• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.317-322
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• 2022

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis (CLA), a chronic contagious disease in small ruminants. The prevalence of CLA has been reported to be >50% in Korean black goats. CLA is difficult to control due to a lack of efficient vaccines and treatment methods. Effective disinfection of the farm environment may be an alternative strategy for reducing the spread of C. pseudotuberculosis. The objective of this study was to evaluate the efficacy of commercial disinfectants against CLA. The six commercial disinfectants, largely composed of sodium dichloroisocyanurate, sodium hypochlorite, potassium monopersulfate triple salt, quaternary ammonium, citric acid, and copper sulfate, were tested against five different genotypes of C. pseudotuberculosis isolated from goat farms in Korea. Efficacy tests were performed in accordance with the disinfectant efficacy test guidelines recommended by the Animal and Plant Quarantine Agency of Korea with slight modifications. All disinfectants except for copper sulfate exhibited >99.99% killing efficacy under hard water conditions following 30 min of incubation, which is the recommended standard treatment time according to guidelines. The minimum bactericidal treatment time was evaluated by employing treatments for durations of 1, 5, and 15 min. The most effective compounds under hard water conditions were sodium dichloroisocyanurate, potassium monopersulfate triple salt, and sodium hypochlorite, exhibiting >99.99% killing efficacy after 1 min of treatment. In the aqueous solution forms, citric acid and the quaternary ammonium compound were the most effective, but required at least 5 min to kill >99.99% of the bacteria. The current study characterizes the killing efficacy of six commercial disinfectant active compounds against C. pseudotuberculosis. Thus, this study provides essential information regarding the efficacy of the disinfectants used to control CLA in goat farms.

• Applied Biological Chemistry
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• v.17 no.3
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• pp.149-176
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• 1974

Eight substituted diphenyl ether herbicides and some of their photoproducts were studied in terms of solution phase photolysis under simulated environmental conditions by using a Rayonet photochemical reactor. The test compounds absorbed sufficient light energy at the wavelength of 300 nm to undergo various photoreactions. All the photoproducts were confirmed by means of tlc, glc, ir, ms, and/or nmr spectrometry. The results obtained are summarized as follows: Solution phase photolysis of C-6989: An exceedingly large amount of p-nitrophenol formed strongly indicates the readiness of the ether linkage cleavage of this compound as the main reaction in all solvents used. Photoreduction of nitro to amino group(s) and photooxidation of trifluoromethyl to carboxyl group were recognized as minor reactions. Aqueous photolysis of p-nitrophenol: Quinone(0.28%), hydroquinone (0.66%), and p-aminophenol (0.42%) were confirmed as photoproducts, in addition to a relatively small amount of an unknown compound. The mechanisms of formation of these products were proposed to be the nitro-nitrite rearrangement via $n{\rightarrow}{\pi}^*$ excitation and the photoreduction through hydrogen abstractions by radicals, respectively. Solution phase photolysis of Nitrofen: Photochemical reduction leading to the p-amino derivative was the main reaction in n-hexane. In aqueous solution, the photoreduction of nitro to amino group and hydroxylation predominated over the ether linkage cleavage. Nucleophilic displacement of the nitro group by hydroxide ion and replacement of chlorine substituents by hydroxyl group or, to a lesser extent, hydrogen were also observed as minor reactoins. Solution phase photolysis of MO-338: Photoreduction of the nitro to amino group was marked in the n-hexane solution photolysis. In the aqueous solution, photoreduction of the nitro substituent and hydroxylation were the main reactions with replacement of chlorine substituents by the hydroxyl group and hydrogen, and cleavage of the ether linkage as minor reactions. Photolyses of MC-4379, MC-3761, MC-5127, MC-6063, and MC-7181 in n-hexane and cyclohexane: Photoreduction of the nitro group leading to the corresponding amino derivative and replacement of one of the halogen substituents by hydrogen from the solvent used were the key reactions in each compound. Aqueous photolysis of MC-4379: Cleavage of the ether linkage, replacement of the carboxymethyl by hydroxyl group, hydroxylation, and replacement of the nitro by hydroxy group were prominent with photoreduction and dechlorination as minor reactions. Aqueous photolysis of MC-3761: Cleavage of the ether linkage, replacement of the carboxymethyl by hydroxyl group, and photoreduction followed by hydroxylation were the main reactions. Aqueous photolysis of MC-5127: Replacement of carboxyethyl by hydrogen was predominant with ether linkage cleavage, photoreduction, and dechlorination as minor reactions. It was obvious that the decarboxyethylation proceeded more readily than decarboxymethylation occurring in the other compounds. Aqueous photolysis of MC-6063: Cleavage of the ether linkage and photodechlorination were the main reactions. Aqueous photolysis of MC-7181: Replacement of the carboxymethyl group by hydrogen and monodechlorination were the remarkable reactions. Cleavage of the ether linkage and hydroxylation were thought to be the minor reactions. Aqueous photolysis of 3-carboxymethyl-4-nitrophenol: The photo-induced Fries rearrangement common to aromatic esters did not appear to occur in the carboxymethyl group of this type of compound. Conversion of nitro to nitroso group was the main reaction.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.31-39
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• 2002

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water column can accumulate in sediments at much higher levels. The purpose of this study was to make optimal treatment and disposal plan o( sediment for water quality improvement in small-scale resevoir based on an evaluation of degree of contamination. The degree of contamination were investigated for 23 samples of 9 site at different depth of sediment in small-scale J river. Results for analysis of contaminated sediments were observed that copper concentration of 4 samples were higher than the regulation of hazardous waste (3 mg/L) and that of all samples were exceeded soil pollution warning levels for agricultural areas. Lead and mercury concentration of all samples were detected below both regulations. Necessary of sediment dredge was evaluated for organic matter and nutrient through standard levels of Paldang lake and the lower Han river in Korea and Tokyo bay and Yokohama bay in Japan. The degree of contamination for organic matter and nutrient was not serious. Compared standard levels of Japan, America, and Canada for heavy metal, contaminated sediment was concluded as lowest effect level or limit of tolerance level because standard levels of America and Canada was established worst effect of benthic organisms. The optimal treatment method of sediment contained heavy metal was cement-based solidification/stabilization to prevent heavy metal leaching.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.60-71
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• 2014

This study was conducted to identify the potential of rape stalk as a raw material for biorefinery process of rape flower. At first, rape stalk (RS) was immersed in distilled water (DW), acetic acid (AA), oxalic acid (OA), sulfuric acid (SA) and sodium hydroxide (SH) solutions, and the content of reducing sugars liberated from immersed RS was analyzed. Glucose, xylose, arabinose and sucrose were detected varying with the immersion type. In particular, 1% AA-immersion of RS for 72 hr was the most effective conditions to liberate glucose from RS. Secondly, the RS residues were used for elementary analysis and fabrication of fuel pellets. In addition to the solution type, concentration of immersion solutions (0%, 1%, 2%) and immersion time (24, 72, 120 hr) were used as experimental factors. The contents of nitrogen, sulfur and chlorine reduced effectively through the immersion of RS in DW, AA and OA solutions. For properties of RS-based pellets, bulk density and higher heating value of RS-based pellets greatly increased with the immersion of RS, and the qualities were much higher than those of the A-grade pellet of the EN standards. Ash content decreased remarkably through the immersion of RS, and was satisfied with the A-grade pellet standard. Durability was negatively affected by the immersion of RS, and did not reached to B-grade of the EN standard. In conclusion, acid immersion of RS can be a pretreatment method for the production of fuel pellet and bioethanol, but use of the immersed RS for the production of high-quality pellets might be restricted due to low durability of immersed-RS pellets. Therefore, further studies, such as investigation of detailed immersion conditions, fabrication of mixed pellets with wooden materials and addition of binders, are needed to resolve the problems.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.265-277
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• 2000

Laboratory experiments were conducted to investigate characteristics for removing ammonia-nitrogens by electrolysis methods. A stainless steel plate is used as the cathode and either $IrO_2{\backslash}Ti$ plate serves as the anode. Experiments were conducted to examine the effects of the operating conditions, such as the current density, retention time, electrode gap, $Cl^-/NH_4{^+}-N$ on the $NH_4{^+}-N$ removal efficiency. Possible optimum range for these operating variables are experimentally determined. The $NH_4{^+}-N$ removal efficiencies between plate type anode and net type anode were about same effect, but electrolytic power using net type anode is low than plate type anode. The $Cl^-/NH_4{^+}-N$ ratio was about $20.0kgCl^-/kgNH_4{^+}-N$ when $NH_4{^+}-N$ removal obtained 73 %, $Cl^-/NH_4{^+}-N$ ratio needs $27.6kgCl^-/kgNH_4{^+}-N$ so as to $NH_4{^+}-N$ completely remove. The removal efficiency of $NH_4{^+}-N$ increase with current density, retention time and $Cl^-/NH_4{^+}-N$ ratio, but decreased with increasing electrode gap. The relationship of operating conditions and $NH_4{^+}-N$ removal efficiencies are $$NH_4{^+}-N_{re}(%)=14.5364(Current\;density)^{0.7093}{\times}(HRT)^{1.0060}{\times}(Gap)^{-0.9926}{\times}(Cl^-/NH_4{^+}-N)^{1.0024}$$ With adding COD or/and alkalinity, relationships are $$NH_4{^+}-N_{re}(%)=9.8408(Current\;density)^{0.6232}{\times}(HRT)^{1.0534}$$ There existed a competition between the removals for $NH_4{^+}-N$ and $COD_{Cr}$ during electrolysis, the removal of $NH_4{^+}-N$ was shown to be dominant. $NH_4{^+}-N$ removal was high as addition of glucose and alkalinity.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.60-65
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• 2014

This study was conducted to investigate the antimicrobial effect of chlorine dioxide ($ClO_2$) on the vase life of cut rose 'Beast' (Rosa hybrida L.). Postharvest treatments to extend the vase life of cut roses were divided into two: holding solution treatment and pulsing solution treatment. In holding solution treatment, the cut roses were treated with preservative solutions containing tap water (TW, control), distilled water (DW), $ClO_2$ 2, 4, 6, and $8{\mu}L{\cdot}L^{-1}$, and compared with a commercialized antimicrobial compound of 8-HQS $200{\mu}L{\cdot}L^{-1}$. In pulsing solution treatment, cut roses were dipped into the $ClO_2$ solutions of 50, 100, 150, 200, and $250{\mu}L{\cdot}L^{-1}$ for 60 seconds and were placed in DW. The air temperature was $18.4^{\circ}C$, RH 51.5%, and light (photosynthetically active radiation, PAR) $3.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ with 12 hour day length. The longest vase life of cut roses was observed in the holding solution with $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ as 13.8 days and pulsing with $200-250{\mu}L{\cdot}L^{-1}$ as 13.5-13.7 days, where vase life were extended four days longer than TW. Whereas, the inclusion of 8-HQS $200{\mu}L{\cdot}L^{-1}$ in vase solution resulted in phytotoxicity. The relative fresh weight and water uptake have similar tendencies. Bacteria inhibition by $ClO_2$ and 8-HQS were very effective. But bacteria at TW and DW treatments on cut flower with stem were detected in $3.7{\times}10^5CFU{\cdot}L^{-1}$ and $6.3{\times}10^5CFU{\cdot}L^{-1}$, respectively (without stem in DW $1.4{\times}10^4CFU{\cdot}L^{-1}$). The $ClO_2$ contents in holding solution of all treatments were scavenged in two-four days after treatment. This study indicated that $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ holding solution treatment and $200-250{\mu}L{\cdot}L^{-1}$ pulsing solution treatment can be applied to extend the postharvest life of cut roses.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.4
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• pp.239-248
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• 2006

This study was conducted not only to investigate effects of different supplementation levels of Acanthopanax senticosus leaves on feed intakes, nutrient digestibility, nitrogen retention, and blood metabolites in Korean black goats but also to obtain basic data for nutritive value of Acanthopanax senticosus leaves and production of high quality functional animal products. Twelve Korean black goats were allotted to treatments in four groups of three goats per treatment and then they were housed in individual metabolism cages with completely random arrangements for 21 days. Four treatments were separated into controls and three different supplementation levels of Acanthopanax senticosus such as 10, 20 and 30%, respectively. For the chemical composition of experimental diets, crude protein (CP) contents of controls were 13.39% and those of supplementation treatments were lowered with increasing levels of Acanthopanax senticosus. Control groups tended to have higher acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents as compared to supplementation groups, but non-fibrous carbohydrate (NFC) contents tended to be higher far supplementation groups than those for controls. Feed intakes had no significant difference among treatments, but digestible dry matter amounts were significantly higher for 20 and 30% supplementation groups than those for other treatments. Dry matter intakes per metabolic body weight and their ratio per body weight were highest in 20% group, but those of 40% groups were lowest (p<0.05). Crude protein, ADF and NDF digestibilities were significantly higher in Acanthopanax senticosus supplementation groups in comparison to controls (p<0.05), and in particular, they were increased with increasing supplementation levels of tranthopanax senticosus. Nitrogen retention was significantly higher for 20 and 30% treatments than those fur controls (p<0.05). Plasma urea nitrogen concentration was significantly lower for 30% supplementation group than those fur controls (p<0.05). Furthermore, plasma triglyceride concentration was significantly lower for Acanthopanax senticosus groups than those for controls (p<0.05). The results showed that supplemental level of 20% Acanthopnnax senticosus leaves to Korean black goats improved nutrient digestibility, nitrogen retention, and plasma urea nitrogen and triglyceride concentrations. Consequently, it might contribute to more efficient production of Korean black goats.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.4
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• pp.113-125
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• 1984

Water supply has been mainly dependent on the construction of the dams in Korea. It is difficult, however, to continue to construct dams for many reasons, such as the decrease of construction sites, the increase of construction costs, the compensation of residents in flooded areas, and the environmental effects. Water demands have increased and are expected to continue increasing due to the concentration of people in the cities, the rise of the living standard, and rapid industrial growth. It is acutely important to find countermeasures such as development of ground water, desalination, and recycling of waste water to cope with increasing water demands. Recycling waste water includes all means of supplying non-potable water for their respective usages with proper water quality which is not the same quality as potable water. The usages of the recycled water include toilet flushing, air conditioning, car washing, yard watering, road cleaning, park sprinkling, and fire fighting, etc. Raw water for recycling is obtained from drainage water from buildings, toilets, and cooling towers, treated waste water, polluted rivers, ground water, reinfall, etc. The water quantity must be considered as well as its quality in selecting raw water for the recycling. The types of recycling may be classified roughly into closed recycle systems and open recycle systems, which can be further subdivided into individual recycle systems, regional recycle systems and large scale recycle system. The treatment methods of wastewater combine biochemical and physiochemical methods. The former includes activated sludge treatment, bio-disc treatment, and contact aeration treatment, and the latter contains sedimentation, sand filtration, activated carbon adsorption, ozone treatment, chlorination, and membrane filter. The recycling patterns in other countries were investigated and the effects of the recycling were divided into direct and indirect effects. The problems of water reuse in recycle patterns were also studied. The problems include technological, sanitary, and operational problems as well as cost and legislative ones. The duties of installation and administrative organization, structural standards for reuse of water, maintenance and financial disposal were also studied.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.195-201
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• 2014

This study was conducted to investigate the current status of hygiene performance and food preparation/storage condition in restaurants during the summer season in order to evaluate the sanitary management systems in restaurants against climate change. Total 30 restaurants located in Gyeonggi participated in a survey in which they were asked current hygiene performance, food preparation/storage condition, and purchasing practices for 5 food ingredients. As results, regarding the performance degree of respondents on food hygiene management, the average scores of 9 questions were well over 4 points. However, only 6.83% of the respondents claimed that they use sanitizers (chlorine) to disinfect food ingredients. About food storage condition, a high proportion of respondents said that they store food materials in plastic bags or airtight containers following pretreatment and use refrigerator for the storage of pretreated food materials. However, 5.55% and 14.85% of respondents answered that they store pretreated food materials in the kitchen or inside of dining room, respectively. Respondents (21.50%) answered that they store pretreated food materials for more than 6 hours before cooking. Therefore, food materials need to be disinfected properly with sanitizer to remove microbial contamination and stored at refrigerator using closed bags or containers before cooking in order to prevent foodborne disease in restaurants especially during summer season.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.138-145
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• 2010

The combined effect of 50 ppm aqueous chlorine dioxide ($ClO_2$) or 0.5% fumaric acid with $5 kJ/m^2$ ultraviolet-C (UV-C) on the postharvest quality of "Flamengo" strawberries was examined. After non-thermal treatment, the samples were stored at $4\pm1^{\circ}C$ for 12 days. The combined treatment of fumaric acid/UV-C reduced the initial populations of total aerobic bacteria and yeast and molds in the strawberries by 2.09 and 2.02 log CFU/g, respectively, compared to those of the control. In addition, after 12 days of storage the yeast and molds population in the combined treatment was 1.72 log CFU/g, compared to 5.10 log CFU/g for the control, resulting in a significant decrease of 3.38 log CFU/g. Postharvest treatments used in this study caused negligible changes in the color of the strawberries. Sensory evaluation results indicated that the combined postharvest treatment provided better sensory scores than did the control. In particular, the overall acceptability scores were higher for the combined treatment groups after 5 days of storage. These results suggest that combined treatment of either 50 ppm $ClO_2$ or 0.5% fumaric acid with $5 kJ/m^2$ UV-C can be useful for maintaining the quality of strawberries.