• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2015.11a
• /
• pp.195-196
• /
• 2015

유해화학물질 이송관로의 실시간 유지관리를 위하여 파손사전 예방감시를 위한 이중구조 파이프 제작, GIS관망 구축을 위한 측량 및 시공 속성정보 수집을 위한 스마트 폰 앱 프로그램 개발, 실시간 감시를 위한 서버프로그램 개발을 수행하였다. 또한, 파일럿규모의 야외시험시설을 구축하여 시스템 동작여부를 확인하였다. 파손 예방은 파이프에 부착된 센서 케이블을 통하여 감지하도록 하였고, 누수는 압력센서를 일정한 간격으로 설치하여 시험하였다. VRS 측량장비와 스마트폰을 연계할 수 있는 앱 프로그램으로 실시간 자료 수집을 수행할 수 있도록 하였고, 감시 서버프로그램을 통하여 실시간 감시 및 알람이 가능하도록 하였다.

• Journal of Preventive Medicine and Public Health
• /
• v.5 no.1
• /
• pp.37-42
• /
• 1972

Mountain Wells are very important water source for the most of the climbers in Seoul area. But the facilities around the wells are not modernized to prevent from contamination of microorganism and the other pollutants. We focussed our intention on the detection of some harmful chemical ingredients and contaminants. A total of 58 wells were examined according to the Standard Methods(APHA) and the following results were obtained: 1) Among the examined 58 wells, only 10 wells were adequate to the drinking water standard, 2) 7.9mg of liberated $CO_2$ was found in the Tchun-Ho-Dong Mineral Well, 3) Chemically harmful ingredients were not found, 4) The Mountain Wells were contaminated by Coliform groups as many as 18 times than rural wells.

• Journal of Korean Society on Water Environment
• /
• v.28 no.5
• /
• pp.669-675
• /
• 2012

Recently, there have been active researches regarding endocrine-disrupting chemicals (EDCs). In this study, fifteen small freshwater streams in Cholla-namdo province, South Korea were investigated with respect to the concentration of the endocrine disruptors - Bisphenol A (BPA), styrene monomer (SM), styrene dimer (SD), and styrene trimer (ST) by gas chromatography-mass spectrometry (GC-MS). Measured concentration of the target compounds in the sampled water ranged from

• Journal of environmental and Sanitary engineering
• /
• v.2 no.2 s.2
• /
• pp.61-67
• /
• 1987

The genus Vibrio contains some of the most important intestinal pathogens of humans, including Vibrio cholerae, the cause of epidemic Asiatic cholera. A group of organisms which have been reffered to as the non-agglutinating vibrio (NAG) do not agglutinate in the Vibrio cholerae 0 group 1 antisera, but are indistinguishable from the 0-1 group both chemically and genetically. Non-O-l Vibrio cholerae can cause isolated as well as focal outbreaks of diarrhea, but the volume of fluid loss does not approach that of classic cholera, and the disease is usually self-limiting. These free-living organisms are found world-widely distributed in the environment including sewage, contaminated water, estuaries, seafood and animals. These strains involved in several cases were isolated from the environment and some patients of diarrhea, and a few epidemiologic reports indicated the wide distribution of the strains throughout the country, giving an attention to the role the organisms may play in an outbreak of diarrhea in Korea. More research on the epidemiology, serologic typing and virulence of the group of organisms, should be, therefore, done to obtain a complete understanding of their role in human disease.

• Journal of Korean Society on Water Environment
• /
• v.38 no.2
• /
• pp.82-94
• /
• 2022

In this study, chemically modified biochar (NSBP500, KSBP500, OSBP500) derived from starfish was utilized to improve the adsorption ability of the SBP500 (Starfish Biochar Pyrolyzed at 500℃) in a solution contaminated with heavy metals. According to the biochar modification performance evaluation batch tests, the removal rate and adsorption amount of NSBP500 increased 1.4 times for Cu, 1.5 times for Cd, and 1.2 times for Zn as compared to the control sample SBP500. In addition, the removal rate and adsorption amount of KSBP500 increased 2 times for Cu, 1.8 times for Cd, and 1.2 times for Zn. The removal rate and adsorption amount of OSBP500 increased 5.8 times for Cu. The FT-IR analysis confirmed the changes in the generation and movement of new functional groups after adsorption. SEM analysis confirmed Cu in KSBP500 was in the form of Cu(OH)₂ and resembled the structure of nanowires. The Cd in KSBP500 was densely covered in cubic form of Cd(OH)₂. Lead(Pb) was in the form of Pb₃(OH)₂(CO₃)₂ in a hexagonal atomic layer structure in NSBP500. In addition, it was observed that Zn was randomly covered with Zn₅(CO₃)₂(OH)₆ pieces which resembled plates in KSBP500. Therefore, this study confirmed that biochar removal efficiency was improved through a chemical modification treatment. Accordingly, adsorption and precipitation were found to be the complex mechanisms behind the improved removal efficiency in the biochar. This was accomplished by electrostatic interactions between the biochar and heavy metals and ion exchange with Ca²⁺.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.190.1-190.1
• /
• 2016

One of the most serious problems faced by billions of people today is the availability of fresh water. According to statistics, 15% of the world's total output of dye products is discharged into the environment as dye wastewater, which seriously pollutes groundwater resources. For the treatment of chemically and biologically contaminated water the advanced oxidation processes (AOPs) shows the promising action. The main advantage with AOPs is the ability to degrade the organic pollutants to $CO_2$ and $H_2O$. For this degradation process the AOPs generation of powerful and non-selective radicals that may oxidize majority of the organic pollutants present in the water body. To generate the various reactive chemical species such as radicals (${\bullet}OH$, ${\bullet}H$, ${\bullet}O$, ${\bullet}HO_2$) and molecular species ($H_2O_2$, $H_2$, $O_2$) in large amount in water, we have used the atmospheric pressure plasma. Among the reactive and non-reactive species, the hydroxyl radical (${\bullet}OH$) plays important role due to its higher oxidation potential (E0: 2.8 V). Therefore, in this work we have checked the degradation of various dyes such as methyl orange, methylene blue and congo red using different type of atmospheric pressure plasma sources (Indirect jet and direct jet). To check the degradation we have used the UV-visible spectroscopy, HPLC and LC-MS spectroscopy. Further, to estimate role of ${\bullet}OH$ on the degradation of dyes we have studied the molecular dynamic simulation.

• Carbon letters
• /
• v.14 no.1
• /
• pp.27-33
• /
• 2013

An increase in population initiating rapid industrialization was found to consequently increase the effluents and domestic wastewater into the aquatic ecosystem. In this research the potentialities of Sambucus nigra L. (SNL) plant in the remediation of water, contaminated with methylene blue (MB), a basic dye were investigated. SNL was chemically impregnated with $KHCO_3$. Operating variables studied were pH, amount of adsorbent and contact time. In general, pH did not have any significant effect on colour removal and the highest adsorption capacity was obtained in 0.035 g MB/g-activated carbon. The Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption models were applied to describe the equilibrium isotherms. The adsorption isotherm data were fitted to the Temkin isotherm. The mass transfer property of the sorption process was studied using Lagergren pseudo-first-order and chemisorption pseudo-second-order kinetic models. The sorption process obeyed the pseudo-second-order kinetic model. The surface area, pores volume and diameter were assessed by the Brunauer-Emmett-Teller and Barrett-Joyner-Halenda methods. The results were compared to those from activated carbon (Merck) and an actual sample. The results indicate that SNL can be employed as a natural and eco-friendly adsorbent material for the removal of dye MB from aqueous solutions.

• Journal of the Society of Disaster Information
• /
• v.12 no.2
• /
• pp.122-129
• /
• 2016

In this study, a dual structured pipe for a preventive monitoring on a accident damage, a smartphone app program for a survey and a construction data collection and a server program for a real-time monitoring were developed. A pilot system was installed in the test field to analyze effects of a system developed in this study. The data for a damage prevention was detected by the attached sensors on the pipe. Exclusion was tested by the pressure sensors to be installed at regular intervals. The app and server programs was enabled to the real-time data collection and real-time monitoring linked by VRS survey equipments and a smartphone.

• Restorative Dentistry and Endodontics
• /
• v.22 no.2
• /
• pp.739-750
• /
• 1997

Treatment of root perforation elicits special considerations due to its blood-contaminated circumstances. It is known that conventional dental restorative materials are all leaking. Calcium sulfate is the material which react with water to become chemically set. This study, therefore, was performed to develop a new compound containing calcium sulfate and to evaluate its physical and biological characteristics. Three materials were used, IRM, calcium sulfate, calcium sulfate-hydroxyapatite compound. The composition of the calcium sulfate-hydroxyapatite compound was basically 50 % of calcium sulfate and 50 % of hydroxyapatite mixed with guajacol. The materials were mixed in conventional way and underwent four physical test procedures, setting time, solubility test, compressive strength, and marginal leakage test. All materials were evaluated under the scanning electron microscope to examine the marginal sealing ability. Animal experiment was also performed to test the materials' tissue response. Twenty-four dog's premolars were tested with either furcation perforations or apical retro-fillings. From the results, we found that calcium sulfate possess the good marginal sealing ability. However, calcium sulfate creates many voids which is caused by crystal thrusting action when it reacts with water. It seemed that the voids caused disintegration of the material which eventually lead to tissue reaction. By compounding calcium sulfate and hydroxyapatite, we were able to obtain the better physical properties but it showed larger marginal gap between the material and the root surface. Within the six weeks observation period, both IRM and calcium sulfate-hydroxyapatite compound showed good tissue responses in animal experiment. It is concluded that calcium sulfate would be the material of choice in root perforation repair, but the physical property needs to be further improved.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.30 no.1
• /
• pp.77-88
• /
• 2010

In order to ensure good animal health and performance, it is essential to produce forages with high feeding value and good hygienic quality. However, huge amounts of forages consumed by ruminants are contaminated with mold prior to harvest or during storage as hay, straw or silage. These mold can grow in forages only when nutrients are available, correct temperature exist, oxygen is present, and unbound water is available. Fungal 'species can be divided into two groups: field fungi and storage fungi. Field fungi invade the forages while the crop is still in the field, require high moisture conditions, and are such as species of Fusarium, Alternaria, Clodosporium, Diplodia, Gibberrella and Helminthosporium. Storage fungi invade forages during storage and need less moisture than field fungi. These such as species of Aspergillus and Penicillium usually do not occur any problem before harvest. Mold growth can spoil the nutritional aspects of the forages and also results in secondary metabolites that are highly toxic to animal, humans and plants. Moldy feeds are less palatable and may reduce dry matter intake. This, in turn, leads to a reduction of nutrition intake, reducing weight gains or milk production. Performance losses of 5 to 10 percent are typical with moldy feeds. Mycotoxins are toxic substances produced by fungi (molds) growing on crops in the field or storages. While greater than 400 mycotoxins have been chemically identified, the biological or veterinary medical impact of only several mycotoxins is known. Mycotoxins have attracted considerable attention as potential causes for poor performance and health disorders in domestic livestock. They can be carcinogenic, hepatotoxic, hematotoxic, immunosuppressive, estrogenic, or mutagenic. So, feeding moldy forages has adverse effects on animal health and milk consumers. Also, this author reported that rice straw hay was contaminated mycotoxigenic fungi such as Penicillium roqueforti and Fusarium culmorum in Korea. Therefore, it is an urgent need to develop an improved post harvest storage method to reduce nutrient loss and mycotoxin contamination of forages, which will have a positive impact on human health.