Water adsorption/desorption over metal-organic frameworks with ammonium group for possible application in adsorption heat transformation

An, Hyung Jun,Sarker, Mithun,Yoo, Dong Kyu,Jhung, Sung Hwa Elsevier 2019 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.373 No.-

<P><B>Abstract</B></P> <P>Typical metal-organic frameworks (MOFs) such as UiO-66 and MIL-125 were modified to introduce –NH<SUB>2</SUB> and –NH<SUB>3</SUB> <SUP>+</SUP>Cl<SUP>−</SUP> groups in order to improve their performances for water adsorption and for possible applications in adsorption heat transformation (AHT). Not only adsorption isotherms but also dynamic water adsorption/desorption (in 10 cycles) results showed that the functionalization, especially loading of the –NH<SUB>3</SUB> <SUP>+</SUP>Cl<SUP>−</SUP> group, was very effective for such purposes. Both the adsorption capacity (especially, at low vapor pressure) and dynamic water uptake (via cyclic adsorption/desorption of water) increased notably with the modification of the MOFs. The positive effect could be explained by hydrogen bonding and electrostatic interactions, which are not possible with the pristine MOFs. Therefore, it could be suggested that loading moieties with charge and ample hydrogen (such as ammonium group) is a very effective means of modifying MOFs for water adsorption or for application in AHT.</P> <P><B>Highlight</B></P> <P> <UL> <LI> Metal-organic frameworks were modified to load amino and ammonium groups. </LI> <LI> The modified MOFs showed highly enhanced performances for water adsorption. </LI> <LI> Adsorption capacity and dynamic water uptake increased much with the modification. </LI> <LI> The favorable effect could be explained with H-bonding and electrostatic interaction. </LI> <LI> The modified MOFs were very stable in dynamic adsorption/desorption for 10 cycles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Improvement of Water-Adsorption Capacity of Silico-Aluminophosphates by Changing Si/Al Ratio and Impregnation of Hygroscopic Salt for Application of Adsorption Chiller

김상겸,조강희,이영우,김종남 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.12

We synthesized a series of silico-aluminophosphates with a CHA-type microporous structure (SAPO-34) under hydrothermal conditions with different silicon to aluminum (Si/Al) ratios and systematically studied the effect of the Si/Al ratio on the structural properties and the water-adsorption capacity of the SAPO-34 adsorbents. The crystallinity, pore volume and surface area of the SAPO-34 increased with an increasing the SiO2/Al2O3 up to 1.0, and the amount of water adsorption also increased with the same trend. However, as increasing the ratio more, these properties became worse. SAPO-34 with SiO2/Al2O3 = 1 exhibited the highest water adsorption amount (0.359 gwater/gsorbent) at 308 K and 30% relative humidity. In order to enhance the water-adsorption capacity further, we impregnated the SAPO-34 with hygroscopic salts, LiCl and CaCl2. The amount of water adsorption at 308 K and 30% relative humidity was increased up to 0.584 and 0.664 gwater/gsorbent for the LiCl@SAPO-34 and CaCl2@SAPO-34 respectively. However, after several cycles of adsorption (308 K, 12 Torr)—desorption (353 K, 42 Torr) conditions of typical adsorption chiller, the CaCl2@SAPO-34 lost more than 81% of its working capacity. On the other hand, LiCl@SAPO-34 maintained well the working capacity during five cycles. SAPO-34 impregnated with LiCl is a highly promising water adsorbent for the application of adsorption chiller.

Experimental Analysis of HTO Adsorption on Activated Carbon in Tritium-Contaminated Water

Jei-Won Yeon,Ji Eun Yang 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

Though many treatment technologies of contaminated water have been developed for a long time, it is still difficult to find a suitable method for large volumes of low radioactivity tritium-contaminated water. For this reason, most of the tritium-contaminated water been discharged to the biosphere or been stored in a special control area as radioactive waste. Activated carbon is a common material, but since there are few data on the treatment of tritium-contaminated water, its adsorption behavior to HTO is worth studied. In our study, for the tritium-contaminated water having a low radioactivity concentration (350-480 Bq/g), adsorption experiments were performed with activated carbon. The effects on the selective adsorption of HTO were investigated for temperature (5-55°C), hydrogen peroxide (1-10wt%) and activated carbon reuse (1-6 times) under non-equilibrium conditions. The treatment of activated carbon significantly reduced the radioactivity of tritium-contaminated water around 60 minutes of adsorption time. In order to clearly analyze the experimental results, positive factors and negative factors on the HTO selectivity were separately evaluated according to the adsorption time. Temperature and the reuse of activated carbon were evaluated as negative factors for HTO selectivity of activated carbon, whereas hydrogen peroxide (> 5wt%) was evaluated as a positive factor. By the evaluation method of separating the influencing factors into two types, the adsorption experimental results of HTO could be understood more clearly.

Removal of Nitrate from Water by Adsorption onto Zinc Chloride Treated Activated Carbon

Bhatnagar, Amit,Ji, Minkyu,Choi, Yang-Hun,Jung, Woosik,Lee, Sang-Hun,Kim, Sun-Joon,Lee, Giehyeon,Suk, Heejun,Kim, Hyoung-Soo,Min, Booki,Kim, Seong-Heon,Jeon, Byong-Hun,Kang, Joon-Wun Taylor Francis 2008 Separation science and technology Vol.43 No.4

<P> Adsorption study with untreated and zinc chloride (ZnCl2) treated coconut granular activated carbon (GAC) for nitrate removal from water has been carried out. Untreated coconut GAC was treated with ZnCl2 and carbonized. The optimal conditions were selected by studying the influence of process variables such as chemical ratio and activation temperature. Experimental results reveal that chemical weight ratio of 200% and temperature of 500°C was found to be optimum for the maximum removal of nitrate from water. Both untreated and ZnCl2 treated coconut GACs were characterized by scanning electron microscopy (SEM), Brunauer Emmett Teller (BET) N2-gas adsorption, surface area and Energy Dispersive X-Ray (EDX) analysis. The comparison between untreated and ZnCl2 treated GAC indicates that treatment with ZnCl2 has significantly improved the adsorption efficacy of untreated GAC. The adsorption capacity of untreated and ZnCl2 treated coconut GACs were found 1.7 and 10.2 mg/g, respectively. The adsorption of nitrate on ZnCl2 treated coconut GAC was studied as a function of contact time, initial concentration of nitrate anion, temperature, and pH by batch mode adsorption experiments. The kinetic study reveals that equilibrium was achieved within one hour. The adsorption data conform best fit to the Langmuir isotherm. Kinetic study results reveal that present adsorption system followed a pseudo-second-order kinetics with pore-diffusion-controlled. Results of the present study recommend that the adsorption process using ZnCl2 treated coconut GAC might be a promising innovative technology in future for nitrates removal from drinking water.</P>

Adsorptive removal of wide range of pharmaceuticals and personal care products from water using bio-MOF-1 derived porous carbon

Bhadra, Biswa Nath,Jhung, Sung Hwa Elsevier 2018 Microporous and mesoporous materials Vol.270 No.-

<P><B>Abstract</B></P> <P>Bio-MOF-1 was pyrolyzed at 1000 °C to obtain highly porous carbon containing oxygen and nitrogen. The bio-MOF-derived carbons (BMDCs) were firstly applied in the adsorptive removal of four pharmaceuticals and personal care products (PPCPs), with a wide range of acidities or basicities, from water. BMDC-12 h, obtained by pyrolysis for 12 h, was very competitive in the adsorption of PPCPs, in terms of both adsorption rate and adsorbed quantity. More importantly, carbon showed the highest adsorption capacities for both basic atenolol (ATNL; 552 mg/g) and acidic clofibric acid (CLFA; 540 mg/g) among all the adsorbents reported so far. The recyclability of BMDC-12 h in adsorption was also confirmed (after solvent washing) by both adsorption and characterization (by nitrogen adsorption and FTIR analyses). The plausible adsorption mechanism was also suggested based on the effect of solution pH on the adsorbed amounts of PPCPs. Electrostatic interaction was the primary mechanism for the adsorption of ATNL. However, CLFA adsorption could be explained mainly by H-bonding, where CLFA was the acceptor for hydrogen donated from BMDC-12 h. BMDC-12 h was suggested as a promising adsorbent for the removal of a wide range of PPCPs from water, based on the remarkably high adsorption capacity, rapid adsorption, and stable reusability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Porous carbon derived from Bio-MOF-1 was applied in removal of PPCPs. </LI> <LI> Bio-MOF-1-derived carbon showed the highest atenolol and clofibric acid adsorption. </LI> <LI> The principal adsorption mechanisms could be defined for each adsorbate. </LI> <LI> The adsorbent showed perfect reusability for successive adsorptions in water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

정수슬러지 유래 흡착제와 첨착활성탄의 암모니아 및 포름알데히드 기체 흡착 성능 비교

이철호 ( Choul Ho Lee ),박나영 ( Nayoung Park ),김고운 ( Goun Kim ),전종기 ( Jong-ki Jeon ) 한국공업화학회 2016 공업화학 Vol.27 No.1

In this study, a pellet-type adsorbent was prepared by using the water-treatment sludge as a raw material, and its physical and chemical properties were analyzed through N2-adsorption, XRD, XRF, and NH3-TPD measurements. Adsorption performance for gaseous ammonia and formaldehyde was compared between the pellet-type adsorbents prepared from water-treatment sludge and the impregnated activated carbon. Although the surface area and pore volume of the pellet-type adsorbent produced from water- treatment sludge were much smaller than those of the impregnated activated carbon, the pellet-type adsorbent produced from water-treatment sludge could adsorb ammonia gas even more than that of using the impregnated activated carbon. The pellet-type adsorbent prepared from water-treatment sludge showed a superior adsorption capacity for ammonia which can be explained by chemical adsorption ascribed to the higher amount of acid sites on the pellet-type adsorbent prepared from water-treatment sludge. In the case of formaldehyde adsorption, the impregnated activated carbon was far superior to the adsorbent made from the water-treatment sludge, which can be attributed to the increased surface area of the impregnated activated carbon.

고품질 청정용수 공급을 위한 FDA 시스템 개발

이광야 ( Lee Kwang Ya ),김해도 ( Kim Hae Do ),최경숙 ( Choi Kyung Sook ),남효석 ( Nam Hyo Seok ),홍민 ( Hong Min ),손종화 ( Son Jong Hwa ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

This study was undertaken to develop water purification system for supplying clean agricultural water, especially for providing high quality of greenhouse cultivation water. The FDA (Filter-Disinfection-Adsorption) system was developed for this purpose. Four water quality categories, SS, BOD, turbidity, E. coli were selected as a basis of development and examination of FDA system. From the field examination, it was found that FDA system was good enough to meet target values of each water quality category after purification process. Apart from the water quality issues, this study also investigated the problems of FDA system in a position of user. A few defects for using FDA system were detected from the user monitoring, such as sustaining proper water temperature, suitable tank capacity, water leaking and pressure problems, etc. Further study will be proceeded to improve and upgrade FDA system in the second research period for supplying high quality of clean irrigation water as well as providing convenience water to farmers.

청정 시설용수 공급을 위한 FDA 시스템 개발

이광야,김해도,최경숙,남효석,홍민,손종화 경상대학교 농업생명과학연구원 2008 농업생명과학연구 Vol.42 No.3

The objective of this study is to develop water purification system for supplying clean agricultural water, especially for providing high quality of greenhouse cultivation water. The FDA (Filter- Disinfection-Adsorption) system was developed through several assessments. Four water quality categories, SS, BOD, turbidity, E. coli were selected as a basis of development and examination of FDA system. From the field examination, it was found that FDA system was good enough to meet target values of each water quality category after purification process. Apart from the water quality issues, this study also investigated the practical problems of FDA system in a position of user. A few defects for using FDA system were detected from the user monitoring, such as sustaining proper water temperature, suitable water tank capacity, leaking and water pressure problems, etc. Further study will be proceeded to improve and upgrade FDA system in the second research period in order to supply high quality of clean irrigation water as well as to provide convenience water for farmers. 우리나라 농촌현실에 적합하면서 고품질의 친환경 농산물 생산을 위한 청정용수공급이 가능한 FDA 시스템을 개발하였다. 기존의 필터제품의 문제점을 개선하고 보다 경제적이고 기능적인 면을 고려하여 시설재배단지에 청정용수공급을 목표로 시설용수공급시스템을 개발하였다. 시설용수 공급시스템 모듈통합기법으로 개발된 FDA시스템은 여과와 흡착 그리고 자외선 모듈을 거치는 과정으로 구성되어 있다. 본 제품의 시작품 생산은 3단계의 평가과정을 거쳐 진행 되었다. 이 과정을 통해 시설용수공급시스템의 구성품별 사양을 제시하고 적정처리용량 및 모듈통합기법을 개발하였으며, 현장 설치지역(시설재배농가)의 재배현황 및 수질을 조사하여 적합한 시설용수 공급시스템 요소기술(살균, 여과)을 설계하였고, 실제 현장에 적용할 수 있는 시작품을 제작하여 현장 설치를 위한 실내 성능시험을 수행하였다. 또한 시작품 현장 설치 후 시설용수 공급시스템 유입 전․후 수질분석을 실시하였으며 모니터링을 통해 시설재배용수 온도조절장치와 폭기 장치에 대한 개선방안을 제시하여 시작품의 보완제작을 실시하였다. 시작품의 현장적용성 평가에서는 시작품의 수질정화능력평가 및 사용자 입장에서의 개선점 파악을 실시하였는데 그 결과 시스템의 수질정화능력은 목표치 이상이었으나, 수온유지, 저수조 용량문제, 누수현상, 역류현상, 적정수압유지 등의 개선점이 파악되었다.

양이온 교환 및 염 함침을 통한 메조다공성 실리카와 유기-금속구조체의 수분 흡착 특성 조절

이은경(Eun Kyung Lee),조강희(Kanghee Cho),김상겸(Sang Kyum Kim),임종성(Jong Sung Lim),김종남(Jong-Nam Kim) 한국청정기술학회 2018 청정기술 Vol.24 No.1

Adsorptive removal of anti-inflammatory drugs from water using graphene oxide/metal-organic framework composites

Sarker, Mithun,Song, Ji Yoon,Jhung, Sung Hwa Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.335 No.-

<P><B>Abstract</B></P> <P>Highly porous metal-organic framework (MOF) composites were synthesized by combining MIL-101(Cr) with graphene oxide (GnO). The porosity of the GnO/MIL-101 composite was increased by composing GnO onto the MOF up to a certain ratio. The GnO/MIL-101 composites were utilized to adsorb anti-inflammatory drugs (AIDs) such as naproxen (NAP) and ketoprofen (KTP) from water. It was observed that GnO/MIL-101 composites displayed highly improved adsorption toward both NAP and KTP relative to pristine MIL-101 and commercial AC. MIL-101_GnO(3%) had a NAP adsorption capacity 2.1 and 1.4 times those of commercial AC and pristine MIL-101, respectively; its adsorption performance was also very competitive with other reported adsorbents. The improved adsorption performance of the composites for NAP was credited to H-bonding because of the presence of several functional groups in the composites. MIL-101_GnO(3%) and NAP act as a H-bond donor and acceptor, respectively. Moreover, MIL-101_GnO(3%) can be regenerated without severe deterioration by simple ethanol washing and can be reused for successive adsorption. Therefore, the GnO/MIL-101 composite is suggested as an efficient adsorbent for the removal of AIDs from water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Highly porous graphene oxide/MOF composites were prepared in one pot synthesis. </LI> <LI> Adsorptive removal of anti-inflammatory drugs was done with the obtained composites. </LI> <LI> MIL-101_GnO(3%) showed remarkable adsorption capacity for AIDs removal. </LI> <LI> Plausible adsorption mechanism was suggested by adsorption in wide conditions. </LI> <LI> MIL-101_GnO(3%) is proposed as a promising/reusable adsorbent for removing AIDs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>