• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.379-392
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• 2010

In these days, constructed wetlands are applied in Korea for various purposes ; post-treatment of effluent in wastewater treatment, management of stormwater and restoration of aquatic ecosystems. However, the removal mechanisms for water pollutant in constructed wetlands are not clearly understood because they are affected by climate, influent characteristics and local constraints. Therefore, this paper is focused on the process that the pollutant, especially nitrogen and phosphorus, of the wetland is removed by. In this study, the main nitrogen removal is performed by nitrification/denitrification mechanism in the rhizosphere of constructed wetlands. And the majority of the phosphorus is removed by adsorption on the substrate of wetland. However the fate of phosphorus in wetlands can be diverse depending on the Oxidation Reduction Potential(ORP), adsorption/desorption, precipitation/dissolution, microbial effect, etc.

• Journal of Wetlands Research
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• v.7 no.4
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• pp.43-50
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• 2005

Wetlands can transform or remove pollutants from water body, such as nitrogen, phosphate, and organics. Many researches were conducted in relation to uptake process by aquatic plants in wetlands. However, water purification processes in wetlands are the results of physical, chemical and biological, especially microbiological reactions. As such, understanding on microbial processes is of great importance. In this study, we used pondor marsh-type wetland microcosms for investigating the water purification capacity and microbial functions, namely, extracellular enzyme activities, nitrification and denitrification. In a pond system, removal efficiencies of $NO_3{^-}$ and $PO{_4}^{3-}$ were 96% and 100 % respectively, while those in a marsh system were 94%, 100% respectively. These high removal efficiencies appeared to be caused by high adsorption ability to soils and microbial functions in wetland.

• Journal of Wetlands Research
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• v.6 no.2
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• pp.57-63
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• 2004

More than 1000 natural and constructed wetlands have been used to improve water quality. The general results showed that the highest removal efficiency was 84% for BOD and the lowest one was 48% for total nitrogen concentration. In addition, total phosphous removal efficiency was 67%, and the removal efficiencies are related to inflow loading. Researches donducted in Korea have focused on input-output mass balance and uptake by aquatic plant. As such little information if available about complex processes regulating water quality and role of microbes. Therefore, to determine the optimal design for construct, and methods to operate constructed wetland, researches about complex mechanisms of contaminant removal and interdisciplinary researches are necessary.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.135-136
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• 1999

대기 침적은 대기중으로 방출된 오염물질의 제거기작으로 널리 알려져 있으며, 대기로부터 자연계의 표면에 침적되는 대기중의 유해물질들이 환경계에 미치는 영향과 그들의 이동을 조절하는 중요한 기작의 하나이다. 그러나 건식 침적의 경우 공간 및 시간적 변화가 크고 침적되는 표면과 대기 사이의 상호 반응이 침적되는 물질의 양에 커다란 영향을 미칠수 있기 때문에 그 측정이 상당히 어렵고 또한 시료 채취시 세심한 주의와 축적된 경험을 요구한다.(중략)

• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.239-246
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• 2012

This study was performed to investigate the removal characteristics and mechanism of heavy metals using pellet-type ceramics(ZS ceramics), in which natural zeolite was mixed and calcined with converter slag. The optimal calcination temperature range was measured to be $600{\sim}800^{\circ}C$. The calcination time had little effect on the removal of heavy metal in acid wastewater. The adequate dose of ceramics was shown to be 2~5% for removal of heavy metals in acid wastewater. The maximum removal capacity of ZS ceramics for heavy metals were observed to be Al 84.7 mg/g, Cd 37.3 mg/g, Cr 81.7 mg/g, Cu 55.6 mg/g, Fe 57.2 mg/g, Mn 32.1 mg/g, Ni 38.0 mg/g, Pb 71.6 mg/g, Zn 46.3 mg/g. The pH played a pivotal role in the removal of heavy metals by ZS ceramics. The analysis results of mechanism exhibited that the ZS ceramics could act as a multi-functional ceramics for removal of heavy metals in acid wastewater by adsorption, ion-exchange, or precipitation.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.6
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• pp.318-324
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• 2017

We evaluated geosmin and MIB biodegradation and adsorption mechanism of biological activated carbon (BAC) and anthracite biofilter. In steady state of BAC process, the geosmin and MIB were completely removed at the 30 min empty bed contact time (EBCT) even though low water temperature ($9^{\circ}C$) in which the activity of attached bacteria decreased. When the water temperature was $26^{\circ}C$, the microbial biomass and activity were higher at the upper layer of the biofilm than at $9^{\circ}C$, and the microbial biomass and activity decreased as the depth was deeper. This is because when the water temperature is high, the biodegradable organic matter (BOM) removal rate in the upper layer is high and the BOM amount that can't be supplied to the lower layer. The Removal rate of geosmin and MIB by BAC process did not show a significant difference compare to activity-inhibited BAC by treated with azide and the biofilter also removed the geosmin and MIB by biological action. It means geosmin and MIB could be removed by competitive relationship between adsorption and biodegradation.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.213-214
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• 2000

입자상 물질을 제거하기 위한 수단으로는 싸이클론, 필터, 전기집진기, 세정탑 등이 있다. 이중에 세정탑은 설치 및 운전이 편리한 반면, 미세 입자 제거 효율이 낮아 산업체에서 제한적으로 사용되고 있다. 이러한 결점, 즉 미세 입자의 제거 효율을 높이기 위해 다양한 형태의 세정탑이 연구되었으나(Laitinen et al., 1997; Fan et al., 1988), 대부분 실험적인 연구로서 세정탑에서 입자의 제거 기작이나 크기 분포 특성을 설명하지는 못한다. (중략)

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.193.1-193
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• 1995

• Journal of Wetlands Research
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• v.20 no.1
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• pp.63-71
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• 2018

The particle filtration mechanisms in an infiltration trench should be varying due to the different hydraulic conditions during stormwater runoff. The understanding of these variations associated with different filtration mechanisms and their effect on the particle removal efficiency is of vital importance. Therefore, a LID (Low Impact Development) system comprising of an infiltration trench packed with gravel and woodchip was investigated during the monitoring of several independent rainfall events. A typical rainfall event was divided into separate regimes and their corresponding flow conditions as well as filtration mechanisms in the trench were analyzed. According to hydraulic conditions, it was found out that filtration changes between vertical and horizontal flows as well as between unsaturated, saturated, and partially-saturated flows. Particle separation efficiency was high (55-76%) and was mainly governed by physical straining during the unsaturated period. It was then enhanced by diffusion during the saturated period (75-95%). When the trench became partially saturated at the end of the rainfall event, the efficiency decreased which was believed to be due to the existence of a negatively charged air-water interface which limited the removal to positively charged particles.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1463-1469
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• 2013

Portland cement used as binding material in combination of ferrous iron for reductive dechlorination of chlorinated organics is already widely studied topic by several researchers. However there is no clear evidence about the component solely responsible in cement for trichloroethylene (TCE) dechlorination. Many researchers suspect that the ettringite, monosulfate phases associated with hydration of cement are responsible active agents for TCE dechlorination. This study deals with synthesizing different pure crystalline minerals like ettringite and monosulfate phases of cement hydration and check individual phase's TCE dechlorinating capacity in combination with ferrous iron. The results indicated that the synthesized minerals showed no reduction capacity for TCE. The findings in the present study is significant as it shows that ettringite and monosulfate phases which were suspected minerals by previous researchers for TCE dechlorination are not reactive. Hence it is suspected that some other mineral or mineral form in cement phase could be responsible for TCE degradation.