• Journal of Wetlands Research
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• v.21 no.4
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• pp.321-333
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• 2019

A primary aspect of low impact development (LID) design that affects performance efficiency, maintenance frequency, and lifespan of the facility is the type of filter media as well as the arrangement or media profile. Several LID guidelines providing media specifications are currently available and numerous studies have been published presenting the effectiveness of these systems. While some results are similar and consistent, some of them still varies and only a few focuses on the effect of filter media type and arrangement on system performance. This creates a certain level of uncertainty when it comes to filter media selection and design. In this review, a synthesis of filter media specifications from several LID design guidelines are presented and relevant results from different laboratory and field studies are highlighted. The LID systems are first classified as infiltration or non-infiltration structures, and vegetated or non-vegetated structures. Typical profiles of the media according to classification are shown including the different layers, materials, and depth. In addition, results from previous studies regarding the effect of filter media characteristics on hydraulic and hydrologic functions as well as pollutant removal are compared. Other considerations such as organic media leaching, clogging, media washing, and handling during construction were also briefly discussed. This review aims to provide a general guideline that can contribute to proper media selection and design for structural LIDs. In addition, it also identifies opportunities for future research.

• Korean Journal of Microbiology
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• v.34 no.4
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• pp.200-206
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• 1998

The distributions and characteristics of bacteria on the deodorizing biofilters were studied as a part of biofiltration research for odor gas removal. The odor gas originated from a currently operating nightsoil treatment plant were mainly nitrogenous compounds of ammonia and amines. The filter media were consisted various ratio of pine bark, nightsoil cast and compost, and were sampled before and after operation of 153 days. Before operation, the level of bacteria on nitrification agar medium, nutrient agar medium and thiosulfate agar medium were around $10^7{\sim}10^8cfu/g$ media. After operation, the level decreased but still high as $10^5{\sim}10^7cfu/g$ media. The bacteria from reactors before and after operations were either rod or coccus after growth on nitrification agar media. The 45 isolated heterotrophic bacteria were further characterized and Pseudomonas, Bacillus, Flavobacterium, Alcaligenes were dominant genera. Genus Alcaligenes was particularly dominant when the isolates were incubated on nitrification agar media first and then transfered to nutrient media. The portion of Alcaligenes in the biofilter increased after operation, and was higher in the media contained nightsoil cast, which showed better treatment than the media with pine bark only.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.483-490
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• 2009

The aims of this study were to evaluate the removal efficiency for various pollutants in urban storm runoff by a filtration device, and to determine design parameters depending on filter media properties. Appropriate selection of filter media will affect the size and life time of the filtration device. Sets of column tests were performed in order to evaluate the removal efficiency by perlite and a synthetic resin. An investigation of surface properties including CEC (cation exchange capacity) and zeta-potential suggested that the perlite had a superior adsorption capability for cationic pollutants. TCODcr and turbidity were analyzed to investigate the removal characteristic of particulate pollutant. In both columns, the particles in the collected storm runoff was almost completely capture with a small EBCT (empty bed contact time) of 2.5 minutes. Complete clogging at the EBCT of 2.5 minutes occurred after 630 minutes in the perlite column and 810 minutes in the resin column. The removal efficiency of TCODcr and turbidity at the EBCT of 2.5 minutes decreased to below 70% due to an wall effect. The removal efficiency for dissolved pollutant (SCODcr) was negligible due to the insufficient contact time for adsorption. The removal of heavy metals (Cu, Zn, Pb) was mostly ascribed to the filtration of particles containing metals, since the relationship between CEC and the removal efficiency was not apparent. The result of this study would be valuable for the application of filtration device to control of urban storm runoff.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.56-56
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• 2012

본 연구는 가정용 및 산업용 유해가스제거용 필터여재의 제조에 관한 것으로 핫멜트(hot-melt) 분사 시스템에 의한 다층구조의 부직포와 활성탄 등의 흡착물질로 구성되는 샌드위치 복합시트 및 필터여 재의 제조에 사용되는 구성재료의 최적화에 관한 연구이다. 스프레이 본딩 시스템에 의한 공정은 종래의 유해가스제거용 필터 미디어의 제조하는 방법인 활성탄과 바인더 역할을 하는 핫멜트 수지를 혼합하여 부직포 원단에 도포하여 활성탄을 부착시키는 공정에 비해 도포되는 핫멜트 수지의 양이 감소에 의한 생산비절감과 충분한 활성탄 도포에 의한 기능성 향상 등에 의해 유해가스 포집율을 높일 수 있으며 공정 이후 스프레이에 의해 도포된 핫멜트수지의 자연건조 방식에 의한, 열원이 불필요하며, 에너지가 절감되며, 속도 향상에 의한 생산성 향상, 분진발생 최소화로 인한 제조현장의 환경개선이 가능할 것으로 사료된다. 1차적으로 본 연구의 필터제조의 최적화를 위해서 스프레이 본딩시스템에 효율적으로 사용가능한 다양한 수지를 검토하였으며, 기존 외산 캐빈필터여재의 미세구조 및 성능특성, 다양한 활성탄의 흡착성능검토, 사용 가능한 여재의 특성분석을 통해 다층구조의 필터 여재에 사용 가능한 구성재료의 최적화에 중심을 두었다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.375-379
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• 2007

폐비닐 여재(Synthetic Waste Polyethylene Media)를 적용한 부착성장식 공정의 유기물 및 질소${\cdot}$인 제거특성에 관한 Pilot Plant 실험 결과 다음과 같은 결론을 얻을 수 있었다. 1) 제거효율은 $RUNI1{\sim}3$에서 $COD_{cr}$ 91.4, 92.4, 93.9%, T-N 56.9, 61.4, 65.1%, T-P는 모든 단계에서 약 45%이상 제거되어 부하변동시에 강한 대처능력을 나타내었다. 2) BOD용적부하 $0.18{\sim}0.40kg/m^3{\cdot}d$, COD용적부하 $0.28{\sim}0.53kg/m^3{\cdot}d$, ${NH_4}^{+}-N$용적부하 $0.12kg/m^3{\cdot}d$을 나타내었다. 3) 도시하수 처리를 위한 생물학적 질소 및 인 제거공법을 본 여재를 이용하여 공정설계시 고려할 사항들과 적절한 대처방법을 다음과 같이 제시할 수 있다. - 1차 침전지에서 유기질소 및 유기인 농도가 높다면 유기질소 및 인 부하량을 감소시키기 위하여 1차 침전지를 설치하되 질소 및 인제거에 유리한 $BOD_5/T-N$, $BOD_5/T-P$를 유지할 수 있도록 체류시간을 1시간미만으로 설계하는 것이 경제적이라고 판단된다. 만일 유기질소와 유기인의 함량이 낮다면 1차 침전지는 제외하는 것이 유리할 것이다. - 여재의 배치는 폭기조에서 용존산소의 균일분포와 슬러지의 적정탈리를 위해 여재를 상하로 배치하거나 또는 여재끼리 일정 간격을 두어 배치하는 것이 바람직하다. 농촌에서의 처분이 문제시 되고 있는 폐비닐을 적용한 본 연구에서의 수처리특성은 기존 하수처리공정에서의 제거효율에 상응하는 처리특성을 나타내었다. 또한 폐비닐 처분의 문제를 해결할 수 있을뿐만 아니라 하수처리시에도 부하변동 등에 강한 대처능력을 나타내어 기존의 하수처리공정에 대체가능성을 나타내었다.

• Journal of the Korean Geotechnical Society
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• v.32 no.2
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• pp.31-41
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• 2016

For sand and zeolite filter media in stormwater BMPs, media breakage effects on infiltration were investigated. Compaction effort and infiltration force were mainly examined for breakage sources. The 1-D column infiltration tests for un-compacted and compacted media filters were conducted to investigate the breakage effect on infiltration. As a result, the following findings were deduced: 1) particle breakage due to filtration forces was found to be relatively minimal; 2) un-compacted media had lesser amount of crushed particles and permeability fluctuations compared to compacted media; 3) even without the presence of suspended solids in the influent, reduction in permeability was found, which resulted from rearrangement and re-entrainment of media particle itself; 4) only media particle breakage resistance is considered, sand was revealed to have better performance compared to zeolite media.

• Journal of Wetlands Research
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• v.20 no.3
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• pp.235-242
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• 2018

The function of vertical subsurface flow wetlands can potentially be reduced with time due to clogging and are often assumed to be occurring when ponding and overflow is observed during rainfall. To investigate their clogging potential, three pilot-scale vertical subsurface flow (VSF) wetland systems were constructed employing woodchip, pumice, and volcanic gravel as main media. The systems received stormwater runoff from a highway bridge for seven months, after which the media were taken out and divided into layers to determine the amount and characteristics of the accumulated clogging matters. Findings revealed that the main clogging mechanism was the deposition of suspended solids. This is followed by the growth of biofilm in the media which is more evident in the wetland employing woodchip. Up to more than 30% of the clogging matter were found in the upper 20 cm of the media suggesting that this layer will need replacement once clogging occurs. Moreover, no signs of clogging were observed in all the wetlands during the operation period even though an estimation of at least 2 months without clogging was calculated. This was attributed to the intermittent loading mode of operation that gave way for the decomposition of organic matters during the resting period and potentially restored the pore volume.

• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.36-45
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• 2016

Sand filters are widely used in infiltration systems to manage polluted urban runoff. Clogging, which is mainly caused by the deposition of sediments on the filter media, reduces the filter system's infiltration capacity, which further limits its lifespan and function. The physical, chemical and biological clogging characteristics of sand filter, therefore, need to be known for effective design and maintenance. Physical clogging behavior and variations in the characteristics of sand filters according to different media depths are examined in this paper. The variations were observed from laboratory column infiltration tests conducted in a vertical flow and fluctuating head condition. It can be seen that an increase in filter media depth results in a high sediment removal performance; however, it leads to a shorter lifespan due to clogging. In the choice of filter media depth to be used in field applications, therefore, the purpose of facilities as well as maintenance costs need to be considered. At all filter media depth configurations, premature clogging occurred because sediments of 100~250 μm clogged the top 15% of filter media depth. Thus, scrapping the top 15% of filter media may be suggested as the first operational maintenance process for the infiltration system.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.10
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• pp.684-693
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• 2012

The stormwater runoff from the increasing paved roads and vehicles resulted in the increase in the pollutants load to adjacent water bodies. The granular media filtration facilities are the most widely adopted to minimize the non-point source pollution from motorways. It is essential to consider the severe variation of hydraulic condition, suspended solid (SS) characteristics, and the medium characteristics for stormwater management filter. In this study, different types of media, including sand, were tested and the performance of downflow sand filters was investigated under various linear velocity and influent solid particle size. Results showed that the best medium is the coarse sand with large grain size, which showed the specific SS removal before clogging of more than $8.498kg/m^2$, the SS removal of higher than 95%, and minimum head loss. Linear velocity did not affect the total solid removal, while the performance was improved when fine solid was introduced. It is suggested that the life of a downflow sand filter bed can be extended by deep bed filtration when influent particles are fine. However, the captured particles can be washed out after a long period of operation.

• Clean Technology
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• v.6 no.2
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• pp.85-92
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• 2000

For increase of recycling rate of steel-making slag, the swine wastewater treatment using steel-making slag as filter media were investigated. As the discharged wastewater from the existing facilities retreated through the laboratory wastewater treatment equipment filled with steel-making slag as filter, pH of retreated wastewater was increased, and the concentration of N, P, COD and BOD were decreased. For the pilot experiment, steel-making slag eliminated suspended substances and absorbed a shock of sudden change of their concentration in influent. COD and BOD were decreased under the influence of them in influent. As calcination increased the amount of free-CaO in steel-making slag, the calcined eliminated phosphorus more effectively and increase pH than the uncalcined.