Tannin cross-linked polyethyleneimine for highly efficient removal of hexavalent chromium

Amine-functionalized MOF-derived carbon materials for efficient removal of Congo red dye from aqueous solutions: simulation and adsorption studies

“… 33 The peaks at 1575 cm −1 and 1458 cm −1 were due to bending vibrations of N–H bonds in PEI. 34 Meanwhile, the peaks at 1350 and 1100 cm −1 were attributed to the stretching vibrations of C–N bonds. 35 Notably, in the FT-IR spectrum of PEI@MDC, the peaks at 1600, 1425 and 1000 cm −1 disappeared.…”

Poly(PEI‐catechol‐tetraethylenepentamine) was prepared by “one‐pot method” for removing Reactive Red 195

“…Figure S5c shows the fine spectrum of N1s in fresh PPCT, where the binding energy peaks appear at 402.2, 399.9, and 398.7 eV, which corresponding to NH 2 + / NH 3 + , NH / NH 2 and C N, respectively. After adsorption (Figure S5d), it can be seen that the binding energy peak of NH 2 + / NH 3 + and NH / NH 2 have shifted significantly, 67 indicating the involvement of protonated amine groups in the adsorption process of RR-195. Therefore, the electrostatic binding between the protonated amine group and the negatively charged SO 3 À ions by RR-195 is the main adsorption force.…”

Preparation of MES@Fe3O4@SiO2-PPy magnetic microspheres for the highly efficient removal of Cr(vi)

“…The physical, chemical, morphological, and magnetic properties of the prepared materials were observed, and related batch adsorption experiments were conducted. The influences of the mass ratio of MFS to Py (10 : 1-10 : 9), the dose of adsorbents (10-150 mg) and pH (2)(3)(4)(5)(6)(7)(8), and reusability on Cr(VI) adsorption were analyzed. Furthermore, the adsorption mechanism of MFSP was investigated through adsorption isotherms, thermodynamic, and kinetic models.…”

“…4 Among them, adsorption technology is currently an effective method for treating low-concentration heavy metal sewage. 5 Therefore, various adsorption materials, such as activated carbon, 6 metal oxides, 7 polymer materials, 8 have been widely adopted to separate Cr( vi ). Despite numerous successful pioneering works, there are still technical problems in production and application such as poor repeatability, high cost, and low reusability.…”