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• 제32권5호
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• pp.451-461
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• 2006

Laboratory scale experiments were conducted to study the conversion of sludge from conventional activated sludge to nitrogen-phosphorus removal sludge using two types of sequencing batch reactor (SBR) systems, a conventional SBR and sequencing batch biofilm reactor (SBBR). The nitrogen and phosphorus removal characteristics were similar between SBR and SBBR and the removal efficiencies were very low when the influent TOC concentrations were low. The nitrogen and phosphorus removal efficiencies in SBR were 96% and 77.5%, respectively, which were higher than those in SBBR (88% and 42.5%) at the high influent TOC concentration. In SBBR, the simultaneous nitrification-denitrification was occurred because of the biofilm process. The variations of pH, DO concentration and ORP were changed as the variation of influent TOC concentration both in SBR and SBBR and their periodical characteristics were cleary shown at the high influent TOC concentration. Especially, the pH, DO concentration and ORP inflections, were cleary occurred in SBR compared with SBBR.

• 상하수도학회지
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• 제24권3호
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• pp.267-276
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• 2010

Many plants have been improved to adapt the target of the biological treatment processes changed from organics to nutrients since the water quality criteria of effluent was reinforced and included T-N and T-P for the municipal wastewater treatment plant. To meet the criteria of T-N and T-P, the conventional biological reactor such as aeration tank in activated sludge system is changed to the BNR (biological nutrient removal) processes, which are typically divided into three units as anaerobic, anoxic and oxic tank. Therefore, the solid separation process should be redesigned to fit the BNR processes in case of the application of the DAF (dissolved air flotation) process as an alternatives because the solid-liquid separation characteristics of microbial flocs produced in the BNR processes are also different from that of activated sludge system as well. The results of this study revealed that the microbial floc of the anaerobic tank was the hardest to be separated among the three steps of the unit tanks for the BNR processes. On the contrary, the oxic tank was best for the removal efficiency of nutrients as well as suspended solid. In addition, the removal efficiency of nutrients was much improved under the chemical coagulation treatment though coagulation was not indispensable with a respect to the solid separation. On the other hand, in spited that the separation time for the microbial floc from the BNR processes were similar to the typical particles like clay flocs, over $2.32{\times}10^3$ ppm of air volume concentration was required to keep back the break-up of the bubble-floc agglomerates.

• 한국산학기술학회논문지
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• 제13권7호
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• pp.3267-3274
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• 2012

371 균주의 해양박테리아를 광양만에서 분리하였다. 우점종은 Pseudomonas aeruginosa, Aeromonas hydrophila, P. fluorescens, P. paucimobilis, Chryseomonas luteola, P. vescularis 등이었다. 영양염과 유기물을 제거할 수 있는 해양박테리아를 탐색하기 위하여 암모니아성 질소(100 mg/L), 질산성 질소(100 mg/L) 및 인(10 mg/L)이 각각 포함된 10 mL의 marine broth 2216 (DIFCO)에 해양박테리아를 접종(1.0%, v/v)하고 12시간 배양하였다. 스크리닝 테스트 결과 25% 이상 $COD_{Cr}$을 제거하는 해양박테리아는 16종, 15% 이상의 암모니아 질소를 제거하는 해양박테리아는 9종, 60% 이상의 질산 질소를 제거하는 해양박테리아는 11종 그리고 90% 이상의 인을 제거하는 해양박테리아는 13종이 분리되었다. Aeromonas hydrophila, Chryseomonas indologenes, Pseudomonas diminuta, Vibrio parahaemolyticus 균주가 유기물 및 영양염류 제거실험을 위해 선정되었다. 회분식 시험을 위해 4종의 해양박테리아를 $COD_{Cr}$ 250 mg/L, $NH_3-N$ 40 mg/L, ${NO_3}^{-}-N$ 40 mg/L, ${PO_4}^{3-}-P$ 10 mg/L이 각각 첨가되어 있는 변형 marine broth에 접종하고, 10시간 배양하면서 제거효율을 측정하였다.

• 청정기술
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• 제6권1호
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• pp.27-38
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• 2000

초고속응집침전공정(URC)은 가중응집제(WCA)를 첨가하고 슬러지를 반송시켜 응결핵으로서의 역할을 수행시킴으로서 floc의 성장속도를 향상시키고, 입자표면의 흡착을 활성화하여 유기물, 중금속, 인 등 수중에 존재하는 오염물을 보다 효율적으로 제거하며, 기존의 응집 공정에 비하여 침전성을 향상시킬 수 있다. 현재까지 하수처리장과 하천, 호소에서 수행된 URC pilot-test와 Jar-test의 결과를 비교 검토하여 가중 응집제와 반송 슬러지에 대한 오염물 제거특성에 대한 연구가 수행되었으며, 수자원의 재이용을 위한 가능성을 평가하였다.

• 한국물환경학회지
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• 제20권1호
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• pp.18-23
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• 2004

In this research, a 2-stage intermittently aerated activated sludge system(IA) and intermittently aerated dynamic flow activated sludge system(DF) were investigated for the removal of nutrients in domestic wastewater. Wastewater was characterized by low C/N( organics/nitrogen) ratio. $COD_{cr}$, $BOD_s$, TKN and TP concentrations of domestic wastewater were 235, 47, 32 and 5.4 mg/L, respectively. Three sets of IA and one set of DF were operated. Three of four systems were added with fermented settled sludge taken from primary settling tank as an external electron donor and the other(IA) for control reactor was operated without addition of electron donor. All systems were operated at same sludge retention time of 20 days and hydraulic retention time of 12hrs. The supplemental electron donor was supplied into the anoxic mode. A higher denitrification rate was observed from the reactors with fermented settled sludge as an electron donor for denitrification compared to that of without addition of organic source. The result of this study indicates that the settled primary sludge, if the fermented at the acid stage, was an excellent electron donor for denitrification. 81 % of TN and 80% of TP were removed from the systems with the supplemental organic source added. However, the control reactor without addition of electron donor showed only 39% of TN and 43% of TP.

• 한국물환경학회지
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• 제23권1호
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• pp.46-51
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• 2007

This research work aims at treating saline wastewater generated from a fish market using four Sequencing Batch Reactors (SBR) operated under different conditions. The effect of C/N ratio (3, 6) and salt concentration (0.5~2%) on organic and nitrogen removal was studied. The synthetic wastewater prepared with glucose ($C_6H_{12}O_6$) as the primary carbon source along with ammonium chloride ($NH_4Cl$) was used in the three reactors. The fill, anoxic, aeration, settle and draw conditions were 2 hr, 4 hr, 4 hr and 2 hr respectively. The fourth reactor was operated at different conditions to investigate the practical feasibility of SBR application to handle fish market wastewater generated in Ulsan city that had fluctuating loading characteristics. Though the unacclimated sludge was initially affected by the salt concentration, the acclimated sludge removed 95% of the organics irrespective of the NaCl concentration and C/N ratio. However, the removal of nitrogen was affected more by C/N ratio than the salt concentration. While handling fish market wastewater, though the organic and nitrogen loading rate were varying between $0.009{\sim}0.259gCOD_{OH}/gVSS/day$ and 0.005~0.034 gN/gVSS/day, the effluent concentrations were far less than the effluent standard of $120mgCOD_{OH}/L$ and 60 mgN/L respectively, except when loading rates were fluctuating and 4 times higher than the average.

• 대한토목학회논문집
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• 제6권1호
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• pp.43-50
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• 1986

오염(汚染)된 원수내(原水內)의 biodegradable 한 유기물(有機物)의 제거(除去)를 위한 호기성(好氣性) 고정미생물막공법(固定微生物膜工法)의 적용가능성(適用可能性)을 확인하기 위하여 본(本) 연구(硏究)가 실시(實施)되었는데, 실험(實驗)은 파쇄(破碎)된 연탄재 또는 화강암을 매질(媒質)로 채운 충전상(充塡床)에 phenol과 무기성(無記性) 영양물질(榮養物質)을 용해(溶解)시켜 만든 합성원수(合成原水)를 주입(注入)함으로써 진행(進行)되었다. 실험결과(實驗結果)에 의하면 유입수(流入水)의 BOD 농도(濃度)가 50 mg/l 이하(以下)이고 체류시간(滯留時間)이 2.7 시간(時間)이었을 때 처리수(處理水)의 TBOD는 6 mg/l 이하(以下)로 유지되었으며, 처리수내(處理水內)의 SS가 응집(凝集)이나 여과(濾過) 등(等)의 재래식(在來式) 정수공법(淨水工法)에 의하여 제거(除去)될 수 있다는 점을 감안한다면 처리수(處理水)의 SBOD는 5 mg/l 이하로 유지될 수 있다. 처리수내(處理水內)의 SS가 낮은 BOD를 나타내었으므로 이들 SS가 대부분 부식질(腐植質)로 구성되었음을 알 수 있다. 이는 반응조내(反應槽內)의 미생물막(微生物膜)이 낮은 F/M 비 때문에 내호흡단계(內呼吸段階)에 있음을 뜻한다. 연구결과(硏究結果)에 따라, biodegradable한 유기물(有機物)로 오염(汚染)된 원수(原水)는 먼저 2~3시간의 체류기간을 가지는 호기성(好氣性) 고정미생물막반응조(固定微生物膜反應槽)로 전처리(前處理)함이 바람직스럽다.