• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.94-103
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• 2014

In this study washing efficiency and desorption isotherms for heavy petroleum oil (HPO), Zn, and Pb bound to complex contaminated soils were examined using various soil flushing agents. Sodium dodecyl sulfate (SDS), methanol, ethylene diamine tetraacetic acid (EDTA), and citric acid were selected as soil flushing agents. 3% (w/v) and 4% SDS showed the highest removal efficiency for HPO, but the difference was not statistically significant (p > 0.05). Thus, 3% SDS was chosen as the best soil flushing agent for HPO. In the case of heavy metals, 0.1-M EDTA showed the highest removal efficiencies. But 0.05-M citric acid was selected due to its economic and eco-friendly strengths. The desorption isotherms obtained using Freundlich and Langmuir models indicated that the maximum desorption characteristics ($K_F$ and $Q_{max}$) of HPO with 4% SDS and 90% methanol and heavy metals with 0.1-M EDTA and 0.1-M citric acid, respectively, were markedly lower than in other cases. In addition, when 4% SDS and 90% methanol were used for HPO in the range of $C_e$ higher than 600 mg/L, and when 0.1M citric acid and 0.1M EDTA were used for Zn and Pb in the range of $C_e$ higher than 300 and 100 mg/L, respectively, the distribution constant converged to certain levels. Thus, constant values of $K_U$ and $K_L$ were determined. It was found that these constants represent the maximum desorption capacity and they can be used as distribution coefficients of desorption equilibrium for the flushing agents. The results of this study provided fundamental information for the selection of the best agents as well as for the process design and operation of soil washing/soil flushing of complex contaminated soils.

• 방사성폐기물학회지
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• 제19권1호
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• pp.39-49
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• 2021

The behaviors of various desorption agents were investigated during the desorption of cesium (Cs) from samples of clay minerals and actual soil. Results showed that polymeric cation exchange agents (polyethyleneimine (PEI)) efficiently desorbed Cs from expandable montmorillonite, whereas acidic desorption solutions containing HCl or PEI removed considerable Cs from hydrobiotite. However, most desorption agents could desorb only 54% of Cs from illite because of Cs's specific adsorption to selective adsorption sites. Cs desorption from an actual soil sample containing Cs-selective clay mineral illite (< 200 ㎛) and extracted from near South Korea's Kori Nuclear Power Plant was also investigated. Considerable adsorbed 137Cs was expected to be located at Cs-selective sites when the 137Cs loading was much lower than the sample's cation exchange capacity. At this low 137Cs loading, the total Cs amount desorbed by repeated washing varied by desorption agent in the order HCl > PEI > NH4+, and the highest Cs desorption amount achieved using HCl was 83%. Unlike other desorption agents with only cation exchange capabilities, HCl can attack minerals and induce dissolution of metallic elements. HCl's ability to both alter minerals and induce H+/Cs+ ion exchange is expected to promote Cs desorption from actual soil samples.

• 한국환경보건학회지
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• 제36권2호
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• pp.95-107
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• 2010

Hand-washing is one of the major factors in personal hygiene and public health. This study was undertaken to investigate the hygienic behavior of food-service employees, focusing on awareness of hand washing, hand washing practices, and the load of index microorganisms (aerobic plate count, total and fecal coliforms, Escherichia coli, and Staphylococcus aureus) on the hands of food-service employees. A questionnaire survey completed by direct interview, direct observation of restrooms by the researcher and trained observers, and microbiological examination according to the Food Code of Korea were carried out. In the survey, a positive attitude toward hand washing compliance was reported; however, improper hand washing and poor hand hygiene of the food-service employees were seen under direct observation. Significant differences (p<0.05) were found between the questionnaire survey and the direct observations in hand washing compliance after using the toilet, duration of hand washing, use of hand washing agents, use of hand washing tools, washing of different parts of the hands, hand-drying method, temperature of water, and method of turning off the water. Samples taken from employees' hands before washing showed higher levels of bacteria than those taken during work and/or after washing (p<0.05). Poor hand washing practices were indicated by the positive results for total and fecal coliforms, E. coli, and S. aureus on the hands of some food-service employees. This study showed that there is a marked difference between the food-service employees' awareness of hand-washing and their actual hand-washing practices. The poor hand hygiene of and improper hand washing by the food-service employees should be addressed for improved food safety.

• 한국염색가공학회지
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• 제17권1호
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• pp.1-6
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• 2005

This study were carried out to investigate the effects of mordants and mordanting methods under the various dyeing conditions such as temperature, time, pH, repetition of dyeing in the silk fabrics with Petasites japonicus leaf. It was the most high K/S values of the silk fabrics dyed with Petasites japonicus leaf according to co mordanting and used cupric sulfate, ferric sulfate as mordanting agents. K/S values of the silk fabrics dyed with Petasites japonicus leaf were increased gradually with dyeing temperature, dyeing time, repetition of dyeing was higher and the optimum pH was pH 7. Silk fabrics were colored yellowish orange and surface color(munsell value) was changed from 8.3YR to 2.0Y by using mordanting agents and those of the silk showed high tone when mordanting with cupric sulfate but decolored and darked when mordanting with ferric sulfate. Washing fastness of silk fabrics were good in 4 ～ 5 grade, so washing fastness of the silk fabrics was significantly improved when washed with the neutral detergent.

• 분석과학
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• 제37권1호
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• pp.1-11
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• 2024

In agricultural households cultivating vegetables and fruits, the use of various pesticides to protect crops from diseases and pests or to control weeds is widely practiced enhancing quality and productivity. However, pesticides can pose a threat to consumer health by remaining on the food surface or migrating into the food interior. Households commonly peel off skins, wash with water, or use chemical methods to remove foreign substances including residual pesticides on the food surface. In this study, we measured the washing rate by comparing the pesticide concentrations before and after washing in the leafy vegetable perilla leaves and the fruits strawberries and apples, which were intentionally exposed to pesticides. We compared washing rates using tap water, a baking soda solution, and a commercially available food-specific cleaning solution. The target pesticides for analysis were azoxystrobin, bifenthrin, boscalid, difenoconazole, flubendiamide, and indoxacarb, and the residual pesticide analysis was performed using GC-MS/MS or LC-MS/MS. The removal rates of pesticides were highest with the food-specific cleaner, followed by baking soda and tap water in order.

• 한국환경보건학회지
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• 제45권3호
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• pp.213-221
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• 2019

Objective: This study was performed to evaluate gender and age differences in hygienic behavior among the general population, focusing on hand-washing habits and the microbial load of hands. Methods: A self-administered questionnaire survey and a separate microbial examination were performed. The Pearson's correlation between hand-washing habits and microbial load was analyzed. Results: In the questionnaire survey on hand-washing habits, gender differences were found in hand-washing frequency, use of hand-washing agents, and hand drying methods (p<0.05). Age differences were found in numbers of washing parts of the hands and also in hand drying methods (p<0.05). Females showed better habits washing hands than did males, as did older people compared to younger. In the microbial examination of indicator bacteria on their hands, younger people tended to show a higher load of total aerobic bacteria than did the older, and females showed a higher load of total coliforms than did males (p<0.05). There were significant relationships between the load of total aerobic bacteria and hand-washing frequency, duration, and method of turning-off water (p<0.05). Conclusions: Although females were expected to show a better practice of hand-washing than were males based on the survey results, they showed a higher level of total coliforms in the hand examination. The older age group showed better hand-washing habits than did the younger age group and had less total aerobic bacteria on their hands. These inter-gender and age differences highlight the need for development and implementation of gender-and age-specific educational programs or campaigns.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권4호
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• pp.31-37
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• 2011

The feasibility study of soil flushing was investigated to remediate lubricant oil and zinc contaminated railway soil. In this study, mixed washing agents of surfactant and inorganic acid/base were used for the simultaneous removal. The mixed washing agent of non-ionic surfactant and HCl removed 15% of the lubricant oil and 40% of zinc, respectively. Alkaline-enhanced soil washing process increased the removal of lubricant oil up to 40%. This is because alkaline solution reduced the interfacial tension between water phase and lubricant oil phase due to the soap formation reaction. To simulate in-situ soil flushing for the remediation of railroad-related contamination, two dimensional soil flushing was carried out based on the results of batch soil washing. In the soil flushing, the removal efficiencies of lubricant oil and zinc were 34% and 16%, respectively. Even though the removal efficiency was low, the mixed washing agent can remove metal and lubricant oil simultaneously.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.178-180
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• 2005

• Journal of Plant Biology
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• 제30권2호
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• pp.109-116
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• 1987

Effects of staining, buffer washing and denaturing agents on the transferrability of RNA fractionated on a methylmercury hydroxide-agarose gel to a nitrocellulose membrane were studied. Ethidium bromide staining and ammonium acetate buffer washing inhibited RNA transfer, while 3% HCHO and 0.5 M NaOH treatments stimulated transfer which was negated in the ammonium acetate buffer. Accordingly, maintenance of primary structure of RNA was proved to be essential for transferring RNA from the methylmercury hydroxideagarose gel to the nitrocellulose membrane.

• 한국염색가공학회지
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• 제20권6호
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• pp.87-91
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• 2008

It is commonly known that water repellency of the fabric treated with fluorocarbon resin brings about a decrease by the washing and recovers by the subsequent heat treatment. In this article, effect of the water repellency was investigated on the nylon 6, triacetate and silk fabrics treated with hydrocarbon and silicon resins. Hydrocarbon and silicon resins have been widely used in the textile finishing as the softening and water proofing agents. The fabrics were treated with hydrocarbon resins, Paragium JQ and RC (Ohara Paragium Chemical Co.) and a silicon resin, Poron MR (Shinetsu Chemical Co.), and then washed and subsequently heat treated. Although the water repellency increased by the resin treatment, it decreased by the washing apparently and recovered a little by the heat treatment. The effect of the heat treatment was small comparing with that of the fluorocarbon resin. Furthermore, as a mechanical property of the treated fabric, KES shearing and bending hysteresis parameters, modulus and hysteresis width of the hydrocarbon resin-treated nylon 6, triacetate and silk fabrics decreased by the heat treatment after washing. Therefore, the treatment is effective at improving the softening of the fabric in water repellent finish.