• Title/Summary/Keyword: Drinking water discoloration

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A study on the removal of particulate matters using unidirectional flushing (단방향 플러싱에 의한 입자성 물질의 제거에 관한 연구)

  • Kim, Dooil;Cheon, Subin;Hyun, Inhwan
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.3
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    • pp.371-380
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    • 2015
  • Particulate matters in a water distribution system are main causes of turbidity and discoloration of tap water. They could be removed by conventional or uni-directional flushing in a water distribution system. The behaviors and required flow velocity of particles are not well known for their flushing. A model water main and hydrant were made from transparent acrylic pipe of 30mm and 16mm in diameter, respectively. We analyzed the effect of flushing velocity, particle density, and particle diameter. We found that the existence of break-though velocities at which particles begin to be removed, and which are affected by their physical properties. The removal efficiencies seemed to be influenced by resuspension capabilities related to their upward movement from the bottom. Heavy particles like scale were hard to remove through upflow hydrant because the falling velocity, calculated using Stokes' law, was higher. Particle removal efficiencies of upward hydrant and downward drain showed minor differences. Additionally, the length between hydrant and control valve affected flushing efficiency because the particulate matters were trapped in this space by inertia and recirculating flow.

Analysis of Color0Difference and Physical Property of Anti-Corrosion Coatings Used in Concrete Tank (콘크리트 수조 구조물에 사용하는 방식코팅재의 화학수 침지에 따른 색차 변화와 물리적 성질의 관계분석 기초 연구 -에폭시 수지계 도료를 중심으로-)

  • Seo, Hyun-Jae;Kim, Dong-Bum;Kim, Yun-Ho;Choi, Sung-Min;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.77-81
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    • 2010
  • This study deals with the analysis of color-difference and physical property of anti-corrosion coatings using at inside of concrete tank for drinking water. Because anti-corrosion coatings are effected by chemical attack, color and physical property are changed. So in this study when epoxy resin coatings of 3 types were received chemical attack by Cl- and NaOH, we present the co-relationship between color-difference and bond strength. For this study, we used the colorimetry, which can measure the degree of color difference on surface of materials. As the results, in case of Cl-, color change is appeared, bond strength also is decreased. From this experiment, we could know that color change due to chemical aging has the deep relationship with physical performance(bond strength) materials. further researches are needed.

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