• Environmental Engineering Research
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• 제14권3호
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• pp.174-179
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• 2009

The InSub system(applied for a patent) was developed, as it combined the indirectly aerated submerged biofiltration(InSub) reactor and Anaerobic/ Anoxic reactor. This system which can eliminate organism and nutrient materials at the same time, which is safe and economical to be maintained and managed is more simple process than the complicated existing biological advanced sewage treatment system. The most suitable HRT of this study showed 9 hours. As looking into the effluent concentration and removal efficiency of each item at 9 hours of HRT, each effluent concentration for $SS,\;BOD5,\;COD_{Mn},\;and\;COD_{Cr}$ was 1.46 mg/L, 7,09 mg/L, 9.84 mg/L and 16.42 mg/L. And their removal efficiency was 96.98%. 90.59%, 77.18% and 83.92%, respectively. Each effluent concentration of T-N and T-P was 10.42 mg/L and 1.04 mg/L. Their removal efficiency was 73.38% and 61.62%, respectively. This pilot plant experiment(the state was without the internal recycling.) followed a variety of HRT. The results confirmed that it was to be advanced sewage treatment system with high efficiency when it combined with the internal recycling.

• 상하수도학회지
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• 제25권5호
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• pp.659-666
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• 2011

Although DAF(Dissolved Air Flotation) has been successfully accepted for water and wastewater treatment, the fundamental characteristics of the process have not been fully investigated. Water is saturated with compressed air to dissolve the air into the water at high pressure in saturation tank. Then the water containing dissolved air is released into a floatation tank at a lower pressure, generating micro-bubbles that rise gently through the water and carry the suspended matter to the surface. This study investigated the removal of sewage using automatic mixture type DAF pump and non-powered flotation tank. Characteristics of two devices were compared and analyzed with samples. The results showed that the PAC exhibited higher performance than other coagulants. When air dosage was 2.5ml/l/min, treatment was stable in operation. In the DAF pump with a pressure of 4 atm., the average size of bubbles was 36.2${\mu}m$. Removal efficiency of SS was 80%. At this time removal efficiency of COD was about 80%, of T-N was 30% and T-P was 70% in stable operation. It was concluded that DAF pump system with micro bubble performed higher efficiencies compared to general DAF system for treating wastewater.

• 환경영향평가
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• 제20권6호
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• pp.857-866
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• 2011

This research categorized EIA target highways into following three types in order to minimize non-point source pollution from highway runoff. 1. Big drainage basin. 2. Small drainage basin. 3. Bridge section. The Natural, Filter and Swirl-Type devices were evaluated in terms of removal efficiency of TSS, BOD, COD, T-N, T-P, compatibility of site selection, economic feasibility, and maintenance convenience through which the final BMP was selected. According to the removal efficiency result, the area of Big and Small Drainage basin and bridge section had higher removal efficiency with natural facility than that of the Filter or Swirl-Type device. To make appropriate selection of highways'BMP for non-point source pollution, this study will aim to contribute to building more environmentally friendly highways by proposing the selection process that is made of 5 stages. 1. Selecting the target drainage basin. 2. Selecting the land for the mitigation facility. 3. Analysing the ease of maintenance. 4. Technically evaluating each installation. 5. Evaluating the effective implementation methods.

• Membrane and Water Treatment
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• 제6권4호
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• pp.339-349
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• 2015

Experiments were carried out using granular activated carbon (GAC) adsorption techniques to treat wastewater contaminated with organic compounds caused by diverse human activities. Two techniques were assessed: adsorbent GAC prepared from coconut shell (GACC) and adsorbent GAC from palm shell (GACP). A comparison of these two techniques was undertaken to identify ways to improve the efficiency of the treatment process. Analysis of the processed wastewater showed that with GACC the removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, total suspended solids (TSS) and total dissolved solids (TDS) was 65, 60, 82, 82 and 8.7%, respectively, while in the case of GACP, the removal efficiency was 55, 60, 81, 91 and 22%, respectively. It can therefore be concluded that GACC is more effective than GACP for BOD removal, while GACP is better than GACC for TSS and TDS removal. It was also found that for COD and turbidity almost the same results were achieved by the two techniques. In addition, it was observed that both GACC and GACP reduced pH value to 7.9 after 24 hrs. Moreover, the optimal time period for removal of BOD and TDS was 1 hr and 3 hrs, respectively, for both techniques.

• 유기물자원화
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• 제28권1호
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• pp.53-64
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• 2020

다단수직형 적층 방식의 질산화조가 포함된 2㎥/d 병합폐수처리 파일럿플랜트를 설치하여, pH8 이상, DO 1mg/L, 내부반송율 4Q이상의 단축질소제거공정의 질산화조 운전 조건으로 약 1년 이상 운영하였다. 음폐수와 침출수의 경제적인 병합 처리를 위하여, 유분이 최소화된 음폐수를 전체 처리량의 5~25%로 조절하여 최적의 병합 비율을 검토하였다. 음폐수의 고형물과 유분을 효과적으로 분리하기 위하여 도입된 3상원심분리기의 주요 처리 효율은 SS는 116,000mg/L에서 55,700mg/L로 약 52% 제거 되었으며, 노르말헥산(N-H)의 농도는 53,200mg/L에서 27,800mg/L로 약 48%로 제거되었다. 운전 기간 중 병합 폐수처리 공정의 BOD 평균 제거 효율은 99.3%, CODcr 94.2%, CODmn 90%, SS 70.1%, T-N 85.8%, T-P 99.2%로 분석되었다. 처리수의 BOD, CODcr, T-N, T-P 평균 농도는 침출수 배출허용 기준("나"지역)을 만족하였으며, SS는 멤브레인조를 적용한 후 만족하였다. 현장의 침출수는 유량조정조의 간헐적 폭기 및 월별 상이한 방출량의 영향으로 병합폐수 중 아질산성 질소의 성분이 비교적 높았다. 아질산성질소가 축적된 상태에서도 완전질산화 후 탈질보다는, 아질산성 질소에서 탈질되는 결과가 나타났다. 또한 운전기간 중 평균 소포제 투입량은 약 2L/d으로 같은 폐수를 처리할 시 필요한 메탄올 투입량 약 2.8L/d 대비하여 경제적인 것으로 보인다.

• 한국축산시설환경학회지
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• 제15권3호
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• pp.209-216
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• 2009

침전 및 고액분리 후 활성오니 공정 즉 분뇨 오수의 2차 처리공정까지를 거친 돈분뇨슬러리를 대상으로 하여 미세용존 오존 및 초음파와 자외선 그리고 과산화수소 등을 조합하여 적용한 고도처리 시험결과를 요약한 주요결과는 다음과 같다. 1. 돼지분뇨 오수 시료를 대상으로 하여 오존과 UV를 적용하였을 경우 전반적으로 색도와 오염성물질의 농도가 줄어드는 경향이 있었다. 2. 미세용존 오존을 이용하여 오존농도 $52\;g/Nm^3$ 조건에서 색도농도가 각기 다른 시료를 대상으로 하여 30분간 반응시켰을 경우 색도는 각각의 처리구 공히 처리시간의 경과에 따라 감소하는 결과를 보였다. COD를 포함한 오염성 물질의 농도도 처리시간의 경과에 따라 감소하였으며 자외선과 과산화수소 등 유기물질의 분해 및 산화력을 가진 물질의 첨가는 오존처리의 효율을 높이는 역할을 하였다. 3. 오존처리에 의해 처리수 중의 대장균과 살모넬라 수가 감소하였으며 과산화수소를 첨가할 경우 그 감소효과는 더 증가하였다는 경향이 있었다. 오존과 과산화수소수를 병합처리 하였을 경우에는 $7.5{\times}10^\;CFU/mL$ 이었던 살모넬라가 처리 후 10분 만에 10 CFU/L 이하로 낮아졌으며 20분 처리 후에는 오존과 과산화수소수를 병합한 처리구에서는 검출되지 않았다. 이 결과는 과산화수소의 짝염기인 ${HO_2}^-$가 OH 라디칼의 생성을 촉진함으로써 살모넬라 등의 세균감소 효과를 높인것에 기인한 것으로 판단된다.

• 한국수자원학회논문집
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• 제47권12호
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• pp.1135-1143
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• 2014

본 연구에서는 사상성 조류로 구성된 수질정화시설의 수질정화효율을 평가하고자 충남 서산시 음암면에 소재한 성암저수지 유입하천 홍수부지에 test-bed를 설치하고 유입하천수를 대상으로 현장적용실험을 실시하였다. 수질항목별로 정화효율을 평가한 결과, SS 80.9%, COD 74.6%, T-N 76.8%, T-P 84.4%, DTN 93.8%, DTP 98.3%의 제거효율을 보였다. 수온에 따른 정화효율은 수온이 약 $20^{\circ}C$로 유지되어 수질정화효율에 미치는 영향은 없는 것으로 나타났다. 수리학적 체류시간(HRT)은 SS 및 TP 처리효율과 유의한 상관성이 있는 것으로 나타났고, 체류시간을 5일로 했을 때 SS, TP 처리효율이 좋은 것으로 나타났다. 유입수의 COD/TN에 따른 처리효율은 TN, TP 모두 C/N비가 낮을수록 증가하였고, 유입수의 COD/TP에 따른 처리효율도 C/P비가 낮을수록 TN, TP 모두 처리효율이 증가하는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권7호
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• pp.957-962
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• 2002

In July, three trials were conducted to evaluate the best sponge type and optimum PMSG dose to be administered to sheep under the Jordanian Badia (arid) conditions. In trial 1, three flocks (n=77, n=18 and n=47 for flocks 1, 2 and 3, respectively) were administered with 40 mg fluorogestone acetate (FGA) intravaginal sponges for 12 days before receiving 600 IU of PMSG at the time of sponge removal. In trial 2, 95 ewes were assigned to 4 groups to receive 300 (n=25), 450 (n=27), 600 (n=22) or 750 (n=21) IU of PMSG following a 12 d FGA 40 mg sponge insertion period. In trial 3, 60 ewes were assigned to 3 groups (n=20) to receive either FGA 30 mg, FGA 40 mg or medroxyprogesterone acetate (MAP) 60 mg intravaginal sponges all followed by an administration of 600 IU of PMSG at sponge removal. In all trials, rams were isolated 1 day before sponge insertion and were allowed back with the ewes at sponge removal. Estrual responses and lambing data were collected. The effects of treatment, milking status and face color on estrual responses and lambing data were examined. In trial 1, greater first cycle conception rate (p<0.05), twinning rate (p<0.01) and the number of lambs born/served ewe (p<0.01) were observed in flock 2 compared with flocks 1 and 3. Neither face color nor milking status had any influence on the measured parameters (p>0.05). Despite low lambing rate in trial 2, ewes receiving 600 IU of PMSG had greater (p<0.05) number of lambs born/served ewe compared with ewes receiving 450 IU of PMSG. Regardless of PMSG dose, intervals to detected estrus occurred 10 h earlier (p<0.01) in dry than lactating ewes. Similar to trial 2, lambing rate was depressed in trial 3. The expression of estrus was advanced (p<0.05) in ewes receiving MAP 60 mg sponges compared with those receiving FGA 30 and FGA 40 mg sponges (42$\pm$3.1, 49$\pm$3.1 and 49$\pm$3.1 h post sponge removal in ewes receiving MAP 60 mg, FGA 30 mg and FGA 40 mg sponges, respectively). Other parameters were not influenced (p>0.05) by sponge type, milking status and face color. Data show that a 600 IU dose of PMSG tends to give the best lambing results. In addition, results indicate that the use 60 mg MAP sponges for estrus synchronization may be more appropriate under the Jordanian Badia conditions during late seasonal anestrus.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 추계학술대회
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• pp.147-152
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• 2004

선박에서 발생되는 오${\cdot}$폐수를 처리하기 위하여 생물학적 영양염류 제거공정에서 질소와 인 등의 제거효율은 유기물의 양과 구성성분에 따라 영향을 받는 경향이었다. 선박에서 발생되는 음식폐기물을 이용하여 생성된 산발효액을 이용하여 영양염류를 효율적으로 제거하기 위한 외부탄소원으로 사용하여 산발효액의 적용성을 평가하였다. 음식폐기물 산발효액의 탈질율을 평가한 결과 질산성 질소가 완전히 제거되는 시간은 140분이였고, 탈질속도는 0.30g $NO_3-N/g\;VSS{\cdot}day$로 나타났다. 산발효액의 주입으로 인하여 유출수 중의 $COD_cr$ 농도가 증가함을 알 수 있었는데 이것은 산발효액에 존재하는 유기물을 미생물이 다 이용하지 못하는 부분이 존재하고 주입량의 증가에 따른 유출수 중의 $COD_cr$ 농도를 증가시켰다. 암모니아성 질소의 성상은 산발효액의 첨가에 크게 영향을 받지 않았으며 산화된 질소의 변화는 산발효액 주입량이 증가할수록 무산소단계에서 농도가 감소하여 전체 제거효율이 증가함을 볼 수 있었다.

• 한국환경보건학회지
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• 제22권3호
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• pp.56-63
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• 1996

The results of the water purification studies using water parsley (Oenanthe javanica) were obtained as follows. The removal rate of nutrient salts increased with longer plant growth periods. The results of this study use the assumption, log(T+1) = $K(C_0-C)^A$, based on Prakish's Theory. The initial concentration was calculated from experimental data. A and K are closely related to the initial concentration. It is possible to model the concentration of residual salts, as time goes by, if concentration is constant. It was observed that water parsley neutralizes acid and alkali substances promptly. The maximum suitable neutralization period is 48 hours. But water parsley withered up in strong acid and alkali solutions within a week. The removal efficiency of Cd progresses in 2 steps, which are unrelated to the initial concentration of Cd. The first part of the curve shows the concentration rapid rate of Cd removal, followed by a levelling off. The removal rate of $NO_x-N$ in the sample water tank containing 0.5 ppm Cd was between 50~80% but the removal rate was less than 20% for the higher concentration. On the other hand, increased amounts of $PO_4-P$ in the sample water tank from the third day on suspected that $PO_4-P$ was desorbed from the water parsley. The accumulation efficiency of Cd in plant was increased in proportion to the initial concentration of Cd. The accumulation phenomenon was observed in the tanks more than 50~100 times.