• 지질공학
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• 제30권3호
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• pp.279-288
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• 2020

샌드댐이란 하천의 횡단에 보 등을 설치하고 확보된 공간에 모래와 같은 투수성 재료와 물을 함께 채운 후, 공극내의 물을 저장하여 사용하기 위한 구조물이다. 주로 아프리카 케냐를 중심으로 많은 사례가 보고되고 있는 샌드댐에 관해 본 연구에서는 샌드댐의 구조적 안전과 취수량 증대를 위한 설계 방안을 제시하였다. 첫째, 샌드댐의 콘크리트 벽체의 안정성을 확보하기 위해 철근을 가시철근으로 연결, 시공의 편리함을 제시했다. 둘째, 지오텍스타일을 이용하여 증발을 45%에서 8%로 감소시킬 수 있었고 수평방향 투수배출량도 크게 줄일 수 있어 취수량은 기존대비 약 2.4배 증가되는 것을 알 수 있었다. 이 밖에도 수질개선을 위한 침사지 설계로 여과효율을 높였고, 토양수분장력계를 통한 모니터링 방법도 제시하였다.

• 한국환경보건학회지
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• 제28권4호
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• pp.23-26
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• 2002

This study was conducted to investigate water quality after construction of straightened concrete block at Tongbok stream and difference of water quality between natural stream and municipal stream artificially straightened. In Tongbok upstream which was natural block having a variety of sand, there was ability to purify pollutants by microorganism and filtration. There was ability to purify pollutants in natural section of the natural midstream which have a diversity and a plenty of sands. In Tongbok upstream BOD concentration was lower than that of reservoir, but in midstream which was straightened concrete block without sand, BOD and NH$_3$-N concentration was higher than that of upstream and deteriorated water quality.

• Coupled systems mechanics
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• 제4권2호
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• pp.157-172
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• 2015

Control of potable water treatment plant (PWTP) is nowadays based on experience. The aim of this article is to show that model based control of treatment process is more efficient than process operation based on experience. Stimela environment is used for modeling of processes of potable water treatment. Application of the model was conducted on PWTP "Crkvice" in Zenica (BiH). This plant has used conventional rapid sand filters. By effective application of the model it is determined the optimal filter run time for different input turbidity of raw water. This results in the possibility of reducing the consumption of backwashing water, lower costs for its pumping and reducing the amount of coagulants. In the existing practice, based on experience, these benefits are not used.

• 대한환경공학회지
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• 제31권11호
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• pp.957-964
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• 2009

홍수터여과에서 원수공급체계의 설계인자를 얻기 위해 모래통 실험과 현장 출수대 실험을 수행하였다. 모래통 실험결과 침투율은 대략 토양의 투수계수에 비례하였으며, 짧은 시간의 휴지는 침투율에 거의 영향을 주지 않았다. 범람과 휴지를 고려한 일평균 침투율은 범람이 길어질수록 증가하여 일정한 값에 수렴하는 경향을 나타냈다. 실험범위에서는 대구와 물금의 토양에서 휴지/범람이 15분/30분일 때 최대 침투율로 각각 6.3 m/day와 1.4 m/day을 얻었으며, 이 값들은 포화투수계수 값의 42%와 70%씩이었다. 토양여과로 인해 투수계수는 완만히 감소하였으며 물금토양에서 8일 동안 27%가 감소하였다. 출수대 실험결과 상주와 구미의 토양에서는 유출유량이 증가함에 따라 범람반경이 증가하며 토양의 포화 투수계수가 클수록 그 증가율은 감소하는 형태를 보였다. 토양면을 완전히 적시는데 필요한 시간 즉, 유출 시작으로부터 범람반경에 도달하는데 필요한 시간은 3~4분에 불과한 것을 알 수 있었다. 또한, 1시간 이내의 휴지시간을 적용하는 경우 전체 범람시간 동안의 평균 침투율에는 거의 변화가 없었다.

• 한국지반공학회논문집
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• 제38권6호
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• pp.41-47
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• 2022

투수성 포장은 강우를 노반으로 침투시켜 지표면 유출량 감소와 수질 개선을 기대하기 위한 기술이다. 수질 개선효과의 증대를 위해 투수성 포장 내에는 필터층을 추가하기도 한다. 본 연구에서는 투수성 포장의 구성 요소인 여재 필터의 성능을 알아보기 위해 석탄 저회-규사 여재에 대한 투수성능과 입자상 물질 제거 효율을 분석하였으며, 석탄저회와 규사를 기본 재료로 하는 5개의 여재를 대상으로 하였고, 입자상 물질로는 60㎛ 이하의 입자를 사용하였다. 순수 규사 시료 혹은 순수 석탄저회 시료는 평균적으로 약 70%의 입자상 물질 제거효율을 보였으나, 혼합 시료의 경우 제거 효율이 약 90%로서, 비점오염 저감시설에 대한 저감율 권고치인 80%를 상회하는 것으로 나타났다. 향후 현장 검증을 통한 투수성 포장 내 여재 필터 성능에 대한 검증 후 도로 시설 혹은 독립적인 여과 장치로 사용할 수 있을 것으로 판단한다.

• 대한환경공학회지
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• 제22권5호
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• pp.919-926
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• 2000

정수장 여과지 모형실험장치를 이용하여 수중입자입도분석에 의한 모래 및 이중여재 여과지에 대한 여과특성 및 효율 평가를 탁도분석과 비교하여 실시하였다. 수중입자입도분석은 여과지의 효율 평가를 위한 훌륭한 평가방법으로 탁도분석에 비해 민감도가 뛰어나 여과유출수의 탁질누출 현상을 뚜렷이 관찰할 수 있었다. 모래여과지의 경우는 여과지속시간 내내 비교적 양호한 수질을 보여, 허용수두하에서는 초기탁질누출보다는 여과말기의 수위상승에 대한 주위가 필요하다. 반면에 이중여재 여과지의 경우는 내부여과에 의한 탁질의 침투가 이루어지므로 최적운영을 위해서는 적절한 여재구성과 각 여과지별로 연속적인 수질모니터링에 의한 탁질누출제어가 요구된다. 또한 보다 안정적이고 효율적인 수질의 확보를 위해서는 여과보조제의 사용도 고려되어야 할 것이다.

• 한국물환경학회지
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• 제23권5호
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• pp.642-649
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• 2007

The effectiveness of add-on tertiary treatment processes for the polishing of the effluent of a biological nutrient removal (BNR) system from a modified $A^2/O$ process has been examined under the field condition with pilot-scale plants. The add-on treatment processes of 1) combined biofilm anoxic reactor and sand filtration, and 2) two-stage denitrification filter had been operated with various operating conditions. The experimental results indicated that two-stage denitrification filter could produced a better polished tertiary effluent. Filtration rate of $150m^3/m^2{\cdot}d$ for the 2-stage denitrifying filter could decrease the nitrate removal probably due to shorter detention time that caused insufficient reaction for denitrification. Two stage denitrification filter operated with M/N ratio of 3.0 and filtration rate of $100m^3/m^2{\cdot}d$ produced the tertiary effluent with nitrate and SS concentraitons of 2.8 mg/L and 2.3 mg/L, respectively. When the operating temperature reduced $30^{\circ}C$ to $18^{\circ}C$, $NO_3{^-}-N$ removal efficiency decreased from 73% to 68%.

• 한국물환경학회지
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• 제21권6호
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• pp.669-675
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• 2005

Biological nitrate removal from groundwater was investigated in the biofilters packed with both gravel/sand and plastic media. Removal of particles and turbidity were also investigated in the 2-stage biofilter system consisted of biofilter and subsequent sand filter. In the single biofilter packed with gravel and sand, nitrate removal efficiency was dropped with the increase of filtration velocity and furthermore, nitrite concentration increased up to 3.2 mg-N/L at 60 m/day. Denitrification rate at the bottom layer below 25 cm was faster 8 times than upper layer in the up-flow biofilter. Nitrite build-up, due to the deficiency of organic electron donors, occurred at the upper layer of bed. Besides DO concentration and organic carbon, contact time in media was the main factor for nitrate removal in a biofilter. The most of the effluent particles from biofilter was in the range from 0.5 to $2.0{\mu}m$, which resulted in high turbidity of 1.8 NTU. However, sand filter followed by biofilter efficiently performed the removal of particles and turbidity, which could reduce the turbidity of final filtrate below 0.5 NTU. Influent nitrate was removed completely in the 2-stage biofilter and no nitrite was detected.

• 상하수도학회지
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• 제29권3호
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• pp.337-345
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• 2015

Two step rapid filter system as a pre-treatment for the injected water into aquifer storage and recovery (ASR) in Korea was developed to reduce physical blockage and secure the volume of the injected water. First, single rapid sand filters with three different media sizes (0.4~0.7, 0.7~1.0 and 1.0~1.4 mm) were tested. Only two sizes (0.4~0.7 and 0.7~1.0 mm) satisfied target turbidity, below 1.0 NTU. However, they showed the fast head loss. To prevent the fast head loss and secure the volume of the injected water, a rapid anthracite filter with roughing media size (2.0~3.4 mm) were installed before a single rapid sand filter. As results, both the target turbidity and reduction of head loss were achieved. It was determined that the media size for a rapid sand filter in two step rapid filter system (i.e. a rapid anthracite filter before a rapid sand filter) was 0.7~1.0 mm. In addition, the effects of coagulant doses on the removal of natural organic matter (NOM), which might cause a biological clogging, were preliminarily evaluated, and the values of $UV_{254}$, dissolved organic carbon (DOC) and SUVA were interpreted.

• Environmental Engineering Research
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• 제22권2호
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• pp.203-209
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• 2017

Innovations in the biofiltration process can provide effective solutions to overcome crucial water pollution problems. The elimination of pollutants is a result of the combined effects of biological oxidation, adsorption and filtration processes. This research aims to evaluate the performance of quartz sand biofiltration for removing total suspended solids, turbidity, color, organic matter, and ammonium from polluted river water and develop an empirical model for designing quartz sand biofilters for the treatment of polluted river water. Experiments were conducted using two biofilter units filled with quartz sand as filter media. A set of experiments were performed to evaluate the effect of hydraulic retention time on biofilter performance in removing water contaminants. The kinetics of organic matter removal were also determined to describe the performance of the biofilter. The results show that biofiltration can significantly remove river water pollutants. Removal efficiency depends on the applied hydraulic retention time. At a hydraulic retention time of two hours, removal efficiencies of total organics, ammonium and total suspended solids were up to 78%, 82%, and 91%, respectively. A model for designing quartz sand biofiltration has been developed from the experimental data.