• Journal of Soil and Groundwater Environment
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• v.11 no.4
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• pp.10-17
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• 2006

Laboratory-scale two-dimensional aquifer physical model studies were conducted to assess the effect of air injection rate and air injection pattern on the removal of disel contaminated soil and groundwater by air/bio-sparging. The experimental results were represented that the optimal conditions in this experiment were as air injection rate of 1,000 ml/min and pulsed air injection pattern(15 min on/off). The results of the TPH reduction, DO consumption and $CO_2$ production indicate the effective biodegradation evidence of diesel. Based on our results, The minimal $O_2$ supply and pulsed air injection pattern could effectively enhance the diesel removal and the pulsing air injection had effect on oxygenation in this system. Thus, the cost of operating air/bio-sparging system will be reduced if optimal air injection rate and pulsed air injection pattern are applied to remediate contaminants.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1186-1192
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• 2005

The relationship between bacteria and anaerobic archaea, sludge yield coefficient and nitrogen removal rate were investigated in intermittent aeration systems(I/A) with added archaea, I/A and conventional activated sludge system. As the archaea solution was added to the I/A reactor, organic removal rate as well as nitrogen removal rate increased. Also, sludge production rate in I/A system added the archaea was maintained lower than other systems because sludge yield coefficient was decreased due to the role of anaerobic archaea such as anaerobic degradation of organics. The experimental data supported the possibility of symbiotic activated sludge system with anaerobic archaea under intermittent aeration, leading to the enhanced nitrogen removal. Crucial results to be presented are: 1) specific oxygen utilization rate(SOUR) of the I/A-arch system was $2.9\;mg-O_2/(g-VSS{\cdot}min)$. SOUR and nitrification rate of the sludge from the I/A-arch system was higher than those from the I/A and A/S reactors. 2) Removal efficiencies of $TCOD_{Cr}$ in the I/A-arch, I/A and A/S reactors were 93, 90 and 87%, respectively. 3) Nitrification occurred successfully in each reactor, while denitrification rate was much higher in the I/A-arch reactor. Efficiencies of TN removal in the I/A-arch, I/A and A/S reactors were 75, 63 and 33%, respectively.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.22-30
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• 2009

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.272-279
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• 2012

In order to effectively treat livestock wastewater in constructed wetlands by natural purification method, removal velocities of pollutants under different injection methods in constructed wetlands were investigated. The removal velocities of chemical oxygen demand (COD), suspended solid (SS), T-N and T-P by continuous injection method were slightly rapid than those by intermittent injection method in full-scale livestock wastewater treatment plant. The removal velocity (K; $day^{-1}$) of COD by continuous injection method was $0.38\;d^{-1}$ for $1^{st}$ bed, $0.13\;d^{-1}$ for $2^{nd}$ bed, $0.17\;d^{-1}$ for $3^{rd}$ bed, $0.05\;d^{-1}$ for $4^{th}$ bed and $0.17\;d^{-1}$ for $5^{th}$ bed. The removal velocities (K; $day^{-1}$) of COD in $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$ and $5^{th}$ beds by intermittent injection method were $0.210\;d^{-1}$, $0.086\;d^{-1}$, $0.222\;d^{-1}$, $0.053\;d^{-1}$ and $0.137\;d^{-1}$, respectively. The removal velocity (K; $day^{-1}$) of SS by continuous injection method was $0.750\;d^{-1}$ for $1^{st}$ bed, $0.108\;d^{-1}$ for $2^{nd}$ bed, $0.120\;d^{-1}$ for $3^{rd}$ bed, $0.086\;d^{-1}$ for $4^{th}$ bed and $0.292\;d^{-1}$ for $5^{th}$ bed. The removal velocities (K; $day^{-1}$) of SS in $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$ and $5^{th}$ beds by intermittent injection method were $0.485\;d^{-1}$, $0.056\;d^{-1}$, $0.174\;d^{-1}$, $0.081\;d^{-1}$ and $0.227\;d^{-1}$, respectively. The removal velocity (K; $day^{-1}$) of T-N by continuous injection method was $0.361\;d^{-1}$ for $1^{st}$ bed, $0.121\;d^{-1}$ for $2^{nd}$ bed, $109\;d^{-1}$ for $3^{rd}$ bed, $0.047\;d^{-1}$ for $4^{th}$ bed and $0.155\;d^{-1}$ for $5^{th}$ bed. The removal velocities (K; $day^{-1}$) of T-N in $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$ and $5^{th}$ beds by intermittent injection method were $0.235\;d^{-1}$, $0.071\;d^{-1}$, $0.171\;d^{-1}$, $0.058\;d^{-1}$ and $0.126\;d^{-1}$, respectively. The removal velocity (K; $day^{-1}$) of T-P by continuous injection method was $0.803\;d^{-1}$ for $1^{st}$ bed, $0.084\;d^{-1}$ for $2^{nd}$ bed, $0.076\;d^{-1}$ for $3^{rd}$ bed, $0.118\;d^{-1}$ for $4^{th}$ bed and $0.301\;d^{-1}$ for $5^{th}$ bed. The removal velocities (K; $day^{-1}$) of T-P in $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$ and $5^{th}$ beds by intermittent injection method were $0.572\;d^{-1}$, $0.049\;d^{-1}$, $0.090\;d^{-1}$, $0.112\;d^{-1}$ and $0.222\;d^{-1}$, respectively.

• KSBB Journal
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• v.18 no.2
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• pp.140-144
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• 2003

The artificial sewage was treated using a vertical flow zeolite-filled reed bed. The artificial sewage was fec into the reed bed for 10 minutes every 6 hours at the hydraulic load 314 L/$m^2$ \ulcorner day. The filtering height of the reed bed was 100 cm and the zeolite mixture was filled in the reed bed. The mixture consisted of the same volume of two types of zeolites ; 0.5~1 mm and 1~3 mm in diameter. Annual average removal efficiency was CO$D_{Cr}$ 95.1%, T-N 49.5%, $NH{_4^+}$-N 99.4% and T-9 56.4%. T-N removal efficiency decreaced remarkably from 73 to 27% with the operating time. Most of T-P was adsorbed in the uper area of the reed bed. The major portion of adsorbed phosphorus was composed of Fe-, Ca- and reductant selubele Fe-P.

• Membrane Journal
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• v.14 no.1
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• pp.66-74
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• 2004

Total resistance of membrane in a micro-filtration system using a metal membrane was mainly attributed to the permeate resistance of cake layer($R_c$), which was formed by deposited particles from the physico-chemical interactions of solids on membrane surface. Intermittent back ozonation was highly effective than the air backwashing for fouling reduction. As far the operational effect, under same ozone injection, the increase of gas flow-rate was more favorable than the increase of injection time far the recovery of permeation flux. As the filtration time was longer, the effect of flux recovery by intermittent back-ozonation decreased. Therefore, it is preferable to operate membrane cleaning before the foulant is consolidated on membrane surface.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.261-268
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• 2014

A sewage was treated using serially combined vertical(VFCW)and horizontal flow sand-filled reed constructed wetland(HFCW) with intermittent feeding. The sand had 1~3 mm diameter. The sewage entering the sewage treatment plant of Gyeonsang National University was fed into the reed constructed wetland bed for 10 minutes every 6 hours at the hydraulic load of $314L/m^2{\cdot}day$ based on the surface ares of the VFCW. In the VFCW effluent pH values were lower than those of the influent, whereas they were higher than those of the influent in the HFCW. DO values were increased in VFCW, but they were decreased in the HFCW. The OTR was $58.72gO_2/m^2{\cdot}day$ in the VFCW and $7.72gO_2/m^2{\cdot}day$ in the HFCW. Average removal efficiencies were SS 94.80%, BOD 90.77%, $COD_{Cr}$ 85.87%, $COD_{Mn}$ 87.72%, T-N 64.74%, $NH_4{^+}$-N 86.44%, T-P 87.70%. Nearly, half of T-N in the effluent was $NO_3{^-}$-N but the concentration of $NO_2{^-}$-N in the effluent was less than 0.64 mg/L.

• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.63-71
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• 2006

This study was conducted to evaluate air injection mode on stabilization of landfill gas and to predict the time for landfill mining. It took 8 times longer for pulse aeration to get to aerobic condition, compared to continuous aeration. It was evaluated that continuous aeration mode is more preferable than pulse mode for rapid air exchange in landfill mining. High correlation ($r^2$ = 0.95) was found between continuous aeration time and time to maintain aerobic condition when $0.2m^3/min$ of air was continuously injected and stopped. The aerobic condition ($CH_4$ < 5%) was maintained for 1.5 times longer than aeration time.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.132-137
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• 2003

This study was carried out to investigate removal character of nitrogen and phosphorus with injection time of acetic acid on SBR, which is one of the biological treatment process. Wastewater used in experiment period was swine wastewater with character, relatively lower organic material concentration than nitrogen concentration. In the experiment with injection time of acetic acid, run 1 wasn't injected acetic acid during the anoxic period, and run 2 was injected intermittently acetic acid during the anoxic period of 15 hours. And run 3 was injected intermittently during the anoxic period of 3hours from end of wastewater filling. And filing time of the wastewater was 20hour from run 1 to run 3. In the study, the highest removal efficiency of organic and nitrogen were obtained by the operating condition of Run 2(the ratio of mixing/aeration time : 16.5/5.5, injection time of acetic acid : 15hours) and T-P was obtained by the operation condition of Run 3(the ratio of mixing/aeration time : 16.5/5.5, injection time of acetic acid : 3hours),and removal efficiency of $BOD_5$, $COD_{Mn}$, $COD_{Cr}$, T-N and T-P in the treated water was 96.1%, 87.7%, 90.6%, 86.6% and 84.5%, respectively.

• Journal of Chest Surgery
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• v.34 no.3
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• pp.224-230
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• 2001

배경: 지속적인 온혈 심성지액을 이용한 심금 보호술이 소개된 이수, 이를 토대로 많은 임상결과가 발표되고 있다. 그러나 지속적 심정지액 주입에 따른 적정한 수술시야 확보와 역행성 관류법에 따른 우심실 보호에 대한 문제들이 제기 되고 있다. 이에 Antonio 등은 포타슘만을 이용한 간헐적 온혈액 심정지술을 이용하여 만족할 만한 임상결과를 보고 하였다. 본 임상연구는 포타슘만을 이용한 간헐적 온혈액 심정지술을 이용하여, 개심술을 시행 받은 70례의 환잔의 임상결과를 분석하여 그 유용성을 알아보고자 하였다. 대상 및 방법: 1998년 5월부터 1999년 1월까지 포타슘만을 이용한 간헐적 온혈액 심정지술을 이용하여 관상동맥 우회술 및 판막수술을 시행한 70명의 환자와 같은 기간 간헐적 냉혈액 심성지술을 이용하여 동일 술자에 의해 수술을 시행한 70명의 임상결과를 비교 분석하였다. 결과: 총 심폐기 사동 시간(98.7$\pm$6.0분, 114.3$\pm$7.5분, p=0.018),수술중 심정지를 위해 필요한 심정지액의 양(1463.0$\pm$68.0cc, 3584.0$\pm$179.0cc, p<0.001), 의식이 회복될 때까지의 시간(3.5$\pm$0.4시간, 4.9$\pm$0.8시간, p=0.044), 기관 삽관의 제거까지의 시간(10.8$\pm$0.8시간, 13.2$\pm$0.6시간, p=0.017), 부정액으로 리도케인(Lidocaine)의 도움이 필요한 경우(75.2$\pm$6.8mg, 114.5$\pm$7.2mg, p=0.006)등에 있어서는 포타슘만을 이용한 간헐적 온혈액 심정지술이 유의성의 있었고, 술수 심근효소의 상승, 사망률과 이환율에 있어서는 두군간의 유의성은 없었다. 결론: 관상동맥 우회술 및 판막수술에 있어 포타슘만을 이용한 간헐적 온혈액 심정지술은 적어도 간헐적 냉혈액 심정지술과 같은 정도의 심근 보호를 할 수 있었으며, 기존의 warm heart surgery의 장점인 심폐기 가동시간이 짧고, 의식회복이 빠른 점과 함께 용적과부학(volume loading)를 줄일 수 있는 장점이 있어 유용한 심근 보호술의 하나로 사료된다.