• KSBB Journal
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• v.17 no.1
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• pp.80-87
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• 2002

Laboratory scale aerobicfanaerobic biofilm reactor was used for simultaneous and stable removal of organics, N and P components to investigate optimum design and operation parameters and to analyze the microbial distribution and consortium structure of nitrification and denitrification bacteria in aerobic and anaerobic biofilm systems. The biofilm reactor was successfully operated for 143 days to show $COD_{cr},\;BOD_5$, SS removal efficiencies of 88, 88, and 97%, respectively. During the experiment period, almost complete nitrification efficiency of 96% was achieved. Denitrification efficiency was about 45% without addition of any external carbon sources. In case of total phosphorus removal, 74% of the inlet phosphorus was removed. Fluorescence in situ hybridization (FISH) results showed that most of the ammonia oxidizing bacteria in the aerobic nitrification zone was found to be Nitrosomonas species while Nitrospira was the representative nitrite oxidizing bacteria. For the denitrification, Rhodobacter, Rhodovulum, Roseebacter and Paracouus were the dominant denitrification bacteria which was 10 to 20% of the total bacteria in numbers.

• Journal of Wetlands Research
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• v.11 no.1
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• pp.115-121
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• 2009

The hybrid constructed wetland(HCW) as tertiary treatment process of a bio industrial wastewater treatment plant was employed to estimate applications for the reuse of final effluent. Raw wastewater was sequently treated through chemical and biological treatment processes and the biologically treated water was flowed into the HCW. The HCW system was composed of two constructed wetlands connected in series; The one is the aerobic constructed wetland with natural air draft system whose driving force for air supply was the difference between the temperature of the air inside the wetland and the ambient air, and the other is the anaerobic/anoxic constructed wetland. Average influent concentrations of BOD, SS, T-N and T-P in the HCW were 53mg/L, 48mg/L, 34mg/L and 3mg/L, respectively. After being treated at HCW, final effluent concentrations of BOD, SS, T-N and T-P were 2.3mg/L, 1.2mg/L, 7.95mg/L and 0.83mg/L, respectively. Referring to a reuse standard for a sewage wastewater, final effluent could sufficiently be reuse as landscaping, washing or agriculture water. HCW system with the aerobic/anaerobic combined constructed wetland could be achieved a high removal efficiency because each constructed wetland was functionalized to be removed efficiently organics, nitrogen and phosphorus. HCW system could be estimated to be successful application as tertiary treatment process of a various industrial and municipal wastewater.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.1
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• pp.91-99
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• 2008

A multilayer tower-type photoreactor, in which $TiO_2$-coated glass-tubes were installed, was used to measure the vapor-phase BTEX removal efficiencies by ozone oxidation ($O_3$/UV), photocatalytic oxidation ($TiO_2$/UV) and the combination of ozone and photocatalytic oxidation ($O_3/TiO_2$/UV) process, respectively. The experiments were conducted under various relative humidities, temperatures, ozone concentrations, gas flow rates and BTEX concentrations. As a result, the BTEX removal efficiency and the oxidation rate by $O_3/TiO_2$/UV system were highest, compared to $O_3$/UV and $TiO_2$/UV system. The $O_3/TiO_2$/UV system accelerated the low oxidation rate of low-concentration organic compounds and removed organic compounds to a large extent in a fixed volume of reactor in a short time. Therefore, $O_3/TiO_2$/UV system as a superimposed oxidation technology was developed to efficiently and economically treat refractory VOCs. Also, this study demonstrated feasibility of a technology to scale up a photoreactor from lab-scale to pilot-scale, which uses (i) a separated light-source chamber and a light distribution system, (ii) catalyst fixing to glass-tube media, and (iii) unit connection in series and/or parallel. The experimental results from $O_3/TiO_2$/UV system showed that (i) the highest BTEX removal efficiencies were obtained under relative humidity ranging from 50 to 55% and temperature ranging from 40 to $50^{\circ}C$, and (ii) the removal efficiencies linearly increased with ozone dosage and decreased with gas flow rate. When applying Langmuir-Hinshelwood model to $TiO_2$/UV and $O_3/TiO_2$/UV system, reaction rate constant for $O_3/TiO_2$/UV system was larger than that for $TiO_2$/UV system, however, it was found that adsorption constant for $O_3/TiO_2$/UV system was smaller than that for $TiO_2$/UV system due to competitive adsorption between organics and ozone.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1733-1738
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• 2008

The treatment efficiency of rotating biological contactors (RBCs) for the high strength of dairy wastewater was investigated. Two different systems were conducted composing of a single RBC with tapered aeration reactors for the system A and a sequential RBCs following tapered aeration reactors for the system B. Experiments using dairy wastewater were conducted for 50 days period of time, in which hydraulic rates were maintained at the constant ratios of 346L per day and variable BOD concentrations were at the range from 1,358mg/L to 829mg/L, the $COD_{cr}$, concentration of the range were from 2,384mg/L to 1,329mg/L, the range of T-N concentrations was from 66mg/L to 38mg/L, and 50% of internal recycle and 50% of sludge return were performed. Results indicated that the removal efficiencies of the system B were higher than those of the system A. The removal efficiencies of system A for the BOD, $COD_{cr}$, T-N and T-P were 97.8%, 96.7%, 87.2% and 82%, respectively. The removal efficiencies of system B for the BOD, $COD_{cr}$, T-N and T-P were as of 98.5%, 98.5%, 91.3% and 89%.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1141-1147
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• 2006

In order to applicate a newly method for powdered activated carbon(PAC) selection based on economic efficiency, PAC adsorption tests were performed for removal of MIB and dissolved organic carbon(DOC) in drinking water supplies. The removal rate of MIB increased when the PAC dose increased. The Coal-based PACs were superior for adsorption of MIB compared to wood-based PACs. PAC adsorption of DOC and $UV_{254}$ were a little different for different PACs and types of raw water, but both were lower than adsorption of MIB. Among the tested PACs, the one called P-1000 was most effective for removal of MIB, DOC and $UV_{254}$. Most of the organics in the tested samples were proven by excitation emission matrix(EEM) results to be fulvic-like materials. Especially, fulvic-like materials, humic-like materials, and soluble microbial byproduct(SMP)-like materials decreased after contact with PAC. P-1000 which had the lowest MIB cost index(MCI) was selected as the optimum PAC for the target water. PAC efficiency and treatability, particle size and distribution, and the cost associated with PAC dosing for MIB removal according to DOC concentration should all be considered before making the final selection of the best PAC for the target water.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1083-1091
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• 2000

The objective of this study is to develop effective and economical treatment processes for the removal of non-biodegradable organics by reusing the sludge generated from Fenton's Oxidation Process. It was found that about 50% of coagulants and 50% of catalyst can be reduced by reusing the sludge generated from Fenton's Oxidation Process. It was also found that the amount of sludge generation can be reduced in coagulation process and Fenton's Oxidation Process. From the results of bench-scale test, it was found that the average removal efficiency increased to 8.5% and the amount of sludge generation was reduced up to 35% by reusing the sludge as coagulant. The average organic removal efficiency increased to 5.3% and the amount of sludge generation was reduced up to 14% by reusing the sludge as catalyst in Fenton's Oxidation. It can be concluded that the reuse of sludge generated from Fenton's Oxidation Process would be reduced cost of chemical consumption and Fenton's sludge treatment.

• Environmental Analysis Health and Toxicology
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• v.17 no.3
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• pp.197-205
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• 2002

Volatile organic compounds (VOCs) are an important public health problem throughout the world. Many important questions remain to be addressed in assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in the analytical determination of VOCs. Personal exposure measurements are needed to evaluate the relationship between microenvironmental concentrations and actual exposures. It is also important to investigate exposure frequency, duration, and intensity, as well as personal exposure characteristics. In addition to air monitoring, biological monitoring may contribute significantly to risk assessment by allowing estimation of absorbed doses, rather than just the external exposure concentrations, which are evaluated by environmental and personal monitoring. This study was conducted to establish the analytic procedure of VOCs in air, blood, urine and exhaled breath and to evaluate the relationships among these environmental media. The subjects of this study were selected because they are occupationally exposed to high levels of VOCs. Environmental, personal, blood, urine and exhalation samples were collected. Purge ＆ trap, thermal desorber, gas chromatography and mass selective detector were used to analyze the collected samples. Analytical procedures were validated with the“break through test”, 'quot;recovery test for storage and transportation”,“method detection limit test”and“inter-laboratory QA/QC study”. Assessment of halogenated compounds indicted that they were significantly correlated to each other (p value < 0.01). In a similar manner, aromatic compounds were also correlated, except in urine sample. Linear regression was used to evaluate the relationships between personal exposures and environmental concentrations. These relationships for aromatic and halogenated are as follows: Halogen $s_{personal}$ = 3.875+0.068Halogen $s_{environmet}$, ($R^2$= .930) Aromatic $s_{personal}$ = 34217.757-31.266Aromatic $s_{environmet}$, ($R^2$= .821) Multiple regression was used to evaluate the relationship between exposures and various exposure deter-minants including, gender, duration of employment, and smoking history. The results of the regression model-ins for halogens in blood and aromatics in urine are as follows: Halogen $s_{blood}$ = 8.181+0.246Halogen $s_{personal}$+3.975Gender ($R^2$= .925), Aromatic $s_{urine}$ = 249.565+0.135Aromatic $s_{personal}$ -5.651 D.S ($R^2$ = .735), In conclusion, we have established analytic procedures for VOC measurement in biological and environmental samples and have presented data demonstrating relationships between VOCs levels in biological media and environmental samples. Abbreviation GC/MS, Gas Chromatography/Mass Spectrometer; VOCs, Volatile Organic Compounds; OVM, Organic Vapor Monitor; TO, Toxic Organicsapor Monitor; TO, Toxic Organics.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.737-742
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• 2013

The purpose of this study was to remove sediments obtained from breeding ground using supersonics and micro-air flotation method. Sediments from Tongyong breeding grounds showed no contaminations of heavy metals but had great amount of organics. Thus, efficient removal of sediments was required to preserve water quality near breeding ground. Supersonics treatment for sediments was determined to be essential because higher removal efficiency of sediments was obtained when supersonics treatment was used. In addition, application of coagulants increased removal efficiency because its usage increased particle size of sediments, which enabled easy trapping of sediments particle into micro-air bubbles. Removal efficiency of sediments slightly decreased from 95.8% (1 g/L) to 83.9% (8 g/L) at the tests for different amount of sediments, but most of tiny particles were removed from water where sand size particles were left in the bottom of reactors.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.70-72
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• 1998

1. 서론 : 최근에 폐수나 지하수 및 음용수에 존재하는 휘발성 유기화합물(Volatile Prganic Compound, VOC)는 심각한 환경오염이 주범이 되고 있다. 이러한 문제를 해결하는 방법으로 흡착, 증류, air stripping 등의 여러 가지 분리기술이 제시되어 왔다. 그러나 전통적인 방법들은 분리된 오염물질이 제2의 상으로 전이된다는 점에서 또 다른 분리공정을 필요로 하는 단점을 지니고 있다. 이에 반해 투과증발공정은 추가적인 분리과정이 없이 효율적으로 오염된 물속의 유기용매를 제거한다는 점에서 많은 관심을 모으고 있다. 이미 알려진 이러한 VOC 제거에는 소수성이면서 고무상인 고분자가 우수한 특성을 가지는 것으로 밝혀졌고 그 중에서 실록산계 고분자가 아주 효과적인 것으로 알려져 있다. 그러나 이러한 실록산계 고분자는 기계적 강도가 약하여 필름의 박막형성능력이 떨어지는 것으로 알려져 있어 이러한 단점을 보완하기 위해 가교구조의 도입이나 공중합체의 구조를 도입하는 연구가 많이 수행되어 왔다. 이러한 연구의 한 방법으로 실록산-아미드공중합체를 이용하여 투과증발에 적용한 연구는 수행되어 왔다. 이들의 제막방법으로 주로 실록산다이아민/방향족다이아민의 비를 달리하거나 실록산다이아민의 분자량의 변화를 달리하면서 실록산-이미드 블록 또는 그래프트중합체를 제조하는 방법을 사용하였다. 이 실험에서는 주로 실록산-이미드의 비율이 낮아지면 유기용매의 선택성에서 물의 선택성으로 바뀌는 percolation point가 관찰되며 이것은 실록산-이미드의 비율이 낮을수록 물속의 유기용매의 제거에 유리하다는 것을 보여준다. 이에 따라 실록산다이아민과 다이안하이드라이드만을 사용한 실록산이미드막이 추천되나 여기에 대한 투과특성연구는 전혀 이루어지지 않았다.정육점이었고 백화점과 재래닭 사육장에서 직접구입도 하고 있었다. 구입 동기는 가족들이 좋아하고 영양가를 생각한다가 62%였으며 구입정보는 주위사람의 권유로 구입하고 있었다. $\bigcirc$ 구입할 때 중점적으로 살펴보는 사항은 신선도와 순수재래종 여부, 위생상태였다. 한편 소비자가 언제나 구입할 수 없다는 의견이 85.2%나 되어 원활한 공급과 시장조성이 아직 정착되지 않고 있었다. $\bigcirc$ 현재 유통되고 있는 재래종닭은 소비자 대부분이 잡종으로 인식하고 있었으며, 재래종과 일반육계와의 구별은 깃털색, 피부색, 정강이색등 외관상으로 구별하고 있었다. 체중에 대한 반응은 너무 작다는 의견이었고, 식품으로의 인식도는 비교적 고급식품으로 인식하고 있다. $\bigcirc$ 재래종닭고기의 브랜드화에 대한 견해는 젊고 소득이 높은 계층에서 브랜드화의 필요성을 강조하고 있다. $\bigcirc$ 재래종달걀의 소비형태는 대부분의 소비자가 좋아하였으나 아직 먹어보지 못한 응답자가 많았다. 재래종달걀의 맛에 대해서는 고소하고 독특하여 차별성을 느끼고 있었다. $\bigcirc$ 재래종달걀의 구입장소는 계란판매점(축협.농협), 슈퍼, 백화점, 재래닭 사육 농장등 다양하였으며 포장단위는 10개를 가장 선호하였고, 포장재료는 종이, 플라스틱, 짚의 순으로 좋아하였다. $\bigcirc$ 달걀의 가격은 200원정도를 적정하다고 하였으며, 크기는 (평균 52g)는 가장 적당하다고 인식하고 있으며, 난각색은 대부분의 응답자가 갈색을 선호하였다. $\bigcirc$ 재래종달걀의 구입시 애로사항은 믿을수 없고, 구입장소를 몰라서, 값

• Journal of Wetlands Research
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• v.20 no.1
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• pp.72-79
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• 2018

Two planter boxes were monitored during their initial year of operation to be able to assess their stormwater runoff and pollutant reduction capabilities and investigate on the design factors affecting their performance. One of the planter boxes provided 85-100% runoff volume reduction for rainfall less than 15 mm and rainfall intensities lower than 5 mm/hr. This reduced to 50-64% during higher rainfall intensities and depths of up to 50 mm. Suspended solids, organics, nutrients, and heavy metals were satisfactorily removed at a range of 40-95%. The other planter box, however, did not produce outflow in all the events and allowed total capture of stormwater. The uncertainty regarding the fate of the runoff in that case required an investigation of the planter box's actual drainage and underground conditions which was deemed outside the scope of the study. Nonetheless, several design improvements and retrofits were suggested based on the provisions of current design guidelines to ensure that the hydraulic and water quality goals are achieved without potential damage to nearby structures. Moreover, continuous monitoring data is required to provide more accurate design evaluation and can serve as a guide in the construction of similar facilities in the future.