• Membrane Journal
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• v.17 no.2
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• pp.99-111
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• 2007

It is impossible to remove toxic organic substances that are recognized as a cancer caused suspicious element in drinking water using the conventional water purification method. This study introduces groundwater into a reaction chamber as an effective amount of water to process this water using a mixed method of AOP oxidation and M/F membrane and purifies it as a desirable level by artificially mixing such toxic substances in order to effectively process the water. Based on this fact, this study configures an optimal operation condition. The VOCs existed in toxic substances was investigated as a term of phenol and toluene, and agricultural chemicals were also investigated as a term of parathion, diazinon and carbaryl. The experiment applied in this study was performed using a single and composite soolution. In the operation condition applied to fully dissolve and remove such substances, the amount of $H_2O_2$ injected in the process was 150 mL of a fixed quantity, the value of pH was configured as $5.5{\sim}6.0$, the temperature was controlled as a range of $12{\sim}16^{\circ}C$, the dissolved amount of ozone was applied more than 5.0 mg/L, the reaction time was determined as an optimal condition, such as $30{\sim}40$ minutes, and the segregation membrane in the same reactor was determined for acquire water drinking of large quantity using a pore size of $0.45{\mu}m$ M/F membrane.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.230-237
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• 2007

This study was carried out to indicate the status of agricultural environment in Yangpyong area which is special protection area for tap water in Han river during three years($1996{\sim}1998$). The main study was on pesticide monitoring, analysis of pesticides in Bokpocheon water and soil. Water in this small river for supplying to the rice was found nine pesticides residues, ranged from 0.1 to 22.7 ppb, similar patterns from survey conducted in National Institute of Agricultural Science and technology, Soil in rice paddy has also low levels of eleven pesticide residues, ranged from 0.002 to 0.55 ppm.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.281-288
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• 2004

In order to extract and analyze complex features of the behavior of animals in response to external stimuli such as toxic chemicals, we implemented an adaptive computational method to characterize changes in the behavior of chironomids in response to treatment with the insecticide, diazinon. In this paper, we propose an energy minimization model to extract the features of response behavior of chironomids under toxic treatment, which is applied on the image of velocity vectors. It is based on the improved active contour model and the variations of the energy functional, which are produced by the evolving active contour. The movement tracks of individual chironomid larvae were continuously measured in 0.25 second intervals during the survey period of 4 days before and after the treatment. Velocity on each sample track at 0.25 second intervals was collected in 15-20 minute periods and was subsequently checked to effectively reveal behavioral states of the specimens tested. Active contour was formed around each collection of velocities to gradually evolve to find the optimal boundaries of velocity collections through processes of energy minimization. The active contour which is improved by T. Chan and L. Vese is used in this paper. The energy minimization model effectively revealed characteristic patterns of behavior for the treatment versus no treatment, and identified changes in behavioral states .is the time progressed.

• Journal of Environmental Science International
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• v.17 no.3
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• pp.287-296
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• 2008

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3', 4,4', 5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs trom PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and $0.17ug/m\ell$ and $713.42{\mu}g/g$ and $3.73{\mu}g/g$, respectively, which contained $20\sim40$ times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.27-34
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• 2015

The aim of this study was to optimize a simple, fast, and economic analytical method for the simultaneous determination of various pesticides (aldrin, p,p'-DDT, o,p'-DDT, p,p'-DDE, ${\alpha}$-endosulfan, ${\beta}$-endosulfan, dieldrin, heptachlor, permethrin, chlordane, deltamethrin, diazinon, bifenthrin, methoprene, propargite, fenpropathrin, cypermethrin, fenvalerate, and fenpropathrin) in milk by using dispersive solid phase extraction (SPE). In this study, two different extraction methods (low temperature cleanup and liquid-liquid partitioning), which were followed by a cleanup process based on dispersive-SPE, were evaluated and compared for the 19 pesticides. The results for all the pesticides were determined by gas chromatography mass spectrometry (GC/MS) with selected-ion monitoring mode, and the matrix effect of the method was evaluated. Comparison of these approaches yielded higher and more consistent recoveries of most pesticides at fortification levels of $1{\mu}g/mL$ using low-temperature fat precipitation, followed by cleanup process based on dispersive-SPE with PSA and C18 as sorbents, than other preparation process. The relative standard deviation was <20 % and the combination of this method were very effective for the cleanup.

• Journal of Food Hygiene and Safety
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• v.2 no.3
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• pp.121-136
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• 1987

As a part of continuing monitoring program since 1983, a study on pesticide residues on Korean agricultural products has been conducted to offer the tolerance of pesticide residues suiting Korean reality. The samples used in this experiment were collected from four areas in five provinces of Korea. The residue, levels of organochlorine pesticide (two kinds), organophosphoric pesticide (eight kinds) and carbamate pesticide (three kinds) on lettuce, garland chrysanthemum, radish Korean, potato, egg plant, green onion, persimmon and sweet potato, and the residue levels of captan and captafol on tomato, green pepper fresh, apple, peach, soybean, cucumber and cabbage Korean were determined by GC-NPD and ECD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1515-1522
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• 2008

Monitoring the pesticide residues in agricultural products is essential to protect consumers, obtain data for risk assessment, and ensure fair trade practices. We developed a multi-residue method for the analysis of 37 pesticides with different physico-chemical properties in agricultural products and analyzed the amount of pesticide residues on about 1,000 samples circulated in South Korea. The samples consisted of 26 different types of agricultural products selected at markets in 14 major cities; cereals (2 species), nuts (1 species) potatoes (1 species), beans (2 species), fruits (3 species), vegetables (16 species), and mushrooms (1 species). In this study, residual pesticides were detected in 23 samples (2.2%) and one sample was detected to be over maximum residue limits (MRLs, 0.1%) for pesticides in foods by the Korea food code. In leafy vegetables such as pepper leaves, radish leaves, cham-na-mul, shin-sun-cho, crown daisy, chwi-na-mul and citrus fruits such as kumquat, 8 kinds of pesticides were detected. Specially, diazinon were detected over MRLs and also, endosulfan, ethoprophos and phenthoate were detected frequently. Based on these results, we investigated the risk assesment from amount of residual pesticide, total %ADI was 1.262%, but the value has not effected on human health.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.265-270
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• 2008

This study examined the effects of treating green tea leaves with ozonated water by evaluating pesticide residue levels and catechin content. The pesticide residue levels of tea leaves treated with carbendazim, captain, diazinon, fenthim, dichlorvos, and chlorpyrifos ranged from 43.2 to 48.2 ppm. For leaves treated by soaking or watering with tap water, or with 0.25 ppm of ozone water for 30 min. Pesticide residue levels were reduced by 24.0-30.2%, 30.3-33.6%, 52.4-70.5%, and 65.5-80.2%, respectively. No major differences in catechin content were observed in the leaves according to the soaking and rinsing treatments using ozonated or tap water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.377-387
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• 1997

Primary fluorescence characteristics of ten standard solutions of organophosphates, sea water, and water from agricultural land were investigated by fluorescence contour. All the standard solutions of organophosphates has shown characteristics countours. Their emission maxima were shown between 296 nm and 437 nm. According to their numbers of emission maxima on the fluorescence contours, the organophosphates can be categorized in two different groups. Ateric and Diazinon are the first group with two emission maxima. DDVP with other seven standard organophosphates belong to the second group. The second group has two subgroups. One is characterized by the similar emission and excitation maxima, which are 310 nm and 280 nm, respectively. Those are DDVP, Hinosan, Kitazin, Locsion, Meta. The other sub-group shows quite different emission and excitation maxima from the first sub-group. They are Monopho, Thaconyl and Gropho and their emisson maxima were in far longer (437 nm) or shorter wavelength (296 nm). From agricutural samples, one of the investigated organophosphates was detetected by its characteristic retention time $(t_r=12min)$. HPIC-fluorescence data gave an additional parameter for differentiation between two organophosphates which has similar excitation and emission maxima.

• Journal of Environmental Policy
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• v.6 no.3
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• pp.33-56
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• 2007

Use of chemicals has greatly increased along with development of human civilization. Concerns about potential effects of chemicals on human health and environment have also grown accordingly. Due to the enormous number of chemicals being used, however, it is neither practical nor feasible to regulate all the chemicals. Therefore, it is necessary to identify chemicals that deserve more immediate attention, based on the effects on receptors to be protected. This study was initiated by the need for developing management policies for Shihwa-Banwol Techno Valley and its vicinities of korea, where complaints and concerns on environmental contamination have been raised for long time. This study to identifies major chemicals that deserve most immediate attention in environmental health management in this area. For this purpose, the study employed CHEMS-1(Chemical Hazard Evaluation for Management Strategies), and used chemical data from Toxics Release Inventory(TRI) and environmental contamination data from the environmental pollution monitoring network. Top priority pollutants identified in Shihwa-Banwol Techno Valley area were metals and volatile organic compounds, such as dichloromethane, trichloroethylene, diazinon, tetrachloroethylene, chromium compounds, tin compounds, chloroacetic acid, ethyl acetate, and zinc compounds, in an order of decreasing importance. An evaluation of physicochemical properties of the priority chemicals and the environmental pollution monitoring network database in Shihwa-Banwol Techno Valley suggested that the media that are of potential concern would be the atmosphere and aquatic environment.