• Title/Summary/Keyword: Recycle water

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Regeneration of Used Commercial Catalyst for deNOx Emitted from Stationary Sources (배연 탈질용 폐촉매의 재생에 관한 연구)

  • Moon, Il-Shik;Cho, Gyoujin
    • Applied Chemistry for Engineering
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    • v.10 no.2
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    • pp.263-267
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    • 1999
  • NO removal activity (per unit of mass) of the used catalyst was seriously decreased as low as 27% of the new catalyst. Since the surface area of the used catalyst was 63% of that of the new one, the mojor reason for the lessened activity of the used catalyst compared to the new one may be due to the decreased surface area by sintering and surface concentration of active materials. Poison may be regarded as another important factor, since it affect the active site of catalyst by heavy metals. To recycle the used catalyst, we focused on the removal of poisoning agents from the catalyst. By using $80^{\circ}C$ water for 30 min upto 2 h, the recycled catalyst demonstrated the best activity and efficiency, which may be due to the removal of both K and Na. Although the recovered activity (per unit of surface area) of the catalyst was 79% compared to the new one, the activity (per unit of mass) of the recovered catalyst was only 49% compared of the activity of fresh catalyst.

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Physical Properties of Polymer Concrete Composites Using Rapid-Cooled Steel Slag (II) (Use of Rapid-Cooled Steel Slag in Replacement of Fine and Coarse Aggregate) (급냉 제강슬래그를 사용한 폴리머 콘크리트 복합재료의 물성(II) (급냉 제강슬래그를 잔골재와 굵은 골재 대체용으로 사용))

  • Hwang, Eui-Hwan;Lee, Choul-Ho;Kim, Jin-Man
    • Applied Chemistry for Engineering
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    • v.23 no.4
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    • pp.409-415
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    • 2012
  • To recycle the steel slag as manufactured composite materials of polymer concretes, we used the atomizing method to make round aggregates from steel slag, which is treated as industrial wastes. A round rapid-cooled steel slag was used to replace fine aggregate (river sand) or coarse aggregate (crushed aggregate), depending on the grain size. To examine general physical properties of polymer concrete composites manufactured from rapid-cooled steel slag, the polymer concrete specimen with various proportions depending on the addition ratio of polymer binder and replacement ratio of rapid-cooled steel slag were manufactured. In the result of the tests, the mechanical strength of the specimen made by replacing the optimum amount of rapid-cooled steel slag increased notably (maximum compressive strength 117.1 MPa), and the use of polymer binder, which had the most impact on the production cost of polymer concrete composites, could be remarkably reduced. However, the mechanical strength of the specimen was markedly reduced in hot water resistance test of polymer concrete composite.

An Experimental Study on Mechanic properties of Hardened Fly-ash (플라이애쉬 경화체의 역학적 특성에 관한 실험적 연구)

  • Jo, Byung-Wan;Kim, Yeung-Jin;Park, Jong-Bin
    • Proceedings of the Korean Institute of Resources Recycling Conference
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    • 2003.10a
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    • pp.134-138
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    • 2003
  • The purpose of this paper is to recycle the fly ash to the valuable resources and settle environment problems which was caused by the fly ash produced from the thermal power plant. Making the fly ash-cement matrix reused fly ash in large quantities, we looked into minutely the physical properties - the elastic modulus, the compressive strength - to increase the usefulness as the building materials for the structure widely. In this paper, the variables are the water-binder(39, 42, 45%), the fine aggregate ratio(37, 41, 45%). Because the fracture energy is influenced by the strength, it is showed to decrease with the increase of W/B and S/a. Besides, we will be able to know that basic properties of the fly ash-cement matrix are similar to that of concrete. But, it is needed to carry out durability experiment on the drying shrinkage, creep, freezing and thawing test to use structural materials.

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Development of a Compression/Absorption Hybrid Heat Pump System Using $NH_3/H_2O$ Mixture for High Temperature Generation ($NH_3/H_2O$를 이용한 압축-흡수식 고온제조 하이브리드 히트펌프 시스템 개발)

  • Kim, Min-Sung;Baik, Young-Jin;Shin, Kwang-Ho;Park, Seong-Ryong;Chang, Ki-Chang;Lee, Young-Soo;Ra, Ho-Sang
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.1249-1254
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    • 2008
  • Industrial low temperature waste heat exists sparse in surroundings but its amount is huge. However, large portion of waste heat is discarded due to its poor recovery quality and inferior application technologies. The heat pump system in this research is based on the hybrid combination of compression cycle and absorption cycle in order to recycle various kind of industrial waste heat effectively. The prime objective is to design a compression absorption hybrid heat pump system which can produce high temperature above the level of $90^{\circ}C$ and low temperature of $20^{\circ}C$ at the same time using waste heat water of $50^{\circ}C$. A mathematical simulation was carried out as a basis to design a prototype 3 RT class hybrid heat pump. From the simulation results, fundamental parameters to design the system were obtained.

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RECYCLING OPTION SEARCH FOR A 600-MWE SODIUM-COOLED TRANSMUTATION FAST REACTOR

  • LEE, YONG KYO;KIM, MYUNG HYUN
    • Nuclear Engineering and Technology
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    • v.47 no.1
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    • pp.47-58
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    • 2015
  • Four recycling scenarios involving pyroprocessing of spent fuel (SF) have been investigated for a 600-MWe transmutation sodium-cooled fast reactor (SFR), KALIMER. Performance evaluation was done with code system REBUS connected with TRANSX and TWODANT. Scenario Number 1 is the pyroprocessing of Canada deuterium uranium (CANDU) SF. Because the recycling of CANDU SF does not have any safety problems, the CANDU-Pyro-SFR system will be possible if the pyroprocessing capacity is large enough. Scenario Number 2 is a feasibility test of feed SF from a pressurized water reactor PWR. Thefsensitivity of cooling time before prior to pyro-processing was studied. As the cooling time sensitivity of cooling time before prior to pyro-processing was studied. As the cooling time increases, excess reactivity at the beginning of the equilibrium cycle (BOEC) decreases, thereby creating advantageous reactivity control and improving the transmutation performance of minor actinides. Scenario Number 3 is a case study for various levels of recovery factors of transuranic isotopes (TRUs). If long-lived fission products can be separated during pyroprocessing, the waste that is not recovered is classified as low- and intermediate-level waste, and it is sufficient to be disposed of in an underground site due to very low-heat-generation rate when the waste cooling time becomes >300 years at a TRU recovery factor of 99.9%. Scenario Number 4 is a case study for the recovery factor of rare earth (RE) isotopes. The RE isotope recovery factor should be lowered to ${\leq}20%$ in order to make sodium void reactivity less than <7$, which is the design limit of a metal fuel.

Identification of Major Fungi and Bacterial Species in Solid Medium Drainage for Circulating Hydroponics System (수경재배 배액 재이용을 위한 주요 곰팡이 및 박테리아 종 파악)

  • Lee, Donggwan;Son, Jinkwan;Kang, Taegyeong;Jang, Jaekyung;Park, Minjung;Lee, Taeseok;Lim, Ryugap
    • Journal of Environmental Science International
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    • v.29 no.11
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    • pp.1109-1123
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    • 2020
  • In this study, the amount of harmful fungi and bacteria contained in the drainage and culture medium from the paprika hydroponic facility is identified. In addition, by proposing the necessity of effective purification of discharged drainage, this study attempted to confirm the possibility of drainage reuse. Finally, this study provides basic data on the basis for calculating the need for purification facilities in the future, as well as improvements in horticulture facility for sustainable agriculture. As a result of the analysis, a total of 12 types of fungi were detected in paprika medium and 10 types of fungi were detected in the drainage, and their densities were 130 and 68, respectively. Among the fungi detected in the media and drainage of the paprika hydroponic facility, the fungi with the highest detection frequency are Fusarium, Phytophthora, and Pythium. In the case of bacteria, a total of 2 types of bacteria were detected in the paprika facilities, and the density was 28 and 23, respectively. Therefore, in order to reuse the drainage and settle the circulating hydroponic cultivation system, a water treatment process capable of appropriate treatment is required.

An Experimental Study on Compression Strength and Carbonation Resistance for Ternary High-Performance Concrete with fly-sah, granulated blast furnace (플라이애쉬와 고로슬래그를 사용한 3성분계 고성능 콘크리트의 강도 및 촉진 중성화에 대한 실험적 고찰)

  • Kwon, Young-Rak;Kim, Hong-Sam;Lee, Chang-Young;Cheng, Hai-Moon;Ahn, Tae-Song
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.445-448
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    • 2008
  • It is essential that concrete component is made up with aggregate, cement and water. But today, Public concern is increasing of a variety structure and ocean environmental, resource recycle. Also, According to heat of hydration rising, Concrete is make a causative of concrete-crack. Concrete-crack cause a falling-off in quality of concrete. consequently, High-performance concrete is evaluated by concrete material properties and carbonation resistance with different admixture(fixing fly-ash 20%), granulated blast furnace slag replacement ratio (30%, 45%) different W/B (26%, 30%, 34%) and XRD(X-ray Diffraction) analysis.

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Durability of Mortar Matrix Replaced with Recycled Fine Aggregates (순환골재(循環骨材)를 혼입(混入)한 모르타르 경화체(硬化體)의 내구(耐久) 특성(特性))

  • Kim, Jong-Pil;Lee, Seung-Tae;Jung, Ho-Seop;Park, Kwang-Pil;Kim, Seong-Soo
    • Resources Recycling
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    • v.16 no.6
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    • pp.20-27
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    • 2007
  • This paper presents a detailed experimental study on the durability properties of mortar matrix made with two kind of recycled fine aggregates(RAA, RAB) and five replacement levels (0, 25, 40, 75 and 100) of the recycled fine aggregates as a partial replacement of natural fine aggregate (NA). The durability properties of mortar matrix was evaluated using compressive strength, chloride ion ingress, sulfate attack and carbonation. The test results indicated that the water absorption and Adhered mortar of the recycled fine aggregate was a major factor controlling durability properties. Hereafter, when using built recycled fine aggregate is expected, appropriate removal Adhered mortar and reasonable replacement ratio of recycled fine aggregates was 25% weight of cement are advised to apply to the concrete materials.

Development of High quality Recycled Aggregate Production Process from Waste Concrete for Resource Circulation System (자원순환형(資源循環型) 사회(社會) 구축(構築)을 위한 고품질(高品質) 순환골재(循環骨材) 생산(生産) 공정(工程) 개발(開發) 연구(硏究))

  • Kim, Kwan-Ho;Cho, Hee-Chan;Ahn, Ji-Whan
    • Resources Recycling
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    • v.18 no.3
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    • pp.27-35
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    • 2009
  • To solve resource exhaustion and waste management problems caused by mass consumption, there are many efforts to change from resource consumption system to recycling system. Specially, interests about management of construction waste have increased, but efficient recycling system of waste concrete is not established yet. In this study, high quality recycled aggregate processing circuit was developed to recycle waste concrete. From the waste concrete which is a hydrated compound with coarse aggregate, fine aggregate, and cement material, high quality recycled coarse aggregate for concrete making was produced by autogenous milling and heat pretreatment method. After then, refinement process was performed to separate fine aggregate and cement material from waste concrete fines by sink float separation and hindered-settling separation. As a result, high quality recycled aggregate was produced from waste concrete by developed processing circuit.

Application of Powdered Waste Glasses and Calcium Carbonate for Improving the Properties of Artificial Lightweight Aggregate Made of Recycled Basalt Powder Sludge (현무암 석분 슬러지를 재활용한 인공경량골재의 물성개선을 위한 폐유리분말과 탄산칼슘의 활용)

  • Park, Soo-Je;Lee, Sung-Eun;Choi, Heebok
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.3
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    • pp.230-236
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    • 2014
  • This study was carried out to investigate the manufacturability of artificial lightweight aggregate as a way to recycle basalt powder sludge, which is a waste produced during the manufacturing process of basalt in Jeju. Powdered waste glasses and calcium carbonate are used to improve the characteristics of manufactured artificial lightweight aggregate. Especially, considering the complex factors of basalt powder sludge, powdered waste glasses, and sintering method, the amount of calcium carbonate is appropriate at the 9 wt.% in order to improve the intumescent of lightweight aggregate. Also, the amount of powdered waste glasses is effective with using less than 50 wt.% and applying the direct sintering method at the same time on decreasing the absorption of lightweight aggregate. Furthermore, in order to manufacture artificial lightweight aggregate of high quality with a low specific gravity and low water absorption, it is considered to be more effective to apply the direct sintering method after the surface of artificial lightweight aggregate is covered with powdered waste glasses.