• Korean Chemical Engineering Research
• /
• v.46 no.4
• /
• pp.732-738
• /
• 2008

Simulated moving bed (SMB) process is a continuous chromatographic technology used to separate a large amount of petrochemicals, fine chemicals, pharmaceuticals, and so on, drawing a great attraction of related industries. With the recent development of biotechnology, the SMB process has been adopted for the separation of various useful bio-products. Attempts to understand the separation mechanism of the SMB process in many aspects are reported in many publications. These researches have dealt with the improvement of SMB for easier operation and solving problem in process. The feed mixture fed into the SMB process may be of different concentration batch by batch rather than in uniform concentration. Retention behaviors of feed (psicose (A) and fructose (B) mixture) existing in the SMB unit in dynamic steady-state and feed (psicose (C) and fructose (D) mixture) newly injected into the SMB were analyzed. It was observed that the existing components, (A) and (B), were eluted relatively faster as the injection time of new feed was earlier during the port-switching period. In addition, the components (C) and (D) were eluted earlier as fresh feed was injected earlier in a port-switching time.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.16 no.2
• /
• pp.57-65
• /
• 2008

Wastewater containing strong organic matter is very difficult to treat by utilizing general sewage treatment plant. but the wastewater is adequate to generate biomass energy (bio-gas; methane gas) by utilizing anaerobic digestion. EcoDays Plug Flow Reactor (E-PFR), which was already proved as an excellent aerobic wastewater treatment reactor, was adapted for anaerobic food wastewater digestion. This research was performed to improve the efficiency of bio-gas production and to optimize anaerobic wastewater treatment system. Food wastewater from N food waste treatment plant was applied for the pilot scale experiments. The results indicated that the efficiency of anaerobic wastewater treatment and the volume of bio-gas were increased by applying E-PFR to anaerobic digestion. The structural characteristics of E-PFR can cause the high efficiency of anaerobic treatment processes. The unique structure of E-PFR is a diaphragm dividing vertical hydraulic multi-stages and the inversely protruded fluid transfer tubes on each diaphragm. The unique structure of E-PFR can make gas hold-up space at the top part of each stage in the reactor. Also, E-PFR can contain relatively high MLSS concentration in lower stage by vertical up-flow of wastewater. This hydraulic flow can cause high buffering capacity against shock load from the wastewater in the reactor, resulting in stable pH (7.0~8.0), relatively higher wastewater treatment efficiency, and larger volume of bio-gas generation. In addition, relatively longer solid retention time (SRT) in the reactor can increase organic matter degradation and bio-gas production efficiency. These characteristics in the reactor can be regarded as "ideal" anaerobic wastewater treatment conditions. Anaerobic wastewater treatment plant design factor can be assessed for having 70 % of methane gas content, and better bio-gas yielding and stable treatment efficiency based on the results of this research. For example, inner circulation with generated bio-gas in the reactor and better mixing conditions by improving fluid transfer tube structure can be used for achieving better bio-gas yielding efficiency. This research results can be used for acquiring better improved regenerated energy system.

• Journal of the Korean Applied Science and Technology
• /
• v.24 no.4
• /
• pp.436-443
• /
• 2007

Anaerobic reductive dehalogenation of perchloroethene (PCE) was studied with lactate as the electron donor in a continuously stirred tank reactor (CSTR) inoculated with a mixed culture previously shown to dehalogenate vinyl chloride (VC). cis-1,2- dichloroethene (cDCE) was the dominant intermediate at relatively long cell retention times (>56 days) and the electron acceptor to electron donor molar ratio (PCE:lactate) of 1:2. cDCE was transformed to VC completely at the PCE to lactate molar ratio of 1:4, and the final products of PCE dehalogenation were VC (80%) and ethene (20%). VC dehalogenation was inhibited by cDCE dehalogenation. Propionate produced from the fermentation of lactate might be used as electron donor for the dehalogenation. Batch experiments were performed to evaluate the effects of increased hydrogen, VC, and trichloroethene (TCE) on VC dehalogenation which is the rate-limiting step in PCE dehalogenation The addition of TCE increased the VC dehalogenaiton rate more than an increase in the $H_2$ concentration, which suggests that the introduction of TCE induces the production of an enzyme that can comtabolize VC.

• Journal of Environmental Science International
• /
• v.15 no.3
• /
• pp.211-219
• /
• 2006

An experimental study on the removal of VOCs gas using a biomembrane reactor were carried out at various inlet gas concentration, specific loading rate, retention time and gas flow rate of volume. The variations of efficiency and various parameters, which are relevant to gas removal, with mixing of soluble gas and without have been discussed. More than 95% of the toluene and methanol present in the feed was successfully removed in each study. The elimination of methanol with mixture of soluble compound of about 300 mg/h corresponds to a portion of 21% if there is a feed stream of 1400 mg/h. On the contrary the maximum efficiency of about 72% of toluene was reached. This is to be rated as a treatment of sorption that the limiting factor of the dismantling speed could be represented by this difficult degradable component. Nevertheless the elimination capacities for this reactor for toluene were on a very high level. For substances which show a very high solubility in silicon rubber an advantage of a bio membrane is clearly shown. Therefore a similarly good result is expected for n-hexane, because of its relatively good permeability which was distinguished during permeation experiments.

• Environmental Engineering Research
• /
• v.25 no.1
• /
• pp.1-17
• /
• 2020

With benefits to the human health, environment, economy, and energy, anaerobic digestion (AD) systems have attracted remarkable attention within the scientific community. Anaerobic digestion system is created from (bio)reactors to perform a series of bi-metabolism steps including hydrolysis/acidogenesis, acetogenesis, and methanogenesis. By considering the physical separation of the digestion steps above, AD systems can be classified into single-stage (all digestion steps in one reactor) and multi-stage (digestion steps in various reactors). Operation of the AD systems does not only depend on the type of digestion system but also relies on the interaction among growth factors (temperature, pH, and nutrients), the type of reactor, and operating parameters (retention time, organic loading rate). However, these interactions were often reviewed inadequately for the single-stage digestion systems. Therefore, this paper aims to provide a comprehensive review of both single-stage and multi-stage systems as well as the influence of the growth factors, operating conditions, and the type of reactor on them. From those points, the advantages, disadvantages, and application range of each system are well understood.

• Fisheries and Aquatic Sciences
• /
• v.17 no.4
• /
• pp.441-448
• /
• 2014

We examined the effects of dietary nutrient content, feeding period, and feed allowance on compensatory growth, food use, chemical composition, and serum chemistry of juvenile olive flounder Paralichthys olivaceus. We placed 720 juvenile fish into 24 400-L flow-through round tanks (30 fish per tank).A $2{\time}2{\time}2$ factorial design (diet: control (C) and high protein and lipid (HPL) ${\time}$ feeding period: 8 and 6 weeks ${\time}$ feed allowance: 100% and 90% of satiation) was applied. Fish were hand-fed twice daily, based on the designated feeding schedule. Weight gain and food consumption were affected by both the feeding period and feed allowance, but not by diet. The food efficiency ratio was not affected by diet, feeding period, or feed allowance, but the protein efficiency ratio and protein retention were affected by diet and feeding period, respectively. We found that the full compensatory growth of fish was not achieved at a restricted feeding allowance.

• Journal of Korean Society on Water Environment
• /
• v.22 no.5
• /
• pp.865-870
• /
• 2006

The behavior and influence of EPS on membrane fouling by changing of hydraulic retention time was investigated, using lab. scale submerged membrane bio-reactor, which was operated with gravitational filtration and fed supernatant of primary sedimentation in waste water treatment plant as influent. The membrane was adopted micro-filter of polyethylene hollow fiber. EPS was analysed as polysaccharides and protein especially, into soluble and bound EPS separately. The concentration of soluble EPS was increased at short HRT, then membrane fouling was rapidly progressed and flux was depressed. The most of EPS clogged membrane pore were polysaccharides, while protein was important parameter affected on membrane fouling because of it's more accumulating in the more term operating.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.5
• /
• pp.1435-1440
• /
• 2013

To investigate the influence of the carbon matrix on the electrochemical performance of Si/C composites, four types of Si/C composites were prepared using graphite, petroleum coke, pitch and sucrose as carbon precursors. A ball mill was used to prepare Si/C blends from graphite and petroleum coke, whereas a dispersion technique was used to fabricate Si/C composites where Si was embedded in disordered carbon matrix derived from pitch or sucrose. The Si/pitch-based carbon composite showed superior Si utilization (96% in the first cycle) and excellent cycle retention (70% after 40 cycles), which was attributed to the effective encapsulation of Si and the buffering effect of the surrounding carbon matrix on the silicon particles.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.209-209
• /
• 2019

저영향개발기법은 자연의 물순환에 미치는 영향을 최소로 하여 개발하는 것을 의마하며 개발로 인한 토지, 물, 대기에 미치는 영향을 경감시키기 위한 친생태적인 우수관리 혹은 토지개발기법을 의미한다. 국내에서는 2012년부터 가이드라인 및 매뉴얼을 제작하여 신도시개발 및 구도시의 환경사업에서 저영향개발기법을 적용하여 우수유출 저감 및 비점오염원 감소, 물순환 등을 환경적 이점이 나타나고 있다. 그러나 국내에서 적용하는 저영향개발기법은 미국 및 유럽의 시설구조를 적용하였으므로, 국내실정에 맞도록 저영향개발기법을 수정 보완하여 유출저감효과를 모의해보고자 한다. 강우발생시 고농도의 도시비점오염원은 차도 및 보도를 중심으로 유출되어 빗물받이를 거쳐 우수관으로 유입된다. 본 연구에서는 차도와 보도 사이의 식수대에 적용가능하도록 식생수로와 침투도랑을 연계한 식생도랑을 설치하여 도로에서 발생하는 고농도의 비점오염원을 저감하고자 하였다. 선행사례로 적용된 공공청사를 대상으로 모니터링 및 모델링을 실시하여 유출저감 및 비점오염원 저감효과를 검토하고, 식생도랑을 적용할 경우의 유출저감효과 및 비점오염저감효과와 비교검토하여 국내실정에 맞는 저영향개발기법을 개발하고자 한다.

• BMB Reports
• /
• v.56 no.7
• /
• pp.392-397
• /
• 2023

In this study, recombinant Fc-fused Prostate acid phosphatase (PAP) proteins were produced in transgenic plants. PAP was fused to immunoglobulin (Ig) A and M Fc domain (PAP-IgA Fc and PAP-IgM Fc), which were tagged to the ER retention sequence KDEL to generate PAP-IgA FcK and PAP-IgM FcK. Agrobacterium-mediated transformation was performed to produce transgenic tobacco plants expressing four recombinant proteins. Genomic PCR and RT-PCR analyses confirmed the transgene insertion and mRNA transcription of PAP-IgA Fc, PAP-IgM Fc, PAP-IgA FcK, and PAP-IgM FcK in tobacco plant leaves. Western blot confirmed the expression of PAP-IgA Fc, PAP-IgM Fc, PAP-IgA FcK, and PAP-IgM FcK proteins. SEC-HPLC and Bio-TEM analyses were performed to confirm the size and shape of the plant-derived recombinant PAP-Fc fusion proteins. In mice experiments, the plant-derived IgA and IgM Fc fused proteins induced production of total IgGs including IgG1 against PAP. This result suggests that IgA and IgM Fc fusion can be applied to produce recombinant PAP proteins as a prostate cancer vaccine in plant expression system.