• Journal of the Korean Society of Industry Convergence
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• v.10 no.1
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• pp.15-20
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• 2007

The aim of this study is to measure the removal characteristics of organic matter and bacteria with the use of ozone to reduce the problems caused by bacteria and organic matter which appear in sea-water is summer season. When the total input of ozone was $1.4mg/{\ell}O_3$, the removal rate of bacteria and E-coli from sea-water proved to be 100%. With the same input of ozone, on the other hand, the removal rate of COD turned to be relatively low, 50%, which was to the fact that sea-water consists of salt matter which is a kind of COD matter. This result supports the idea that we can keep using ozone steadily in the future to remove organic matters and bacteria from sea-water because ozone destructs relatively less salt matter in sea-water. Also, the treatment effect rate of SS, turbidity and organic matters such as $NH_3$-N, $NO_3$-N etc, was very high. As a result, we assume that the treatment of organic matter in sea-water with ozone is very effective

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.83-89
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• 2013

Microbiological treatment, chlorination, and ozonation are usually used for water treatment. However, there is weakness that these methods can't decompose and eliminate recalcitrant organic pollutants perfectly. It is possible to eliminate recalcitrant organic pollutants when photocatalysis of $TiO_2$ is used. In this study, the removal efficiencies of organic pollutants by using photocatalyst of $TiO_2$ in the slightly polluted golf club water hazard and a river were investigated. The amount of $TiO_2$ was divided into three categories of 1 g/L, 2 g/L and 4 g/L in order to investigate the adequate amount of $TiO_2$ and the removal efficiency. UV light was used as a light source for the reaction of photocatalyst. As a conclusion in this study, the efficiency of turbidity removal was increased in proportion to the amount of $TiO_2$ until 4 hours. After then the turbidity was gradually decreased. Finally, the optimum concentration of $TiO_2$ was 4 g/L. The efficiency of COD removal was increased in proportion to the amount of $TiO_2$ regardless of time.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.41-49
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• 1999

The water treatment by was performed to remove VOC and organic substances in the multi-stage ozone contactor. Ozone is mainly utilized to change the chemical structures of organic substance, of which finally has the purpose to degrad them. The removal efficiency of VOC has 20~60% at the ozone concentration of 3 ppm, in case of trichloroethylene, its efficiency is reduced by 85% at the ozone contact time of 8 min. Design factors such as the number of stage, ozone concentration, zone contact time are determined for optimal treatment in the multi-stage contactor.

• Journal of Korean Society on Water Environment
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• v.20 no.1
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• pp.24-31
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• 2004

This study was initiated to evaluate the efficiencies of DEPHANOX and Modified-DEPHANOX, which were devoloped to enhance nitrogen removal efficiency in municipal wastewater treatment. In the results, removal efficiency of organic matters was not affected much by increased loading rate of organic matters which is contained in influent. The nitrogen removal efficiencies according to the loading rate of influent TN was decreased drastically in conditions of over $0.2kg/m^3{\cdot}day$, which is T-N loading rate, and the DEPHANOX process was affected more sensitively than the M-DEPHANOX was. When the temperature was altered from $25^{\circ}C$ to $16^{\circ}C$ at HRT 6hrs, the removal efficiency of ammonia nitrogen was still over 90% and it was concluded that both DEPHANOX and M-DEPHANOX were strong enough to endure temperature variation. Moreover, both processes showed over 90% in ammonia removal efficiencies in over HRT 5hrs, so it was concluded that they were strong in HRT variation. M-DEPHANOX process showed a higher value than DEPHANOX did in T-N removal efficiency to the extent of 4~21 %, which resulted from differency of denitrification rates and the biosorption efficiency of organic matter in both processes. In the condition of HRT less than 4hrs, concentrations of ammonia nitrogen contained in effluents and nitrification reactors, might be sensitively affected by biosorption efficiency of organic matters in first separation tank. In the effect of effluent nitrate concentration in phosphorus removal, the more effluent nitrate concentration was decreased, the more phosphorus removal efficiency was increased. This result is related to the decrease of concentration of effluent nitrate which resulted from nitrification inhibition by decreased HRT.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.101-112
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• 2013

Integrated process with coagulation and microfiltration as an advanced water treatment has been expanded its application in recent years due to its superb removal of particles and natural organic matter. In usual, effectiveness of coagulation sometimes determines performance of the whole system. Several new polymeric coagulants introduced to water utilities for better efficiency were studied in this paper. Three polymeric coagulants (i.e., PACl, PACs, and PAHCs) along with alum were evaluated for removal of natural organic matter, especially for reduction of trihalomethane formation potential, for which regulation has become stringent. Turbidity removal was closely related to pH variation showing the reduced turbidity removal by PACs due to the decreases in the pH of supernants at high doses. The four coagulants showed different organic matter removal during coagulation and affected the removal in microfiltration. For instance, DOC concentration was not reduced by microfiltration when PAHCs were used however 10 % of DOC removal was observed by microfiltration with alum coagulation. Coagulation pretreatment also impacted the THM removals, i.e., approximately 30 % of THMs and 13 % of DOC was removed by microfiltration only, but 40 to 67 % of THMs and 30 % of DOC was removed by the integrated process. Strategies on selection of coagulants are needed depending on characteristics of target pollutants in raw waters.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.556-562
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• 2015

In order to remove the organic substances and the nitrate-nitrogen contained in wastewater, some researchers have studied the simultaneous removal of organics and nitrogen by using different biocathode microbial fuel cells (MFCs). The operating conditions for removing the contaminants in the MFCs are the external resistances, HRTs, the concentration of the influent wastewater, and other factors. This study aimed to determine the effect of the external resistors and organic loading rates, from the changing HRT, on the removal of the organics and nitrogen and on the production of electric power using the Denitrification Biocathode - Microbial Fuel Cell (DNB-MFC). As regards the results of the study, the removal efficiencies of $SCOD_{Cr}$ did not show any difference, but the nitrate-nitrogen removal efficiencies were increased by decreasing the external resistance. The maximum denitrification rate achieved was $129.2{\pm}13.54g\;NO_3{^-}-N/m^3/d$ in the external resistance $1{\Omega}$, and the maximum power density was $3,279mW/m^3$ in $10{\Omega}$. When the DNB-MFC was operated with increasing influent organic and nitrate loading by reducing the HRTs, the $NO_3{^-}-N$ removal efficiencies were increased linearly, and the maximum nitrate removal rate was $1,586g\;NO^3{^-}-N/m^3/d$ at HRT 0.6 h.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.3
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• pp.136-144
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• 2001

Two organic materials, peat and rock wool were used for removal of $H_2S$ by a biofilter inoculated with night soil sludge. By gradually increasing the inlet load of $H_2S$, the complete removal capacity, which was defined as the inlet load of $H_2S$ that was complete removed, and the maximum removal capacity of $H_2S$, which was the value when the removal capacity leveled off for organic materials, were estimated. Both values for Rock wool are larger than peat, based on a unit dry weight of material. By using kinetic analysis, the maximum removal rate of $H_2S$, $V_m$, and the saturation constant, $K_s$, were determined for all packing materials and the values of $V_m$ for rock wool was found to be larger. By using the kinetic parameters, the removal rates for $H_2S$ were compared both packing materials, and rock wool showed better performance for the removal of $H_2S$ in the inlet concentration range of 0~200ppm.

• KSBB Journal
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• v.27 no.3
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• pp.145-150
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• 2012

This study was accomplished using packed bed column reactors that contain nonsurface-modified polypropylene media and surface-modified media from hydrophobic surface property into hydrophilic property by ion beam irradiation. The objectives of this research was investigated the characteristics of organic compounds removal and microbe attachment from sewage of school cafeteria in these reactors. In 736.8 mg/L of the average inflow $COD_{Cr}$ concentration the reactors with and without surface modification showed 81.8% and 70.3% of average $COD_{Cr}$ removal efficiencies, respectively, which proves the $COD_{Cr}$ removal efficiency of surface-modified media reactor is higher than that of nonsurface-modified media reactor. After 90 days, there were maximum differences between modified system and non-modified system. In that time the maximum removal efficiency of $COD_{Cr}$ was 96.5% in modified system and was 85.2% in non-modified system that showed removal efficiency of surface-modified media system is 11.3% higher than that of nonsurface-modified media system. The average removal efficiency of SS was 80.4% for the surface modified system and 61.6% for the non-modified system under same condition. Also, the reactor of surface-modified media has advantage on microbe attachment and biofilm formation.

• Journal of Environmental Health Sciences
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• v.20 no.4
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• pp.36-44
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• 1994

A study was carried out in order to investigate the removal efficiencies and removal characteristics of heaw metals such as Pb, Cd, Cr, Cu in raw water by one of conventional water treatment processes. The coagulants used in this study were Alum and PAC. Three kinds of water samples were provided: kaolin water, kaolin water mixed with humic acid and raw water from Han River mixed with suspended matter deposited on raw water inlet pipe. Heaw metals were added to the water samples with their respective turbidity, and jar tests were performed. In the results from heaw metal removal studies, lead might be adsorbed or exchanged on the particle surface (SS) rather than react with organic matter added. Cadmium was affected on the dissolved organic matter. Chromium was affected by the both dissolved organic matter and SS concentration, and the restabilization and the enmeshment appeared at moderate (50~80 NTU) and high (100 NTU) turbidity as defined in this experimenL The removal efficiency of copper was relatively little affected by the dissolved organic matter but by SS concentration in comparison with other heavy metals. In these studies as to the raw water turbidities and concentration of heaw metals, it is proved out that the removal efficiency on heaw metals in both cases of PAC and Alum as coagulants was not significantly different.

• Journal of Environmental Health Sciences
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• v.36 no.6
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• pp.502-509
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• 2010

In this study, the (phosphorous removal) the characteristics of phosphorous removal due to (the iron compound precipitated) iron compound precipitation by iron electrolysis in (the anoxic. oxic process) anoxic and oxic processes (equipped with the) in an iron precipitation device were analyzed. During the device operation period, the average concentration of BOD, T-N, and T-P were 219.9 mg/l, 54.6 mg/l and 6.71 mg/l, respectively. The BOD/$COD_{Cr}$ ratio was 0.74, and the BOD/T-N and BOD/T-P ratios were 4.0 and 32.8, respectively. The removal rate of (the organic matters) organic matter (BOD and $COD_{Cr}$) was very high at 91.6% or higher, and that of nitrogen was 80.5%. The phosphorous concentration (of the final) in the treated water was 0.43 mg/l (0.05-0.74 mg/l) on average, and the removal efficiency was high at 90.8%. The soluble T-P concentrations in (an) the anoxic reactor, oxic reactor (II) and final treated water were 1.99 mg/l, 0.79 mg/l and 0.43 mg/l, respectively, which indicated that the phosphorous concentration in the treated water was very low. Regardless of the changes in the concentrations of (organic matters) organic matter, nitrogen and phosphorous in the influent, the quality of the treated water was relatively stable and high. The removal rate of T-P somewhat increased with the increase in the F/M ratio in the influent, and it also linearly increased in proportion to the T-P loading rate in the influent. In the treatment process used in this study, phosphorous was removed (using) by the precipitated iron oxide. Therefore, the consumption of organic (matters) matter for biological phosphorus removal was minimized and (most of the organic matters were) was mostly used as the organic carbon source for the denitrification in the anoxic reactor. This (can be an economic) treatment process (without the need for the supply of additional organic matters) is economic and does not require the supply of additional organic matter.