https://scholars.lib.ntu.edu.tw/handle/123456789/547661
標題: | Covalent organic framework EB-COF:Br as adsorbent for phosphorus (V) or arsenic (V) removal from nearly neutral waters | 作者: | Yang, C.-H. Chang, J.-S. Lee, D.-J. DUU-JONG LEE |
關鍵字: | Adsorbent; Anion; Arsenate; Covalent organic framework; Phosphate; Temperature dependence | 公開日期: | 2020 | 卷: | 253 | 來源出版物: | Chemosphere | 摘要: | The covalent organic framework (COF) is made light elements linked by covalent networks. This study synthesize and characterized, and for the first time applied the produced EB-COF:Br as adsorbent for phosphate and arsenate removal from nearly neutral waters. The synthesized COF was first proven structurally stable in solutions of 75% H3PO4, 6 M HCl, or 6 M NaOH. Then the phosphate adsorption onto the EB-COF:Br was shown to be an endothermic process with maximum adsorption capacity at 25, 35 and 45 °C as 25.3, 34.7 and 35.3 mg/g COF, respectively; and the corresponding arsenate adsorption process being an exothermic process with maximnum adsorption capacity as 53.1, 27.5 and 5.1 mg/g, respectively. The synthesized COF could also effectively adsorb phosphate and arsenate ions from river water (pH 7.45) but at reduced adsorption capacities. The electrostatic interactions between the negative charge on phosphate or arsenate ions and the positively charged ([dbnd]N+–) of COF, and the hydrogen bondings between H atom on phosphate or arsenate ions and the (–C[dbnd]O) group of COF were the dominating mechanisms for the present adsorption process. The strong electrostatic interactions for arsenate contributed to its higer adsorption capacity than noted for phosphate at 25 °C. However, the disturbed hydrogen bonding induced by mismatched sizes of arsenate ion and the adsorption sites surrounded by the ([dbnd]N+–) and the (–C[dbnd]O) groups reduced the stability of arsenate to against temperature and external anion challenges. The use of the EB-COF; Br as industrial adsorbent was also discussed. © 2020 Elsevier Ltd |
URI: | https://www.scopus.com/inward/record.url?eid=2-s2.0-85083043240&partnerID=40&md5=b742f81115e7b000c7f5c1126f081b55 https://scholars.lib.ntu.edu.tw/handle/123456789/547661 |
ISSN: | Yang, C.-H.;Chang, J.-S.;Lee, D.-J. | DOI: | 10.1016/j.chemosphere.2020.126736 | SDG/關鍵字: | Chemical elements; Electrostatics; Hydrogen bonds; Ions; Sodium hydroxide; Adsorption capacities; Arsenate adsorption; Arsenic (v) removal; Covalent organic frameworks; Endothermic process; Exothermic process; Phosphate adsorption; Positively charged; Adsorption; adsorbent; arsenic; arsenic acid; phosphorus; river water; arsenic acid derivative; metal organic framework; phosphate; adsorption; arsenate; arsenic; chemical binding; ion exchange; phosphate; phosphorus; pollutant removal; river water; adsorption; adsorption kinetics; aqueous solution; Article; comparative study; controlled study; covalent bond; crystal structure; freeze thawing; heavy metal removal; hydrogen bond; scanning electron microscopy; static electricity; surface area; surface charge; synthesis; temperature dependence; chemistry; kinetics; pH; procedures; temperature; water management; water pollutant; Adsorption; Arsenates; Hydrogen-Ion Concentration; Kinetics; Metal-Organic Frameworks; Phosphates; Temperature; Water Pollutants, Chemical; Water Purification |
顯示於: | 化學工程學系 |
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