• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.117-124
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• 2005

Appropriate removal of pollutants from combined sewer overflows(CSOs) and stormwater runoff is of primary concern to watershed managers trying to meet water quality standards even under a wet weather condition. Harmful substances associated with particles besides TSS and BOD are subjected to removal prior to discharge into the natural waters. Effectiveness of five major hydrodynamic separation technologies, Vortechs, Downstream Defender including Storm King for CSOs control, CDS, Stormceptor, and IHS, were evaluated in this study. There is not sufficient information for accurate evaluation of the removal efficiency for the pollutants from the stormwater runoff and CSOs. Based upon limited engineering data, however, all technologies were found to be effective in separation of heavy particles and floating solids. Technologies utilizing screens seem to have advantage in the treatment capacity than the other technologies relied fully on hydrodynamic behavior. The IHS system seems to have a strong potential in application for control of CSOs because of unique hydrodynamic behavior as well as a flexibility in opening size of the screens. Size of the particulate matter in the CSOs and stormwater runoff is found to be the most important parameter in selection of the type of the hydrodynamic separators. There exists an upper limit in the solids removal efficiency of a hydrodynamic separator, which is strongly dependent upon the particle size distribution of the CSOs and stormwater runoff.

• Journal of Korea Water Resources Association
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• v.47 no.12
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• pp.1135-1143
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• 2014

This study was carry out to evaluate of water purification in oxidation pond with filamentous algae mat. It is the water treatment process in the small rural streams to remove the organic materials and nutrients. We used the filamentous algae mat (FAM) which selectively predominate the filamentous algae to prevent the additional contamination by algae outflow, and we conducted a experiment on the water treatment process using the aquatic plants such as Eichhornia crassipes. The removal efficiencies (%) of water quality parameters were SS 80.9%, COD 74.6%, TN 76.8%, TP 84.4%, DTN 93.8% and DTP 98.3%, respectively. Temperature, a effect factor, was $21.8{\pm}5.9^{\circ}C$ during the operating period, according to temperature had no effect on the removal efficiencies of pollutants. Hydraulic retention time (HRT) strongly correlated with removal efficiencies (%) of SS and TP having r=0.414 (p<0.005), r=0.446 (p<0.005), respectively, and when HRT was 5day had highly removal efficiency (%) in SS and TP. TN and TP removal efficiency increased with ratio decreasing in both COD/TN and COD/TP of Influent.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.117-126
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• 2015

Reductive degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by nanoscale zero-valent iron (nZVI) was investigated to evaluate the feasibility of using it for in-situ groundwater remediation. Batch experiments were conducted to quantify the kinetics and efficiency of RDX removal by nZVI, and to determine the effects of pH, dissolved oxygen (DO), and ionic strength on this process. Experimental results showed that the reduction of RDX by nZVI followed pseudo-first order kinetics with the observed rate constant (k_obs) in the range of 0.0056-0.0192 min⁻¹. Column tests were conducted to quantify the removal of RDX by nZVI under real groundwater conditions and evaluate the potential efficacy of nZVI for this purpose in real conditions. In column experiment, RDX removal capacity of nZVI was determined to be 82,500 mg/kg nZVI. pH, oxidation-reduction potential (ORP), and DO concentration varied significantly during the column experiments; the occurrence of these changes suggests that monitoring these quantities may be useful in evaluation of the reactivity of nZVI, because the most critical mechanisms for RDX removal are based on the chemical reduction reactions. These results revealed that nZVI can significantly degrade RDX and that use of nZVI could be an effective method for in-situ remediation of RDX-contaminated groundwater.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.421-422
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• 2002

병원은 환자가 모여 치료를 받는 곳이지만 이곳에 모인 대부분의 환자 중 맡은 사람이 감염증을 갖고 있거나 다른 환자에 대해 전염원이 될 가능성이 있으며 병에 대한 감수성이 높다(홍영이, 1983). 즉, 백혈병 및 암 환자들이 (특히, 골수암) 수술실에서 수술을 마치고 무균실로 옮기는 과정이나 골수이식을 받을 경우 병원 내에서 이동할 때 저항력이 없는 상태에서 외부 병원균으로부터 신체 내에 감염을 막을 방법이 현재로서는 전혀 없다(산업자원부 2002). (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2010.04a
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• pp.534-535
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• 2010

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2009.10a
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• pp.516-517
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• 2009

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.397-398
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• 1999

활성탄은 1,000m$^2$/g 이상의 큰 표면적을 가지며, 이것을 활용하여 공업적인 용도로 예부터 탈취제와 같은 흡착제로서 이용되고 있다. 최근에는 생활 수준의 향상으로 인해 악취에 대해 민감해져서 악취 제거제로서 활성탄의 사용량은 갈수록 늘어나고 있는 추세이다. 특히 우리나라의 경우 공업단지 주변에서의 악취에 대한 민원이 급증함으로써 여러 악취발생업체에서 악취 제거장치로서 활성탄을 이용하는 곳이 많아지고 있다.(중략)

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.76-76
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• 2017

• Advances in environmental research
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• v.6 no.1
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• pp.1-14
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• 2017

New technologies or improvement of the existing technologies are required to enhance the efficiency of removal of pollutants from wastewater. In this study we attempted to produce and test the activated carbon produced from the refused tea waste for the removal of dyes from wastewater. The objectives of this investigation were to produce activated carbon from refused tea waste by chemical activation, evaluate its performance for the removal of color produced from Acid Yellow 36, and the modeling of its dye removal with the kinetic study. The activation was performed in two steps namely carbonization at $375{\pm}25^{\circ}C$ and chemical activation with HCl at $800^{\circ}C$ under the absence of Oxygen. Adsorption isotherms and kinetic studies were performed with a textile dye, Acid Yellow 36, at different concentrations (20-80 mg/L). The maximum dye removal (~90%) observed at 80 mg/L dye concentration and it reduced at low dye concentrations. Maximum adsorption (71.97 mg/g) was recorded at 96 h at $29{\pm}1^{\circ}C$. Low pH increased the dye adsorption (pH=2; 78.27 mg/g) while adsorption reduced at high pH levels indicating that the competition occurs in between OH- ions and AY36 molecules for the adsorption sites in RTAC. The Langmuir isotherm model clearly explained the dye adsorption, favorably, by RTAC. Moreover, kinetic studied performed showed that the pseudo second order kinetic model clearly describes the dye adsorption. Based on the results obtained in this study, it can be concluded that RTAC can be used for the removal of textile dyes.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.463-471
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• 2020

A 1,000 ㎥/d DAF(dissolved air flotation) pilot plant was installed to evaluate the performance of the floating process using the Nakdong River. Efficiency of various DAF operations under different conditions, such as hydraulic loading rate, coagulant concentration was evaluated in the current research. The operation conditions were evaluated, based on the removal or turbidity, TOC(total organic carbon), THMFP(trihalomethane formation potential), Mn(manganese), and Al(aluminum). Also, particle size analysis of treated water by DAF was performed to examine the characteristics of particles existing in the treated water. The turbidity removal was higher than 90%, and it could be operated at 0.5 NTU or less, which is suitable for the drinking water quality standard. Turbidity, TOC, and THMFP resulted in stable water quality when replacing the coagulant from alum to PAC(poly aluminum chloride). A 100% removal of Chl-a was recorded during the summer period of the DAF operations. Mn removal was not as effective as where the removal did not satisfy the water quality standards for the majority of the operation period. Hydraulic loading of 10 m/h, and coagulant concentrations of 40 mg/L was determined to be the optimal operating conditions for turbidity and TOC removal. When the coagulant concentration increases, the Al concentration of the DAF treated water also increases, so coagulant injection control is required according to the raw water quality. Particle size distribution results indicated that particles larger than 25 ㎛ showed higher removal rates than smaller particles. The total particel count in the treated water was 2,214.7 counts/ml under the operation conditions of 10 m/h of hydraulic loading rate and coagulant concentrations of 60 mg/L.