• 한국식품위생안전성학회지
• /
• 제9권4호
• /
• pp.229-235
• /
• 1994

It is very important to investigate the sanitary chemical conditions of farmwaters used for cattle breeding in the dairy farms. For this purpose we examined pH, KMnO4 consumption, total hardness, chloride, sulfate, NH3-N, NO3-N, fluoride, lead, iron, manganese, cadmium, copper, zinc and chrome in the farmwaters sampled 2 times(spring and summer)in Choongcheongnam and Kangwon Province. The pH of farmwaters in Choongcheongnam and Kangwon Province was 6.49$\pm$0.09, 6.70$\pm$0.06, total hardness 90.21$\pm$7.07, 64.53$\pm$6.38 mg/ι, consumption of KMnO4 4.13$\pm$0.62, 4.34$\pm$0.26mg/ι, NO3-N 6.51$\pm$0.55, 3.61$\pm$0.58 mg/ι, chloride ion 20.51$\pm$1.99, 5.41$\pm$1.36 mg/ι and sulfate ion 6.61$\pm$1.02, 7.28$\pm$1.30 mg/ι, respectively. But NH3-N was scarcely detected. Fluoride, iron, lead, cadmium, zinc, manganese and chrome were not detected from the tested farmwaters. There was high significance between each other in total hardness, NO3-N, chloride ion and sulfate ion. There was regional and seasonal significance in only NO3-N but only regional significance in total hardness and chloride ion.

• 환경위생공학
• /
• 제8권1호
• /
• pp.117-127
• /
• 1993

When incineration method is utilized as a disposal process of sludge, the treatment generally consists of thickening, dewatering and incineration, implying that sludge dewaterability has a colose relationship with operating condition of a thickener. Dewatering factors should be, therefore investigated for achieving effective sludge treatment. No research on this has been performed in Korea. This study has focused on the evaluation on the effects of thickener operating variables on sludge dewatering, including sludge feed types and retention time. Mixing ratio of the first and the second sludge and operation time were varied in order to observe the change of dewaterability and optimum input of chemical conditioner.

• 환경위생공학
• /
• 제17권1호
• /
• pp.12-19
• /
• 2002

This study was carried out to investigate the optimal condition for granite particle coagulation process by using various chemical coagulation agents. The coagulation of a suspended granite particle was monitored by using various different coagulants, such as $Al_2(SO_4)_3{\cdot}14H_2O,{\;}FeCl_3{\cdot}6H_2O,{\;}SA-solution(KOH{\;}+{\;}Al(OH)_3{\;}+{\;}K_2CO_3{\;}mixture)$ and jade particle. To accomplish this study, analysis of water quality, removing Turbidity and Packing Density were measured with jar-tester. In the results of this experiment, it was found that the removal rate of the granite particle was increased with the decrease of the pH of the sludge. The turbidity(NTU) at the above coagulants was reduced from 95% to 98%. Removed of Turbidity and Packing Density was more efficiency to the SA-solution than others.

• 환경위생공학
• /
• 제13권3호
• /
• pp.72-78
• /
• 1998

For investigation into gas permeation characteristics, the porous alumina membrane with asymmetrical structure, having upper layer with 10 nanometer under of pore diameter and lower layer with 36 nanometer of pore diameter, was prepared by anodic oxidation using DC power supply of constant current mode in an aqueous solution of sulfuric acid. The aluminium plate was pre-treated with thermal oxidation, chemical polishing and electrochemical polishing before anodic oxidation. Because the pore size depended upon the electrolyte, electrolyte concentration, temperature, current density, and so on, the the membranes were prepared by controling the current density, as a very low current density for upper layer of membrane and a high current density for lower layer of membrane. By control of current quantity, the thicknesses of upper layer of membranes were about $6{\;}{\mu}m$ and the total thicknesses of membranes were about $80-90{\;}{\mu}m$. We found that the mechanism of gas permeation depended on model of the Knudsen flow for the membrane prepared at each condition.

• 환경위생공학
• /
• 제10권1호
• /
• pp.86-96
• /
• 1995

Alum recovery has recently gained more attention because many water utilities need to improve their sludge handling and disposal practices. As part of an overall sludge management program recovery can reduce the amount of solids and allow for reuse of the recovered Alum as a coagulant. This study was examined the effectiveness of Alum recovery from the Sludge at the D water treatment plant in Kwangju city. The results were summarized as follows 1. Alum recovery was obtained sufficiently acidification(An optimum condition was pH2-3) With $H_{2}SO_{4}$ to settled sludge. In this case recovered liquid Alum from sludge of 2.1% solids concentration at pH 2.1 was contains Aluminum $1,602mg/{\ell}$(as $Al_{2}O_{3}$ 0.3% ) and other metal of low level. 2. It was an optimum condition to all reuse of recovered Alum as a coagulant that rate of Commercial Alum:Recovered Alum=$14{\mu}{\ell}/{\ell}{\;}:{\;}200{\mu}{\ell}/{\ell}$ In a result of Jar Tests. 3. It was a result of Alum recovery from sludge, the reduction effect of amount of solids was about 57.4%. 4. If all recovered Alum were reused the reduction effect of solid wastes disposal cost and chemical drug's cost was about 22%.

• 한국임상수의학회지
• /
• 제8권2호
• /
• pp.157-170
• /
• 1991

Effects of recombinant bovine somatotropln(${\gamma}$BST) on hematologie and blood chemical values were investigated in twenty-five multiparous Holstein dairy cows. Recombinant BST was administered by two different routes ; intramusculary(12.5mg and 25mg/day) and subcutaneously(500mg and 750mg) in sustained-release vehicle every 2 weeks beginning 4 weeks postpartum and continuing for 7 months. Whole blood and serum samples were collected 0, 1, 2, 3, 5, and 7 months after beginning of treatments from control and ${\gamma}$BST-administered groups. Hematologic values including RBC, PCV, HB, MCH, MCHC, WBC and differential counts of treatment groups receiving ${\gamma}$BST were similiar to those of control group. Blood chemical values observed were total protein, albumin, A/G ratio, glucose, cholesterol, Ca, Pi, Ca/pi ratio, total bilirubin, creatinine, BUN, alkaline phosphatase, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase. There were no significant differences in blood chemical values of cows administered with ${\gamma}$BST from those of control. Although some blood chemical values were fluctuated at a certain observation period, they were remained within the normal physiological ranges. It is concluded from the observations of these experiments that the dose and dosage froms of ${\gamma}$BST employed in this work might not affect hematologic and blood chemical values in dairy cows under the normal sanitary condition and adequate nutritional balance.

• 환경위생공학
• /
• 제24권1호
• /
• pp.1-12
• /
• 2009

The various environmental problems that we face on today are basically about environmental quality. Since early 1960s affluent material was produced because of remarkable economic growth by many cooperations. However, for the lack of environmental policy, environmental pollutions has been serious. The central government should transfer the producing and consuming structure to environmental affinity through the regulations for developing Korea as a model of environmental nation which takes an active part in global environmental programme and in which the environment and economy are well harmonized. Moreover, the central government should take the lead in prevention of environmental pollution through the direct policies such as strengthening the discharge limit or setting up environmental basic institutions by securing budget for conserving environment. This thesis emphasize on the public institution among many environmental basic institutions for environmental anti-pollution project. It will find the problems with running those institutions, and will suggest the preview of improvement. Also, it is necessary to investigate of variation trend for inflow and pollutant loading to environmental infrastructure as increased of the diffusion rate as established and maintenance of sewer system. The purpose of this study is to investigate for inflow and pollutant loading to environmental infrastructure, and also to provide the method of efficiently maintenance and management. The results obtained were summarized as follows; 1. Survey of actual condition on operation and management of environmental infrastructure was evaluated the propriety of treatment process and problem of plant management. 2. Analysis of pollutant loading contribution for river system of environmental infrastructure with data analysis of water quality measuring network. 3. To investigate on case study for efficiently maintenance and management of environmental infrastructure. The result on this study was provide the method of efficiently maintenance and management with survey for establish and repair of sewer system and survey of actual condition on operation and management of environmental infrastructure in the water area of discharge to Geum River System. Application as guideline for establish and management of environmental infrastructure, and management of Geum River System. Also, application for preliminary data for fulfill-assess of total effluent regulation of water pollution.

• 환경위생공학
• /
• 제6권1호
• /
• pp.7-25
• /
• 1991

Until now, pure drinking water grnerally menas the water without taste, odor, general bacteria, coliform, and other exotic substance. Such a definition has been changing recently due to the finding of numerous other inorganic and organic substances unknown to us. 10 years ago, major causes of death were infectious agents and parasites contained in water, but recently, it has become apparent that some substances contained in drinking water cause cancer and heart diseases. We must drink about 2L of water everyday in order to maintain healthy condition. Waters used for drinking include tap water, well water, spring water, filtered water, etc., but the quality of drinking water has more polluted due to the industrial development and population increase. For example, industrial waste waters from industrial plants pollute the water supply sources ; toxic substances contained in the waste waters pollute the ground water sources by penetrating the geological strata, and municipal, livestock, public building waste waters also pollute the water supply sources. Sometimes, the polluted surface waters were announced to be polluted by various kinds of orgainc substance, and it is reported that the pollution of ground water by orga nic substances has few in number but high in its concectration comparing with those of surface water. As the water quality pollution level increases, so the amount of disinfectant also increase. For example, chlorine solution, one of widely used disinfectants, creates trihalomethane(THM), a carcinogen, and halogen compounds. According to Oliver, through chlorine disinfection process, humine substance and chlorine create bolatile organic halide and nonvolatile organic halide by chemical reaction. There are tens or hundreds filtering devices, but filtering principles and maintenance metjhods are different, so their efficiency tests are needed. According to Smith, the effeciency tests aginst over 30 Ameican filtering devices show that 10 devices can remove 85% of volatile organics and further studies on filtered waters are underway. In consideration of important impacts of polluted drinking water on national health, authors studied the state of water quality pollution against tap water used as drinking water, filtration device passed water, ground water, and conserved drinking water ; tested the efficiency of filtration devices for tap water ; tried to sep up the detection method by using ion chromatography based on negative ion and positive ion by using single column, and attemped the simple filtration method for general households.

• 환경위생공학
• /
• 제13권3호
• /
• pp.148-157
• /
• 1998

Leachate is a result of the percolation of precipitation, uncontrolled runoff, and irrigation water into the landfill and can also include water initially contained in the waste as well as infiltrating groundwater. Behaviour of leachate by rainfall was studied to evaluate the variation of leachate generation and contaminants by rainfall in Sudokwon Landfill from January 1998 to October 1998. The quantity of leachate generated was measured with a flow meter, and the concentrations $BOD_5$, CODcr, T-N, $NE_3-N$, SS of leachate were also measured. Principal outcome obtained in this study are as follows : the quantity of leachate generated was the highest on August, the highest leachate generation volume in this period was 11,913㎥ and the lowest was $6,261m^3$. Although the similar amount of precipitation of 80mm applied to the two samples, there were difference in leachate generation due to precipitation duration, precipitation frequency, wet condition of solid wastes. As the result of regression analysis, the correlation coefficients(r) between the quantity of leachate generated and precipitation were 0.823, 0.976 between $BOD_5$ and CODcr, 0.992 between T-N and $NE_3-N$. As the quantity of leachate generated increased 48%, the concentration of $BOD_5$ and CODcr decreased 51% and 50% respectively. Therefore it was showed that the pollutant concentrations in leachate were diluted by precipitation. The concentrations of $BOD_5$ and COBcr in the rainy season were 2000~4000mg/1, 4000~6000mg/1 respectively, and 1000~3000 mg/1, 3000~5000 mg/l in the dry season. The loading of SS, $BOD_5$, CODcr(kg/month) on July was increased by 2.9 times, 2.8 times, 2.2 times with a basis on March. Therefore countermeasure of treatment facilities according to increase of loading by rainfall in summer is necessary.

• 한국건축시공학회지
• /
• 제24권1호
• /
• pp.43-53
• /
• 2024

본 연구에서는 실리콘 실란트 총 6종을 제작하여 곰팡이 저항성 시험 방법인 ASTM G 21, LH 전문 시방(LHCS 41 40 12) 시험과 신규 제정된 KS F ISO 21265 시험법에 따라 곰팡이 저항성을 평가하였다. 그 결과, KS F ISO 21265 시험법이 ASTM G 21과 LH 전문 시방(LHCS 41 40 12) 시험법에 비해 곰팡이 저항성 평가에 대한 변별성이 더 큰 것으로 판단되었으며, 알콕시 경화형 실란트에 비해 옥심 경화형 실란트의 곰팡이 저항성이 더 큼을 확인하였다. 또한, KS F ISO 21265 시험법에서는 50℃에서 4주간 침수 후 곰팡이 저항성을 평가하는 조건 도입을 통해 실란트의 장기적인 곰팡이 저항성 평가가 가능할 것으로 판단된다.