• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.19-25
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• 2007

Process analysis with ASM3 (Activated Sludge Model3) was performed to offer basic data for the optimization of aerated biofilter (ABF) process design and operation. This study was focused on the simulation of the nitrification reaction in ABF which was a part of the advanced nutrient treatment process using bio-adsorption. The ABF process has been developed for the removal of suspended solids and nitrification reaction in sewage. A GPS-X (General Purpose Simualtor-X) was used for the sensitivity analysis and operation assessment. Sensitivity of ASM3 parameters on ABF was analysed and 4 major parameters ($Y_A$, $k_{sto}$, ${\mu}_A$, $K_{A,HN}$) were determined by dynamic simulation using 70 days data from pilot plant operation. The optimized values were 0.14 for $Y_A$, 3.5/d for $k_{sto}$, 2.7/d for ${\mu}_A$ and 1.1 mg/L for $K_{A,HN}$, respectively. Simulation with optimized parameter values were conducted and TN, $NH_4{^+}-N$ and $NO_3{^-}-N$ concentrations were estimated and compared with measured data at the range of 10 min to 4 hrs of hydraulic retention time (HRT). The simulated results showed that optimized parameter values could represent the characteristics of ABF process. Especially, the ABF showed relatively high nitrification rate (60%) under very short HRT of 10 min. As a consequence, the ABF was thought to be successfully used in the site which having high variation of influent loading rate.

• Membrane Journal
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• v.10 no.4
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• pp.220-229
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• 2000

Deionized water and wastewater flux were discussed using module set 1-7 composed of ultrafiltration hollow fiber type modules and reverse osmosis spiral wound type modules. The separation characteristics of ultrafiltration and reverse osmosis membranes were discussed with the variation of applied pressure and temperature. Turbidity and SS were removed effectively from ultrafiltration mem¬brane, and removal efficiency of COD, T-N, and TDS using reverse osmosis membrane was very efficient. Permeate flux increased linearly with the increase of applied pressures and temperature. It was shown that ultrafiltration and reverse osmosis membranes were suitable Lo the advanced treatment and reuse of oil refinery process effluent.

• Ecology and Resilient Infrastructure
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• v.3 no.3
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• pp.182-188
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• 2016

This study evaluated structural alternatives for managing water quality problems by reinterpreting and then applying the robustness-cost index (RCI) for urban flood problems. Cases of endogenous hormone pollution in treated sewage and proliferation of protozoa in intake-water were chosen as representative examples because they have different types of regulation standards for the treatment. Current facilities and structural alternatives with robustness indices (RIs) greater than unity were determined to be robust. The RI was combined with the cost index (CI) to obtain the RCI values. For the endogenous hormone pollution in treated sewage, a human-oriented estrogen $17{\beta}$-estradiol was selected as a target pollutant. The RI and RCI values for a structural alternative, extension of the current sewage treatment facility for advanced treatment, were greater than the values for the current practice of conventional activated sludge process. For the intake-water pollution by protozoa, UV and ozone disinfection facilities were evaluated for inactivation of Cryptosporidium parvum. The RCI values for ozone disinfection were greater than those for UV disinfection. Based on the results and the logics involved in the calculation of RCI for water quality issues we studied, we proposed procedures for establishing and implementing structural alternatives for the restoration from and prevention of outbreaks of water quality problems.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.168-168
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• 2016

BDD(Boron Doped Diamond) 전극은 전위창이 넓고, 다른 불용성 전극에 비해 산소발생과전압이 높아 물을 전기화학적인 방법으로 처리하는 영역에 있어 매우 효과적일 뿐만 아니라, 전통적인 불용성 전극에 비해 전극 표면에서 수산화 라디칼(-OH)과 오존(O3)의 발생량이 월등히 높아 수처리용 전극으로서의 유용성이 매우 높다. 따라서 BDD 전극을 수처리용 전극에 사용하는 경우 수산화 라디칼(-OH)과 오존(O3), 과산화수소(H2O2) 등과 같은 산화제의 생성은 물론이고, 염소(Cl2)가 포함되어 있는 전해액에서는 차아염소산(HOCl)이나 차아염소산이온(OCl-)과 같은 강력한 산화제가 발생되어 전기화학적 폐수처리, 전기화학적 정수처리, 선박평형수 처리 등의 분야에 널리 활용될 수 있다. 본 연구에서는 상온 및 상압에서 운전이 가능하고 난분해성 오염물질 제거 효과가 뛰어난 전기화학적 고도산화공정(Electrochemical Advanced Oxidation Process, EAOP)에 적합한 대면적의 BDD 전극을 개발하고 자 하였다. 이러한 BDD 전극의 성막 방법으로는 필라멘트 가열 CVD, 마이크로파 플라즈마 CVD, DC 플라즈마 CVD 등이 널리 알려져 있는데 최근에는 설비의 투자비가 비교적 저렴하고, 대면적의 기판처리가 용의한 필라멘트 가열 화학기상증착법(Hot Filament Chemical Vapor Deposition, HFCVD)이 상업적으로 각광을 받고 있다. 따라서 본 연구에서는 HFCVD 방법을 이용하여 반응 가스의 투입비율, BDD 박막의 두께, 기판의 재질 등에 따른 여러 가지 성막 조건들을 검토하여 $100{\times}100mm$ 이상의 대면적 BDD 전극을 개발하였다. Fig. 1은 본 연구를 통하여 얻어진 BDD 전극의 표면 및 단면 SEM이다.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.10-17
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• 2013

Heavy oil residue upgrading process was being used in conventional refinery process. Recently, as the importance of non conventional energy development is growing up, the commercial projects of heavy oil upgrading are getting more active than before. For having competitive business model in the resource competition, non conventional energy development should be considered as an important business strategy. In developing oil sands, extra heavy oil, and shale gas, canadian oil sands and extra heavy oil have great importance in substitution of conventional oil consumption. In oil sands development, the bitumen, which is extracted from oil sands, has great value after upgrading or refining process. Similar process is being used current conventional refinery process. The bitumen is highly viscous hydrocarbon. This bitumen includes impurities which can not be treated in conventional refinery process. As this reason, specified process is needed in bitumen or extra heavy oil upgrading process. Moreover, there will be additional specified facilities in the process of production, transportation and marketing. In oil sands, there are various kinds of commercial upgrading process. Extraction, dilution, coking and cracking method were being used commercially.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.645-654
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• 1994

Photocatalytic oxidation conditions of reactant recirculation flow rate 275 mL/min, aeration rate 2 LPM and $UV+TiO_2+H_2O_2$(500 mg/L) proved to be appropriate for water including organic materials treatment. With increasing turbidity and suspended solids concentration, at turbidity 10 NTU-suspended solids concentration 29 mg/L the phenol degradation efficiency increased, which in turn decreased at turbidity 50 NTU-suspended solids concentration 170 mg/L, however no significant differences were observed, demonstrating similar results with those obtained at zero turbidity and suspended solids concentration. The degradation efficiency of phenol decreased with increasing influent phenol concentrations. The $UV+TiO_2+H_2O_2$ photocatalytic advanced oxidation process conducted is considered to be possibly applied to the drinking water treatment, and the post-treatment process of biological wastewater treatment.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.421-421
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• 2021

도시화, 산업화로 인해 하수처리장 유입하수 내 질소 농도가 증가하면서 그에 따른 부영양화 발생, 수생태계에 독성을 미치는 등의 악영향 또한 증가하게 되었다. 하수 내 고농도 질소를 처리하기 위해 1990년 초 연구가 시작되어 현재 보편적으로 사용되고 있는 생물학적 질소 제거 공정은 산소공급과 외부탄소원 보충 과정에서 상당한 비용이 소요된다. 이와 같은 문제점이 대두됨에 따라 고도의 질소 제거 공정이 요구되면서, 경제적으로 개선이 이루어져 기존의 질산화·탈질 공정보다 효율적인 혐기성 암모늄 산화 공정(ANaerobic AMMonium OXidation, ANAMMOX)이 제안되었다. ANAMMOX 공정은 혐기성 조건 아래 전자공여체와 전자수용체로써 암모니아성 질소와 아질산성 질소를 이용해 질소가스 형태로 질소를 제거하는 공정이다. 질산화·탈질 공정과 비교했을 때, 폭기과정에서의 산소요구량 감소, 외부탄소원 불필요, 질소 제거 과정 단축 등의 장점을 가진다. 본 연구는 수처리공정에서의 ANAMMOX 공정의 적용 가능성을 확인하고, 암모니아성 질소대비 아질산성 질소 비율에 따른 Mainstream ANAMMOX 공정의 효율 비교를 통해 공정의 안정성과 높은 제거효율을 확보할 수 있는 NH₄⁺ 대비 NO₂^- 비율을 도출하는데 목적이 있다. 실험실 규모의 Mainstream ANAMMOX 반응조에 적용한 비율은 선행연구를 비롯한 화학양론식에서 제시된 비율을 바탕으로 산정하였다. 1.00부터 1.30의 전체적인 비율을 Initial과 Advanced 2개의 구간으로 나누어 운전한 결과, 각 구간의 NH₄⁺ 제거효율은 각각 58~86%, 94~99%였다. NH₄⁺ 대비 NO₂^- 비율이 증가함에 따라 공정의 안정성이 확보되고, NH₄⁺ 및 총질소(TN) 제거효율이 증가하는 경향이 나타났다. 본 연구의 결과는 수처리공정에서의 안정적인 ANAMMOX 공정 적용을 유도하고, ANAMMOX 공정의 성능개선을 도모하는 연구의 기초로 활용될 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.02a
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• pp.113-197
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• 2004

우리나라에서는 수질개선을 위하여 하수처리분야에 1993년부터 1997년까지 총 7조 7,705억원을 투자하였으며, 방류수 수질기준 강화 측면에서는 1996년 1월 1일부터 총인(T-P)과 총질소(T-N)의 방류수 수질기준을 수질환경보전법에 명시하여 규제하기 시작하여, 2008년 1월 1일부터 BOD 및 SS 10mg/L, T-N 20mg/L, T-P 2mg/L로 전국적으로 강화할 계획이다. 그러나, 수질개선을 위한 투자액 중 서울 등 대도시의 하수처리시설이나 하수관거 투자액이 절대적으로 많은 부분을 차지하고 있으므로, 상수원수의 뚜렷한 개선효과는 미미한 실정이다. (중략)

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.240-246
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• 2005

Humic substances HS) from process waters at advanced water treatment plant consisted of GAC and Ozone/GAC processes were isolated and extracted by physicochemical fractionation methods to investigate their characteristics. They are characterized for their functionality, chemical composition, spectroscopic characteristics using FT-IR and $^1H$-NMR spectroscopy. Humic fraction gradually decreased from 36.3% to 24.2% from 0.45 to 0.30 mgC/L) through ozonation and carbon adsorption. The humic fraction was isolated into the phenolic and carboxylic groups using A-21 resin, and the concentration of phenolic groups gradually decreased from 38.4% to 23.5% (from 4.9 to $3.2\;{\mu}M/L$ as phenolic-OH) through ozonation and carbon adsorption. In the case of carboxylic groups, the concentration decreased from 61.6% to 43.3% (from 7.8 to $5.8\;{\mu}M/L$ as COOH) through the water treatment processes. On the other hand, concentrations of those roups decreased from 38.4% to 24.0% and 61.6% to 44.9% through carbon adsorption without ozonation, respectively. The structural changes of HS identified from FT-IR and $^1H$-NMR were consistent with the results from the isolation of functional groups in HS.

• Environmental engineer
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• v.21 s.210
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• pp.68-71
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• 2004

[ $\circ$ ] 본 기술은 기존의 A2O공법과 Sludge Blanket Filtration(SBF)을 단위공법으로 조합한 공정으로서 각 생물반응조의 미생물 농도를 6,000mg/ 이상의 고농도로 운전하여 생물학적 유기물,질소 및 인 제거효율을 극대화하고자 하는 기술 $\circ$ 또한 활성슬러지 반응조로부터 유입된 슬러지를 SBF에서 미세기포를 이용하여 부상시킴으로써 수면에 농축 슬러지층을 형성시키고 이 부