• Journal of the Korean earth science society
• /
• v.36 no.1
• /
• pp.125-135
• /
• 2015

The purpose of this study were to sample particulate matter and analyze its elements and microorganisms for secondary school science project. The particulate matter was sampled on the rooftop a four-store building at a university in Chungju province. A simplified capturing system was developed with the parts, motor-pump, innet, $1.0{\mu}m$ teflon filter, filter-holder, etc. Using the system, this study had sampled particulate matter during Dec., 2013-Jun., 2014. Then, this study analyzed the elements and microorganisms of the sampled particulate matter. Results have been shown that the particulate matter derived China urban area is mainly consisted of the artificial pollutant, such as Cu, Zn, Cd, Ni, Pb. In addition, this study has been shown that microorganisms, such as bacteria and fungi, are included in the particulate matter. Therefore, this study suggests a new systemic investigation and monitoring about the particulate matter, specially originated from China. Also, this study provides a sample for secondary school science experiment.

• Food Science and Industry
• /
• v.54 no.1
• /
• pp.11-28
• /
• 2021

Air pollution caused by particulate matters (PM) has become a global issue. PM is known to threaten human health by causing respiratory and cardiovascular disease. PM can be introduced to human gastrointestinal track through food intake, causing inflammation and changes in gut microbiota. Even at low PM concentrations, prolonged exposure to PM can cause significant accumulation of PM in food products. The adsorption of PM onto food surfaces is expected to be strongly influenced by the properties of food surfaces, but few studies have been reported. This paper examines several important food surface properties that may affect the interactions between PM and food surfaces, including surface wettability, surface charge, and surface microstructure. Understanding the adsorption of PM onto food surfaces can provide useful guidance for classifying PM-sensitive foods and controlling food chains, including cultivation, processing, preservation, and cooking, to ensure food safety against PM.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2007.10a
• /
• pp.132-133
• /
• 2007

• Korean Journal of Microbiology
• /
• v.48 no.2
• /
• pp.134-140
• /
• 2012

Asian dust storms originating in the arid desert of China and Mongolia usually occur from late winter through spring, and more than one million tons of dust per year is transported to the Korean Peninsula by the prevalent westerly winds. We supposed that these dust particles could include bioaerosols and act as carriers of microorganisms. In order to clarify the dynamics of microorganisms moving with these particles, the concentration and composition of microorganisms associated with settled particles were compared between samples collected during Asian dust events and those under non-dust periods. From February to April 2008, settled dust particles were collected at one location in Ulsan using rainfall meter of 200 mm diameter. During this period, there was one Asian dust event in Ulsan. The bacterial concentrations were higher in samples collected during Asian dust event than those under non-dust period, whereas fungal concentrations were rather similar regardless of the Asian dust event. We analyzed 16S rRNA gene sequences of 45 bacterial isolates obtained from the settled particle samples. These isolates belonged to either genus Bacillus or genus Streptococcus and were tentatively identified as B. amyloliquefaciens, B. aryabhattai, B. atrophaeus, B. licheniformis, B. megaterium, B. methylotrophicus, B. pumilus, B. sonorensis, B. subtlis, B. vallismortis, S. epidermidis, and S. succinus. In cases of fungal isolates, genera such as Mucor, Alternaria, Cladosporium, and Aspergillus were tentatively identified from samples collected at both Asian dust and non-Asian dust periods. It appears that endospore-forming bacteria such as Bacillus sp. rather than fungal spores are more likely to be associated with Asian dust particles.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.2
• /
• pp.1204-1210
• /
• 2014

New control methods are proposed for indoor air quality by removing fine airborne dust-particles. As suspended fine dust-particles contain inorganic dust as well as fine organic bacteria, studies for simultaneous control of these contaminants are required. In this study, photocatalytic disinfection of indoor suspended microorganisms such as E. coli and Bacillus subtilis is performed by three types of photocatalysts with UVA irradiation. The UVA irradiation strength was controlled to the minimum $3{\mu}W/cm^2$, and ZnO, $TiO_2$, and ZnO/Laponite ball were used as the catalysts. The results indicate that E. coli was removed over 80 % after about 2 hours of reaction with UVA and all three types of photocatalysts, whereas only with UVA, around 50 % E. coli removal was obtained. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilizing capacity to $TiO_2$. However, in case of B. subtilis, which has thick cell wall in its spore state, disinfection was not effective under the low UVA irradiation condition, even with the catalysts. Further studies need to figure out the optimal UVA irradiation ranges as well as photocatalysts doses to control airborne dust, to provide healthy clean air environment.

• Proceedings of the KAIS Fall Conference
• /
• 2010.05b
• /
• pp.1115-1118
• /
• 2010

최근 실내공기질에 대한 관심이 높아지면서 실내공기질을 쾌적하게 유지하기 위한 다양한 기술에 대한 연구가 활발히 이루어지고 있다. 기존에는 미세먼지와 부유미생물 등이 가장 중요한 오염물질이었으나, 최근에는 이산화탄소가 크게 각광받고 있다. 이산화탄소는 그 자체가 환기의 지표이기도 하지만, 최근의 저탄소 녹색성장 기조에 따라 환기에 의한 냉난방 에너지 비용을 절감하는 방안에 대한 관심도 크게 높아지고 있다. 본 연구에서는 제올라이트를 이용하여 실내공간의 이산화탄소를 제어하는 방안에 대하여 기술하였다. 소형 lab-scale의 이산화탄소 흡착성능 평가시스템을 제작하고, 이를 이용하여 제올라이트의 이산화탄소의 흡착성능을 알아보았다. 또한, 본 시스템의 실용화를 위해서는 이산화탄소가 흡착한 제올라이트의 재생이 필요한데, 이를 위하여 다양한 온도와 압력 등의 조건 하에서 이산화탄소의 탈착성능을 TSA/PSA를 이용하여 알아보았다. 흡착실험을 통하여 제올라이트를 이용한 실내공간용 이산화탄소의 저감 효과를 확인할 수 있었다. 그러나, 탈착실험 결과 2~5회 정도 열탈착 시킨 후에는 이산화탄소의 흡착 성능이 현저하게 감소하여, 이를 개선하기 위한 방안의 개발이 필요함을 알 수 있었다.

• Journal of the Institute of Convergence Signal Processing
• /
• v.19 no.4
• /
• pp.167-173
• /
• 2018

We propose an air purification system that utilizes aerial plant parts and root zone of indoor plants where light is insufficient and air circulation is bad. In order to maximize the air purification effect of the plant, the aerial plant parts illuminates mixed light combining blue and green LED and CRI(Color Rendering Index) LEDs close to natural light, respectively. And the root zone was forcibly circulated by the fan to use the soil as a filter. The indoor air purification system combined with the light source and the fan removed most polluted air in the shortest. In the case of mixed light and CRI LEDs of indoor air purification system, fine dust decreased by 14%, 14.2%, and TVOC(Total volatile organic compounds) decreased by 7.5% and 9.4%, respectively. In the experiment in which the fan was operated for 15 minutes, the TVOC decreased to 97.8%. The photosynthesis of the plant and the use of soil as a filter were able to purify polluted air in a short time. And the fan's temporary operation gave the similar effect of continuous operation.

• Microbiology and Biotechnology Letters
• /
• v.48 no.4
• /
• pp.455-462
• /
• 2020

Leuconostoc mesenteroides CJNU 0705 was isolated from a breast milk sample and identified by 16S rRNA gene sequencing and confirmed by its ability to produce dextran from tryptic soy agar plates supplemented with 2% sucrose. This strain can absorb various heavy metals including lead (Pb) and cadmium (Cd) which are both found in fine dust and have been shown to be harmful to human skin. In addition, Leu. mesenteroides CJNU 0705 has demonstrated antimicrobial activity against Propionibacterium acnes, the primary causative agent of acne. Given these traits it was natural to evaluate the use of this strain in the fermentation of several natural extracts from green tea, carrot, annual wormwood, parsley, broccoli, and corn silk, which are known to improve skin health, to see if it could increase their dextran content when supplemented with no sucrose, 2% sucrose, or 2% sucrose and 3% yeast extract. The extracts supplemented with both yeast and sucrose were found to produce the most dextran, which was confirmed by the scanning electron microscope (SEM) images. These results suggest that Leu. mesenteroides CJNU 0705 and its fermented natural extracts could be used as functional materials for improving human skin health.

• Tuberculosis and Respiratory Diseases
• /
• v.59 no.3
• /
• pp.279-285
• /
• 2005

Background : Ambient particles during Asian dust events are usually less than $10{\mu}m$ in size, and known to be associated with the adverse effects on the general population. There is little evidence linking Asian dust to adverse effects on the airways. In 2002, the authors found that particulate matter during Asian dust events had an effect on the symptoms and pulmonary function of patients with bronchial asthma. An aggravating factor might be that of a viral infection, but this remains unclear. Conversely, it has been speculated that African dust may carry the virus responsible for foot and mouth disease. Asian dust events are also likely to be responsible for transporting viruses, some of which are pathogenic, and common in many environments. Therefore, in this study, air samples were screened for the presence of viruses. Methods : Air samples were collected 20 times each during Asian dust events and under non-dust conditions, for at least 6 hours per sample, using a high volume air sampler (Sibata Model HV500F), with an airflow rate of 500L/min, between April and August 2003, and between April and August 2004. The samples were then screened for the presence of targeted viruses (Influenza A, B, Hog cholera virus, and Aphthovirus) using a polymerase chain reaction method. Results : One Asian dust event occurred between April and August 2003, and 3 between April and August 2004, with a 24 hour average PM10 level of $148.0{\mu}g/m^3$. The 24 hour average PM10 level was $57{\mu}g/m^3$. There was a significant difference in the PM10 concentration between dusty and clear days. No viruses (Influenza virus, Aphthovirus, and Hog cholera virus) were identified in the air samples obtained during the dusty days. Conclusions : Although no virus was detected in this study, further studies will be needed to identify suspected viruses carried during Asian dust events, employing more appropriate virus detection conditions.

• Journal of Wetlands Research
• /
• v.22 no.4
• /
• pp.312-320
• /
• 2020

Various LIDs with natural water circulation function are applied to reduce urban environmental problems and environmental impact of development projects. However, excessive Infiltration and evaporation of LID facilities dry the LID internal soil, thus reducing plant and microbial activity and reducing environmental re duction ability. The purpose of this study was to develop a real-time measurement system with complex sensors to derive the management plan of LID facilities. The test of measurable sensors and Internet of Things (IoT) application was conducted in artificial wetlands shaped in acrylic boxes. The applied sensors were intended to be built at a low cost considering the distributed LID and were based on Arduino and Raspberry Pi, which are relatively inexpensive and commercialized. In addition, the goal was to develop complex sensor measurements to analyze the current state o f LID facilities and the effects of maintenance and abnormal weather conditions. Sensors are required to measure wind direction, wind speed, rainfall, carbon dioxide, Micro-dust, temperature and humidity, acidity, and location information in real time. Data collection devices, storage server programs, and operation programs for PC and mobile devices were developed to collect, transmit and check the results of measured data from applied sensors. The measurements obtained through each sensor are passed through the Wifi module to the management server and stored on the database server in real time. Analysis of the four-month measurement result values conducted in this study confirmed the stability and applicability of ICT technology application to LID facilities. Real-time measured values are found to be able to utilize big data to evaluate the functions of LID facilities and derive maintenance measures.