• 멤브레인
• /
• 제22권1호
• /
• pp.46-53
• /
• 2012

본 연구에서는 석탄 화력발전소의 연소 후 $CO_2$ 회수 기술인 알칸올 아민 수용액을 이용한 아민흡수법에서 전체 운전비의 80% 가량을 차지하는 탈거에너지의 저감을 위해 새로운 탈거기술인 분리막을 이용한 감압탈거 기술을 제시하고자 한다. 막의 소재로는 소수성막인 PE (polyethylene)를 지지체로 하고 $5{\mu}m$ 두께의 PDMS (polydimethylsiloxane)를 코팅한 복합막을 제조하여 적용하였으며, 흡수액으로 MEA (monoethanolamine) 30 wt% 수용액을 사용하였다. 온도의 변화에 따른 영향을 알아보기 위하여 흡수액 온도를 $25{\sim}80^{\circ}C$로 변화시켜 이산화탄소의 탈거특성을 살펴보았으며, 흡수용액의 $CO_2$ 함량($CO_2$ loading)에 따른 영향을 고찰하기 위하여 $CO_2$ 함량을 변화시켰다. 또한 감압탈거 시 탈거측 압력을 60~360 mmHg(abs.)로 변화시켜 진공도에 따른 탈거특성을 연구하였다. 아민수용액의 온도가 증가할수록, 이산화탄소 부하량이 증가할수록 이산화탄소의 탈거량은 증가하는 경향을 보이고 있으며, 감압이 감소함에 따라 이산화탄소의 탈거량 역시 증가하고 있는 것을 확인하였다. 막의 안정성 실험 결과 PTFE 단일막에 비하여 PDMS-PE 복합막의 경우 감압탈거 막공정에 적용하기 안정한 막이라고 판단된다.

• Membrane and Water Treatment
• /
• 제10권2호
• /
• pp.127-137
• /
• 2019

The D2EHPA/TBP co-extractants immobilized PolyHIPE membrane can be used for the selective separation of Mn (II) from Co (II). By solvent-nonsolvent method, D2EHPA/TBP co-extractants can be effectively immobilized into PolyHIPE membrane. The pore structure of PolyHIPE membrane and the presence of TBP enhance the stability of immobilized co-extractants. The optimal operating conditions for the separation of Mn (II) and Co (II) are feeding phase at pH 5.5, sulfuric acid concentration in the stripping phase of about 50 g/L and stirring speed at 400 rpm. The D2EHPA/TBP co-extractants ratio of 5:1 shows synergetic effect on Mn/Co separation factor about 22.74. The removal rate and recovery rate of Mn (II) is about 98.4 and 97.1%, respectively, while for Co (II) the transport efficiency is insignificant. The kinetic study of Mn (II) transport shows that high initial flux, $J_f^o=80.1({\mu}mol/m^2s)$, and maxima stripping flux, $J_s^{max}=20.8({\mu}mol/m^2s)$, can be achieved with D2EHPA/TBP co-extractants immobilized PolyHIPE membrane. The stability and reusability study shows that the membrane can maintain a long term performance with high efficiency. High purity of Co (II) and Mn (II) can be recovered from the feeding phase and stripping phase, respectively.

• 한국환경과학회지
• /
• 제18권1호
• /
• pp.15-19
• /
• 2009

Early studies claimed that heterotrophic dinoflagellates Pfiesteria piscicida and related genera may produce a putative water-soluble toxin that causes death of fish and other marine animals. Several methods were tested to visualize plate morphology of Cryptoperidiniopsis brodyi and Pfiesteria piscicida. Cellulose plates of cells were exposed and visualized- by a membrane stripping method using Triton X-100. While calcofluor M2R white stain could readily bind to the thecal plates, details of the plate tabulation were difficult to observe. Fixation with osmium tetroxide $(OsO_4)$ produced well preserved cells with little morphological distortion, but thecal plates could not be visualized. Scanning electron microscopy (SEM) observation using the membrane stripping method showed distinctive plate tabulations between C. brodyi and P. piscicida suggesting that this method is a useful tool for morphological identification of lightly armored dinoflagellates.

• Membrane and Water Treatment
• /
• 제9권1호
• /
• pp.23-31
• /
• 2018

In this study, a new method called as multi-dropped liquid membrane (MDLM) which is more practical and more effective than other liquid membrane techniques is applied for transport of Zn(II) has been studied. HCl as the stripping solution and D2EHPA dissolved in kerosene as the membrane solution, has been examined. The effects of stripping solution concentration, carrier concentration, temperature and pH in the feed phase on the transport of Zn(II) have also been investigated. As a result, the optimum transport conditions of Zn(II) were obtained, i.e., the concentration of HCl solution was 0.25 M, the concentration of D2EHPA was $8{\times}10^{-3}M$, and pH value in the donor phase was 5.00. Under the optimum conditions, the transport percentage of Zn(II) was up to >99% during the transport time of 80 min when the initial concentration of Zn(II) was $120mgL^{-1}$. The activation energy is calculated as $5.30kcalmol^{-1}$. The value of calculated activation energy indicates that the process is diffusionally controlled by Zn(II) ions. The experiments have demonstrated that D2EHPA derivative is a good carrier for Zn(II) transport through MDLM in the study.

• Membrane and Water Treatment
• /
• 제8권6호
• /
• pp.575-590
• /
• 2017

PolyHIPEs membrane prepared with styrene (St), divinylbenzene (DVB), and ethylhexyl acrylate (EHA) can yield a unique pore structure provided by large voids highly interconnected by many small window throats. With the advantageous pore structure, PolyHIPE presents a potential as a support for carrier facilitated transport membrane. Tricaprylmethylammonium chloride (Aliquat 336) can be efficiently incorporated into the PolyHIPE membrane by a two-step solvent-nonsolvent method to obtain an Aliquat 336-immobilized PolyHIPE membrane with good stability. The study of Cr (VI) transport through Aliquat 336-immobilized PolyHIPE membrane indicates that the membrane has high initial flux and maxima stripping flux ($J_f^o=15.01({\mu}mol/m^2s)$, $J_s^{max}=6.15({\mu}mol/m^2s)$). The reusability study shows that the Aliquat 336-immobilized PolyHIPE membrane can maintain high Cr(VI) recovery efficiency even after 15 cycles of operations. The developed membrane was also used in the separation of Cr (VI) from other anions (i.e., $SO_4{^{2-}}$ and $NO_3{^-}$) and other cations (i.e., Ni (II), Mg (II) and Cu (II)) with good selectivity.

• Membrane and Water Treatment
• /
• 제4권4호
• /
• pp.223-236
• /
• 2013

The paper presents an experimental set-up for osmotic membrane distillation, which can be operated continuously for several weeks. NaCl solutions were used as an osmotic solution. The influence of osmotic solution concentration on the obtained permeate flux is presented. The experimental set-up was equipped with a system for the regeneration of dilute brine. The regeneration was carried out using a method of natural evaporation to the air surrounding the installation. The evaporation area was created by the Białecki rings, assembled in the form of tower. The obtained evaporation rate was sufficient to maintain a constant NaCl concentration (over 300 g/L), for air with the relative humidity in the range of 30-80%. Accurel PP S6/2 hydrophobic polypropylene membranes were used in the study. The membranes exhibited 100% rejection for 600 h of the process duration.

• 대한화학회지
• /
• 제52권2호
• /
• pp.148-154
• /
• 2008

2-Propylpiperidine-1-carbodithioate(PPCD)I 로 수식화한 octadecyl로 결합된 실리카 막 디스크로 구리(II) 이온의 잔유양의 추출과 간단하고 빠르게 원자흡수분광법(AAS)으로의 정량법을 소개한다. 추출효율과 흐름속도, pH, 형 태, 벗김 산의 가장 적은 양에 대해 연구되었다. Anthraquinone 유도체의 2 mg로 수식한 막디스크의 최대 용량은 425 μg Cu2+ 이었다. 제안한 방법의 검출한계는 7 ng/ml이다. 이 방법은 다른 시료와 온천수 시료로부터 Cu2+의 회수에 적용하 였다.

• Membrane and Water Treatment
• /
• 제9권6호
• /
• pp.463-471
• /
• 2018

The present paper deals with the liquid-liquid extraction and flat sheet supported liquid membrane studies of Pd(II) separation from nitric acid medium using a novel synthesized ligand, namely, N,N,N',N'-tetraethyl-2,2-thiodiethanthiodiglycolamide (TETEDGA). The effect of various diluents and stripping reagents on the extraction of Pd(II) was studied. The liquid-liquid extraction studies showed complete extraction of Pd(II) in ~ 5 min. The influence of nitric acid and TETEDGA concentration on the distribution of Pd(II) has been investigated. The increase in nitric acid concentration resulted in increase in extraction of Pd(II). Stoichiometry of the extracted species was found to be $Pd(NO_3)_2{\cdot}TETEDGA$ by slope analysis method. Extraction studies with SSCD solution showed negligible uptake of Pt, Cr, Ni, and Fe, thus showing very high selectivity and extractability of TETEDGA for Pd(II). The flat sheet supported liquid membrane studies showed quantitative transport of Pd(II), ~99%, from the feed ($3M\;HNO_3$) to the strippant (0.02 M thiourea diluted in $0.4M\;HNO_3$) using 0.01 M TETEDGA as a carrier diluted in n-dodecane. Extraction time was ~160 min. Parameters such as feed acidity, TETEDGA concentration in membrane phase, membrane porosity etc. were optimized to achieve maximum transport rate. Permeability coefficient value of $2.66{\times}10^{-3}cm/s$ was observed using TETEDGA (0.01 M) as carrier, at 3 M, $HNO_3$ feed acidity across $0.2{\mu}m$ PTFE as membrane. The membrane was found to be stable over five runs of the operation.

• 유기물자원화
• /
• 제29권1호
• /
• pp.37-46
• /
• 2021

가축분뇨에 함유된 질소와 인은 환경오염 유발 물질이지만 다양한 산업에서 사용되는 필수 자원이기도 하다. 본 연구에서는 가축분뇨에서 질소 회수에 활용되고 있는 스트리핑, 건조 및 탄화, 이온 교환, 전기투석에 대해 소개하였고, 2011년부터 2020년도까지 국내·외에서 수행한 실규모 연구 현황과 해외 실증플랜트 운영 사례를 분석하였으며 상기 조사결과를 바탕으로 공정별 평가를 실시하였다. 또한, 대표적인 기술인 스트리핑의 주요 운전인자인 pH, 온도, 기액비 등의 적정 범위를 제시하였고, 바이오가스화 공정 연계 시 예상되는 물질수지를 제공하였다. 본 연구에서 제시한 정보는 향후 관련 국내 정책 수립 및 실규모 플랜트 운전 시 유용한 자료로 활용이 가능할 것으로 판단된다.

• Membrane and Water Treatment
• /
• 제9권5호
• /
• pp.327-334
• /
• 2018

The nano/micro composites with highly porous surface area have attracted of great interest, particularly the synthesis of porous and thin film sheets of high performance. In this paper, an easy method of cost-effective synthesis of thin film ceramic fiber membranes based on Hydroxyapatite, and activated carbon by turned into studied to be applied within the service-facilitated the transport of radioactive waste such as $^{90}Sr$, $^{137}Cs$ and $^{60}Co$) as activated product of radioisotopes from ETRR-2 research reactor and dissolved in 3M $HNO_3$, across a thin flat-sheet supported liquid membrane (TFSSLM). Radionuclides are transported from alkaline pH values. The presence of sodium salts in the aqueous media improves in $HNO_3$, the lowering of permeability because the initial $HNO_3$ concentration is improved. The study some parameters on the thin sheet ceramic supported liquid membrane. EDTA as stripping phase concentration, time of extraction and temperature were studied. The study of maximum permeability of radioisotopes for all parameters. The pertraction of a radioactive waste solution from nitrate medium were examined at the optimized conditions. Under the optimum experimental 98.6-99.9% of $^{90}Sr$, 79.65-80.3% of $^{137}Cs$ and $^{60}Co$ 45.5-55.5% in 90-110 min with were extracted in 10-30 min, respectively. The process of diffusion in liquid membranes is governed by the chemical diffusion process.