• 상하수도학회지
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• 제14권3호
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• pp.231-239
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• 2000

Water treatment processes produce sludges resulting from water clarification. Sludge production amount increases each year and its treatment and disposal is growing to social problems according to water demand increase. Water treatment plant sludges can be modified to soil cover in sanitary landfill site through the lime treatment. Compression strength of $1.0kg/cm^2$ or more is recommended for soil cover material in municipal landfilling site. Compression and shear strength properties of modified sludges showed material property improvement applicable for soil cover alternatives. Solidification effect of the modified sludge was observed through the scanning electron microscope. Extraction tests for hazardous components in sludges revealed that extraction levels of cadmium, copper, and lead were below the regulated criteria. When adding 10% calcium hydroxide to water treatment plant sludges, the modified sludges can reach material properties for cover soil after 28 days solidification reaction.

• 상하수도학회지
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• 제19권6호
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• pp.781-790
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• 2005

Granular Activated Carbon(GAC) is widely used in drinking water treatment. Many of the problems occurring in the GAC process are associated with the operation goal and performance. The purpose of this study were to evaluate the design, operation, and performance of granular activated carbon process in D water treatment plant. The optimal operation conditions of GAC process such as backwashing condition, granular activated carbon replacement time were discussed. The design, operation and performance of GAC process is influenced by their raw water characteristics and placement within the treatment process sequence. A critical analysis of plants experience and the information from the literature identifies the effectiveness of GAC process and indicates where modifications in design and operation could lead to improved performance. It would be useful to evaluate and optimize the GAC process in other treatment plant.

• Composites Research
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• 제26권3호
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• pp.165-169
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• 2013

This work presents the tensile properties and water uptake behavior of plasma treated abaca fibers reinforced epoxy composites. The composites were prepared by vacuum assisted resin transfer molding. The effects of treatment on tensile properties and sorption characteristics of abaca fiber composites in distilled water and salt solution at room temperature were investigated. The tensile strength of the composites increased with plasma treatment. With plasma treatment, an improvement of 92.9% was obtained in 2.5 min exposure time in plasma. This is attributed to high fiber-matrix compatibility. Less improvement on tensile properties of hybrid treatment of sodium hydroxide and plasma was obtained. However, both treatments reduced overall water uptake in distilled water and salt solution. Hydrophilicity of the fibers decreased upon plasma and sodium hydroxide treatment, which decreases water uptake.

• 상하수도학회지
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• 제24권6호
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• pp.723-734
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• 2010

With a belief of high water quality production and less chemical usage, membrane technology including Microfiltration (MF), Ultrafiltration (UF), and Nanofiltration(NF) is being employed more and more in drinking water treatment process. However, due to higher energy consumption of UF and NF, MF is normally used for drinking water treatment especially in a plant of large scale. In this investigation, performance ofsand filtration and membrane filtration was compared regarding removal of various water quality parameters, such as TOC, DOC, KMnO4 consumption, THMFP, and HAAFP. Two lines of pilot plant have been operated, one of which line is a traditional advanced water treatment process which includes sedimentation, sand filtration, ozonation, and activated carbon, and the other line is an alternative treatment process which includes sedimentation with inclined plate, MF membrane, ozonation, and activated carbon. For the first about 4months of period, MF filtration showed similar or little bit higher performance than sand filtration. However, after about 4month later, sand filtration showed much higher performance in removing all parameters monitored in the investigation. It was found that sand filtration is a better option than MF filtration as far as microbial community is fully activated in sand filter bed.

• 상하수도학회지
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• 제33권4호
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• pp.311-319
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• 2019

The purpose of this study was to analyze water treatment characteristics, including the efficiency of removing algae from water purification plants, by installing a demonstration facility for decontamination of algae, including natural algae remover injection equipment, in the water purification plant. Jar-test showed that the optimum injection of natural decontaminant was 20 mg/L. Of the water contaminant treatment efficiency of the intake and water purification plants, Chl-a averaged 74.0% elimination efficiency from $5.0mg/m^3$ to $1.3mg/m^3$ and the maximum treatment efficiency was 91.5% removal efficiency when the inflow concentration of Chl-a was $11.8mg/m^3$. In addition, 51.2% and 47.1% of the taste and odor indicator items, geosmin and 2-MIB, resulted from the overgrowth and decaying of algae, respectively, to identify toxic substances and odor reduction effects. In addition, elimination efficiencies of SS and Turbidity materials were higher than 70.0%. In the injection of natural algae remover, no effects such as sudden changes in water quality due to secondary reactions were found, and appropriate levels were maintained under water treatment conditions.

• 물과 미래
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• 제29권1호
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• pp.191-202
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• 1996

기존의 정수처리기법으로는 처리되지 않는 여러 가지 유기물질의 처리를 위해 상수고도처리가 도입되고 있다. 국내실정에 적합한 고도정수처리 시스템의 개발과 아울러, 이를 실생활에 도입할 경우의 소요비용과 사회적 영향에 대한 연구도 필요하다. 본 연구에서는 고도정수처리시스템의 설비비와 유지보수비를 산정하는 방법을 오존과 활성탄, 그리고 막분리 시스템을 중심으로 제시하고 이를 정부예산과 비교하여 타당성을 검증하였다. 또한 이를 바탕으로 투자비와 시설용랑에 관한 일반적인 관계식도 유도하였다. 한편, 정수된 상질의 물을 수요자에게 공급하는 방안을 네 가지로 검토하고 이를 부산지역에 적용하였다. 생산량과 수송체계에 따른 각각의 대안을 경제적/사회적 측면에서 비교한 결과, 음용수만을 고도정수처리하여 관로를 통하지 않고 병물로 공급하는 방안이 수질을 떨어뜨리지 않으면서 가장 경제성이 있는 방법인것으로 나타났다.

• 상하수도학회지
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• 제25권4호
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• pp.511-517
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• 2011

To evaluate carbon emission in water treatment processes, LCA (life cycle assessment) was applied to 8 multi-regional water treatment plants (WTPs) from intake to supply of tap water. Investigation of 8 WTPs revealed that average carbon emission for 1 $m^3$ of tap water was 221 g. Major carbon emission sources in water supply system were intake and supply processes. Meanwhile, mixing process was the main carbon emission source in unit water treatment processes. Carbon emission was proportional to the turbidity and COD of raw water. Intake of better raw water and minimization of energy consumption in unit processes are needed to reduce carbon emission in the WTPs. In addition, comparison of carbon emission among WTPs can be used as a parameter for optimization of operation and maintenance of water treatment processes.

• 상하수도학회지
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• 제38권1호
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• pp.1-15
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• 2024

Occurrence of process environment changes, such as influent load variances and process condition changes, can reduce treatment efficiency, increasing effluent water quality. In order to prevent exceeding effluent standards, it is necessary to manage effluent water quality based on process operation data including influent and process condition before exceeding occur. Accordingly, the development of the effluent water quality prediction system and the application of technology to wastewater treatment processes are getting attention. Therefore, in this study, through the multi-channel measuring instruments in the bio-reactor and smart multi-item water quality sensors (location in bio-reactor influent/effluent) were installed in The Seonam water recycling center #2 treatment plant series 3, it was collected water quality data centering around COD, T-N. Using the collected data, the artificial intelligence-based effluent quality prediction model was developed, and relative errors were compared with effluent TMS measurement data. Through relative error comparison, the applicability of the artificial intelligence-based effluent water quality prediction model in wastewater treatment process was reviewed.

• Computers and Concrete
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• 제34권1호
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• pp.123-135
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• 2024

Strain-hardening cement-based composites (SHCC) under cracked condition exhibits remarkable capillary absorption due to water ingress from multiple cracks. Surface treatment using water repellent agents is an effective way for improving water resistance of SHCC, but the water resistance may remarkably decrease when cracks penetrate impregnation depth. Another way is to add water repellent agents directly into the mixture, offering SHCC integral water repellency even if cracks form later. However, although integral water repellent treatment has been proved feasible by previous studies, there is still lack of simulation work on the treated SHCC for evaluating its durability. This study presents a simulation method for capillary absorption of cracked SHCC with integral treatment based on a multi-scale approach proposed in the authors' previous work. The approach deals with water flows in bulk matrix and multiple cracks using two individual transport equations, respectively, whereas water absorbed from a crack to its adjacent matrix is treated as the mass exchange of the two equations. In this study, the approach is enhanced for the treated SHCC by integrating the influencing of water repellency into the two transport equations as well as the mass exchange term. Using the enhanced approach, capillary absorption of water repellent SHCC under cracked condition is simulated, showing much more reduced water ingress than the untreated concrete, which is consistent with total absorption data from previous tests. This approach is also capable of simulating water spatial distribution with time in treated SHCC reasonably.

• 한국응용과학기술학회지
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• 제33권3호
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• pp.411-420
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• 2016

The objective of this study was to determine the effect of drinking water containing trimethyl glycine or ascorbic acid on growth performance and blood parameter profiles of duck exposed to scorching heat stress. A total of 480 ducks were randomly assigned to the following eight experiment groups for 42 days : control group C with general water, treatment group 1 (T1) with drinking water containing 100 ppm ascorbic acid, treatment group 2 (T2) with drinking water containing 200 ppm ascorbic acid, treatment group 3 (T3) with drinking water containing 300 ppm ascorbic acid, treatment group 4 (T4) with drinking water containing 400 ppm trimethyl glycine, treatment group 5 (T5) with drinking water containing 800 ppm trimethyl glycine, treatment group 6 (T6) with drinking water containing 1,200 ppm trimethyl glycine, treatment group 7 (T7) with electrolytes of KCl (0.5%) + $NaHCO_3$ (1.0%)+NaCl (0.5%). Our results revealed that the body weights and feed intakes of treatment groups, especially T3 and T6, were increased compared to the control group, where as the feed conversion ratios of treatment groups were decreased (p<0.05). Blood levels of total cholesterol, triglyceride, LDL-C, glucose, AST, ALT and pH in treatment groups were lower compared to those in the control group (p<0.05). Blood levels of red blood cell, platelets profiles, electrolyte and gas in treatment groups were higher compared to those of the control group (p<0.05).