Lijun You,Ke Xu,Guanjun Ding,Xinming Shi,Jumei Li,Shaoyun Wang,Jiabin Wang
Magnetic covalent organic framework modified by Fe 3 O 4 nanoparticles (Fe 3 O 4 @COF) were facile synthesized and used as adsorbent for the adsorption of bisphenols from aqueous solutions. The Fe 3 O 4 @COF is synthesized by catalyst-free Schiff base reaction of melamine and terephthalaldehyde, and synthesis strategy is flexible and controllable. The as prepared Fe 3 O 4 @COF was characterized by TEM , PXRD , TGA and BET analysis. The Fe 3 O 4 @COF possessed large specific surface area (335.2 m 2 /g), high chemical and thermal stability, and high saturation magnetization (49.6 emu/g), which in favor of rapid magnetic separation and efficient adsorption in the adsorption process. The effects of temperature, adsorbent dosage, pH and salt concentration on the adsorption of bisphenols (BPA and BPAF) were studied. The as-prepared adsorbent showed an excellent adsorption ability for BPA and BPAF , and the max adsorption capacity of BPA and BPAF could reach 140 and 290.4 mg/g. The adsorption kinetic fitted the pseudo-second-order kinetic model and the adsorption isotherm followed the Freundlich isotherm equation. Moreover, the Fe 3 O 4 @COF presented favorable re-use performance, which kept over 81.4% removal efficiency of bisphenols after five consecutive recycles. The high adsorption performance and reusability make the Fe 3 O 4 @COF a promising adsorbent for the removal of bisphenols.
Jinna Xiao,Zhengzheng Liao,Jie Zhang,Haijiao Xie,Zhentao Li
Herein, we reported the straightforward synthesis of chitosan-coated microporous organic network (CS-MON) designed to enhance the adsorption of bisphenols from water. Initially, an amino-functionalized microporous organic network was synthesized using 2,5-diethynylbenzene-1,4-diamine and 2,4,6-tris(4-bromophenyl)-1,3,5-triazine via a Sonogashira coupling reaction. Subsequently, a chitosan layer was introduced onto the network’s surface through a cross-linking polymerization, yielding the CS-MON. The incorporation of chitosan significantly improved water dispersibility and provided additional interaction sites for bisphenols. The adsorption performance and mechanism were systematically investigated. According to the Langmuir isotherm model, the material exhibited high adsorption capacity of 666.7, 602.4, and 450.5 mg/g. The rate constants k 2 of 0.163, 0.113, and 0.114 g/mg/min for bisphenol A, bisphenol F and bisphenol S, respectively, based on the pseudo-second-order model, outperforming many previously reported adsorbents. The adsorbent can maintain its adsorption capacity for bisphenol A across a wide range of pH levels and was unaffected by co-existing inorganic ions, ionic strength, and humic acid. Additionally, the adsorbent maintained an adsorption efficiency exceeding 95 % for bisphenol A even after 20 cycles. The remarkable adsorption performance was primarily governed by hydrogen bonding, π-π, π-π electron-donor-acceptor, and hydrophobic interactions. The CS-MON was also successfully used in flow-through filtration experiments and tested with real water samples, demonstrating its potential for application in wastewater treatment.
危险品化学品经营许可证（带存储）