Considering the characteristics of aldehydes among volatile organic compounds, a combined process was established by linking an absorbent and a photocatalytic reactor. Experiments to find the optimal operating conditions of the combined process showed that as the amount of photocatalyst coating increases, the wavelength of the ultraviolet lamp used becomes shorter, the photodegradation rate becomes faster, and the removal efficiency increases. It was also demonstrated that by controlling the relative humidity during the connection process of the combined process, the re-evaporation phenomenon at the front end (absorption area) of the hybrid process can be improved and the removal efficiency at the back end (photocatalytic reaction area) can be significantly enhanced. This confirmed the need for a combined process that complements the advantages and disadvantages of each process.

Oysters are the most widely produced shellfish culture in Korea and 90% of their weight. Main component of oyster shell is CaCO3 and an appropriate calcination temperature was derived using thermo-gravimetric analysis. The difference in components for each calcination temperature was confirmed and the adsorbent was manufactured by activation. The oyster shell adsorbent surface area was 5.72m2/g with pores in the mesopore range. The adsorption amount was 37.44 mg/g. Therefore, the possibility of using oyster shell as an adsorbent was confirmed.

Vulnerable populations in healthcare facilities are more sensitive to exposure to indoor air pollutants, and therefore are more affected by such pollutants than the general population. This was the underlying reason why studies of indoor air pollutant concentration distribution and health risk assessment have been conducted targeting facilities, such as daycare centers, medical facilities, elderly care facilities, and postnatal care centers. However, previous studies have mainly focused on daycare and medical facilities for their research, and relatively speaking, studies conducted on the other venues are lacking. Therefore, this study aims to present the current status of indoor air quality and perform a health risk assessment in regard to Formaldehyde exposure at postnatal care centers and elderly care facilities. Here, the study focused on facilities that had undergone pollution level inspections from January 2017 to December 2021. A total of 81 postnatal care centers and 48 elderly care facilities were selected as the subject of the study. Then, the study utilized concentrations of five elements (CO2, HCHO, PM10, PM2.5, TBC) to determine the status of indoor air quality of both postnatal care centers and elderly care facilities. For health risk assessment, HCHO concentration was used. The investigation demonstrated that the yearly average concentration of the five elements stood within the indoor air quality maintenance standards, and the ratio of PM2.5 to PM10 in the two types of facilities was distributed as high as about 70%. In addition, the study showed that HCHO and TBC demonstrated a positive correlation when the relationship between indoor temperature and humidity with the five elements was examined. The health risk assessment showed that the cancer risk level of postnatal care center users stood below 10-6, below the level that is perceived as an acceptable risk. The cancer risk of workers from both postnatal care centers and elderly care facilities and elderly care facility users exceeded the acceptable risk level of 10-6, but was shown to be below 10-4, the maximum acceptable risk.

This study was performed to investigate the effects of water molecules on ozone oxidation of acetaldehyde using a manganese oxide catalyst at room temperature. The catalytic ozone oxidation was conducted at different relative humidity (RH) conditions of 0%, 50%, and 80%. As the RH increased, both ozone and acetaldehyde removal efficiencies dropped due to competitive adsorption on the surface of the catalyst. At the highest RH of 80%, the oxidation reaction was severely retarded, and oxidation by-products such as acetic acid were formed and adsorbed on the surface. After the ozone oxidation of acetaldehyde, the regeneration of the catalyst using ozone alone was tested, and the further oxidation of accumulated organic compounds was investigated under the RH conditions of 0%, 50%, and 80%. When the highest relative humidity was introduced in the regeneration step, the ozonation reaction with the by-products adsorbed on the catalyst surface decreased due to the competitive reaction with water molecules. These findings revealed that, only when relative humidity was low to minimize the formation of by-products, the ozone oxidation of acetaldehyde using the manganese oxide catalyst at room temperature can be feasible as an effective control method.

Recently, there has been growing interest in harmful substances released from household items such as volatile organic compounds (VOCs) and this has increased people’s environmental awareness. In this study, adhesives and manicures were used as samples of indoor household goods and formaldehyde emission and tested over time under temperature conditions of 15oC, 25oC, 35oC, and 45oC. The small chamber method as the indoor air quality process test method was employed and used to evaluate the concentration of formaldehyde emissions. As a result, formaldehyde emissions gradually decreased over time in both tests using adhesives and manicures. The cumulative emission showed a logarithmic function over time, and the formaldehyde can be released for longer periods of time at lower temperature conditions. The logarithmic value and response time showed linear relationships, and it can be inferred that the formaldehyde was released from the sample through the first order reaction. Furthermore, the relationship between temperature and velocity constants which was determined using the Arenius linear equation showed that the reaction rate of formaldehyde can be estimated by a temperature change.

In this study, a manganese catalyst on the surface of a ceramic support was developed for the removal of odor emitted from barbecuing restaurants. Its ozone oxidation at room temperature was tested using acetaldehyde (CH3CHO), the most dominant compound in the barbecuing odor, and the ozonation efficiency under wet conditions was also studied. The manganese catalyst was made with the honeycomb-type ceramic support, and an acid pretreatment was applied to increase its specific surface area, resulting in an increase of the degree of dispersion of manganese oxide. The acetaldehyde removal efficiency using the manganese catalyst on the acidpretreated support (Mn/APS) increased by 49%, and the ozone decomposition rate and the CO2 conversion rate also increased by 41% and 27%, respectively. The catalyst without surface pretreatment (Mn/S) showed a low efficiency for the acetaldehyde ozonation, and other organic compounds such as acetic acid (CH3COOH) and nonanal (CH3(CH3)7CHO) were found as oxidation by-products. In comparison, CO2 was the most dominant product by the ozonation of acetaldehyde using the Mn/APS. When the relative humidity was increased to 50% in the influent gas stream, the acetaldehyde removal efficiency using the Mn/APS decreased, but only the production rates of CO2 and acetic acid were changed. As a result, the manganese oxide catalyst on the surface of the acid-pretreated honeycomb support manifested high acetaldehyde ozonation even at humid and room temperature conditions.

트랜스 신남알데하이드(TCA)는 계피의 활성성분 중 하나로 알려져 있으며, 항바이러스, 항균, 항진균 뿐 아니라 일부 암세포주에서 항암 작용이 있다고 보고된 바 있다. 하지만, 위암세포주에서의 보고는 미비하며 그 작용기전에 대해서는 밝혀진 바가 없다. 본 연구에서는 위암 AGS 세포주에 대한 증식 억제작용 및 그 기전을 살펴보았다. TCA는 농도의존적으로 AGS 세포의 생존율을 억제하였다. AGS 세포 형태로 보아 TCA에 의한 세포사멸을 확인할 수 있었다. 그 기전을 확인하기 위하여, 세포사멸 관련 단백질의 발현양을 조사한 결과, TCA는 p53과 Bax의 단백질 발현을 증가시켰다. 또한, 분절된 caspase 9 및 PARP 의 발현이 증가되는 것으로부터 TCA가 AGS 세포주의 세포사멸을 유도하였음을 알 수 있었다. 본 연구결과로부터 TCA가 위암에 대한 항암 활성이 있음을 확인하였으며, 추후 지속적인 연구를 통해 항암제 후보물질로 기대된다.

The Odor-causing compounds from grilled meat restaurants are mainly ammonia, aldehydes, and volatile organic compounds (VOCs). Acetaldehyde is known to have the greatest odor contribution. This study examines the application of silica gel for acetaldehyde in gas stream. Heat-pretreated silica gel showed relatively good adsorption performance and at 150oC, its breakthrough capacity reached up to 51 mg/g. By using Thomas' dynamic model, which well estimated the adsorption performance in this study, the effects of inlet concentration and retention time on adsorption capacity were evaluated. The adsorbent saturated with acetaldehyde was regenerated by reducing the pressure, which was controlled by the vacuum pump. The design factors were found to be 10 sec−1 of space velocity, -184 kPa·hr of desorption condition, and 10 to 1 of the ratio of cross sectional area to the height for the fixed-bed. The cyclic operation of adsorption and desorption step in the fixed bed packed with silica gel appeared to have 7.0-8.8 mg/g of acetaldehyde removal capacity and 99% of regeneration.

To abate the problem of odor from restaurants, a hybrid adsorbent consisting of organic and inorganic materials was developed and evaluated using acetaldehyde as a model compound was deveioped and evaluated. Powders of activated carbon, bentonite, and calcium hydroxide were mixed and calcinated to form adsorbent structure. The surface area of the hybrid adsorbent was smaller than that of high-quality activated carbon, but its microscopic image showed that contours and pores were developed on its surface. To determine its adsorption capacity, both batch isotherm and continuous flow column experiments were performed, and these results were compared with those using commercially available activated carbon. The isotherm tests showed that the hybrid adsorbent had a capacity 40 times higher than that of the activated carbon. In addition, the column experiments revealed that breakthrough time of the hybrid adsorbent was 2.5 times longer than that of the activated carbon. These experimental results were fitted to numerical simulations by using a homogeneous surface diffusion model (HSDM); the model estimated that the hybrid adsorbent might be able to remove acetaldehyde at a concentration of 40 ppm for a 5-month period. Since various odor compounds are commonly emitted as a mixture when meat is barbecued, it is necessary to conduct a series of experiments and HSDM simulations under various conditions to obtain design parameters for a full-scale device using the hybrid adsorbent.

In order to protect the health of students and to prevent environmental harm, the School Health Law has been enacted and enforced. In the current “School Health Law Enforcement Rule”, school facilities, such as student desks and chairs, are required to use a small amount of formaldehyde emission values. In this study, an analysis was conducted with the purpose of using the basic data for the adjustment of the present emission standard. The formaldehyde exposure trend in the classroom was evaluated by examining the newly purchased student desks and chairs. As a result of measuring the compound levels in ten schools, the new student desks and chairs seemed to have contributed little to indoor formaldehyde levels. Only one classroom out of ten schools exceeded the threshold of 100 μg/m³ in Class 2 (without new desks and chairs) [(2)103.7 μg/m³]. A measurement of the classrooms exposed to formaldehyde for more than 10 years did not exceed the standard value. It is also very likely to be a source of contamination due to the recent construction (within 6 months) of indoor building materials, which was the dominant feature of the nine new schools. Although the study comprised a limited measurement, the appraisal results are suitable for HCHO emission.

This study aims to evaluate the relationship with the concentration and odor intensity using the odor sensory method for 5 types of aldehyde compounds and styrene. For the measurement, 13 panelists were selected by several criteria through a panel test. The estimation showed that the correlation of the concentration with odor intensity for the 12 compounds including of the sulfur compounds, ammonia, and trimethylamine can be reasonably expressed by the equation I = Aㆍlog C + B (I : odor Intensity, C : material concentration, A : material constant, B : constant). The equations show the sensivities of intensity change for the change of concentration. According to the increase of concentration the odor intensities for acetaldehyde and iso-valeraldehyde increase larger than for the other aldehydes. Regulation standards of 12 species of odor substance concentraton and odor intensity by using the correlation equation was reviewed for adequacy. It was evaluated that the regulation standards on site boundary in operation are too low for NH₃, DMDS, and iso-valeraldehyde and too high for TMA. The result of this study is suggested to be used as a base data for research on measures to improve the regulation standards for complex odor concentration on site boundary in operation.

According to a recent government study, development and distribution of functional building materials are increasing in Korea.
In this study, we evaluated reduction performance of formaldehyde and toluene by sorptive building materials using small-scale chamber(20L) test method for 7 days.
According to the results of this study, 18 building materials showed that the effects of formaldehyde reduction among the 23 building materials. And the number of the building materials with respect to its ability to reduce the concentration of toluene was relatively small.
The mean sorption rate and total amount of sorption for formaldehyde were 36.8% and 1,525.4㎍/㎡, respectively. The sorption rate and total amount of sorption for formaldehyde were in the range 1.5∼78.4% and 87.5∼3,086.0㎍/㎡, respectively.
And the mean sorption rate and total amount of sorption for toluene were 11.6% and 1,054.4㎍/㎡, respectively. The sorption rate and total amount of sorption of toluene were in the range 0.1∼62.4% and 29.6∼6,764.0㎍/㎡, respectively.
In most cases, the performance of the building materials with respect to its ability to reduce the concentration of pollutants has steadily decreased within 7 days.

This study was aimed to evaluate the relationship between the concentration and dilution factor (ratio) using the Air Dilution Olfactory Method, which is suggested in the Standard Method of Odor Compounds, by measuring dilution factor for 5 types of aldehyde compounds and styrene. For the measurement, 13 panelists were selected by several criteria through panel test. Panelists chosen for their closely similar sensitivities provide more reproducible values. The estimation showed that the correlation of the concentration with dilution factor for the 12 compounds including the sulfur compounds, ammonia, and trimethylamine can be reasonably expressed by the equation log C=Af∙logD+F(Af: material constant, F: constant). The result of this study is suggested to be used as a base data for research on measures to improve the regulation standards for complex odor concentration on site boundary in operation, as well as a correlation between the concentration and dilution factor for the designated foul odor substances, and their characteristics.

This study was to assess the lifetime cancer and non-cancer risk on exposure to volatile organic compounds (VOCs) and formaldehyde of worker and user at public facilities in Korea. We measured the concentrations of formaldehyde and VOCs in indoor air at 160 public buildings that 5 kinds of public facilities (30 hotel, 30 fitness center, 25 gosiwon, 30 reading-room and 45 video-room) all over the country. There were estimated the human exposure dose and risks with averages of the using-time and frequency for facility users and office workers, respectively. Carcinogens (benzene and formaldehyde) were estimated the lifetime excess cancer risks (ECRs). Non-carcinogens (toluene, ethylbenzene, xylene, and styrene) were estimated the hazard quotients (HQs). HQs of four non-carcinogens did not exceed 1.0 for all subjects in all facilities. Higher HQs of toluene were observed at the reading-room. The average ECRs of formaldehyde and benzene for facility worker and user were 1×10^-4~1×10^-6 level in all facilities. The estimated ECRs for reading-room were the highest and the fitness center and gosiwon were the next higher facilities. Because lifetime ECRs of carcinogens exceeded 1×10^-4 for facility worker in the most facilities, risk management of formaldehyde and benzene in the facilities was necessary. IAQ guidelines should be determined strictly to prevent occurrence of disease caused by poor IAQ beforehand.

An effective method, use of a 2,4-dinitrophenylhydrazine (DNPH) derivatization and high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection, has been used for separation carbonyl compounds. In particular, acetonitrile/water composition as a mobile phase could not separated acrolein/acetone and 2-butanone/ butyraldehyde. In this study, however, that"s compounds separated using acetonitrile/water/tetrahydrofuran as a mobile phase. The resolution was 1.48 and 1.46, respectively. Also, aldehydes and ketones was shown different decrease rate and increase resolution at increase tetrahydrofuran ratio. But butyraldehyde become coeluted methacrolein. Therefore, it is need to consider of mobile phase for separation of butyraldehyde.

In this study, we attempted to evaluate the relationship between dilution‐to‐threshold (D/T) ratio derived by air dilution sensory (ADS) test and the concentration levels of both individual odorant (using H₂S and acetaldehyde (AA)) and their mixture. For the purpose of our comparative study, we prepared both standard gases of two individual compounds and their mixture at 9 concentration levels. Each of all these samples were analyzed by ADS test, and the results were analyzed in relation to their odor intensity. The results of individual odorant samples showed the two contrasting characteristics of each individual compound. H2S generally showed sensitive detection at low concentration but less sensitive detection with increasing concentration. In contrast, AA showed fairly contrasting trend with slow increasing sensitivity. When the D/T ratios estimated from individual samples were used to predict those of mixed samples, the results were reflecting the mixed effects of the basic characteristics owned by each individual compound. As the lower and upper odor intensities of mixed samples were best reflected by AA and H2S, respectively, the D/T ratio of mixed samples complied with the larger D/T values of each compound at a given odor intensity.

Five kinds of odorous aldehyde were investigated at industrial complex in Busan. Samples were collected by DNPH cartridge at 24 work places, 81 samples in 44 sites, and analysed by HPLC/UV system. Acetaldehyde was detected in 78 samples with range of 1.2~299.7 ppbv. Propionaldehyde, butyraldehyde, n-valeraldehyde and i-valeraldehyde were detected in 7 samples, 11 samples, 2 samples and 9 samples, respectively. Measured concentration of propionaldehyde, butyraldehyde, n-valeraldehyde and iso-valeraldehyde were ranged 14.8~74.1 ppbv, 1.6~132.0 ppbv, 11.7~13.3 ppbv and 113.9~8858.9 ppbv, respectively. Among total analysed samples, 15 samples were over than degree 3 of calculated odor intensity. All of i- Valeraldehyde detected samples were showed over than degree 3. The work places subsisted aldehydes with high concentrations were related with leather-factory wastes disposal plant, leather, feedstuff, producing synthetic seasoning and textile mill.

This study was performed to analysis the concentration of TVOC, 5VOC and formaldehyde for building material of total 262 using 20L test chamber. The concentration of TVOC, 5VOC and formaldehyde were measured 1.001㎎/㎡･h, 43.032㎍/㎡･h, 0.012㎎/㎡･h, respectively. TVOC concentration of paint and floor covering occupied the largest concentration of the indoor building materials as 2.689㎎/㎡･h, 2.120㎎/㎡･h, respectively. 5VOC concentration of floor covering was measured 106.636㎍/㎡･h. Toulene and xylene were occupied the largest part of the 5VOC as 51.2% and 33.1%, respectively. The concentration of formaldehyde for furniture materials occupied the largest concentration of the indoor building material as 0.072㎎/㎡h.

Formaldehyde is important because of its irritant and toxic properties, mutagenicity and carcinogenicity, In this study, liquid chromatography/mass spectrometry (LC/MS) was used for the analysis of formaldehyde after derivatization with 2,4-dinitrophenylhydrazine (DNPH) cartridge. Analytical parameters such as linearity, repeatability and minimum detection limit were evaluated. The linearity (r²) was 0.9999 when analyte concentration ranges from 50 to 400 ㎍/L. The relative standard deviation (%RSD) was 0.83% for the concentration of 400 ㎍/L, and the minimum detection limit (MDL) was 0.27 ppbv. We investigated the distribution of formaldehyde concentrations based on a total of 96 samples(industrial area : 32, complex boundary line : 32, affected (residential) area : 32) measured at the Shi-Hwa industrial complex from April to October 2006. By the statistical analysis of these measurement data, the average level of formaldehyde from industrial area, complex boundary line, and affected area was 2.7, 2.1, and 2.2 ppb during the daytime (10:00~16:00), and 1.4, 1.1, and 1.6 ppb during the nighttime (19:30~23:00), respectively. And also, we investigated the emission concentrations of formaldehyde from various emission sources of 33 individual companies located in the Shi-Hwa industrial complex from September to November 2006. The results of our study showed that the emission concentrations of formaldehyde greatly varied according to industrial and source types. The emission concentrations of formaldehyde showed in the descending oder of 11.4 ppm for insulation cable process, 2.0 ppm for sand casting process, 1.7 ppm for synthesis rubber process, and 1.3 ppm for hexamine process.