• Journal of the Korean Applied Science and Technology
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• v.41 no.1
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• pp.19-26
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• 2024

Recently, separation membranes have been applied to fields such as water supply, sewage treatment, gray water reuse, and air pollution control. Chemical cleaning technology is attracting attention among the methods of reusing these expensive separation membranes. It was found that the separation membrane could be regenerated using chemical cleaning. Specifically, it was found that the use time of the separation membranes regenerated by chemical cleaning was sustainable for more than 1,700 hours. Additionally, it was found that the flux recovery ratio after chemical cleaning was maintained at least 60%. In addition, the flux recovery ratio of HYDREX 4710, an organic membrane cleaner, and 4703, an inorganic membrane cleaner, was 76% and 62%, respectively, showing the highest flux recovery ratio among the chemicals used. Considering that the target raw water of this study is biological secondary treatment water, it was suggested that chemical cleaning could be actively used to regenerate separation membranes in future water treatment.

• Journal of Animal Environmental Science
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• v.2 no.1
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• pp.79-86
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• 1996

Solid/Liquid(S/L) separation is crucial for biological treatment of animal wastewater. Liquid portion from S/L separation has less BOD-load and proper post-strip treatment can be obtained. Screen or declined sieve was normally used to separate the solid parts. For better separating efficiency a vibration and a cylindrical separator were constructed and tested. The results are summarized as follows; Solids removal efficiency and moisture content of separated solid were 15~26% and 85~88%, respectively for the vibration separator. for the cylindrical separator, solid removal efficiency and moisture content of solid were 16~39% and 86~89%, respectively. The greatest amount of drymatter was obtained when operating vibration separator with 10$^{\circ}$ inclination and 100% vibrating power. For the cylindrical separator maximum efficiency was obtained with 40 rpm and 19$^{\circ}$ inclination. The vibration and the cylindrical separator have shown 21% and 26% in BOD removal, respectively. These two types of separator were proved to be applicable methods for animal wastewater separation.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.649-655
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• 2004

The behavior of biological particles in DAF (dissolved air flotation) process was analyzed by employing PBT (Population balance theory). After decline growth phase of activated sludge, the value of the initial collision-attachment efficiency was increased over than 0.35 corresponding relatively high value in the whole life cycle of microorganism. For practical application of DAF as a solid separation process. It is desirable that microbial particles should be operated to perform high solid removal efficiency in biological wastewater treatment.

• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.596-605
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• 2019

Proton-conducting perovskite ceramic materials are highly promising for solid electrolytes as well as catalysts at high temperatures. Therefore, they possess an outstanding potential for the membrane reactor in which both reaction and separation occur at a same time. Especially, in the case of hydrogen production catalyst, hydrogen separation, and the membrane reactor coupled with catalyst and separation, extensive results have been reported on the effect of the dopant in the solid electrolytes, temperature, and composition of reactants on the performance. In this review, the recent research trend on the application of proton-conducting ceramic materials to hydrogen production catalyst, hydrogen separation, and membrane reactor is surveyed. Moreover, the potential application and prospect of these materials to the next-generation hydrogen production and separation is discussed.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.769-778
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• 2009

Performances and internal behaviors of the upflow hybrid anaerobic filters treating a dairy wastewater were analyzed to identify the functions and roles of the modular crossflow media and sludge bed layer and to discover their interrelationship in the filter. The media could perform independent biological and physical separation role without buildup of sludge bed, while the role of sludge bed was dependent on the function of the media. The filter packed with the crossflow media did not necessarily require the formation of sludge bed when treating a dairy wastewater. Biological contribution of the media was controlled by that of biologically active sludge bed complementing mutually each other. The gas-liquid-solid separation capability of the media was indispensible to ensure the active biological role of sludge bed, since sludge bed buildup without the media had no independently effective biological function. It was believed that the filter in itself could also function as a selector for physical gas-liquid-solid separation resulting in selectively concentrating particles with superior settleability in sludge bed. The sludge bed in the filter played a key role in the physical solids capture from influent as well as biological organics removal.

• Environmental Engineering Research
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• v.19 no.4
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• pp.395-399
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• 2014

Operation characteristics of the sequencing batch reactor (SBR) process with electro-flotation (EF) as a solid liquid separation method (EF-SBR) were investigated. EF-SBR process showed excellent solid-liquid separation performance which enabled to separate biosolids from liquid phase within 30 min and to extend cyclic reaction time. Although influent organic loading rate was increased stepwise from 5 to 15 g COD/day, food to microorganisms (F/M) ratio could be maintained about 0.3 g COD/g VSS/day in EF-SBR because biomass concentration could be easily controlled at desired level by EF. However, it was impossible to increase biomass concentration at the same level in control SBR (C-SBR) process because solid-liquid separation by gravity settling showed a limitation at higher mixed liquor suspended solids (MLSS) concentration with 60 min of settling time. Total chemical oxygen demand (TCOD) removal efficiency of EF-SBR process was not decreased although influent organic loading rate became 3 times higher than initial value. However, it was seriously deteriorated in C-SBR process after increasing the rate over 10 g COD/day, which was accounted for insufficient organic removal by relatively higher food to microorganisms (F/M) ratio as well as biosolids wash-out by a limitation of gravity sedimentation.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.2
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• pp.234-238
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• 2008

Coarse pore filter could be an alternative of membrane for solid-liquid separation in an activated sludge reactor because of inexpensive cost of the filter material and high flux at low filtration pressure. However such filter module has much less specific filtration area compared to the membrane. Therefore a certain effort is required to increase the specific filtration area in the module design of such coarse pore filter for solid-liquid separation in an activated sludge reactor. In this study, tubular type coarse pore filter was designed at various diameter and configuration. The filtration performance was investigated to separate solid in the activated sludge reactor for domestic wastewater treatment. Tubular type coarse pore filter module could be successfully applicable to solid separation in the activated sludge reactor. The design parameters were the tube diameter of 10mm and vertical installation. Smaller diameter of the tube caused faster increase of the filtration pressure because of the hydraulic head loss in the tube channel.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.117-125
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• 2003

Experimental and theoretical works were performed for the separation of large polyelectrolyte, such as DNA, in a column packed with gel particles under the influence of an electric field. Since DNA quickly orient in the field direction through the pores, this paper presents how intraparticle convection affects the residence time distribution of DNAs in the column. The concept is further illustrated with examples from solid -liquid systems, for example, from chromatography Showing how the column efficiency is improved by the use of a n electric field. Dimensionless transient mass balance equations were derived, taking into consideration both diffusion and electrophoretic convection. The separation criteria are theoretically studied using two different Peclet numbers in the fluid and solid phases. These criteria were experimentally verified using two different DNAs via electrophoretic mobility measurements. which showed how the separation position of the DNAs varies in the column in relation to the Peg/Pef values of an individual DNA. The residence time distribution was solved by an operator theory and the characteristic method to yield the column response.

• Nuclear Engineering and Technology
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• v.50 no.7
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• pp.1184-1189
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• 2018

Pyroprocessing uses various molten salts during electrochemical unit processes. Reaction products after the electrochemical processes must contain a significant amount of residual salts to be separated. Vacuum distillation is a common method to separate the residual salts; however, its high operation temperature may cause side reactions. In this study, a simple rotation technique using centrifugal force was suggested to separate the residual salts from the reaction products at relatively low temperature compared to the distillation technique. When a reaction product container with porous wall rotates inside a vessel heated above the melting point of the residual salt, the residual salt in the liquid phase is separated through centrifugal force. It was shown that the $LiNO_3-Al_2O_3$ mixture can be separated by this technique to leave solid $Al_2O_3$ inside the container, with a separation efficiency of 99.4%.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.446-448
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• 2000

In this study, we investigated the theoretical and experimental study for separation of solid-liquid suspensions of water and fine particles using acoustic standing wave. When the acoutic force was not applied, the separation efficiency was decreased as flow rate was increased. When it was applied, the separation efficiency was maintained over 95%.