• Title/Summary/Keyword: Improvement of Water quality

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Particle Removal in a Rainwater Storage Tank, and Suggestions for Operation & Design (빗물저장조에서 입자의 제거특성 및 운전과 설계시 고려사항)

  • Mun, Jungsoo;Yoo, Hyoungkeun;Han, Mooyoung
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.1
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    • pp.131-138
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    • 2007
  • A rainwater utilization facility consists of its catchment area, treatment facility, storage tank, supply facility and pipes in general. The rainwater storage tank which occupies the largest area of the facility has been usually considered quantitatively for determining the storage capacity. Hence, there is little information on water quality improvement by sedimentation in a rainwater storage tank in operation. In this study, we measured the rainwater quality in a rainwater storage tank in operation during late spring and summer, and showed water quality improvement of turbidity removal of 25~46% by sedimentation in a rainwater storage tank under a fixed water level without inflow and outflow after runoff ceased. It is necessary to have a considerable distance between the inlet and outlet of the tank and, if possible, it is recommended that the design should allow for an effective water depth of over 3 m and supply rainwater near the water surface. The operation method which increases the retention time by stopping rainwater supply for insuring low turbidity is recommended when the turbidity of rainwater runoff is high. And also more efficient operation and maintenance of the rainwater utilization facility is expected through the tailored design and operation of the facility considering particle removal and behavior.

Quality Improvement in Centrifugal Barrel Finishing Machine (원심바렐연마기공에 있어서 품질향상 대책)

  • 홍순교
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.280-283
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    • 1995
  • In centrifugal barrel finishing, it is easy to establish the optimum working conditions for different workpieces. As they are adjusted in trial and error practically, production efficiency and quality are some- times low In the present paper, firstly, installation of the barrel finishing machine, finishing purpose and working conditions have been analyzed in order to eliminate the defects of the finished surface. Secondly, on the basis of this result, quantity of the water and selection of the media and the compound, etc. have been investigated. As a result, production efficiency and quality have been improved under the specified optimum working conditions. In addition, durability of the media and the compound has been tested experimentally. As a result, it was found that the expected life of the media is about 85 hrs and that of the compound is about 5 hrs. Besides high quality control has been achieved by newly proposed inspection at regular intervals.

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Water Quality Conservation in Rural Areas of Japan - Case Study of Rural Sewerage Project -

  • Taniyama, Shigetaka;Sugita, Hideo
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42
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    • pp.50-60
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    • 2000
  • In this presentation I would like to introduce the Rural Sewerage Project, subsidized by the Ministry of Agriculture, Forestry and Fisheries (MAFF), for the purpose of water quality conservation and improvement of life in rural areas of Japan. Specifically, it will cover background information on the inauguration of the Project, its strong points, wastewater technology and some of its problems, system of the Project, etc.

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Future Direction of Water Quality Standards in Korea (우리나라 물환경 기준의 개선방향)

  • Lee, Jae-Kwan;Cho, Soon;Chung, Il-Rok;Hwang, Soon-Jin
    • Journal of Korean Society on Water Environment
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    • v.22 no.5
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    • pp.737-747
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    • 2006
  • Ministry of Environment (MOE) of Korea has been implementing the water quality management policy to focus on the control of organic matters (BOD and COD) for 28 years since 1978 when the water quality standards had been established. However, the government and the public have begun to recognize the necessity of creating the best water environment for people and aquatic life, and also formulating the various measures of water pollution, Consequently, MOE of Korea is establishing the basic plan of water environment management, with the vision of "Clean Water, Eco River 2015." The major targets of water environment management plan are to maintain ecosystem health and to protect water quality from various hazardous substances in water bodies. In order to achieve the major targets, it is essential to amend the water quality standards, which bring about the systematic management of various pollutants and healthy ecosystem. Introduction of the new techniques of water environment assessment is also prerequisite to maintain sustainable water environment. These can be accomplished under the consideration of following suggestions in environmental quality standards. First, several criteria should be complemented in water quality standards; they include the improvement of the current water quality classification system, the strengthening and supplement of relevant parameters considering human health in the standards, the introduction of biotic indices, and management standards on eutrophication. Secondly, it should be considered to introduce the biological water quality standards using biotic indices and the management standards for sediments. Lastly, it needs to introduce or develop an ecological status classification which could be used in the assessment of the water environment as a whole.

Introduction of Water Safety Plan in Korea (물안전계획(Water Safety Plan)의 국내 도입방안)

  • Kim, Jin-Keun
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.4
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    • pp.535-545
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    • 2012
  • Recently, drinking water quality has significantly improved with the progress of water treatment technologies, however, customer's trust on tap water is still relatively low. Low trust on water quality is mainly due to vague anxiety. Therefore, to improve customer's trust on drinking water quality new strategy such as water safety plan(WSP) which recommended by WHO and IWA should be introduced. WSP can be defined as an approach which uses comprehensive risk assessment and risk management approach that encompasses all steps in water supply from catchment to consumer to ensure the safety of a drinking water supply. In this study, cases on WSP introduction in other countries as well as strategy for the introduction of WSP in Korea were investigated. In addition, recommendations on the improvement of the current water contamination response manual was suggested based on the analysis of the existing manual at a full scale water treatment plant.

Improvement Effect of the HyungGae-Water on Quality of Life in Children and Adolescents with Pruritus (한방입욕제(형개수) 사용을 통한 소양증을 호소 소아청소년의 삶의 질 개선효과)

  • Jeong, Kyung Sik;Baek, Young Hwa;Yoo, Jong Hyang;Hwang, Man Ki;Choi, Young Jin;Kim, Yun Hee;Lee, Si Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.32 no.3
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    • pp.178-183
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    • 2018
  • Pruritus is the most prominent symptom of atopic dermatitis and other skin diseases. It is not easily improved and is a major factor that threatens the quality of life of patients and their families. The purpose of this study was to evaluate the effect of HyungGae-Water, which was bath preparation made from Korean medicine herbs, for children and adolescents suffering pruritus. The participants were 50 boys and girls aged from 2 to 15 years old. The HyungGae-Water was used once a day for 6 weeks, and we were followed up three times every two weeks. Of 50 participants enrolled, 47 completed the study. The outcome variables were dermatology quality of life scales in children, pruritus VAS, and investigator global assessment (IGA). The results of the study show that the dermatology quality of life is significantly improved and the VAS of pruritus has meaningful changes. In the IGA, moderate or severe improvement was observed in 48.9% and slight improvement in 17%. There were seven suspected or less relevant adverse events using HyungGae-Water. The present results suggest that the HyungGae-Water has alleviating effect for the pruritus in children and adolescents.

Estimation for Raw Water Quality of Manganese Concentrations from Archived Data in Small-scale Water Systems (소규모 정수처리장에서 모니터링 자료를 이용한 원수의 망간농도 예측에 관한 연구)

  • Min, Byung-Dae;Yamazaki Kimiko;Koizumi Akira;Koo, Ja-Yong
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.4
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    • pp.547-554
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    • 2011
  • In small-scale water systems, the measurement of quality of raw water in running water is generally implemented when the quality of water is stable and frequency of measurement is low. However, units such as water temperature and pH, which are easily monitored, are frequently measured. In establishing an improvement plan for a water treatment system, the range of concentration of the target material present in the raw water of the running water provides relevant information. If the concentration of target material can be specified by the quality of water of data items that are measured daily, inverse estimation of the range of concentration is possible as well. In this paper, we took note of manganese in the raw water from Ogasawara-mura, Tokyo, and estimated the manganese concentration in the raw water of the running water for the past five years. Based on the results obtained, we have proposed a manganese removal system, considering the current situation and geographical conditions of Ogasawara-mura.

Physical and Chemical Management Practices for Improving Water Quality in Channel Catfish Ictalurus punctatus Aquaculture

  • Seo, Jin-Won
    • Journal of Aquaculture
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    • v.15 no.1
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    • pp.49-60
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    • 2002
  • Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

Lake Water Quality Modelling Considering Rainfall-Runoff Pollution Loads (강우유출오염부하를 고려한 호수수질모델링)

  • Cho, Jae-Heon;Kang, Sung-Hyo
    • Journal of Environmental Impact Assessment
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    • v.18 no.2
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    • pp.59-67
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    • 2009
  • Water quality of the Lake Youngrang in the Sokcho City is eutrophic. Jangcheon is the largest inflow source to the lake. Major pollutant sources are stormwater runoff from resort areas and various land uses in the Jangcheon watershed. A storm sewer on the southern end of the lake is also an important pollution source. In this study, water quality modelling for Lake Youngrang was carried out considering the rainfall-runoff pollution loads from the watershed. The rainfall-runoff curves and the rainfall-runoff pollutant load curves were derived from the rainfall-runoff survey data during the recent 4 years. The rainfall-runoff pollution loads and flow from the Jangcheon watershed and the storm sewer were estimated using the two kinds of curves, and they were used as the flow and the boundary data of the WASP model. With the measured water quality data of the year 2005 and 2006, WASP model was calibrated. Non-point pollution control measures such as wet pond and infiltration trench were considered as the alternative for water quality management of the lake. The predicted water quality were compared with those under the present condition, and the improvement effect of the lake water quality were analyzed.

Household's Willingness to Pay for Piped Water Quality Improvement in Wonju (원주시 가구의 상수도 수질개선에 대한 지불의사액 추정)

  • Yoo, Seung-Hoon;Shin, Chul-Oh;Yang, Chang-Young
    • Journal of Environmental Policy
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    • v.5 no.3
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    • pp.79-103
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    • 2006
  • This paper attempts to examine household's willingness to pay (WTP) for piped water quality improvement in Wonju, where the local government are planning to implement a piped water quality improvement program. We apply a contingent valuation (CV) method to obtain at least a preliminary evaluation of the WTP. The CV survey was rigorously designed to comply with the guidelines for best-practiced CV studies. We surveyed a randomly selected sample of 250 households in Wonju and asked respondents questions in person-to-person interviews about how much they would be willing to pay for the program. Respondents overall accepted the contingent market and were willing to contribute a significant amount (1,583 to 2,776 won), on average, per household per month. This willingness varies according to individual characteristics such as sex, education level, and income. The aggregate value of the program in Wonju amounts to approximately 1.99 billion won to 3.49 billion won per year. The household values can be the benefits that ensue from the program and compared with the costs of the program to determine whether the program is economically desirable.

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