• Title/Summary/Keyword: 알칼리제

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Removal of Microalgae Using Inorganic Coagulants in Coagulation and Sedimentation Processes for Water Treatment (응집.침전공정에서 무기고분자응집제를 이용한 미세조류의 제거)

  • Cheong, Cheong-Jo
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.1
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    • pp.85-89
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    • 2008
  • The purpose of this study is to understand the removal possibility of microalgae using inorganic coagulants in coagulation and sedimentation process for water treatment. Removal of microalgae was studied according to coagulant type(Alum and PAC), coagulation factors(alkalinity, coagulant dosage, and setting time), and size fraction of microalgae. The contribution of applied coagulants for removal of microalgae was also examined. The removal rate of the microalgae by change of alkalinity was most high in 25 mg/L of alkalinity(Alum) as 87.2% and 30 mg/L of that(PAC) as 90.1%. Optimal coagulant dosage to remove the microalgae was 40 mg/L(removal effi.; 88.1%), and PAC was 50 mg/L(removal effi.; 90.1%). Alum was better than the PAC to remove the microlgae. In the water treatment processes such as rapid slow mixing and sedimentation the removal efficiency of microalgae with coagulants was 2 times higher than that of without. In optimal condition, the removal efficiencies of microalgae were nanoplankton > microplankton > picoplankton. Especially, the removal efficiency of the picoplankton was very low as below 30%.

Strength Properties According to the Conditions of Low Carbon Inorganic Composite Using Industrial By-product (산업부산물을 사용한 저탄소 무기결합재의 조건별 강도특성)

  • Lee, Yun-Seong;Lee, Sang-Soo;Song, Ha-Young
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.1
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    • pp.54-63
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    • 2012
  • The purpose of this study is to examine the potential for reducing the environmental load and $CO_2$ gas when cement is produced by using cement substitutes. These substitutes consisted of blast furnace slag, red mud and silica fume, which were industrial by-products. The most optimum mix was derived when alkali accelerator was added to low carbon inorganic composite mixed with industrial by-product at room temperature. It is determined that hardened properties and the results of compressive strength tests changed based on CaO content, Si/Al, the mixing ratio and the amount of alkali accelerator, curing conditions and W/B. The results of test analysis suggest that the optimum mix of low carbon inorganic composite is CaO content 30%, Si/Al 4, the mixed ratio of alkali accelerator $(NaOH:Na_2SiO_3)$ 50g:50g, the amount of alkali accelerator 100g and W/B 31%. In addition, if contraction is complemented, low carbon inorganic composite with superior performance could be developed.

Geology and Ore Deposit of the Apdong Nb-Ta Mine, North Korea (북한 압동 니오븀-탄탈륨(Nb-Ta) 광산의 지질 및 광상)

  • 이재호;김유동
    • Economic and Environmental Geology
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    • v.36 no.6
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    • pp.407-413
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    • 2003
  • The geology of the Apdong Nb-Ta deposit, is hosted by alkali metasomatites, consist of Upper Proterozoic sedimentary rocks, alkali syenites(Hoamsan intrusive) of Phyonggang Complex(late Paleozoic to early Mesozoic), Jurassic granite and Quaternary basalt. Alkali syenites are distinguished as alkali amphibole-pyroxene syenite, alkali amphibole-biotite syenite, biotite-nepheline syenite, biotite syenite, and quartz-alkali amphibole-pyroxene syenite. Alkali metasomatites are the products of intense post-magnatic metasomatism, and form the Nb-Ta ore bodies as the belt, irregular vein and lenticular types in the southern part of Hoamsan intrusive. The ore mineralization is characterized by the occurrence of pyrochlore, zircon, and small amounts of columbite, fergusonite. magnetite, fluorite, molybdenite, ilmenite, titanite, apatite, and monazite. Pyrochlore is one of the niobium/tantalum oxides and contains substantial amounts of rare earths and radioactive elements. The compositional varieties of pyrochlore can be defined: (1) enriched in tantalum, uranium and cerium, (2) substantially tantalum- and fluorine-poor, and (3) enriched in thorium or barium. The geochemical characteristics, ore textures and mineral occurrences indicate that alkali metasomatism of the mineralizing fluid was the dominant ore-forming process.

An Experimental Study on Efficiency Recovery Impregnation Alkalization Agent Apply cement pastes - about impregnation alkalization agent- (시멘트 경화체에 적용되는 알칼리 부여제의 성능회복에 관한 시험적 연구 - 알칼리부여제에 대하여 -)

  • 김광기;조규현;박선길;김성식;송병창;정상진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.829-834
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    • 2002
  • Carbonation of concrete used impregnation alkalization agent construction reinforcement, recovery of pH, elevation improve, in which efficiency decline mternal force of number and durability because of impregnation alkalization agent applyment general standard, used concrete. Material quality not understanding lack of study and stadard. This study investigate change of PH. recovery depth of impregnation alkalization agent, recovery depth belong a mount of aggregate that comparision, analysis parity.

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Penetration Depth and Porosity of Alkali Silicate Concrete Impregnants (알칼리 실리케이트계 침투성 표면보호제의 침투깊이 및 공극특성)

  • Song, Hun;Chu, Yong-Sik;Lee, Jong-Kyu
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.521-522
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    • 2009
  • This study is concerned with elevating the penetration depth after carbonation and porosity change of concrete structures by applying alkali silicate hydrophilic impregnants including lithium and potassium silicates.

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Study on the Characteristic of Non Cement Matrix using Blast Furnace Slag (고로슬래그를 사용한 무시멘트 경화체의 특성 연구)

  • Park, Sun-Gyu
    • Proceedings of the Korea Contents Association Conference
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    • 2013.05a
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    • pp.101-102
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    • 2013
  • 시멘트 및 건설산업은 그 제조과정에서 다량의 이산화탄소를 배출하기 때문에 지구온난화 문제를 가속화시키고 있는 것으로 알려져 있다. 따라서 이러한 시멘트를 대체할 수 있는 재료 개발에 많은 연구가 이루어지고 있으며, 철강산업 부산물인 고로슬래그 미분말은 그 중 하나의 재료라 할 수 있다. 고로슬래그 미분말은 물과 직접 반응하지 않으나 알칼리 환경하에서는 물과 반응하여 CSH 수화물을 생성하게 된다. 본 연구에서는 알칼리 자극제를 첨가한 경우의 무시멘트 경화체에 대한 강도 및 수화 특성에 대하여 분석하고자 하였다.

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