• Journal of Korean Society for Atmospheric Environment
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• 제18권E1호
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• pp.13-20
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• 2002

The electrical and chemical properties of the dielectric barrier discharge (DBD) process for the benzene removal were investigated. The benzene removal was initiated with the applied voltage higher than the discharge onset value. The removal efficiency over 95 % was obtained at approximately 1.6 kJ lite $r^{r-1}$ of the electrical energy density. The increase of the inlet concentration decreased the removal efficiency. However, the benzene decomposition rate increased with the inlet concentration . While the increase of the gas retention time enhanced the removal efficiency, the decomposition rate decreased. Identification of the optimum condition between the decomposition rate and the removal efficiency is required for field applications of the DBD process.s.

• 아시안잔디학회지
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• 제10권2호
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• pp.143-150
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• 1996

The removal rates of gross production and organic matters were investigated in the Lake Paldangho. In 1995 and 1996, soils and litter sarraples were collected and annual mean production and removal rates were calculated. Communities in the Lake Paldangho were Phragrnites communis, Miscanthus sacchariflorus, Typha aegustata and Scirpas tahernaemoutani. Removal constants of aquatic plant communities estimated by the mathematical theoretical models, were 0.826, 0.567, 0.571 and 0.751, respectively. The durations of reaching half of initial organic amounts were 0.839 yeras, 1.221 years, 1.213 years and 0.922 years respectively at the steady state of removal and accumulation for organics For organics, the rapidity of removal were more speedy P. communis, S.tahernaemontani, T. augustata, M sacehariflorus in order. The times needed for 99% removal were 6.051 years, 6.651 years, 8.752 years and 8.811 years, respectively. Key wotds:Gross production, Organic matters, Lake Paldangho, Phragmites communis, Mis-ca ethus sacchariflorus, Typha angustata, Scirpus tahernaemoutani., Removal constants.

• 산업기술연구
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• 제26권B호
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• pp.3-10
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• 2006

In this study, the of MBBR(moving bed biofilm reactor) process for Phosphorus Removal efficiency depending on seasons and the factors affecting phosphorus removal efficiency in the process is evaluated. As a result of experiment, T-P removal efficiency has its highest value in winter, (80.8%). and T-P removal efficiency has its lowest value in autumn, (49%). Optimum SRT for Phosphorus Removal revealed is about 8.8 days and process performs more efficiently as the temperature decreases. It is accepted that nitrate to anaerobic zone is affecting the Phosphorus removal process. With increasing the organic loading rate, Phosphorus removal efficiency also increases. Also, an experiment has been conducted to find out the highest efficiency according to Media existence and it has revealed that Media addition provides better phosphate removal.

• 한국환경과학회지
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• 제7권5호
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• pp.697-705
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• 1998

$Pb^{2+}$ removal capacity and initial $Pb^{2+}$ removal rate were compared between non-biomaterials (granular activated carbon, powdered activated carbon, ion exchange resin, zeolite) and biomaterials (activated sludge, Aureobasidium pullulans, Saccharomyces cerevisiae). The $Pb^{2+}$ removal capacity of biomaterials were greater than that of non-biomaterials, generally. The $Pb^{2+}$ removal capacities of non-biomaterials and biomaterials were shown on the order of ion exchange resin ＞ zeolite ＞ granular activated carbon ＞ powdered activated carbon and A. pullulans ＞ S. cerevisiae ＞ activated sludge, respectively. In the initial $Pb^{2+}$ removal rate, the non-biomaterials showed powdered activated carbon ＞ granular activated carbon ＞ zeolite ＞ ion exchange resin and the biomaterials showed A. pullulans ＞ activated sludge ＞ S. cerevisiae. Comparing the $Pb^{2+}$ removal capacity and initial $Pb^{2+}$ removal rate of activated sludge with those of other non-biomaterials and biomaterials, activated sludge may have an availability on the removal of heavy metal ions by the economical and pratical aspects.

• 한국잠사곤충학회지
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• 제42권2호
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• pp.78-82
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• 2000

In this study, a comparative removal of chlorine from aqueous solutions of mulberry leaf powder(MLP) and activated carbon(AC) was investigated. The chlorine removal capacities of MLP and AC were shown as a function of contact time, pH and initial chlorine concentration. Optimum contact time and removal pH value of MLP were determined as 2 hr and pH 10, respectively. Chlorine removal increased with increasing initial chlorine concentration up to 1.3g/L. Both Langmuir and Freundlich adsorption models were suitable for describing the short-term removal of chlorine by MLP and AC. According to Freundlich adsorption isotherms, the maximum removal capacity of MLP(0.264 mg Cl$_2$/mg) was nearly two times greater than that of AC(0.56 mg Cl$_2$/mg). These results suggested that MLP might potentially be used as an alternative to traditional water treatment materials for removal of residual chlorine in drinking water or process wastewater.

• 한국멀티미디어학회논문지
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• 제20권1호
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• pp.32-42
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• 2017

This paper proposes a new haze removal method for moving image sequence. Since the conventional dark channel prior haze removal method adjusts each color component separately in RGB color space, there can be severe color distortion in the haze removed output image. In order to resolve this problem, this paper proposes a new haze removal scheme that adjusts luminance and saturation components in HLS color space while retaining hue component. Also the conventional dark channel prior haze removal method is developed to obtain best haze removal performance for a single image. Therefore, if it is applied to a moving image sequence, the estimated parameter values change rapidly and the haze removed output image sequence shows unnatural glitter defects. To overcome this problem, a new parameter estimation method using Kalman filter is proposed for moving image sequence. Experimental results demonstrate that the haze removal performance of the proposed method is better than that of the conventional dark channel prior method.

• 한국물환경학회지
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• 제20권2호
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• pp.104-109
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• 2004

Removal of nutrients from domestic sewage or industrial wastewater is needed to protect surface waters from eutrophication. This research was carried out to remove the nitrogen (N) and phosphorus (P) from the wastewater using the iron oxide obtained from the steel industry and the natural zeolite, respectively. This research was conducted in both batch and continuous systems. The removal efficiency of the nutrients was evaluated in the batch system using the varying concentrations of zeolite and iron oxide added. The removal efficiency of N was 60% at the 8g of zeolite added. In the same condition, the removal efficiencies of N were 76% and 82% at 12g and 16g of zeolite added, respectively. Removal efficiency of P was 80% as 8g of iron oxide was added. The removal efficiency of P was correspondingly increased as the concentration of iron oxide was increased. Continuous column system was also used to evaluate the removal efficiency of N and P by the addition of zeolite and ferric oxide, respectively. Removal efficiencies of N were compared in the mixed packing, two stage, and four stage columns, respectively. The removal efficiencies (80%) of N in the separate packed columns (two and four stages) were higher than the mixed packing column (400%) after 90 hr. Whereas, the removal efficiencies of P were similar to each other in the three columns.

• 한국농공학회논문집
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• 제53권6호
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• pp.85-91
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• 2011

Three different types of wetlands (unplanted wetland, reed planted wetland, cattail planted wetland) were constructed at the mouth of Seokmoon reservoir with 910 $m^2$ each to examine the effects of wetland plant on pollutant removal rate in constructed wetland, and operated for 9 years (2002~2010). Water depth of the wetland was maintained at 0.3~0.5 m, flow rate was about 40~200 $m^3$/day, and retention time was managed at about 1~5 days. There was no difference in removal rate of SS, TN, and TP between reed wetland and cattail wetland. Removal rate of SS and TN in planted wetland with reed and cattail were higher than unplanted wetland, whereas removal rate of TP in unplanted wetland was higher then planted wetland. The monthly variation of removal rate in planted wetlands was high compared with unplanted wetland. From the long term monitoring results, SS and TN removal rates of period3 (2008~2010) were higher than period1 (2002~2004) in planted wetland, whereas TP removal rate was decreased as time goes on. Overall, pollutant removal rate in constructed wetland was more influenced by existence of plants than by plant species. Although constructed wetland is operated long term period, SS, TN, and TP removal rate (SS 90 %, TN 60 %, TP 40 %) can be maintained high values.

• 한국염색가공학회지
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• 제14권2호
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• pp.40-50
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• 2002

In order to remove the pollutants effectively in the dye wastewater by chemical precipitation process, coagulation arid flocculation test were carried out using several coagulants on various reaction conditions. It was found that the Ferrous sulfate was the most effective coagulant for the removal of disperse dye(B79), and we could get the best result lot the removal of disperse dye(B56) in the aspects of TOC removal efficiency and sludge field. When the Ferrous sulfate dosage was $800mg/\ell$, the sludge settling velocity was very fast>, and the color was effectively removed in the disperse dye(B79) solution. Although the color removal was ineffective when the Alum was used as a coagulant, the sludge field was decreased in comparison with the Ferrous sulfate or the Ferric sulfate was used in the disperse dye(B56) solution. The general color removal effect for the disperse dye(B56 and B79) solutions, the Ferric sulfate was more proper coagulant than the Alum. It was showed that TOC removal was improved 5% and over by the addition of Calcium hydroxide, and $30mg/\ell$ of sludge yield was decreased(B79). When Alum or Ferric sulfate was used as a coagulant, pH condition for most effective color removal was 5 in B56 solution. In case of Ferrous sulfate as a coagulant, most effective pH condition for color removal was 9. When Ferric sulfate or Ferrous sulfate was used as a coagulant, pH condition for most effective color removal was 9 in B79 solution.

• 한국환경보건학회지
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• 제45권6호
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• pp.561-568
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• 2019

Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.