• Environmental engineer
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• s.181
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• pp.70-75
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• 2001

본 연구는 '99년 7월에 벤처형 중소기업 기술개발 지원사업으로 신규 계약된 과제로서 상수원수의 전처리 및 하수 2차 침전수의 재처리 공정에 활용될 생물 산화 여과지를 개발하는 것이다. 생물 산화 여과 system은 상수 원수의 전처리, 상수도의 고도정수 처리, 하수 및 폐수처리에 이용될 수 있는 것으로, 특히 물리적 여과기능과 포기 과정을 통한 산화 기능을 포함하는 생물학적 분해 및 자연정화처리환경을 유지하여 수질이 악화된 상수도의 전·후처리나 하.폐수의 3차 처리에 적용하기 위한 것이다. 생물 산화 여과 시스템은 여과지의 하부 장치에 균등한 공기(산소)공급시설을 하여 여과층에 연속적으로 공기를 공급하면서 여과를 함으로서 생물막 여과 및 산화 기능으로 유기물질, 철, 망간 등을 제거하고 공기의 부상력에 의하여 조류, 부유물질, 냄새 등을 동시에 제거하는 System이다. 현재 상수처리 공정으로서의 생물 산화 여과지 개발을 위해 Bench-scale과 semi-pilot plant를 거쳐 Y시 M취수장애 pilot plant를 설치하여 연구를 진행중에 있으며, 또한, G시 G하수처리장에 하수처리 공정에 관한 연구를 위해 pilot plant를 설치하고 하수 3차 처리와 저농도 하·폐수 처리를 중심으로 연구중에 있다. 아래의 연구 결과는 정수처리 공정 연구를 위한 Bench-scale plant실험을 통해 얻은 결과치이며 현재까지 진행된 연구는 주로 정수처리 공정 중심으로 이루어 졌으나 pilot plant에서는 정수 및 하수처리에서의 생물산화여과공정의 연구가 진행중이다. 현재 연구가 진행중이므로 각 인자별 최적운전조건 등은 계속적인 실험과 연구를 통해 찾아지겠으나 현재까지 수행된 연구자료를 기반으로 볼 때 생물산화 여과장치는 탁도, SS, VSS 등의 제거에 탁월한 효능을 보이고 있다. 수처리용 장치로서의 이러한 기본적인 기능 이외에 NPOC, DOC 제거에도 뛰어난 효능을 보이고 있으며 특히 정수처리 공정에서 문제시 되고 있는 동절기 암모니아성 질소제거 또한 큰 가능성을 보여주고 있다. 그 동안 외국기술에 전면 의존해 오던 생물 산화 여과방식의 국내개발은 비용 절감뿐만 아니라 국내 실정에 맞는 기술개발이라는 점에서 향후 그 적용 범위를 넓혀 갈 수 있을 것이다.

• Journal of the Korean Geosynthetics Society
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• v.10 no.1
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• pp.29-36
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• 2011

The remediation efficiency of the contaminant through laboratory experiment of the pilot scale was evaluated for the influence factors in the contaminated soils for the applicability of the prefabricated vertical drain system. It was performed numerical analysis by the method that the finite element and finite differences based on the drawn result about the remediation of contaminated soils. The parametric analysis for the applied parameter value was performed. In the pilot scale remediation experiment, as a result of evaluating with the minimum limit concentration ratio, in the case of dense and loose conditon, the remediation time was much longer. And the remediation efficiency was rapidly progressed as the time was elapsed. It was analyzed that the contaminant concentration is reduced around the extraction well as the contamination remediating rate by numerical analysis result as the time was elapsed.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.108-113
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• 2004

Korea Gas Corp. has developed the design technology of the LNG storage tank. The membrane to be applied inside of the LNG storage tank is provided with corrugations to absorb thermal contraction and expansion caused by LNG temperature changes. It is very important to measure their thermal strains under LNG temperatures by analytical and experimental stress analysis of the membrane. We have developed a stress measurement system using strain gages and measured the strain during cooldown and storing the LNG. We also analyzed the measured data by comparison with the FEM data. On the basis of these results, we could design and assure the application of the Kogas Membrane to large scale LNG storage.

• Environmental Engineering Research
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• v.20 no.3
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• pp.277-284
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• 2015

Experiments for highly concentrated contaminants in pig waste slurry were carried out for the feasibility test of a pilot-scale innovative process scheme of engaging autothermal thermophilic aerobic digestion (ATAD) and expended granular sludge bed (EGSB) followed by sequencing batch reactor (SBR) system. Contaminants in pig waste slurry such as organic substance, total nitrogen (TN), ammonia nitrogen and total phosphorus (TP) contents were successfully reduced in the system. Total volatile solids (TVS) and chemical oxygen demands (COD) for organic matter in the feed were 32.92 g/L and 42.55 g/L respectively, and they were reduced by about 98.7% and 99.2%, respectively in the system. The overall removal efficiencies for TN and ammonium nitrogen were found to be 98.1 and 98.5%, respectively. The overall removal efficiency for total phosphorus was also found to be 92.5%. Faecal coliform density was reduced to <$1.2{\times}10^4CFU/g$ total solids. Biogas and $CH_4$ were produced in the range of 0.39-0.85 and $0.25-0.62m^3/kg$ [VS removed], respectively. The biogas produced in the system comprised of $295{\pm}26ppm$ (v/v) [$H_2S$].

• The KSFM Journal of Fluid Machinery
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• v.18 no.2
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• pp.37-42
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• 2015

In the purpose of this study, we investigate the characteristics of the pilot-scale wastewater treatment system applied to BAF, MBR and IPNR as examining the removal efficiency of organic pollutants and operating factors in small decentralized wastewater treatment systems, and operating factors. For long-term operation period of more than nine months, pilot-scale plant operating results appeared very stable. This results were the removal efficiency of BOD was 80.3% above and removal efficiency of COD with an average of about 91.0%, satisfied the final effluent water quality standards. TN in the final effluents was the average concentration of 7.9 mg/L, was satisfactory water quality standards 10 mg/L of TN.

• Membrane Journal
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• v.9 no.3
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• pp.185-192
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• 1999

The ultrafiltration characteristics of wafer processing wastewater produced from semicon¬ductor industry was investigated for wastewater reuse. Using the pilot-scale ultrafiltration system con¬taining poly sulfone hollow fiber membranes (MWCO : 10,000, 20,000, 30,(00), the membrane performance, such as flux, rejection rate and concentration factor for flux was examined. The SDhs, turbidity, electrical conductivity and concentration of Si particles were measured, and the possibility of permeate reuse was validated from the experimental results. It was shown that the flux was recovered by the sweeping with air and water effectively. The permeate flux of 30,000 MWCO membrane was about 5 times higher than that of 10,000 and 20,000 MWCO membranes. The concentration of Si particle in the saw wastewater was analyzed 3.8-5.6 mg/$\ell$ and that of Si particle in the permeate was analyzed less than 0.2${\mu}g$/$\ell$. This means the rejection of silicon particle was over 96%.

• Environmental Engineering Research
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• v.11 no.2
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• pp.63-76
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• 2006

Multivariate analysis and batch monitoring on a pilot-scale sequencing batch reactor (SBR) are described for integrated wastewater treatment management system, where a batchwise multiway independent component analysis method (MICA) are used to extract meaningful hidden information from non-Gaussian wastewater treatment data. Three-way batch data of SBR are unfolded batch-wisely, and then a non-Gaussian multivariate monitoring method is used to capture the non-Gaussian characteristics of normal batches in biological wastewater treatment plant. It is successfully applied to an 80L SBR for biological wastewater treatment, which is characterized by a variety of error sources with non-Gaussian characteristics. The batchwise multivariate monitoring results of a pilot-scale SBR for integrated wastewater treatment management system showed more powerful monitoring performance on a WWTP application than the conventional method since it can extract non-Gaussian source signals which are independent and cross-correlation of variables.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1445-1453
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• 2013

The scale-up criterion of constant oxygen mass transfer coefficient ($k_La$) was applied for the production of itaconic acid (IA) in a 50 L pilot-scale fermentor by the fungal cells of Aspergillus terreus. Various operating conditions were examined to collect as many $k_La$ data as possible by adjusting the stirring speed and aeration rate in both 5 L and 50 L fermentor systems. In the fermentations performed with the 5 L fermentor, the highest IA production was obtained under the operating conditions of 200 rpm and 1.5 vvm. Accordingly, we intended to find out parallel agitation and aeration rates in the 50 L fermentor system, under which the $k_La$ value measured was almost identical to that ($0.02sec^{-1}$) of the 5 L system. The conditions of 180 rpm and 0.5 vvm in the 50 L system turned out to be optimal for providing almost the same volumetric amount of dissolved oxygen (DO) into the fermentor, without causing shear damage to the producing cells due to excessive agitation. Practically identical fermentation physiologies were observed in both fermentations performed under those respective operating conditions, as demonstrated by nearly the same values of volumetric ($Q_p$) and specific ($q_p$) IA production rates, IA production yield ($Y_{p/s}$), and specific growth rate (${\mu}$). Specifically, the negligible difference of the specific growth rate (${\mu}$) between the two cultures (i.e., $0.029h^{-1}$ vs. $0.031h^{-1}$) was notable, considering the fact that ${\mu}$ normally has a significant influence on $q_p$ in the biosynthesis of secondary metabolites such as itaconic acid.

• Environmental Engineering Research
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• v.14 no.3
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• pp.195-199
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• 2009

A series of laboratory-scale corrosion experiments was carried out to observe the effect of dissolved oxygen (DO) in the presence of other water quality parameters, such as hardness, Cl-, and pH using various pipe materials. In addition, a simulated loop system was installed at a water treatment plant for pilot-scale experiment. Laboratory-scale experiment showed that corrosion rates for galvanized steel pipe (GSP), carbon steel pipe (CSP), and ductile cast iron pipe (DCIP) were decreased to 72%, 75%, and 91% by reducing DO concentration from 9${\pm}$0.5 mg/L to 2${\pm}$0.5 mg/L. From the pilot scale experiment, it was further identified that the average ionization rate of zinc in GSP decreased from 0.00533 to 0.00078 mg/$cm^2$/d by controlling the concentration of DO. The reduction of average ionization rate for copper pipe (CP) and stainless steel pipe (SSP) were 71.4% for Cu and 63.5% for Fe, respectively. From this study, it was concluded that DO could be used as a major parameter in controlling the corrosion of water pipes.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.4
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• pp.445-448
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• 2008

The application of the membrane filtration process has been increased for the drinking water treatment system because of excellent quality of treated water compared with the sand filtration process. The selection of suitable pre-treatment processes and optimum flux according to the characteristics of raw water are important factors for the design of membrane processes. In this study, the most efficient pre-treatment processes for drinking water was selected by investigating the effects of pre-treatment processes on the operational stability of the membrane filtration process. Both lab-scale and pilot-scale experiments were conducted. In the lab-scale test, the effect of pre-treatment processes on the stability of the membrane filtration process was investigated indirectly by comparing the performance of membrane flux for raw water, pre-treated water, and membrane permeated water. In the pilot-scale test, the usefulness of prefiltration processes was assessed by comparing the performance of single membrane process and hybrid coagulation-membrane process. The results indicated that the coagulation process contributed to the stabilization of trans-membrane pressure (TMP) by removing contaminants on membranes, though the pre-filtration process had little effect on the TMP.