• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.103-115
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• 1996

The purpose of this study was to establish acceptable criteria for the design of simple water treatment plant in rural areas. To develop efficient simple water treatment methods for rural areas, water quality in the study areas was investigated and rapid and slow filtrations in pilot-scale were tested under various conditions. The main results of this study are as follows. It was found that the water qualities of the study areas exceed the drinking water standards, which implies that some treatments are required in rural areas. Treatment efficiencies of both rapid sand and dual-media (sand and anthracite) filtration without pre-treatment such as flocculation and sedimentation are very low, which were turned out to be unadequate for the rural areas. Treatment efficiencies of both vertical and horizontal slow filtration without chlorination are very high for consumed $KMnO_4, NH_3-N, NO_3-N$, turbidity, and very low for coliform and bacteria. Treatment efficiencies of both vertical and horizontal slow filtration with chlorination are very high over the most pollutants. A slow filtration with chlorination is efficient for the rural areas. An adequate depth of sand layer is over 60 cm. A horizontal filtration is more economical than a vertical filtration. A horizontal filtration can be operated for a relatively long periods of time without sand washing or replacement because clogging is removed by simple back-washing.

• Textile Coloration and Finishing
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• v.16 no.1
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• pp.34-39
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• 2004

Dyeing properties of Glycyrrhizae Radix was investigated with silk fabrics. Dyeing water is a type of chalcone, it showed yellow in IR spectrum. K/S value showed high in following conditions; Glycyrrhizae Radix $200g/1\ell4 water, $80^{\circ}$ of dyeing temperature, 90 minute of dyeing time. Glycyrrhizae Radix dyeing water has higher K/S value in alkalinity(pH9) than in neutrality(pH7) or acidity(pH3) conditions. K/S value showed highest in pH5 premordant method of alkalinity dyeing water condition. The color of silk fabric dyed with Glycyrrhizae Radix is yellow. The change of color did not show by mordant treatment. K/S value showed higher in mordant treatment than nonmordant. Light fastness showed over 3 degree in nonmordant, premordant, simmordant(Al,Cu,Fe) and postmordant(Cu). Water fastness showed over 3 degree in dyeing water(pH3, pH5, pH7). Dry cleaning fastness showed over 3 degree in all dyeing methods. Washing fastness is showed in 2-3 degree; Al in nonmordant, premordant, simmordant and Cu in simmordant are 2-3 degree. Perspiration fastness is nearly 3-4 degree in premordant and simmordant. Perspiration fastness shows high in premordant, simmordant than postmordant. The fastness of light, water, dry cleaning, washing, perspiration shows better nonmordant, premordant, simmordant than postmordant method.

• Journal of the Korean Dietetic Association
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• v.4 no.2
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• pp.235-244
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• 1998

Hand washing is an important component of hygiene program for food handlers. Hands can be a source of direct or indirect contamination of foods with pathogenic microorganisms. In this study, the effectiveness of hand washing methods and the use of 70% alcohol solution against transient skin bacteria was tested in an university foodservice facility. 70% alcohol solution is sprayed for 5 seconds automatically when hands are placed in the dispenser. Samples were taken using swab technique in meat cutting area, vegetable trimming area, and vegetable cutting area: before and after washing hands according to planned methods, and after being sprayed with 70% alcohol solution after washing hands. The bacteriological analysis of total plate counts, coliform, fecal coliform of food handlers' hands was done. Statistical data analysis was completed with Mann-Whitney U test and Kruskal-Wallis model using the SPSS program. The levels of initial contamination of workers' hand were significantly different by the work areas($x^2$=9.156, p<0.01). Workers in the vegetable trimming area had more heavily soiled hands than in the other work areas. Mean of TPC counts and coliform was 8.97×$10^5$ CFU/12.4$cm^2$, 2.93×$10^2$ MPN/12.4$cm^2$ respectively, but fecal coliform was not detected. Transient bacteria were removed from hands after washing and using 70% alcohol solution but were not removed completely. Mean reduction percentage in TPC varied among work areas and ranged from 93.19% to 94.99%, and in coliforms from 97.31% to 100%. A significant difference in TPC was found between before and after hand disinfection (Z=-2.714, p<.01) and between standardized hand washing procedures and un-standardized hand washing procedures(z=-2.301, p<.01). Subjects using the hand sanitizer showed a great elimination of TPC(99.45% reduction), but this effect was valid only after following proper washing procedures. Based on the results, the most effective hand washing method was recommended as the combination of the standardized hand washing procedure with warm-water and use of the 70% alcohol solution. The results can be used to develop hand hygiene programs and training strategies for enhancing hand hygiene practices for food handlers in foodservice operations.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.418-422
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• 1984

In order to determine the removal efficiency of pesticide residues in fruits and vegetables by washing processes, samples of lettuce, young Chinese radish, Chinese cabbage, green red pepper, strawberry and grape were artificially contaminated with malathion and washed according to the household practices. After three times washings with water, the remaining ratios of malathion residues in grape, green red pepper, strawberry, young Chinese radish, lettuce and Chinese cabbage were 9.7%, 25.2%, 28.0%, 29.7%, 38.9% and 57.5%, respectively. After washing with detergent solution followed by two times rinsing with water, the remaining ratios of malathion residues in the same food samples were 1.6%, 8.3%, 15.8%, 24.8%, 27.2% and 45.9%, respectively. The removal efficiency of malathion by detergent washing was significantly higher than the water washings only. The removal ratio of malathion residues was the highest in the first washing and the ratio fell greatly in the following washings. The removal efficiency was not quite different in the temperature range of $5-35^{\circ}C$ of the washing solution, but the efficiency at $100^{\circ}C$ was 2-3 times higher than other temperature ranges.

• Resources Recycling
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• v.32 no.6
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• pp.18-24
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• 2023

This study undertook initial investigations into the carbonation of chlorine bypass dust, aiming to apply it as a raw material for cement and as an admixture for concrete. Various experimental methods, including XRD(X-ray diffraction), XRF(X-ray fluorescence), and particle size distribution analyses, were employed to verify the physical and chemical properties of chlorine bypass dust, with and without water washing. The mineral carbonation extent of chlorine bypass dust was examined by considering the dust type, stirring temperature, and experiment duration. Notably, a higher degree of mineral carbonation was observed in water-washed bypass dust than its non-water-washed counterpart, indicating an elevated calcium content in the former. Furthermore, an augmented stirring temperature positively impacted the initial stages of mineral carbonation. However, divergent outcomes were observed over time, contingent upon the specific characteristics of dust types under consideration.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.103-104
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• 2004

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.170-179
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• 2012

We examined pretreatment methods eliminating potassium and sodium efficiently for coir bag used in hydroponics by analyzing drainage coming from coir bags. In the first experiment we investigated for six coir bags with the high market shares. The three types of pretreatment were washing coir bags with only water for 7 days (W7S0), washing with water for 4 days and further with nutrient solution for 3 days (W4S3), and washing with only nutrient solution for 7 days (W0S7). In the second experiment we tested reproducibility of the experiment results for Bio Grow and coco Mix among six coir bags used in the first experiment to verify the results. As a result, the best pretreatments for the pH stabilization were W4S3 and W0S7. The EC value of the drainage was stabilized to less than 1.0 that is the same as EC of the supply solution on the fourth day in all treatments. The nutrients of the drainage in W7S0 was stabilized in 3~4 days but calcium and magnesium were depleted. We assessed that washing longer than 4 days was waste of water. The stabilization of coir bags in W0S7 was similar to it in W4S3, but washing with the nutrient solution for 7 days seemed to be uneconomical. The reproducibility experiment for two coir bags ensured the results in the first experiment. Therefore, the pretreatment method, which is the most simple to implement and economic, seems to wash with water for 3 days and then with the nutrient solution for 1 day before planting on coir bag.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.787-798
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• 2005

The objectives of this study were to assess extraction kinetics of heavy metals with extraction times and to assess extraction efficiencies of heavy metals with concentrations and kinds of washing solutions. Target materials were obtained from disused metal mines. Washing solutions were water, HCl(0.1, 0.3, 1.0 N), EDTA(0.01, 0.05, 0.1 M), and sodium dodecyl sulfate(SDS, 0.1. 0.5, 1.0%). Extraction efficiencies of heavy metals by water and SDS were below 1%, and extraction efficiencies of Zn and Cd were higher than those of Pb and Cu. As results, water and SDS were not effective in extracting heavy metals from mine tailings as washing solution, but extraction efficiencies of Pb and Cu with SDS solution increased as extraction time increased. Extraction kinetics of heavy metals with HCl and EDTA were faster than those with water and SDS. The majority of heavy metals were extracted within 6 hours, and extraction kinetics was almost independent of the solution concentration. Extraction kinetics of heavy metals after 6 hours was slow, but extraction kinetics was dependent on the solution concentration. Also, as concentrations of HCl and EDTA solution were stronger, heavy metals were extracted rapidly and extraction efficiencies were increased. The extraction efficiency was high in order of Cd>Pb>Zn>Cu in using 1.0 N HCl, and Pb>Cd>Zn>Cu in using 0.1 M EDTA. Consequently, extraction effectiveness was highest for Pb in using HCl, and for Pb and Cd in using EDTA with concentration increase. Extraction time of over 6 hours was not effective in extracting heavy metals.

• The Korean Journal of Ceramics
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• v.7 no.1
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• pp.16-19
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• 2001

For the fast dry of the aqueous tape, the process which water was reaplaced by organic solvent was proposed. Socalled, it was the solvent washing dry. Three organic solvents (methanol, ethanol and acetone) were selected for the washing solvent. The weight loss of the washed tapes was measured to evaluate the dry rate of the tapes and dried tapes were examined the generation of the cracks with the variations of the organic solvent and the washing time. Methanol, ethanol and acetone were available organic solvents for this method. The tapes washed in methanol, ethanol and acetone were dried rapidly for twenty minutes. After thirty minutes, the weight losses were not found any more, The solvent of the lower surface tension can decreases the crack of dried tape. If solvent substitutes water completely, though it was fast dried, crack can be eliminated.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.503-509
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• 2018

Endive is widely consumed in a fresh-cut form owing to its rich nutritional content. However, fresh-cut vegetables are susceptible to contamination by pathogenic bacteria. This study investigated the antibacterial activities of the combined treatment of cinnamon leaf oil emulsion containing cetylpyridinium chloride or benzalkonium chloride (CLC and CLB, respectively) as a cationic surfactant and ultrasound (US) against Listeria monocytogenes and Escherichia coli O157:H7 on endive. The combined treatment of CLC or CLB with US reduced the population of L. monocytogenes by 1.58 and 1.47 log colony forming units (CFU)/g, respectively, and that of E. coli O157:H7 by 1.60 and 1.46 log CFU/g, respectively, as compared with water washing treatment. The reduction levels of both pathogens were higher than those observed with 0.2 mg/ml sodium hypochlorite. In addition, the combined treatment showed no effect on the quality of the fresh-cut endive (FCE). In particular, the degree of browning in FCE was less for the treatment group than for the control and water washing treatment groups. Thus, cationic surfactant-based cinnamon leaf oil emulsions combined with US may be an effective washing treatment for the microbial safety of FCE.