In order to minimize a building energy consumption with ventilation, a development of smart ventilation system is very important. In this study, a dry adsorbent that is main element of smart ventilation system was developed for removing indoor CO2, and evaluate the adsorption performance. Specific surface area, pore characteristic and crystal structure of the modified sorbent was measured to analyze physical properties. From this analysis, it was found that the developed absorbent has a low specific surface area, due to mesopores of substrate was filled with metal contained raw material. Additionally, through analysis of the adsorption properties, the developed adsorbent was shown a adsorption form of mesopore (type Ⅳ), which means adsorption amount was rapidly increased at the part of high-pressure. Order to applying for the field, chamber test was performed. Continuous column tests (2,500 ppm) and batch chamber tests (4 m3, 5,000 ppm) showed CO2 removal efficiency of 95% and 88% within 1 hour, respectively.

This study was carried out to estimate odors emitted from toilets in Mugunghwa trains. Two parameters, odor intensity and odor concentration, were used for odor estimation. A direct olfactory method to observe odor intensity for 67 toilets and an air dilution olfactory method to estimate odor concentration for 6 samples were performed. Results showed that odor concentrations in toilets in trains ranged from 6 OU/m3 to 30 OU/m3, and odor intensity in 67 toilets varied from 0 degree to 3.3 degree. The results suggest that odors emitted from existing toilets should be controlled because the odor intensity in 16 toilets reached a level that resulted in complaints about the odor.

In this study, this researcher measured the indoor concentration of radon in elementary schools located in Chungcheongnamdo, and conducted a questionnaire survey from June 2008 to June 2011. Indoor radon densities of elementary schools by season were 86.4 Bq/m3 in winter, 71.2 Bq/m3 in fall, 61.1 Bq/m3 in spring, and 40.5 Bq/ m3 in summer in order. Among flooring materials by construction material, the radon level of concrete was 57.8 Bq/ m3, and cement was 71.5 Bq/m3. For exterior wall materials, it was established that the density of cement, concrete, wood, and soil was 102.9 Bq/m3, 64.4 Bq/m3, 51.0 Bq/m3, and 48.7 Bq/m3, respectively. In addition, for radon densities according to distances between a detector and floors, 150 cm and under was recorded at 99.3 Bq/m3, 151 to 200 cm was recorded at 62.6 Bq/m3, and 201 cm and more was recorded at 59.2 Bq/m3 sequentially. From the results of analyzing correlations between radon concentrations and factors affecting the indoor radon concentrations in elementary schools, it was discovered that the nearer the distances to floors were and the older the construction was(r = 0.300), the higher were indoor radon concentrations. With regard to factors influencing the indoor radon concentrations in elementary schools, derived from multiple regression analysis, it was revealed that distances from floors has the greatest influence(β = 0.354, p < 0.05). And it was determined that the construction year was also a factor contributing to indoor radon levels. This had an explanation power of 27.9%.

In this study, the growth kinetics of sulfur oxidizing bacteria, Acidithiobacillus thiooxidans, and the effect of dissolved oxygen were determined in low pH conditions for the effective removal of high concentrations of hydrogen sulfide. A dual growth kinetic was applied to identify the microbial growth rate at different hydrogen sulfide and oxygen concentrations in the liquid. A modified Monod-Gompertz equation was deemed most appropriate to examine the growth kinetic parameters of A. thiooxidans. The half saturation constants of hydrogen sulfide and oxygen for the modified Monod-Gompertz equation were found to be 0.9 and 1.1 mg/L, respectively. In addition, a bioreactor model, where the Monod-Gompertz equation was modified, was applied to simulate dissolved oxygen concentrations required for the removal of hydrogen sulfide. As a result, the dissolved oxygen concentrations were 0.5, 1.0, 1.5, and 3.3 mg/L, which were necessary to remove hydrogen sulfide to less than 10 ppm at the influent concentrations of 100, 500, 1000 and 3000 ppm, respectively. The required minimum dissolved oxygen concentrations under various conditions including reactor volume, gas retention time, and microbial concentrations can be determined using the numerical model developed in this study.

Hazardous air pollutants such as NO2, VOCs and PM10 were measured Daegu, Korea in major micro-environments,where housewives spend the most of their time, and personal exposure times were estimated by using time activitypatterns and exposure scenarios. The major microenvironments of housewives were selected using the ‘Time-UseSurvey’ conducted by the National Statistical Office in Korea in 2009. A total of 4,514 (weekdays) and 3,063(weekends) housewives were recruited for the ‘Time-Use Survey.’ It seems that housewives are spending about80% of their time in the house, and about 5% of their time outdoors during weekdays and weekends. The indoor/outdoor ratio of the average concentration of NO2 was more than 1, which indicated that the source was indoors.Toluene was shown to have higher concentrations indoors than outdoors. Ethylbenzene and xylene displayedsimilar characteristics to toluene, and the concentration ratio for indoor/outdoor was shown to be 1.29 ± 0.76 and1.04 ± 0.45, respectively, higher concentrations indoors. Based on the results of the time activity patterns ofparticipants, 3 kinds of exposure scenarios were formulated. The spent time and air concentration in eachenvironment were assumed as normal and lognormal distribution, respectively. And then the Monte-Carlosimulation was conducted. According to the result of the simulation, the exposures to hazardous air pollutantsrevealed an increasing pattern as housewives visits other indoor environments such as supermarkets.

Algal problem in drinking water treatment is being gradually increased by causing deterioration of water supplies therefore, especially taste and odor compounds such as geosmin and 2-MIB occur mainly aesthetic problem by its unpleasant effects resulting in the subsequent onset of complaints from drinking water consumer. Recently, geosmin and 2-MIB are detected frequently at abnormally high concentration level. However, conventional water treatment without advanced water treatment processes such as adsorption and oxidation process, cannot remove these two compounds efficiently. Moreover, it is known that the advanced treatment processes i.e. adsorption and oxidation have also several limits to the removal of geosmin and 2-MIB. Therefore, the purpose of this study was not only to evaluate full scale nanofiltration membrane system with 300 m3/ day of permeate capacity and 90% of recovery on the removal of geosmin and 2-MIB in spiked natural raw water sources at high feed concentration with a range of approximately 500 to 2,500 ng/L, but also to observe rejection property of the compounds within multi stage NF membrane system. Rejection rate of geosmin and 2-MIB by NF membrane process was 96% that is 4% of passage regardless of the feed water concentration which indicates NF membrane system with an operational values suggested in this research can be employed in drinking water treatment plant to control geosmin and 2-MIB of high concentration. But, according to results of regression analysis in this study it is recommended that feed water concentration of geosmin and 2-MIB would not exceed 220 and 300 ng/L respectively which is not to be perceived in drinking tap water. Also it suggests that the removal rate might be depended on an operating conditions such as feed water characteristics and membrane flux. When each stage of NF membrane system was evaluated relatively higher removal rate was observed at the conditions that is lower flux, higher DOC and TDS, i.e., 2nd stage NF membrane systems, possibly due to an interaction mechanisms between compounds and cake layer on the membrane surfaces.

Ultrapure water (UPW) is water containing nothing but water molecule (H2O). The use of UPW is increasing in many industries such as the thermal and nuclear power plants, petrochemical plants, and semiconductor manufacturers. In order to produce UPW, several unit processes such as ion exchange, reverse osmosis (RO), ultraviolet (UV) oxidation should be efficiently arranged. In particular, RO process should remove not only ions but also low molecular weight (LMW) organic matters in UPW production system. But, the LMW organic matter removal data of RO membranes provided by manufacturers does not seem to be reasonable because they tested the removal in high concentration conditions like 1,000 ppm of isopropyl alcohol (IPA, MW=60.1). In this study, bench-scale experiments were carried out using 4-inches RO modules. IPA was used as a model LMW organic matter with low concentration conditions less than 1 ppm as total organic carbon (TOC). As a result, the IPA removal data by manufacturers turned out to be trustable because the effect of feed concentration on the IPA removal was negligble while the IPA removal efficiency became higher at higher permeate flux.

본 연구에서는 염 농도에 따른 간장의 발효과정 중에 microflora와 향미의 변화를 분석하였다. 전체적으로 4.8%와 8.4%, 12.0%, 15.6% 시료의 호기성균과 호염성균 생균수에 대해서는 큰 증감 없이 유사한 경향으로 나타났다. 발효초기에는 Bacillus amyloliquefaciens, B. licheniformis, B. subtilis가 주를 이루었다. 유산균이나 곰팡이의 미생물총균수 패턴은 모든 염도 별로 거의 유사하게 낮게 나타났으며, 발효 초기에만 발견되었다. 효모 또한 4.8% 간장에서만 2 log CFU/g 이하의 낮은 수치를 보였다. Aldehydes, alcohols, acids의 경우 발효초기부터 발효 3개월까지 저염화 시료에서 많이 생성되었다

Nowdays, costumer’s washing behavior were often times for remove to light-duty dirt. The purpose of this study is to provide the most effective washing conditions of detergent concentration and temperature conditions for help save energy and water resources required to the washing process. Washing conditions were as follows: 2 kinds of detergents and 4 types of artificially soiled fabrics were used. Detergent concentration was 0%, －10%, and －20% below the recommended conc. of manufacturer’s standard. Temperature of bath was 20℃ and 40℃. The results of this study were as follows: First, washing performances of all kind of artificially soiled fabric improved as the temperature of bath at 40℃. Second, the test was conducted under the condition of decreasing respectively －10% and －20% below of the recommended concentration of manufacturer’s standard detergent. The average of washing efficiency was not considerably affected by the reduction of 10% below of manufacturer’s standard. Third, in case of the water temperature were 20℃, polyester/cotton blended fiber were higher degree of washing efficiency than cotton fiber.

For introducing the groundwater quality assessment using background concentration of groundwater, several methods had been studied to estimate the background concentration of groundwater and to suggest the background concentration of study area. Some methods such as Box whisker plot, Percentile and Cumulative probability distribution had been adopted to estimate background concentration, and it was evaluated that the Cumulative probability distribution method presents more reasonable background concentration because it can consider the data distribution. So we estimated the background concentration of study area using cumulative probability distribution method. We suggested the background concentration for each hydrogeology respectively in case hydrogeological water quality similarity is very low.

The research on the actual condition of indoor asbestos concentration in Korea has not been thoroughly accomplished up to now. In this research the ratio of asbestos-containing buildings and indoor asbestos concentration was studied. This investigation was conducted in 2012 and 2013 and buildings were categorized based on region, building type by use, existing space(ground or basement), and construction year, respectively. Also the indoor asbestos concentration change was monitored to evaluation the efficiencies of two types of asbestos-concentration abatement devices.As a result, the ratio of asbestos-containing buildings in Seoul was largely decreased. The ratio of asbestos-containing buildings was higher in hospitals and schools regionally and in ground buildings than in basement. The average indoor asbestos concentrations were 0.0011, 0.0008 piece/cc in 2012 and 2013 investigation, respectively. Those values were much lower than standards(0.01 piece/cc), therefore the threat of indoor asbestos concentration might be negligible. In asbestos-concentration abatement experiments, the circulation velocity of ventilator were changed 2-6.7 m/sec. With 6.7 m/sec of velocity of ventilator, the concentration of indoor asbestos was fluctuated and maximum value was 2.4 piece/cc. With 4.5 and 2 m/sec of velocities of ventilator, the maximum concentration of indoor asbestos was fluctuated and maximum value was 0.9 piece/cc. This indicated that the concentration of indoor asbestos was decreased partly due to the free drop of asbestos. From these results, the proper velocity of ventilator seems to be between 4.7 and 6.5m/sec under this circumstance and further research is required. These research results may be used to guideline of asbestos management policy.

It is important to predict chlorine decay with different water purification processes and distribution pipeline materials, especially because chlorine decay is in direct relationship with the stability of water quality. The degree of chlorine decay may affect the water quality at the end of the pipeline: it may produce disinfection by-products or cause unpleasant odor and taste. Sand filtrate and dual media filtrate were used as influents in this study, and cast iron (CI), polyvinyl chloride (PVC), and stainless steel (SS) were used as pipeline materials. The results were analyzed via chlorine decay models by comparing the experimental and model parameters. The models were then used to estimate rechlorination time and chlorine decay time. The results indicated that water quality (e.g. organic matter and alkalinity) and pipeline materials were important factors influencing bulk decay and sand filtrate exhibited greater chlorine decay than dual media filtrate. The two-component second-order model was more applicable than the first decay model, and it enabled the estimation of chlorine decay time. These results are expected to provide the basis for modeling chlorine decay of different water purification processes and pipeline materials.

This study was conducted to evaluate the growth of lactic acid bacteria and quality characteristics of Baechu kimchi prepared with four types of salt (Solar salt, Flower salt, Hanju salt, and Roasted salt) at two different concentrations (10, 15%) during storage. The quality characteristics of kimchi were examined by investigating acid production, growth of lactic acid bacteria, sensory properties, salinity, texture, and color characteristics. Baechu kimchi was fermented for 18 days at 10oC. The pH and total acidity did not change during storage according to type and concentration of salt. Growth of lactic acid bacteria was not affected by type of salt, whereas it was inhibited at 15% salt concentration after 9 days of fermentation. In the quantitative descriptive analysis of sensory properties, kimchi prepared with 10% salt showed significantly higher scores in term of overall acceptability (p<0.05). Meanwhile, there was no significant difference by type of salt. For texture characteristics, hardness of kimchi prepared with 10% salt was significantly higher than that with 20% salt. For color characteristics, L value (brightness) and b values (yellowness) of kimchi prepared with 10% salt increased during fermentation, whereas a value (redness) did not change by type and concentration of salt. The results of this study show that there were no considerable differences in quality characteristics of Baechu kimchi prepared with various types and concentrations of salt. However, Solar salt resulted in more favorable sensory properties and salinity of kimchi than any other types. Further, kimchi prepared with 10% salt showed significantly higher scores in terms of overall acceptability, growth of lactic acid bacteria, salinity, texture, and color characteristics.

감자 가공용 신품종‘새봉’의 무병주 대량생산을 위하여 microponic system에서 배양액의 농도변화가 감자 소식물체 생육에 미치는 영향을 구명하고자 수행 하였다. 조절한 감자 배양액의 농도는 EC 0.2, 0.6, 1.0, 1.4, 1.8, 14.0dS·m−1수준 이었으며 감자 조직배양묘는 생장점과 잎을 2개 포함한 1.5cm길이로 잘라 50mL 유리병(glass vial) 에 1개씩 치상하여 18일, 또는 21일간 2회에 걸쳐 하였다. 배양액량은 용기 당 2mL씩 넣고 10일 후 1 mL를 첨가 하였으며, 환경조건은 일장 16시간, 온도 23 ± 1oC, 40mmol−2·s−1의 백색 LED에서 실험 I의 배양액농도는 EC 0.2, 1.0, 14dS·m−1였으며, 실험 II의 배양액농도는 0.6, 1.0, 1.4, 1.8dS·m−1로 조정하였다. 치상 7일 후 소식물체의 생존율은 0.2dS·m−1에서 90%, 0.6dS·m−1에서 100%, 1.0dS·m−1에서 100%, 1.4dS·m−1에서 0%, 1.8dS·m−1에서 0%, 14.0dS·m−1에서 0% 이었다. 배양액의 전기전도도를 1.0dS·m−1으로 조절한 처리에서 이식 2일 후 뿌리가 발육 되어 소식물체 생육이 왕성하게 생장하여 18일 만에 7개 의 엽, 길이 5cm, 생중 0.5g이상의 식물체로 생육하였다. 배양액의 농도를 0.6dS·m−1으로 조절한 처리에서는 이식 4일 후부터 뿌리가 발육되어 21일 후 5개의 엽, 길이 4cm, 생중 0.2g을 가진 식물체로 생육하였다. 따라서 microponic system에서 무병 감자 묘 대량생산을 위해서는 감자배양액의 전기전도도를 0.6~1.0dS·m−1 조절하여 관리하는 것이 효과적임을 알 수 있었다.

비육돈사의 슬러리에 함유된 악취물질의 농도를 계절별로 비교하여 초지 및 농경지에 살포되는 분뇨의 악취강도를 예측하고자 수행되었다. 1.비육돈사의 슬러리에 함유된 휘발성유기물의 계절별 농도 비교페놀류 중 p-크레졸 농도는 봄, 여름 및 가을에 차이가 없었지만, 페놀, 인돌 및 스카톨 농도는 여름과 가을에 비해 봄에 높았다(p<0.05). 돼지 슬러리의 경우 p-크레졸과 스카톨이 악취강도에 큰 영향을 주기 때문에 계절에 따른 휘발성유기물의 악취강도 차이는 크지 않을 것으로 판단된다. 2.비육돈사의 슬러리에 함유된 휘발성지방산의 계절별 농도 비교휘발성지방산의 경우 악취강도가 높지 않은 단쇄지방산의 농도는 봄철이 여름과 가을보다 높았으나(p<0.05), 악취강도가 상대적으로 높은 이성체지방산의 농도는 계절별로 숫자적인 차이는 보였지만 통계적인 차이는 없었다(p> 0.05). 계절에 따라 휘발성지방산이 악취강도에 미치는 영향은 높지 않을 것으로 판단된다. 결과적으로 봄철에 악취물질의 농도가 더 높은 것은 온도, 환기 및 돈사내부로 유입되는 물의 양에 의한 것으로 추정되며, 여름철은 슬러리에서 생성되는 악취농도 보다 환기에 의해 휘산되는 양이 많아서 슬러리의 악취농도가 감소되거나 증가되지 않았을 가능성이 있는 것으로 판단된다. 이상의 연구결과를 종합하면 비육돈사의 슬러리를 초지 또는 농경지에 살포하였을 때 계절에 의한 악취강도의 차이는 크지 않을 것으로 기대된다.

초지 또는 농경지에 살포되는 퇴비와 액비에 의해 발생될 수 있는 악취민원에 대처하기 위하여, 돼지의 분과 뇨에 존재하는 악취물질 농도를 비교 분석하였다. 1.비육돈의 분과 뇨에 함유된 휘발성유기물의 농도 비교페놀, p-크레졸 및 페놀류 농도는 분 보다 뇨에서 높았으며(p<0.05), 분 보다 뇨에 축적된 비율이 페놀은 138배, p-크레졸은 545배 높았다. 인돌 농도는 분 보다 뇨에서 높았으며, 스카톨은 뇨 보다 분에서 높았다(p<0.05). 휘발성유기물은 대부분 뇨로 배설되었으며, 이 중 농도 및 악취강도가 가장 높은 물질인 p-크레졸이 뇨에 많이 함유되어 있다. 돼지 분뇨를 고액분리 하였을 때 퇴비로 이용되는 고체보다 액비로 이용되는 액상물질에서 악취가 훨씬 강할 것으로 예측된다. 2.비육돈의 분과 뇨에 함유된 휘발성지방산의 농도 비교아세트산과 단쇄지방산 농도는 분 보다 뇨에서 높았으며 (p<0.05), 부티르산과 프로피온산은 차이가 없었다(p> 0.05). 이성체지방산 중 I-부티르산의 농도는 뇨 보다 분에서 높았지만(p<0.05), I-발레르산과 이성체지방산은 차이가 없었다(p>0.05). 휘발성지방산 중에서 아세트산과 프로피온산은 분에서 각각 65와 20%, 뇨에서는 각각 93과 4%로 휘발성지방산의 대부분을 차지하였지만 아세트산과 프로피온산을 포함하는 단쇄지방산은 악취강도가 낮다. 반면에 악취강도가 상대적으로 높은 이성체지방산은 분과 뇨 간에 차이가 없기 때문에 휘발성지방산이 악취강도에 미치는 영향은 크지 않을 것으로 판단된다. 이상의 연구결과를 종합하면, 돼지 분뇨의 악취물질 중 악취강도가 높은 p-크레졸은 뇨에 많이 함유되어 있기 때문에 퇴비와 액비 생산과정 중 액상처리 시 악취강도가 매우 높을 것으로 추정된다. 다만, 악취강도는 휘발성지방산의 농도 변화에 따라 차이가 있을 것으로 생각된다.

This study was conducted to analyze dust mite allergen and bacterial endotoxin concentrations in the subwaycabins. For this aim, we sampled dust using a vacuum cleaner on cabin seats of subway trains operating in threeSeoul Metro Lines from April to May in 2011. The concentration of dust mite allergen and endotoxin were1,137.51±806.26ng/g and 5,742.1(4.68)EU/g, respectively. While, the concentration of dust mite allergen washigher on cabin seats of subway trains in Line B(1,487.61±930.59ng/g) than on those of trains in Lines A andC(641.9±398.3 and 1,344.9±822.4ng/g). All measurements did not exceed the National Workshop Guidelineof 2,000ng/g. While, bacterial endotoxin concentration [GM (GSD)] was higher on cabin seats of subway trainsin Line A [12,373.21(4.97EU/g)] than on those of trains in Line B and C8,520.77(3.98) and 1,631.43(1.88)EU/g. Dust mite allergen concentrations were strongly influenced by the portion of underground (on the subway line)and endotoxin concentrations were significantly correlated with the number of passengers using the subway lines.Seats for seniors and the week showed relatively higher concentrations compared to seats for general passengers.But, no significant difference of dust mite allergen and endotoxin concentrations in the subway cabins was foundrelating to seat type (p=0.451, p=0.564). There was no correlation between the dust mite allergen levels andendotoxin levels in the subway cabins (p=0.439).

한반도의 낙엽성 참나무인 졸참나무(Quercus serrata)의 생태적 지위폭이 CO2 농도와 온도가 상승하였을 때 광, 수분 그리고 영양소 구배에서 어떻게 변화하는지 알아보고자 유리온실에서 대조구와 온난화처리구로 구분하여 재배한 후, 유식물의 20가지 형질을 측정하고 생태적 지위폭을 계산하였다. 그 결과, 생태적 지위폭은 광구배에서 대조구보다 온난화처리구가 넓어졌고, 수분과 영양소 구배에서는 대조구보다 온난화처리구가 좁아졌다. 이것은 지구온난화 진행 시 졸참나무는 광 환경에 대한 내성이 증가되고, 수분과 영양소 환경에 대한 내성이 감소될 것으로 예측할 수 있다. 주성분분석(PCA) 결과, 각 환경 구배에서 요인 1과 요인 2에 의해 대조구와 온난화처리구가 구분되었다. 생태학적 반응은 다양한 형질이 종합적으로 관여하며, 그 중에서 식물의 생산량을 나타내는 형질이 많은 부분 관여하는 것으로 판단된다.