• 한국토양비료학회지
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• 제20권2호
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• pp.153-159
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• 1987

천연(天然) 제오라이트, 벤토나이트, 버미큐라이트에 의한 $^{42}K$, $^{45}Ca$ 흡착(吸着)이 Frendlich와 Langmuir 등온흡착방식(等溫吸着方式)에 맞는지, 또한 이들 흡착체(吸着體)에 흡착(吸着)된 방사성(放射性) 핵종(核種)이 $NH_4$에 의해서 탈착(脫着)되는 정도(程度)를 이들 광물(鑛物)의 결정구조적(結晶構造的) 특성(特性)과 관련시키면서 상호(相互) 비교(比較)해 봤다. 우선 $^{42}K$, $^{45}Ca$ 흡착(吸着)은 두 가지 흡착방식(吸着方式)에 잘 맞는다. Langmuir 최대흡착량(最大吸着量)은 버미큐라이트를 제외(除外)하고는 제오라이트와 벤토나이트 모두 $^{42}K$ 흡착량(吸着量)이 $^{45}Ca$ 흡착량(吸着量) 보다 많다. $^{42}K$ 흡착량(吸着量)의 크기를 보면 zeolite(Zt) > Bentonite (Bt) > Vermiculite (Vt)의 순(順)이고 $^{45}Ca$의 경우는 Bt>Vt>Zt이다. 제오라이트가 $^{42}K$를 $^{45}Ca$ 보다 더 많이 흡착(吸着)하는 것은 이온반경(半徑)과 제오라이트 공동(空洞)의 크기와 밀접한 관계가 있는 것으로 보여진다. Ca 이온반경(半徑)은 작기 때문에 공동(空洞)으로 부터 빠져 나온다. 벤토나이트가 $^{45}Ca$를 더 흡착(吸着)하는 것은 하전밀도(荷電密度)가 K의 하전밀도(荷電密度) 보다 크기 때문이라고 본다. $^{42}K$, $^{45}Ca$의 흡착강도(吸着强度)는 Langmuir 정수(定數)(k)와 비교(比較)해 보면 $^{42}K$의 경우는 k값이 $^{45}Ca$의 k값 보다 작다. k값이 작으면 흡착강도(吸着强度)는 약(弱)하다고 본다. $^{42}K$의 탈착율(脫着率)은 Zt>Bt>Vt 의 순(順)이고 $^{45}Ca$는 Vt>Zt>Bt 의 순(順)이다. 버미큐라이트의 $K^+$에 대한 선택적 고정은 제외하고 k값이 작은 것이 탈착율(脫着率)은 높다. 결론적(結論的)으로 제오라이트는 다른 개량재(改良材)보다 $^{42}K$를 더 흡착(吸着)하고 방출(放出)도 많다. 벤토나이트는 다른 개량재(改良材)보다 $^{45}Ca$를 더 흡착(吸着)하나 탈착(脫着)은 적다.

• 설비공학논문집
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• 제25권8호
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• pp.457-463
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• 2013

Nowadays, adsorption chillers have been receiving considerable attention, as they are energy saving and environmentally benign systems. A fin tube type heat exchanger in which adsorption/desorption takes place is required with more compact size. The adsorption chiller is expected to have high energy efficiency in utilizing the waste heat exhausted from a process. The objectives of this paper are to scrutinize the effect of design parameters on the adsorption performance, especially the fin pitch of the fin tube, and to develop an optimal design fin tube heat exchanger in a silica gel/water adsorption chiller. From the numerical results, the fin pitch of 2.5 mm shows the highest adsorption rate, compared to other fin pitches, such as 5 mm, 7.5 mm and 10mm. Also, the adsorption rate is affected by the cooling water and hot water temperature.

• Advances in environmental research
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• 제12권1호
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• pp.17-40
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• 2023

This article presents studies of the adsorption process in a continuous system of fluoride solutions at a concentration of 30 mg/L using a bone char packed in fixed-bed columns, as well as regeneration studies in the same system using HNO₃, HCl and NaOH at 0.01, 0.1 and 1 M. The Thomas Model, Artificial Neural Networks (ANNs), Numerical Integration and Mass Transfer Zone were used for the modeling of asyemmetrical breakthrough curves obtained from the fluoride adsorption on bone char. The maximum adsorption capacity of the breakthrough curves was estimated, and various design parameters of the columns were obtained for the different operating conditions. Results showed that an improvement in the modeling capabilities of the Thomas model can be obtained using ANNs. Moreover, ANNs are useful for determining reasonable and accurate design parameters of packed-bed adsorption columns. This modeling approach can be useful for the process system engineering of dynamic adsorption systems involved in the field of water treatment and purification. It is important to highlight that the obtained results indicate that, when using HCl or HNO₃ at a concentration of 0.1 M, a large number of adsorption-desorption cycles are obtained and, therefore, the highest values of adsorption capacity, which leads to a reduction in operation costs.

• 공업화학
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• 제17권4호
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• pp.349-356
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• 2006

실리카($SiO_{2}$)지지 루테늄-니켈(Ru/Ni) 합금에 있어서 Ru/Ni 몰함량비와 일산화탄소(CO)의 분압의 변화에 따른 CO의 흡착 및 탈착거동에 대한 연구를 FT-IR을 이용하여 수행하였다. $Ru-SiO_{2}$ 시료에 CO를 흡착시켰을 때 $2080.0cm^{-1}$, $2021.0{\sim}2030.7cm^{-1}$, $1778.9{\sim}1799.3cm^{-1}$, $1623.8cm^{-1}$의 위치에 네 흡수띠가 관찰되었고 진공탈착시 $2138.7cm^{-1}$, $2069.3cm^{-1}$, $1988.3{\sim}2030.7cm^{-1}$의 위치에 세 흡수띠가 관찰되었다. $Ni-SiO_2$ 시료에 CO를 흡착시켰을 때 $2057.7cm^{-1}$, $2019.1{\sim}2040.3cm^{-1}$, $1862.9{\sim}1868.7cm^{-1}$, $1625.7cm^{-1}$의 위치에 네 흡수띠가 관찰되었고, 진공탈착 시켰을 때 $2009.5{\sim}2040.3cm^{-1}$, $1828.4{\sim}1868.7cm^{-1}$의 위치에 두 흡수띠가 관찰되었다. $Ru-SiO_{2}$ 시료와 $Ni-SiO_{2}$ 시료에서 관찰된 IR 스펙트럼은 이전의 보고와 근사적으로 일치한다. Ru/Ni(9/1, 8/2, 7/3, 6/4, 5/5; 몰 함량비)-$SiO_{2}$ 시료에서는 CO를 흡착시켰을 때 $2001.8{\sim}2057.7cm^{-1}$, $1812.8{\sim}1926.5cm^{-1}$, $1623.8{\sim}1625.7cm^{-1}$의 위치에 세 흡수띠가 관찰되었으며, 진공탈착시 $2140.6cm^{-1}$, $2073.1cm^{-1}$, $1969.0{\sim}2057.7cm^{-1}$의 위치에 세 흡수띠가 관찰되었다. Ru/Ni-$SiO_{2}$ 시료에서 CO를 흡착시켰을 때 Ru/Ni의 몰 함량비가 9/1 경우 관찰된 IR 스펙트럼의 모양이 $Ru-SiO_{2}$ 시료에서 CO를 흡착시켰을 때의 모양과 거의 같음이 관찰되었고 Ru/Ni의 몰 함량비가 8/2 보다 작아지면 관찰된 IR 스펙트럼의 모양이 $Ni-SiO_{2}$ 시료에서 CO를 흡착시켰을 때의 모양과 거의 같다. 따라서 Ru/Ni-$SiO_{2}$ 시료 표면에 존재하는 합금 뭉치의 표면에 몰 함량비보다 니켈이 많이 존재한다는 추정이 가능하다. $SiO_{2}$ 지지 Ru/Ni 시료에서 조성의 변화에 따른 CO 흡수띠 파수의 이동을 $SiO_{2}$ 표면에 분산되어 있는 합금뭉치 표면의 조성, 합금뭉치 표면의 조성에 따른 Ru과 Ni 원자의 원자 크기의 차이로 인한 합금뭉치 표면에서 스트레인의 변화, 합금뭉치 표면에서 결합에너지와 전자밀도분포 변화, 합금뭉치 표면에서 표면구조의 변화와 관련이 있음은 분명하다. Ru/Ni 합금결정 표면에서 CO 흡착에 대한 LEED 및 Auger를 이용한 연구, 실리카겔과 Ru/Ni 합금 뭉치와의 상호작용, Ru/Ni 합금 표면에서 CO 흡착에 대한 MO 계산 등의 연구가 진전되어 진다면 이러한 복잡계에 대한 규명에 도움이 될 것으로 보인다.

• 멤브레인
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• 제25권1호
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• pp.60-66
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• 2015

다공성 전극표면에 이온교환고분자를 직접 casting하여 만들어진 복합탄소전극의 성능을 알아보기 위해서 NaCl 수용액을 이용하여 흡착시간, 공급액 농도, 유속, 탈착전압에 따라 흡/탈착실험을 진행하였다. 유입수가 100 mg/L일 때 동일 조건에서 흡착시간이 3분에서 5분으로 증가하면서 제거율이 3% 증가하였는데 이는 유입수의 셀 내부 잔류시간의 증가로 인한 것으로 사료되며 또한 유속이 15 mL/min에서 23 mL/min 증가하면서 효율이 12% 정도 낮음을 보인 것은 유속이 상승하면서 유입수의 셀 내부 잔류시간이 짧아지면서 나타나는 영향으로 사료된다. 유입수의 농도를 200 mg/L로 증가하였을 때 효율은 100 mg/L보다 10~15% 정도 낮은 값을 보였는데, 이는 탈착구간에서 완전탈착이 되지 않아 나타나는 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3570-3576
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• 2013

Poly(methacrylic acid)-functionalized SBA-15 silicas (denoted as P-x-PMA/SBA-15 where x is molar ratio of TSPM/(TEOS+TSPM) in percentage in the initial mixture) were synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent and then polymerization by methacrylic acid in the presence of ammonium persulfate as an initiator. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and $N_2$ adsorption-desorption at 77 K. The investigation of phenol adsorption in aqueous solution on the materials showed that the poly(methacrylic acid)-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of various kinds of hydrogen bonds. The adsorption data were fitted to Langmuir isotherms and the maximum adsorption capacity of the three functionalized materials P-5-PMA/SBA-15, P-10-PMA/SBA-15, and P-15-PMA/SBA-15 to be 129.37 mg/g, 187.97 mg/g, and 78.43 mg/g, respectively, were obtained. The effect of the pH on phenol adsorption was studied.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.203-203
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• 2011

The importance of stepped single-crystal surfaces as model catalysts has been well recognized [1]. We re-investigated the adsorption properties of $H_2$ and CO, most important species in platinum-based catalysts, on nearly defect-free and highly stepped surfaces of one and the same Pt(111) crystal. While both being symmetric and single-peaked from the nearly defect-free surface, temperature-programmed desorption (TPD) spectra from the highly stepped surface saturated at 90 K with H and CO were triply- and doubly-peaked, respectively. Once pre-adsorbed, CO preempted step and then terrace sites, inhibiting the dissociative $H_2$ adsorption completely. Pre-adsorbed H inhibited the CO adsorption on terrace sites only, leaving defect sites intact for CO adsorption even at the saturation H precoverage. On defect-free Pt(111), while pre-adsorbed CO inhibited the dissociative $H_2$ adsorption completely, pre-adsorbed H could not inhibit the CO adsorption completely. These intriguing, but interesting results are discussed in terms of energetics/kinetics and the role of surface step sites in the dissociative adsorption of $H_2$ on Pt(111) [2].

• 한국염색가공학회지
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• 제5권2호
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• pp.99-108
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• 1993

In one dyeing system of silk/synthetic blend fabrics (polyester, nylon, acetate) with acid dyes/disperse dyes, dyeability and desorptibility of disperse dyes on silk fabric and transfer from dyed silk fabrics to synthetic fabrics by color difference were examined. When silk dyed with C.I. Disperse Red 19 and C.I. Disperse Red 60 at 10$0^{\circ}C$ for 60 minutes, color difference of dyed silk were $\Delta$E=56.72, $\Delta$E=47.65 for blank silk, respectively. The desorption rate of the dyed silks were measured in boiling bath with and without dye-free synthetic fibers. The desorption rate of dyed silk was effected by affinity of synthetic fabrics contained. When silk dyed with Red 19 and Red 60 was reduced at 10$0^{\circ}C$ for 60 minutes, the decolouration rates of dyed silk were 75% and 40%, respecdtively.

• 환경위생공학
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• 제14권1호
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• pp.80-87
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• 1999

According to the fact that algae, which is usually used as a biosorbent, contains chlorophyll, we used the chlorophyll as an adsorbent. In this study, chlorophyll is immobilized by agar, which was made of platan, oak, ginkgo and pine. We investigated the removing capacity of biosorbents to toxic heavy metals (Pb, CU, Cd, Zn) in the single ion solution. Then the experimental parameters were pH, reaction time and concentration of heavy metal ions.The optimum conditions for the adsorption of heavy metals were as follows : pH range was 4~5, reaction time was 40mon, and the highest ratio of the removing rate was 50~70 ppm. The order of the amount of Pb, Cu and Cd removed was specified as oak > ginkgo > pine > platan in these conditions and as pine > ginkgo > oak > platan at Zn. Fro the results of the desorption experiments, we found that the heavy metal with the highest ratio of desorption in the single ion adsorbent was Cu.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.497-501
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• 2005

This study deals with the removal of mercury species using a packed-bed column with spherical aminated chitosan material. These adsorbents revealed a high adsorption capacity for mercury species. Experiments with feed solutions of 10 ppm Hg dissolved in distilled water showed an excellent removal with a sharp increase of the filter effluent concentration after a total throughput of 900 bed volumes of feed water. Up to $95\%$ desorption was reached by using 3 bed volumes of 0.01 N EDTA solution. EDTA could be recovered by means of sulfuric acid with about $75\%$ efficiency. Almost the same results were obtained in repeated sorption and desorption experiments at identical conditions. The experiments demonstrated that the sorbents possessed practically no sorption capacity for alkaline earth ions ($Ca^{2+}\;and\;Mg^{2+}$). Their influence on the sorption of mercury was negligible. In experiments with spiked tap water of the Karlsruhe Research Centre and a feed mercury concentration of 0.01 mg/l, the breakthrough of Hg was observed only after a total throughput of about 6,000 bed volumes of feed water.