• Title/Summary/Keyword: Waste Factors

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On decrease program of Radioactive Wastewater and Sewages in High Dose Radioiodine Therapy Ward (고용량 방사성옥소 치료병실의 오.폐수 저감화를 위한 연구)

  • Ryu, Jae-Kwang;Jung, Woo-Young;Shin, Sang-Ki;Cho, Shee-Man
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.1
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    • pp.19-26
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    • 2008
  • Purpose: In general, We discharged radioactive wastewater and sewages less than $8.1{\times}10^{-13}$ Ci/ml in a exclusive water-purifier tank. Our hospital operating three exclusive water-purifier tank for radioactive wastewater and sewages of 60 tons capacity respectively. In order to meet the criteria it need a enough decay more than 125 days per each exclusive tank. However, recently we fell into the serious situation that decay period was decreased remarkably, owing to the wastewater amount increased rapidly by enlarge the therapy ward. For that reason, in this article, I'd like to say the way that reducing of radioactive wastewater and sewages rationally. Materials and Methods: From January, 2006 to October, four hundred and two cases were analyzed. They were all hospitalized during 3 days and 2 nights. We calculated the average amount of water used (include toilet water used, shower water used, washstand water used, $\cdots$), each exclusive water-purifier tank's decay period, as well as try to search the increased factors about water-purifier tank inflow flux by re-analysis of the procedure of radioisotope therapy step by step. Results: We could increase each exclusive water-purifier tank's decay period from 84 days to 130 days through the improvement about following cause: (1) Improvement of conventional toilet stool for excessive water waste $\rightarrow$ Replacement of water saving style toilet stool (2) Prevention of unnecessary shower and wash (3) Stop the diuretics taking during hospitalization (4) Analysis of relationship between water intakes and residual dose of body (5) Education about outside toilet utilization before the administration (6) Changed each water-purifier tank's maximum level from85% to 90% Conclusion: The originality of our efforts are not only software but hardware performance improvements. Incidentally the side of software's are change of therapy procedures and protocols, the side of hardware's are replacement of water saving style toilet stool and change of each water-purifier tank's maximum level. Thus even if a long lapse of time, problem such as return to the former conditions may not happen. Besides, We expect that our trials become a new reasonable model in similar situation.

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Bacteriocidal Effects of Ultraviolet Irradiation for Reducing Bovine Mastitis Derived from Environmental Contamination (우분뇨 유래 젖소 유방염 저감을 위한 자외선 조사 살균의 효과 규명)

  • Kim, Dong-Hyeok;Lim, Jung-Ju;Lee, Jin-Ju;Jang, Hong-Hee;Jang, Dong-Il;Lee, Seung-Joo;Lee, Hu-Jang;Min, Won-Gi;Kwon, Sun-Hong;Kim, Sang-Hun;Oh, Kwon-Young;Kim, Suk
    • Korean Journal of Environmental Agriculture
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    • v.27 no.4
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    • pp.435-440
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    • 2008
  • Bovine mastitis is an important disease causing serious economic loss in dairy production and food poison in public health. The major causative agents of bovine mastitis include Escherichia coli (E. coli), Streptococcus agalactiae (S. agalactiae), Staphylococcus aureus (S. aureus). These bacteria were found in milk and environmental condition such as feces, water, soil and so on. Recently, many cases of mastitis are derived from environmental contamination of micro-organisms, which important factors for the spread of this disease in farm. Ultraviolet irradiation (UV) has been used as disinfection for waste and water in clinical and industrial facilities. Moreover the UV irradiation has been used as useful bactericidal agents to remove bacterial biofilms in environmental condition. In this study, we determined the bacterial replication in different percentage of water content (PWC) in sterilized saw dust and feces complexes from farm, and results showed that slightly decreased growth pattern of E. coli and S. agalactiae but increased growth pattern of S. aureus in various PWC (200, 400 and 600%) until 144 h incubation. In the bacteriocidal effect of UV irradiation to bacteria in saw dust and feces complex, the results showed that bacteriocidal effect was depended on the UV irradiation time, irradiation distance and PWC. Especially the antibacterial activity of UV irratiation is stronger in low PWC (50%), long time irradiation (50 sec), and short distance (5 cm) than other condition of this study. Furthermore UV irradiation with stirring showed increased the bactericidal effect compared without stirring. These results suggested that bovine mastitis causing agents may survive long time in environmental condition especially saw dust and feces complexes in farm and can cause a various disease including mastitis. Moreover, these data can be used as basis for application and development of UV disinfection to control of bovine mastitis from environmental contaminated bacteria in dairy farm.

Cesium Sorption to Granite in An Anoxic Environment (무산소 환경에서의 화강암에 대한 세슘 수착 특성 연구)

  • Cho, Subin;Kwon, Kideok D.;Hyun, Sung Pil
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.2
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    • pp.101-109
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    • 2022
  • The mobility and transport of radioactive cesium are crucial factors to consider for the safety assessment of high-level radioactive waste disposal sites in granite. The retardation of radionuclides in the fractured crystalline rock is mainly controlled by the hydrochemical condition of groundwater and surface reactions with minerals present in the fractures. This paper reports the experimental results of cesium sorption to the Wonju Granite, a typical Mesozoic granite in Korea, performed in an anaerobic chamber that mimics the anoxic environment of a deep disposal site. We measured the rates and amounts of cesium (133Cs) removed by crushed granite samples in different electrolyte (NaCl, KCl, and CaCl2) solutions and a synthetic groundwater solution, with variations in the initial cesium concentration (10-5, 5×10-6, 10-6, 5×10-7 M). The cesium sorption kinetic and isotherm data were successfully simulated by the pseudo-second-order kinetic model (r2= 0.99) and the Freundlich isotherm model (r2= 0.99), respectively. The sorption distribution coefficient of granite increased almost linearly with increasing biotite content in granite samples, indicating that biotite is an effective cesium scavenger. The cesium removal was minimal in KCl solution compared to that in NaCl or CaCl2 solution, regardless of the ionic strength and initial cesium concentration that we examined, showing that K+ is the most competitive ion against cesium in sorption to granite. Because it is the main source mineral of K+ in fracture fluids, biotite may also hinder the sorption of cesium, which warrants further research.

Evaluation of microplastic in the inflow of municipal wastewater treatment plant according to pretreatment methods (전처리 방법에 따른 하수처리장 유입수에서의 미세플라스틱 성상분석 평가)

  • Kim, Sungryul;Gil, Kyungik
    • Journal of Wetlands Research
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    • v.24 no.2
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    • pp.83-92
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    • 2022
  • The amount of the plastic waste has been increasing according to global demand for plastic. Microplastics are the most hazardous among all plastic pollutants due to their toxicity and unknown physicochemical properties. This study investigates the optimal methodology that can be applied to sewage samples for detecting microplastics before discussing reducing microplastics in MWTPs. In this study, the effect of different pretreatment methods while detecting microplastic analysis of MWTP influent samples was investigated; the samples were collected from the J sewage treatment plant. There are many pretreatment methods but two of them are widely used: Fenton digestion and hydrogen peroxide oxidation. Although there are many pretreatment methods that can be applied to investigate microplastics, the most widely used methods for sewage treatment plant samples are Fenton digestion and H2O2 oxidation. For each pretreatment method, there were factors that could cause an error in the measurement. To overcome this, in the case of the Fenton digestion pretreatment, it is recommended to proceed with the analysis by filtration instead of the density separation method. In the case of the H2O2 oxidation method, the process of washing with distilled water after the reaction is recommended. As a result of the analysis, the concentration of microplastics was measured to be 2.75ea/L for the sample using the H2O2 oxidation method and 3.2ea/L for the sample using the Fenton oxidation method, and most of them were present in the form of fibers. In addition, it is difficult to guarantee the reliability of measurement results from quantitative analysis performed via microscope with eyes. A calibration curve was created for prove the reliability. A total of three calibration curves were drawn, and as a result of analysis of the calibration curves, all R2 values were more than 0.9. This ensures high reliability for quantitative analysis. The qualitative analysis could determine the series of microplastics flowing into the MWTP, but could not confirm the chemical composition of each microplastic. This study can be used to confirm the chemical composition of microplastics introduced into MWTP in the future research.

Lithium Distribution in Thermal Groundwater: A Study on Li Geochemistry in South Korean Deep Groundwater Environment (온천수 내 리튬 분포: 국내 심부 지하수환경의 리튬 지화학 연구)

  • Hyunsoo Seo;Jeong-Hwan Lee;SunJu Park;Junseop Oh;Jaehoon Choi;Jong-Tae Lee;Seong-Taek Yun
    • Economic and Environmental Geology
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    • v.56 no.6
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    • pp.729-744
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    • 2023
  • The value of lithium has significantly increased due to the rising demand for electric cars and batteries. Lithium is primarily found in pegmatites, hydrothermally altered tuffaceous clays, and continental brines. Globally, groundwater-fed salt lakes and oil field brines are attracting attention as major sources of lithium in continental brines, accounting for about 70% of global lithium production. Recently, deep groundwater, especially geothermal water, is also studied for a potential source of lithium. Lithium concentrations in deep groundwater can increase through substantial water-rock reaction and mixing with brines. For the exploration of lithim in deep groundwater, it is important to understand its origin and behavior. Therefore, based on a nationwide preliminary study on the hydrogeochemical characteristics and evolution of thermal groundwater in South Korea, this study aims to investigate the distribution of lithium in the deep groundwater environment and understand the geochemical factors that affect its concentration. A total of 555 thermal groundwater samples were classified into five hydrochemical types showing distinct hydrogeochemical evolution. To investigate the enrichment mechanism, samples (n = 56) with lithium concentrations exceeding the 90th percentile (0.94 mg/L) were studied in detail. Lithium concentrations varied depending upon the type, with Na(Ca)-Cl type being the highest, followed by Ca(Na)-SO4 type and low-pH Ca(Na)-HCO3 type. In the Ca(Na)-Cl type, lithium enrichment is due to reverse cation exchange due to seawater intrusion. The enrichment of dissolved lithium in the Ca(Na)-SO4 type groundwater occurring in Cretaceous volcanic sedimentary basins is related to the occurrence of hydrothermally altered clay minerals and volcanic activities, while enriched lithium in the low-pH Ca(Na)-HCO3 type groundwater is due to enhanced weathering of basement rocks by ascending deep CO2. This reconnaissance geochemical study provides valuable insights into hydrogeochemical evolution and economic lithium exploration in deep geologic environments.

Changes in Phytosterol Content in Cobs and Kernels During Physiological Maturity of Corn Ears (옥수수 이삭 등숙 기간 동안 속대와 종실의 Phytosterol 함량 변화)

  • Jun Young Ha;Young Sam Go;Jae Han Son;Mi-Hyang Kim;Kyeong Min Kang;Tae Wook Jung;Beom Young Son;Hwan Hee Bae
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.68 no.4
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    • pp.392-401
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    • 2023
  • Corn (Zea mays L.) is one of the world's most important crops, along with wheat and rice, with a global corn production expected to reach 1,154.5 million tons in 2023. Considering this grain production, The generation of corn cob is expected to reach approximately 207.8 million tons in 2023. However, as an agricultural by-product, corn cobs are often considered waste and remain underutilized. Phytosterols, which are abundant in vegetable oils such as corn oil, provide a number of health benefits, including liver health, cholesterol reduction, and protection against chronic diseases such as diabetes. In this study, we investigated the potential of Kwangpyeongok ears, which are commonly used as grain and silage corn in Korea. We also examined the variation in phytosterol content with the maturity of corn ears to identify the optimal time for utilization. At the beginning of physiological maturity, corn cobs had 113.3 mg/100g DW of total phytosterols, which was highest phytosterol abundance during the growth stage. Corn kernels also had the highest phytosterol content at the beginning of physiological maturity. While previous studies on corn bioactive compounds have mainly focused on the kernels, the results of this study highlight that cobs are an excellent source of these compounds. Furthermore, phytosterol levels were influenced by genetic factors and developmental stages, suggesting the to increase the use of cobs as a source of bioactive compounds.

Structural Adjustment of Domestic Firms in the Era of Market Liberalization (시장개방(市場開放)과 국내기업(國內企業)의 구조조정(構造調整))

  • Seong, So-mi
    • KDI Journal of Economic Policy
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    • v.13 no.4
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    • pp.91-116
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    • 1991
  • Market liberalization progressing simultaneously with high and rapidly rising domestic wages has created an adverse business environment for domestic firms. Korean firms are losing their international competitiveness in comparison to firms from LDC(Less Developed Countries) in low-tech industries. In high-tech industries, domestic firms without government protection (which is impossible due to the liberalization policy and the current international status of the Korean economy) are in a disadvantaged position relative to firms from advanced countries. This paper examines the division of roles between the private sector and the government in order to achieve a successful structural adjustment, which has become the impending industrial policy issue caused by high domestic wages, on the one hand, and the opening of domestic markets, on the other. The micro foundation of the economy-wide structural adjustment is actually the restructuring of business portfolios at the firm level. The firm-level business restructuring means that firms in low-value-added businesses or with declining market niches establish new major businesses in higher value-added segments or growing market niches. The adjustment of the business structure at the firm level can only be accomplished by accumulating firm-specific managerial assets necessary to establish a new business structure. This can be done through learning-by-doing in the whole system of management, including research and development, manufacturing, and marketing. Therefore, the voluntary cooperation among the people in the company is essential for making the cost of the learning process lower than that at the competing companies. Hence, firms that attempt to restructure their major businesses need to induce corporate-wide participation through innovations in organization and management, encourage innovative corporate culture, and maintain cooperative labor unions. Policy discussions on structural adjustments usually regard firms as a black box behind a few macro variables. But in reality, firm activities are not flows of materials but relationships among human resources. The growth potential of companies are embodied in the human resources of the firm; the balance of interest among stockholders, managers, and workers of the company' brings the accumulation of the company's core competencies. Therefore, policymakers and economists shoud change their old concept of the firm as a technological black box which produces a marketable commodities. Firms should be regarded as coalitions of interest groups such as stockholders, managers, and workers. Consequently the discussion on the structural adjustment both at the macroeconomic level and the firm level should be based on this new paradigm of understanding firms. The government's role in reducing the cost of structural adjustment and supporting should the creation of new industries emphasize the following: First, government must promote the competition in domestic markets by revising laws related to antitrust policy, bankruptcy, and the promotion of small and medium-sized companies. General consensus on the limitations of government intervention and the merit of deregulation should be sought among policymakers and people in the business world. In the age of internationalization, nation-specific competitive advantages cannot be exclusively in favor of domestic firms. The international competitiveness of a domestic firm derives from the firm-specific core competencies which can be accumulated by internal investment and organization of the firm. Second, government must build up a solid infrastructure of production factors including capital, technology, manpower, and information. Structural adjustment often entails bankruptcies and partial waste of resources. However, it is desirable for the government not to try to sustain marginal businesses, but to support the diversification or restructuring of businesses by assisting in factor creation. Institutional support for venture businesses needs to be improved, especially in the financing system since many investment projects in venture businesses are highly risky, even though they are very promising. The proportion of low-value added production processes and declining industries should be reduced by promoting foreign direct investment and factory automation. Moreover, one cannot over-emphasize the importance of future-oriented labor policies to be based on the new paradigm of understanding firm activities. The old laws and instititutions related to labor unions need to be reformed. Third, government must improve the regimes related to money, banking, and the tax system to change business practices dependent on government protection or undesirable in view of the evolution of the Korean economy as a whole. To prevent rational business decisions from contradicting to the interest of the economy as a whole, government should influence the business environment, not the business itself.

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