Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ13C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ13C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ13C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.

A large amount of small and medium-sized metal waste is generated during the decommissioning of nuclear power plants (NPPs). Metal waste is mostly contaminated with low-level radioactive, so it needs decontamination for self-disposal and recycling. A large amount of Organic Decontamination Liquid Waste during decontamination will be generated. The generated organic liquid waste is low in concentration, so the decomposition efficiency is low in the decomposition process. A conditioning process is necessary to concentrate at a high concentration. For effective treatment for Organic Decontamination Liquid Waste, the composition of organic liquid waste and conditioning process were analyzed. Organic acids, metal ions, radioactive nuclides, surfactants, etc. are present in the Organic Decontamination Liquid Waste, and suspended solids are sometimes generated by various reactions. According to previous studies, the concentration of organic acids including surfactants obtained results from several tens of ppm to a maximum of 1,000 ppm, so the maximum value of 1,000 ppm was assumed. For the composition and total amount of metal ions, the average value (52.7wt% Fe, 16.3wt% Ni, 15.1wt% Cr, 15.9wt% Mn) of the distribution of metal species removed by the actual decontamination process is applied, and the total amount is 1,000 ppm was assumed. As for the radionuclides, only 60Co and 137Cs, which are expected to be mainly present, were considered, and 60Co was assumed to be 2,000 Bq/g and 137Cs to be 360 Bq/g by referring to the literature. The amounts of suspended solids were assumed to be 500 ppm by referring to the characteristics of the liquid waste generated in the decontamination process of the NPPs. Based on the estimated value, a reaction formula was established and a simulated Organic Decontamination Liquid Waste was prepared. As a result of measurement using an analysis device, the composition of the estimated and simulated Organic Decontamination Liquid Waste had similar values. The conditioning and treatment process largely consists of pretreatment, conditioning, decomposition processes. Organic Decontamination Liquid Waste goes through a pretreatment process to remove impurities with large particles. In the conditioning process, treated water that has passed through the UF/RO membrane system is discharged into the environment. At this time, Concentrated water goes through a decomposition process for processing the Organic Decontamination Liquid Waste, and is discharged to the environment through a secondary RO membrane system. The conditioning process is the low-concentration Organic Decontamination Liquid Waste in the UF membrane system is forming a micelles in an RO membrane system, concentrating it to a high concentration and then go through a recirculation process in the UF membrane system. An experiment was conducted to confirm whether the concentration of surfactants occurred during the conditioning process. As a result of the experiment confirmed that the highly concentrated surfactant formed micelles and was filtered out in the UF membrane system.

This paper proposes a mathematical model that can calculate the luminescence characteristics driven by alternating current (AC) power using the current-voltage-luminance (I-V-L) properties of organic light emitting devices (OLED) driven by direct current power. Fluorescent OLEDs are manufactured to verify the model, and I-V-L characteristics driven by DC and AC are measured. The current efficiency of DC driven OLED can be divided into three sections. Region 1 is a section where the recombination efficiency increases as the carrier reaches the emission layer in proportion to the increase of the DC voltage. Region 2 is a section in which the maximum luminous efficiency is stably maintained. Region 3 is a section where the luminous efficiency decreases due to excess carriers. Therefore, the fitting equation is derived by dividing the current density and luminance of the DC driven OLED into three regions, and the current density and luminance of the AC driven OLED are calculated from the fitting equation. As a result, the measured and calculated values of the AC driving I-V-L characteristics show deviations of 4.7% for current density, 2.9% for luminance, and 1.9% for luminous efficiency.

IMO에서는 선박으로부터 온실가스 감축을 위해 선박의 에너지효율 증진에 관한 논의를 진행하고 있다. 현재, 선박으로부터 발생되는 폐열을 이용한 ORC 발전 시스템을 적용함으로써 선박으로부터 높은 에너지 변환 효율을 기대할 수 있다. 이 기술은 물보다 더 낮은 온도 범위에서 증발하는 프레온 또는 탄화수소 계통의 유기 매체를 작동 유체로 사용한다. 이를 통해 상대적으로 낮은 저온에서 증기 (기체)를 생성 및 동력을 발생시킬 수 있다. 본 연구에서는 유기 랭킨 사이클인 ORC 발전 시스템에서 냉매와 폐열 사이 열·유동해석 (Analysis of Heat flow)을 3D 시뮬레이션 기법을 이용하여 구조물의 내·외부에 흐르는 유체가 온도 변화, 속도 변화, 압력 변화 및 질량 변화를 통해서 구조물에 어떤 영향을 미치는지를 분석하고자 하며, 동 연구는 이 기법을 이용하여 ORC 발전 시스템에서 냉매와 선박 주기 관의 배기가스로부터 일어나는 열교환기의 열전달을 해석하였다.

The concentrations of volatile organic compounds (VOCs) and odor-inducing substances were measured using selected ion flow tube mass spectrometers (SIFT-MS) and a drone equipped with an air quality monitoring system. SIFT-MS can continuously measure the concentration of VOCs and odor-inducing substances in realtime without any pre-treating steps for the sample. The vehicle with SIFT-MS was used for real-time measurement of VOC concentration at the site boundaries of pollution sources. It is possible to directly analyze VOCs concentration generated at the outlets by capturing air from the pollution sources with a drone. VOCs concentrations of nine spots from Banwol National Industrial Complex were measured by a vehicle equipped with SIFT-MS and were compared with the background concentration measured inside the Metropolitan Air Quality Management Office. In three out of the nine spots, the concentration of toluene, xylene, hydrogen sulfide, and methyl ethyl ketone was shown to be much higher than the background concentration. The VOCs concentrations obtained using drones for high-concentration suspected areas showed similar tendencies as those measured using the vehicle with SIFTMS at the site boundary. We showed that if both the drone and real-time air quality monitoring equipment are used to measure VOCs concentration, it is possible to identify the pollutant sources at the industrial complex quickly and efficiently check sites with high concentrations of VOCs.

There has been growing concern over the emissions of formaldehyde and VOCs from automotive interior materials, as these could have an important impact on the in-vehicle air quality (IVAQ) of automotive vehicles. Odor along with VOCs refers to the automotive interior smell emitted directly or indirectly from any part of an automotive interior, based on human olfactory senses and a comfort evaluation of vehicle quality. The objective of this paper is to compare the odor intensity using GC/MS analysis method and odor sensory test in accordance with ISO 12219-2. For the compounds having low odor threshold value and high VOC concentration, it was found that there was the same tendency in each field of odor whether the instrument analysis method or the odor sensory test method was used.

xTiO2-ySiO2 system photocatalysts were developed by sol-gel method based on the change of production parameters, and their structure of crystallization and the specific surface area were measured. Considering the efficiency of the ethanol and phenol degradation using the catalyst, the conclusions were obtained as follows: By means of X-ray analysis of xTiO2-ySiO2 powder that is obtained from Titanium and Silicon alkoxide by sol-gel process, it is shown that crystal structure of anatase type is a dominating structure and, on the other hand, the structure of rutile also partly exists. The increase of SiO2 contents causes the decrease of the degree of crystallization of the gel, whereas the specific surface area preferentially increases. It is shown that more than 90% of ethanol and phenol are degraded when reaction time is about three and an hours, and the maximum degradation rate of ethanol and phenol is shown in 60TiO2-40SiO2 catalyst.

먹는 물 내에 존재하는 발암원인으로 의심되는 유기화학물질을 재래식 정수처리방법으로 제거한다는 것은 불가능하다. 이들을 AOP산화 & M/F membrane 혼성공정법을 이용하여 목적하는 처리수로 처리하고자 지하수를 반응조에 유효용량으로 유입하고 유기화학물질을 인위적으로 투입 혼합하여 충분히 희석시키고 이것을 효율적으로 처리하기 위해 최적운전조건을 도출하였다. 유기 화학물질 중 VOCs는 페놀과 톨루엔을 그리고 농약은 파라치온, 다이아지논과 카바닐을 대상으로 조사하였다. 실험은 각각 분류별 단일용액과 혼합용액으로 수행하였으며, 실험결과 충분한 분해 및 제거를 위한 운전조건은 H2O2는 150 mL로 정량 주입하고, pH는 5.5~6.0, 온도는 12~16℃로 일정하게 유지하고, 용존오존량은 5.0 mg/L이상, 반응시간은 30~40분이 최적 조건이었으며 그리고 같은 반응기 내 분리막의 사용은 0.45 μm 공경크기의 M/F membrane을 이용하여 대량의 음용수를 얻기 위한 결정이었다.

Background : This study was investigated the effect of organic fertilizer application and stem training methods on the growth and yield of Cynanchum willfordii. Methods and Results : Traditional species, C. willfordii conducted the test to the field in Chungbuk ARES, Korea. Two methods, non-supporting (custom) and I-shape supporting was used for stem training method. Planting spacing was adjusted to 30 (interrow spacing) x 20 cm (intrarow spacing) and other key management is the followed the cultivation manual for standard medicinal crops. Organic fertilizer application is conducted in mid-March before planting of C. willfordii. Registered organic agricultural materials such as fungal cultures (CC), mixed organic materials (MO), fermented and mixed expeller cake (EC), and fermented fowl dropping (FD) was used. Application rate is based on the nitrogen application rate after soil testing. Plant height was both good in all at I-shape supporting (266.7 ㎝) and all in non-supporting (160.8 ㎝); however, stem diameter was more thicker in custom (4.6 ㎜) of I-shape supporting and EC (4.8 mm) of non-supporting. Number of branched stem were good at EC from I-shape supporting and non-supporting, as well as leaf growth. SPAD value was evaluated in MO (52.7) of I-shape supporting and EC (52.3) of non-supporting. Number of branched root per organic fertilizer were showed 7.0 at MO from I-shape supporting, but 7.3 at FD from non-supporting. While length of main root were 27.0 cm in MO of I-shape supporting and 31.3 ㎝ in FD of non-supporting. Root weight also more heavier in EC (66.3 g) of I-shape supporting and FD (53.0 g) of non-supporting. When applied organic fertilizer, total density of soil microorganisms were changed into 38.4 ppm in custom; however, it more plentiful of 90.7 ppm in MO, it showed good effect on the replication of soil microbiota. Conclusion : From the investigated results, MO of I-shape supporting was good at overall growth, including good tendency of roots growth.

As economic growth and development of the living standard causes increasing production of organic waste, the desire to take advantage of organic waste to produce energy is also increasing. Organic waste-to-energy can contribute to improving energy independence through domestic energy security as well as improving the environment by reducing the need for landfills. This paper attempts to quantitatively analyze the non-market benefits arising from the organic waste-to-energy policy. To this end, we apply a contingent valuation (CV) that is most widely used to measure the nonmarket benefits. As for the willingness to pay (WTP) elicitation method, we employed the one-and-one-half-bounded dichotomous choice (DC) model, which produces higher statistical efficiency than the single-bounded DC model and yields greater consistency than the double-bounded DC model. In the CV survey result of 1000 Korean households, a total of 586 households (58.6%) revealed zero WTP. This implies that the use of the mixture model to deal with zero WTP responses was a suitable approach in our study. The yearly mean WTP was computed as KRW 3598 for the next ten years per household, which is statistically significant at the 1% level. Expanding the value to the national population gives us KRW 67.3 billion per year and this value demonstrates the non-market benefits of the organic waste-to-energy policy. This quantitative information could be utilized as a significant reference in the implementation of the organic waste-to-energy policy.

In this study, corrosion potential (Ecorr), corrosion rate, and polarization resistance were measured aimed at inorganic inhibitors (passive film type) and organic inhibitors (absorption type). The experiment was conducted using potentiostat for the variable molar ratio and chloride ion concentration of the components of inhibitors in an aqueous solution of saturated calcium hydroxide targeting corrosion. As a result, it was possible to ensure an anticorrosive performance of at least a 1.2 molar ratio of inorganic inhibitors. Also, the organic inhibitors ensured the prevention of the anticorrosive performance of at least about a 0.3 molar ratio. It also showed the tendency that between polarization resistance and corrosion rate, Ecorr and corrosion rate is inversely proportional to the linear. Conversely, the tendency between polarization resistance and Ecorr is proportional to the linear. Also, a distinct difference in organic and inorganic inhibitors’ relationship to Ecorr, corrosion rate, and polarization resistance was not shown.

In this study, in order to comprehend performance of corrosion inhibitor, the experiment study was conducted about corrosion characteristic 3 steps(0.0, 0.6, 1.2) of Chloride by added amount of inorganic(Ca(NO2)2) and organic(DMEA) corrosion inhibitor by the corrosion inhibitor types about 0.6kg/m3, 2.4kg/m3 based on Chloride ion content 1.2kg/m3 for service life prediction of concrete structure by using Poteniostat. As a results, the excellent anti-corrosive performance of organic corrosion inhibitor was seen that absorption types organic corrosion inhibitor has excellent anti-corrosive performance compared to the inorganic nitrous acid corrosion inhibitor by the added amount of corrosion inhibitor