• 상하수도학회지
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• 제24권1호
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• pp.73-83
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• 2010

This study was performed to increase the removal efficiency of the biofilter packed with granular sulfur in municipal wastewater reclamation facility. Constituent units were influent water tank, denitrification tank, BOD reduction tank and outlet. And, the major operation factor is a biofilter packed with submerged granular sulfur. Actual wastewater and synthetic wastewater were used as influent wastewater. Experimental condition was divided into two phases according to the amount of a phosphorus coagulant. Total phosphorus removal efficiency was insignificant at mode I that phosphorus coagulant was not injected. The average influent and effluent total phosphorus concentrations at mode II were 0.5 ~ 1.0 mg/L and 0.27 mg/L, respectively. As for COD and BOD effluent concentrations, COD was 3.0 mg/L and BOD was 1.0 mg/L. Additionally, nitrogen removal rates were high at low influent DO concentration. In conclusion, a new process, biofilter packed with granular sulfur is expected to treat high-rate nitrogen wastewater and expected to be utilized as an alternative of technological innovation for the nitrogen treatment.

• 대한환경공학회지
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• 제32권12호
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• pp.1087-1093
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• 2010

독립영양탈질은 추가적인 질소 제거를 위해 메탄올과 같은 고가의 외부탄소원을 필요로 하지 않는다는 면에서 효과적이고 경제적인 방법이다. 본 연구에서는 고농도 질소 농도를 함유한 하수에 대한 황탈질 평가를 통해 설계 및 운영인자의 도출에 필요한 기초자료를 확보하고자 하였다. 입상황으로 충진된 황탈질조는 유동형 스폰지 담체를 이용하여 영양염류를 제거하는 고도처리 공정 후단에 파일럿 규모로 설치되었다($Q=18\;m^3/day$). 외부 알칼리 주입 없이 황탈질조 유입수 내 알칼리(평균 $169.4{\pm}20.8\;mg$ $CaCO_3/L$)만을 활용하였고, 2.45시간의 체류시간으로 운영된 황탈질조 내 추가적인 질산성 질소의 제거를 통해 최종 처리수의 총질소가 7.0 mg T-N/L 이하로 도출되었다. 파일럿 설비 평가를 통해 동절기 저수온($15^{\circ}C$ 이하)에서도 60~80%의 안정적인 황탈질 제거효율을 나타내었으며, 2.78 ppm 이내의 Alum 주입 시 황탈질 성능에 거의 영향을 주지 않는 것으로 나타났다. 황탈질조에서 제거된 질산성 질소 대비 소모된 알칼리도는 $4.09{\pm}1.29\;g$ $CaCO_3/g$ ${NO_3}^-$-N로 도출되었고(이론값 4.57 g $CaCO_3/g$ ${NO_3}^-$-N), 황탈질조 유입수 내 질산성 질소의 전환에 필요한 알칼리도 이상을 포함하였다. 입상황의 소모량은 943.8 g S/day로서, 구형입상황의 마모 및 역세 시의 유실 등에 의해 이론적 소모량인 400.1 g S/day 대비 2.4배 정도 높게 나타났다.

• 상하수도학회지
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• 제19권6호
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• pp.720-727
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• 2005

This study was performed to advance nitrogen removal efficiency by employing an single biofilter packed with granular sulfur, which consists of nitrification occurring at upper part and denitrification at lower part of the reactor. Continuos nitrification/denitrification was carried out with different alkalinity sources, which were $NaHCO_3$ and $CaCO_3$(limestone). In the downflow nitrification/denitrification biofilter packed with granular sulfur, first, terms for nitrogen removal was decided. As results, nitrification and denitrification rate with NaHCO3 at 0.85 kg $NH_4^+-N/m^3{\cdot}d$ were accomplished $0.80kg\;N/m_3{\cdot}d$, $0.43kg\;N/m^3{\cdot}d$, respectively. In the sulfur/limestone packed downflow nitrification/denitrification biofilter, sulfur and limestone were mixed packed, preliminary test showed sulfur/limestone mixing ratio was 3:1 and that was ideal. In the result, nitrification and denitrification rate at $0.7kg\;NH_4^+-N/m^3{\cdot}d$ were accomplished$0.65kg\;N/m^3{\cdot}d$, $0.34kg\;N/m^3{\cdot}d$, respectively. In general, employing granular sulfur can be implemented for only denitrification, but this system can accomplish nitrification as well as denitrification in a single reactor even though low carbon concentration was present in influent limiting to nutrient removal process. This biofilter system of limestone and granular sulfur packed together can successfully apply for nutrient removal effectively.

• 상하수도학회지
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• 제25권3호
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• pp.383-390
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• 2011

In this study, a process combined biofiltration with sulfur-utilizing autotrophic denitrification and membrane separation was proposed to examine the efficiency of nitrogen removal. As an experimental device, hollow-fiber module was installed in the center of reactor to generate the flux forward sulfur layer in the cylinder packed with granular sulfur. In addition, a simple module was installed in activated sludge aeration tank which inside and outside of sulfur-using denitrification module was covered with microfilter and the module was considered as an alternative of clarifier. The experiment for developing new MBR process was carried out for three years totally. As the results of first two-year experiment, successful nitrogen removal performance was revealed with lab-scale test and pliot scale plant using artificial wastewater and actual plating wastewater. In this year, pilot scale test using actual domestic wastewater was performed to prove field applicability. As the results, high-rate nitrogen removal performance was confirmed with about 0.19 kg ${NO_3}^--N/m^3$ day of rate. Also significant fouling and pressure increase were not found during the experiment. And, the production ratio of sulfate and the consumption ratio of alkalinity showed a slightly higher value about 311 mg ${SO_4}^{2-}/L$ and 369 mg $CaCO_3$/L, respectively. In conclusion, the developed MBR process can be utilized as an alternative for retrofiting existing wastewater plants as well as new construction of advanced sewage wastewater treatment plants, with cost-effective merit.

• 상하수도학회지
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• 제19권2호
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• pp.200-208
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• 2005

In this study, a new submerged membrane bioreactor process packed with granular sulfur (MBR-GS) was operated to identify the biological nitrogen removal behaviors with plating wastewater containing high-strength $NO_3{^-}$ concentration. The continuous denitrification was carried out at $20^{\circ}C$ with various nitrogen loading rates using synthetic wastewater, which composed of $NO_3{^-}$ and $HCO_3{^-}$, but also actual plating wastewater, which was collected from the effluent of the H metal plating company. As a result, high-rate denitrification in the range of $0.8kg\;NO_3{^-}-N/m^3\;day$ was accomplished at nitrogen loading rate of $0.9kg\;NO_3{^-}-N/m^3\;day$ using synthetic wastewater. Also, higher-rate denitrification with actual plating wastewater was achieved up to $0.91kg\;NO_3{^-}-N/m^3\;day$ at the loading rate of $1.11kg\;NO_3{^-}-N/m^3\;day$. Additionally, continuous filtration was possible during up to 30 days without chemical cleaning in the range of 20 cmHg of transmembrane pressure. On the basis of the proposed stoichiometry, ${SO_4}^{2-}$ production could be estimated efficiently, while observed alkalinity consumption was somewhat lower than theoretical value. Consequently, a new process, MBR-GS is capable of high-rate autotrophic denitrification by compulsive flux and expected to be utilized as an alternative of renovation techniques for nitrogen removal from not only plating wastewater but also municipal wastewater with low C/N ratio.

• 한국환경과학회지
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• 제7권6호
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• pp.773-782
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• 1998

The adsorption experiment of phenol(Ph) from aqueous solution on granular activated carbon was studied in order to design the fixed-bed adsorption column. The experimental data were analyzed by unsteady-state, one-dimensional heterogeneous model. Finite element method(FEM) was applied to analyze the sensitivity of parameter and to predict the fixed-bed adsorption column performance on operation variable changes. The prediction model showed similar effect to mass transfer and intraparticle diffusion coefficient changes suggesting that both parameter present mass transfer rate limits for GAC-phenol system. The Freundlich constants had a greater effect than kinetic parameters for the performance of fixed-bed adsorption column. FEM solution facilitated prediction of concentration history in solution and within adsorbent particle.

• 보존과학회지
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• 제9권1호
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• pp.21-32
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• 2000

구미시 황상동에 위치한 마애여래입상 (보물 제 1122 호)의 구성 암석은 흑운모-각섬석 화강섬록암으로서 약 30 여 개의 불연속적 동일 암체로 구성되어 있으나, 보관석은 역질 사암이다. 마애불 주변에 노출된 암괴의 대부분은 $N25{\sim}45^{\circ}W$의 주향과 거의 수직($70{\sim}85^{\circ}SE$)에 가까운 배면경사를 갖는 절리들이 발달되어 있다. 마애불 본체의 암괴들은 균열된 채 서로를 지지하고 있으나, 접합점에서는 심한 기계적 및 화학적 풍화를 받아 붕괴위험에 쳐해 있다. 또한 상부와 배면으로부터 발생하는 토압과 응력에 의하여 본체는 전면으로 두상은 좌측으로 기울어져 있다. 이 마애불을 이루는 암석의 풍화등급은 HW에 속하며, 조암 광물의 대부분은 화학적 및 광물학적 풍화에 의하여 점토 광물과 철수산화 광물로 교대되어 있다. 마애불의 표면에는 지의류와 선태류가 서식하고 있으며 모근과 포자류가 암석의 생물학적 풍화를 촉진시키고 있고, 절리대에는 이미 토양화가 진행되어 잡초가 서식하고 있다. 보존과학적 측면에서 볼 때, 이 마애불의 구조적 안정을 위해서는 불안정한 암괴의 제거가 필수적이며 불균형의 재발생과 마애불의 전면으로 작용하는 응력을 최소화하기 위하여 암석 지지공법에 의한 본체의 지보가 필요하다. 균열이 심한 절리면에는 암석용 충진제를 사용하여 수경화 처리가 선행되어야 할 것으로 보이며, 마애불에 미치는 지면의 습도를 저감하기 위한 차수벽 또는 차단막의 설치도 고려되어야 할 것이다. 또한 표면에 피복된 지의류와 토양화가 진행된 불연속면에 서식하는 잡초를 제거하기 위한 생화학적 처리가 필요하다.

• 한국물환경학회지
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• 제22권2호
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• pp.300-307
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• 2006

The combined SHARON (Single reactor system for High ammonium Removal Over Nitrite)-ANAMMOX (Anaerobic ammonium oxidation) reactor were operated in mesophilic condition ($35^{\circ}C$). In this study, microbial granulation and characteristics of SHARON and ANAMMOX sludges were investigated using settling test, Scanning Electron Microscopy (SEM) and Fluorescence In Situ Hybridization (FISH). In SHARON reactor, Aerobic granulation with diameter of 1.5~2.5 mm was accomplished but aerobic granulation was weaker than anaerobic granular sludge. Initial seed sludge of ANAMMOX reactor was used as attached media for biofilm growth. ANAMMOX sludge was more compact and rounder rather than seed sludge. Though ANAMMOX sludge has high activity, it has lower settling ability than the seed granule. The color of ANAMMOX sludge was changed from dark to redish brown granular with diameter of 1~2 mm. In FISH of ANAMMOX sludge, high fraction of Candidatus B. stuttgartiensis which paid great role of nitrogen conversion was detected. Also, FISH results reveals that ANAMMOX bacteria inhabit at inner parts near surface, having advantages in utilization of substrates and protection from oxygen inhibition.

• 자원환경지질
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• 제35권3호
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• pp.191-201
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• 2002

구봉 금-은광상은 선캠브리아기 경기육괴의 호상 또는 화강편마암내에 발달된 단열대(NE, NW)를 따라 충진한 함 금-은괴상석영맥광상이다. 이 광상의 광화작용은 여러번의 단열작용에 의해 형성된 동일시기의 석영맥으로 구성되어있다. 산출되는 광석광물은 주로 유비철석, 황철석, 섬아연석, 황동석, 방연석과 소량의 자류철석, 백철석, 에렉트럼 등이다. 에렉트럼의 공생광물에 따른 산출빈도와 산출량은 각각 유비철석(44.5%, 54.3%), 석영(24.3%, 33.8%), 황철석(12.6%, 0.1%), 방연석(11.0%, 4.8%), 섬아연석(5.0%, 7.0%), 황동석(2.5%, 0.02%)의 순이다. 에렉트럼의 산출형태는 불규칙형(41.6%), 반원형(34.7%), 신장형(17.0%) 및 입상형(6.6%)이다. 에렉트럼의 입자 크기는 2 um에서 150 um 까지 다앙하게 산출되나 30 um 이하가 전체의 90.9%를 차지한다. 에렉트럼의 화학조성은 26.39∼72.51 Au atomic% 이다. 공생광물에 따른 에렉트럼의 화학조성(Au atomic %)은 유비천석-황철석-섬아연석-석영(44.97∼71.75), 석영(44.37∼72.51), 섬아연석 -황동석 (35.40∼41.01), 황철석-황동석-석영-방연석 (26.39∼54.84), 방연석 (28.49∼53.28) 이다. 그러므로 이들 결과를 부유선광시 고려한다면 금의 회수율을 향상시키는데 도움이 될 것이다.

• 생물환경조절학회지
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• 제17권4호
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• pp.330-335
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• 2008

가지 주요 해충 약제방제 체계 확립을 위하여 아바멕틴 유제와 스피노사드 입상수화제 체계 처리에 의한 방제효과를 조사하였다. 해충 발생 초기에 시험약제 교호로 7일 간격 2회, 10일 간격 2회, 7일 간격 3회, 10일 간격 3회 처리하여 방제효과를 조사하였다. 모든 처리구에서 처리후 28일 까지 꽃노랑총채벌레 밀도는 엽당 $0.3{\sim}1.8$마리, 점박이응애는 엽당 0.0마리로 높은 밀도 억제 효과와 방제지속 효과가 인정되었다. 아메리카잎굴파리와 온실가루이는 약제 처리후 밀도억제 효과는 높았으나 약효 지속기간은 꽃노랑총채벌레와 점박이응애보다 짧은 경향이었다. 이상의 결과 가지에서 문제시되는 꽃노랑총채벌레, 점박이응애, 온실가루이, 아메리카잎굴파리를 동시에 방제하기 위해서는 발생초기부터 10일 간격으로 3회 처리하는 방법이 가장 효과적인 것으로 생각되었다.