• Asian Journal of Atmospheric Environment
• /
• v.11 no.4
• /
• pp.300-312
• /
• 2017

To improve the understanding of secondary organic aerosol (SOA) formation from the photo-oxidation of anthropogenic and biogenic precursors at the regional background station on Baengnyeong Island, Korea, gas phase and aerosol chemistries were investigated using the Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-ToF-MS) and the Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS), respectively. HR-ToF-AMS measured fine particles ($PM_1$; diameter of particle matter less than $1{\mu}m$) at a 6-minute time resolution from February to November 2012, while PTR-ToF-MS was deployed during an intensive period from September 21 to 29, 2012. The one-minute time-resolution and high mass resolution (up to $4000m{\Delta}m^{-1}$) data from the PTR-ToF-MS provided the basis for calculations of the concentrations of anthropogenic and biogenic volatile organic compounds (BVOCs) including oxygenated VOCs (OVOCs). The dominant BVOCs from the site are isoprene (0.23 ppb), dimethyl sulphide (DMS, 0.20 ppb), and monoterpenes (0.38 ppb). Toluene (0.45 ppb) and benzene (0.32 ppb) accounted for the majority of anthropogenic VOCs (AVOCs). OVOCs including acetone (3.98 ppb), acetaldehyde (2.67 ppb), acetic acid (1.68 ppb), and formic acid (2.24 ppb) were measured. The OVOCs comprise approximately 75% of total measured VOCs, suggesting the occurrence of strong oxidation processes and/or long-range transported at the site. A strong photochemical aging and oxidation of the atmospheric pollutants were also observed in aerosol measured by HR-ToF-AMS, whereby a high $f_{44}:f_{43}$ value is shown for organic aerosols (OAs); however, relatively low $f_{44}:f_{43}$ values were observed when high concentrations of BVOCs and AVOCs were available, providing evidence of the formation of SOA from VOC precursors at the site. Overall, the results of this study revealed several different SOA formation mechanisms, and new particle formation and particle growth events were identified using the powerful tools scanning mobility particle sizer (SMPS), PTR-ToF-MS, and HR-ToF-AMS.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.27 no.2
• /
• pp.67-73
• /
• 2019

In this study, to optimize the production and utilization of biogas for organic waste resources, the precision monitoring of on-site facilities and the energy balance by facility were analyzed, and the solutions for field problems were investigated, and the design and operation guidelines for pretreatment facilities and generators were presented. Gas pre-treatment is required to solve frequent failures and efficiency degradation in operation of high quality refining facilities, and processing processes such as desulfurization, dehumidification, deoxidization, dust treatment, volatile organic compounds, etc. Since these processes are substances that are also eliminated from the high-quality process, quantitative guidelines are not presented in the gas pretreatment process, but are suggested to operate during the processing process as a qualitative guideline. In particular, dust, siloxane, and volatile organic compounds are the main cause of frequent failure of high-quality processes if they are not removed from the gas pretreatment process. Design of the biogas high-quality process. The operation guidelines provide quality standards [Methane content (including propane) of 95% or more] with 90% or more utilization of the total gas generation, two systems, and a margin of 10% or more. It also proposed installing gas equalization tank, installing thermal automatic control system for controlling equalization of auxiliary fuel, installing dehumidification device at the back of high quality for removing moisture generated in the process of gas compression, installing heat-resisting facilities to prevent freezing of facilities in winter and reducing efficiency, and installing membrane facilities in particular.

• Analytical Science and Technology
• /
• v.20 no.6
• /
• pp.453-459
• /
• 2007

This study is for investigation of indoor conditions with air contamination after occupation 120 households in brand-new apartments by measuring the concentration of VOCs and carbonyl compounds. It has been found that TVOC (total volatile organic compounds; TVOCs) were $688.61{\mu}g/m^3$ after moving in. And formaldehyde, toluene, m, p-xylene, acetone and ethylbenzene were $158.56{\mu}g/m^3$, $146.58{\mu}g/m^3$, $69.28{\mu}g/m^3$, $63.80{\mu}g/m^3$ and $29.65{\mu}g/m^3$, respectively. The mean concentrations of indoor air pollutants tend to decrease along an increase dwelling period. But, the mean concentration of d-limonene increased from 2 months to 10 months. Also, toluene, ethylbenzene, m, p, o-xylene amounted to 38.8 % among VOCs studied, this ratio tend to decrease along with and increased dwelling period.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.9
• /
• pp.793-802
• /
• 2009

Adsorption properties were estimated for the organic silicon compounds (siloxanes) in an actual landfill gas (LFG) using adsorbents such as coconut activated carbon, coal activated carbon, silica gel, sulfur adsorbent, carbonized sludge, and molecular sieve 13X. Coconut activated carbon showed the highest removal efficiency of more than 95%. The desorption of hexamethyldisiloxane (L2) from the adsorbent, however, resulted in the remarkable concentration variation of the compound in the treated gas. Silica gel, which had high adsorption capacity for L2 in single substance adsorption experiment in the other study, could not remove the component in the actual landfill gas while it adsorbed well octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in the LFG. Therefore the elimination of hexamethyldisiloxane is an important factor to determine the level of total organosilicon compound in pretreated landfill gas. Moreover, the L2 from the actual landfill gas was effectively adsorbed by the serial adsorption test using two columns packed with coconut activated carbon which has the great capacity of siloxanes removal among others. In order to utilize efficiently LFG as a renewable energy, the emission and adsorptive characteristics of the substance to be treated should be considered for the organization, operation, and management of pretreatment process.

• Korean Journal of Plant Resources
• /
• v.35 no.4
• /
• pp.455-463
• /
• 2022

The effects of freeze-drying (FD), room-temperature drying (RD), and room-temperature drying after roasting (RDAR) on the volatile organic compounds (VOCs), sugar content, flavonoids, and antioxidant activity of Hallabong peel tea were tested. This experiment was conducted to collect a basic information for developing of peel tea. FD samples showed lower total soluble solids and VOCs than other drying treatments. RDAR samples showed a significant difference in VOCs and visual color of FD samples. The reduced VOCs in FD samples was caused by freeze drying treatment; identical VOCs composition of hallabong peel was detected from condensed ice of freeze-drying machine. Metabolomics analysis showed no difference among three drying treatments. In addition, antioxidant activity and total phenolic compounds were not significantly different from three different drying treatments. Thus, RD or RDAR is a suitable drying method for hallabong peel tea rather than FD method in terms of VOCs and economical reasons.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.1
• /
• pp.35-43
• /
• 2010

The main purpose of this study is to offer informations about the current conditions and basic data of sediments for the urban streams in the Busan city. Total 14 urban streams were selected and sediment samples were collected. Then, It was investigated the sediment qualities though the measurement of pH, proximate analysis, elemental analysis, COD, organic carbon content, volatile solid content and heavy metal concentration. Results show that COD, organic carbon content, volatile solid content and heavy metal concentration of sediment are determined in the range of $1.20{\sim}75.07mg\;L^{-1}$, 0.19~11.54%, 0.23~34.21% and $0.4{\sim}732.6mg\;kg^{-1}$, respectively. Finally, Analysis data of sediments were compared with USEPA sediment quality standards and ontario sediment quality guidelines. As a result, when compared with USEPA sediment quality standards, total 9 samples were evaluated as heavily polluted and total 3 samples were evaluated as moderately polluted. But, when compared with ontario sediment quality guidelines, total 3 samples were evaluated as Severe effect level and total 10 samples were evaluated as lowest effect level.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.10
• /
• pp.1682-1689
• /
• 2013

The objective of the present study is to elucidate the physicochemical and microbial properties of Korean traditional rice wine, Makgeolli, supplemented with mulberry during the fermentation process. Four hundred grams of mulberries (20% of the total amount of rice) were ground and incorporated into the rice solution (3.5 L of distilled water, 2.0 kg of rice, 28.0 g of yeast, and 80.0 g of nuruk). The rice solution was then placed in a water bath set at $28^{\circ}C$ and left to ferment for 7 days. The alcohol contents between the control and mulberry Makgeolli were not significantly different. The pH values of the control and mulberry Makgeolli decreased and the total acidity values were elevated after a 7-day fermentation. In the microbial analysis, the total viable cell count, lactic acid bacteria count and yeast count increased considerably through the 7-day fermentation process. For all the samples, the glucose and succinic acid contents were highest among all free sugars and organic acids, respectively. Forty-eight different volatile compounds were found in all the samples after the 7-day fermentation process.

• Horticultural Science & Technology
• /
• v.28 no.3
• /
• pp.476-483
• /
• 2010

Total bacterial populations were cultured from the Hydroball cultivation media in the rhizospheres of 9 different plants including $Hedera$ $helix$ L. and $Dracaena$ $deremensis$ cv. Warneckii Compacta, etc. These cultured bacterial populations were studied to test if the bacterial populations in the plant growing pots may play a role on removal of volatile organic compounds (VOCs) such as benzene and toluene in the air. To meet this objective, first, we tested the possibility of removal of VOCs by the cultured total bacteria alone. The residual rates of benzene by the inoculation of total bacterial populations from the different plant growth media were significantly different, ranging from 0.741-1.000 of $Spathiphyllum$ $wallisii$ 'Regal', $Pachira$ $aquatica$, $Ficus$ $elastica$, $Dieffenbachia$ sp. 'Marrianne' Hort., $Chamaedorea$ $elegans$, compared to the control with residual rate of 0.596 (LSD, $P$=0.05). This trend was also similar with toluene, depending on different plants. Based on these results, we inoculated the bacterial population cultured from $P.$ $aquatica$ into the plant-growing pots of $P.$ $aquatica$, $F.$ $elastica$, and $S.$ $podophyllum$ inside the chamber followed by the VOCs injection. The inoculated bacteria had significant effect on the removal of benzene and toluene, compared to the removal efficacy by the plants without inoculation, indicating that microbes in the rhizosphere could play a significant role on the removal of VOCs along with plants.

• Journal of Korean Society for Atmospheric Environment
• /
• v.23 no.3
• /
• pp.332-343
• /
• 2007

The concentrations of major volatile organic compounds (VOCs) were measured using a passive sampler in the leather industries, Shihwa and Banwol industrial complex. The leather industries were classified into four groups in raw materials and main product. The concentrations of total VOCs measured in process for ${\ulcorner}$ manufacture of reconstituted leather and special treated leather${\lrcorner}$was highest. The main VOCs measured in the leather industries was found to be toluene with a average concentration of 1,200 ppb. The major group selected in the leather industries was divided into three groups by the fingerprint analysis and the principal component analysis. The major VOCs in the groups classified by fingerprint analysis were found to be dependent on the characteristics of raw materials and main products.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.981-985
• /
• 2008

Construction company's role is getting bigger recently because of interest of indoor air quality problem. The using environment-friendly building finishing material is the most benefit method to reduce pollutants in house. It is confirmed the actual condition of environment-friendly building finishing material such as wallpapers, wooden flooring boards, glues, paints, adhesives, plaster boards that are used the work of apartment construction in 2006-2007. It shows that environment-friendly materials have excellent grade mostly, general materials have pass I, pass II grade mostly and are high TVOC emission.