• 상하수도학회지
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• 제19권3호
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• pp.357-362
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• 2005

Poly-${\gamma}$-glutamic acid (${\gamma}-PGA$), which is extracted from fermented soybeans, is a high molecular weight, adhesive, and negatively charged(anionic) polymer. Recently, ${\gamma}-PGA$ has gained attention due to its potential as polymer. The objectives of this study were to examine the applicability of ${\gamma}-PGA$ as a coagulant and/or a coagulant aid, to evaluate the efficiency of ${\gamma}-PGA$ for the removal of Organic and Ammonium substance in wastewater treatment. The effect of coagulation was evaluated for the removal of SS and organic matter using poly aluminum chloride(PACI) as well as newly developed ${\gamma}-PGA$. The maximum COD removal rate of 63% and the SS of 78% were occurred at the dosage of 50mg/L ${\gamma}-PGA$ only. The most effective removal for particulate and organic matter was occured when both PACI and ${\gamma}-PGA$ were applied at the rate of 20:1(10mg/L PACI and 0.5mg/L ${\gamma}-PGA$). When mixed with PACI, only small portion of ${\gamma}-PGA$ was enough to improve removal efficiencies of organic and particulate matter in wastewater. This result showed the positive potential of ${\gamma}-PGA$ as a new coagulant materials for wastewater treatment.

• 한국환경보건학회지
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• 제18권2호
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• pp.57-61
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• 1992

This study was made for enhanced removal of N and P by intermittented aeration Activated Sludge Process. Experiment were conducted to find the effects of aeration interval and nutrient removal efficiency. When applied aeration interval were 30~60 min, 2~4 h, 4~8 h, organic matter was not affected while phosphorous removal was aeration interval 30~60 min. Also, when applied mixing intensity were 15, 30, 45 and 60 rpm, organic matter was not affected while removal was maximum at 15 rpm. Total nitrogen and phosphorous removal were in the range of 76 and 85%. Density and MLSS of Sludge were in the range of 2.3~2.6 and 7198~7810 mg/l. Release of phosphorous from activated sludge under unaerobic condition was increased as pass time.

• 한국환경보건학회지
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• 제19권4호
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• pp.33-37
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• 1993

The problem for the removal of phosphorus increased due to reasons like eutrophication control. However its removal and operating criteria were not well developed. This study was made for enhanced removal of P by iron contactor by intermittent aeration activated sludge process. Experiment was conducted to find the effects of organic substance load and HRT, nutrient removal efficiency. When applied organic substance load and HRT, II &III reactor were good treatment efficient while come from Fe of iron contactor. Release of phophorus from II &III reactor sludge under anaerobic condition was low. As the process developed, the content of released ionized Fe from iron contactor increased. In addition, the rate of phosphorus removal became accelerating, and the removed sludge was stabilized in the existence of insoluble status.

• 대한환경공학회지
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• 제35권5호
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• pp.381-387
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• 2013

UASB-ABF (Up-flow anaerobic sludge blanket-aerated bio-filter) 시스템을 이용한 하수의 혐기성처리 방법에서 질소와 인을 제거하는 공법에 대하여 연구하였다. 160일간의 UASB-ABF 시스템을 운영한 결과 유출수 반송을 통하여 TCOD뿐만 아니라, TN과 TP를 효율적으로 제거할 수 있었다. 무반송의 경우 UASB 반응조에서 유기물 제거효율은 64%에 머물었으나, 반송률 120%, 180%, 240%로 증가한 결과 각각 92%, 95%, 96%로 향상되었다. 반송률 180% 이상에서는 유기물 제거효율 증가폭은 크지 않았다. ABF 유출수 반송으로 TN 제거효율이 크게 향상되었다. TN 제거효율은 무반송 조건일 때 18%에서 82%로 향상되었으며, UASB에서 지속적인 유기물질 제거로 인하여 ABF에서 질산화효율은 안정적으로 95% 이상으로 타나났다. ABF 유출수 반송으로 TP 및 $PO{_4}^{3-}$-P 제거효율이 모두 향상되었다. TP의 경우 무반송에서는 거의 제거되지 않았으나, 반송률이 120%, 180%, 240%에서는 각각 51%, 63%, 71%로 향상되었고, 주로 UASB에서 제거되었다.

• 한국환경보건학회지
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• 제27권3호
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• pp.27-34
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• 2001

This paper discussed the shape effect of ceramic support carrier in order to facilitate biomass immobilization. The shape of ceramic support carrier was modified hollow pipe type into hollow gear type. After seeding, microorganisms were attached in crevices where protection from shear forces or surfaces where easy to contact with support carrier surface. In case of hollow gear type carrier, initial attachment rate was faster than that of hollow pipe type and obtained thick biofilm. Synthetic wastewater(COD:75~880 mg/L, organic loading rate:0.36~4.22 kgCOD/㎥.d) was treated aerobic fixed bed biofilm reactor where 100% of the volume was filled with the ceramic carrier. COD removal efficiency of reactor filled with gear type support carrier was a little high withing 70 days, and then showed similar removal efficiency. It was found that highly loaded operation with up to 4.22 kgCOD/㎥.d was possible in both reactor. Total biomass amounts of pipe type was higher than gear type, however, attached biomass of gear type was higher than that of pipe type.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.231-234
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• 2004

The experiments on some organic materials used in SAPS are carried out for the better sulfate reduction efficiency and the longer lifetime. Organic materials include spent mushroom compost, sewage sludge, oak chip compost and the combination of there. Reactors with mushroom compost, sewage sludge, the mixture of mushroom compost and sewage sludge, and the mixture of mushroom compost and oak chip compost maintained pH higher than 6.0. Reactors with mushroom compost, the mixture of mushroom compost and sewage sludge, and the mixture of mushroom compost and oak chip compost maintained reduction condition. Reactors with sewage sludge, oak chip compost and the mixture of sewage and oak chip compost produced COD less than 2,000ppm. Reactors with sewage and the mixture of mushroom compost, sewage sludge, oak chip compost showed about 60% of sulfate removal ratios.

• 한국환경보건학회지
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• 제32권5호
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• pp.446-450
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• 2006

In order to treat the wastewater containing organic compound, pre-treatment system connected with MSP(molecular separation process) was investigated. With the aim of selecting an optimum process of Fenton's oxidation, removal efficiency of each process in the optimum reaction condition was recommended. The $Fe/H_{2}O_{2}$(ferric sulfate to hydrogen peroxide)reagent is referred to as the Fenton's regent, which produces hydroxyl radicals by the interaction of Fe with $H_{2}O_{2}$. The powerful oxidizing ability and extreme kinetic reactively of the hydroxyl radical was well established. Increasing dosage of $Fe/H_{2}O_{2}$ increased removal efficiency as molar ratio of $Fe/H_{2}O_{2}$ between 0.2 and 2.5. Optimum dosage of molar ratio was 1. The removal efficiency for reaction condition was increased as pH decreased when the molar ratio of $Fe/H_{2}O_{2}$ was 1.7. Fenton's oxidation was most efficient in the reaction time 35 min for complex wastewater. Also, coagulation aid experiments using kaolin resulted in 3% of kaolin dosage.

• 상하수도학회지
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• 제11권4호
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• pp.43-53
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• 1997

In this research, the synthetic livestock wastewater was prepared to study the characteristics of organic matter removal, the change of VFA production, and the amount of gas production with respect to the change of ammonium nitrogen concentration in the waste using anaerobic fixed bed process, which is an anaerobic biofilm process. The HRT and operation temperature were 1 day and $35{\pm}1^{\circ}C$, respectively. Also, the characteristics of organic matter removal and the inhibitory effect on microorganism in the anaerobic process were studied on the organic loading and ammonium nitrogen concentration. The results obtained were as follows: For COD loading of $10kg/m^3$-day and five levels of ammonium nitrogen concentration ranging from 1,000 to 5,000 mg/L, organic removal efficiencies were about 81, 74, 67, 58, and 51%, and gas productions were 3,860, 3,520, 3,240, 3,020, and 2,790 ml/l-day, respectively. Average methane contents in the gas produced on COD loading of $10kg/m^3$-day was about 76%. Throughout the whole period of experiment, remaining VFA (as COD base) in the effluent was over 90% of remaining COD. This result indicated the inhibitory effect of high concentration of ammonium nitrogen through the facts that accumulated VFA was almost COD and organic removal efficiency decreased also with the increase of ammonium nitrogen. Especially, that implys which high concentration of ammonium nitrogen not only inhibits methane forming bacteria, but also acid forming bacteria.

• 유기물자원화
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• 제15권3호
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• pp.121-128
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• 2007

이 연구의 목적은 배기가스로부터 생성된 신성가스 중 HCl의 제거를 위해 기존의 건식 반응기와 여과집진기를 사용하였다. 흡착제는 중탄산나트륨($NaHCO_3$)를 시용하였으며 흡착제($NaHCO_3$) 의 성능, 효율을 평가한다. 이러한 중탄산나트륨의 성능, 제거효율을 평가하여, 중탄산나트륨이 건식 반응기에서의 최적의 운전조건을 분석하였다. 체류시간, 당량비, 온도, 여과집진기의 압력등을 운전조건으로 하였으며 체류시간은 1.5sec로 고정하였고, 중탄산나트륨 주입비(당량비)를 1SR, 1.25SR으로 조절하였고, 온도는 $160^{\circ}C$, $180^{\circ}C$, $200^{\circ}C$로 하였고, 여과집진기의 압력은 210mmAq, 230mmAq, 250mmAq로 하였다. 이 연구에서는 온도가 큰 영향은 없고, 압력과 당량비가 많은 영향을 끼치는 것을 알 수 있다. 최적의 운전조건은 주입비 1SR에서 $180^{\circ}C$, 230mmAq이다. 이 조건에서의 제거율은 99.50%로 나왔다.

• 유기물자원화
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• 제10권1호
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• pp.68-74
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• 2002

본 연구는 매립지로의 재순환에 의해 생물학적으로 전처리된 생활폐기물 위생매립장의 침출수를 대상으로 잔류된 생물학적 난분해성 부식질(humus)과 잔류 색깔(color)의 제거를 위해 전기분해법의 적용가능성을 검토하기 위해서 수행되었다. 연구를 통해 얻어진 결과는 다음과 같다. 1) 매립층을 통과한 침출수의 전기분해에서 CODcr과 Color의 제거율은 70~80%범위였고, Color의 제거에서 전기분해만으로도 배출기준을 충족하고 있음을 나타내었다. 2) pH7~8범위에서 가장 높은 제거율을 나타내었다. 3) 양극(+)으로 Al, Fe, Stainless를 사용했을 때 CODcr과 Color의 제거율은 Fe, Al, Stainless순으로 높았고, 반응물의 침전성 또는 전기적인 응집 후의 제거효율을 고려하면 Fe전극이 가장 높았다. 4) 본 연구에서 CODcr과 Color의 동시 제거를 위한 조건은 양극(+)은 Fe, 전극간격은 2cm 그리고 8volt의 전압에서 40분간이었다.