Insight into the synergistic adsorption-reduction character of chromium (VI) onto poly(pyrogallol-tetraethylene pentamine) microsphere in synthetic wastewater

Facile fabrication of the ultra-high-performance adsorbent can effectively ameliorate the Cr(VI)-pollution elimination in sewage control. Herein, a simple synthesis strategy is proposed to tap a versatile chelating resin poly(pyrogallol-tetraethylene pentamine) (PPTA) with respect to Cr(VI) removal from solution. Multiple changing factors which affect the adsorption behavior of PPTA are explored sequentially, such as initial pH, adsorbate concentration, adsorbent dosage, temperature, foreign ions, etc. The microstructure and functional mechanism of synthetic adsorbent are investigated systematically by means of various characterizations including TEM, EDS, FT-IR, XPS, etc. Consequently, the as-prepared PPTA-3 microsphere by reactant ratio of 1: 1 represents a brilliant synergistic adsorption and reduction result for Cr(VI) by the drastic electrostatic interaction of -NH3+ and -OH2+ groups, including satisfactory removal efficiency which closes to 100 % in low concentration, favorable specificity for the influence from coexistent ions (Mo(VI), Mn(VII), Cl-, Cr(III), etc), and passable recyclability. Following the surpassingly fitting with Langmuir isotherm model, its maximum capacity reaches 714.29 mg g-1 at 30 degrees C. The removal performance is essentially in agreement with the pseudo-second-order kinetics, simultaneously, suffers the rate-limiting impact depending on intra-particle diffusion process. In brief, this newly developed chelating resin presents an effective means with regard to the Cr(VI)-wastewater treatment or other uses in the future. (c) 2021 Elsevier Inc. All rights reserved.

Automated summary

The facile fabrication of ultra-high-performance adsorbent can effectively improve Cr(VI) pollution elimination in sewage control. The PPTA-3 microspheres exhibit outstanding synergistic adsorption and reduction results for Cr(VI), showing close to 100% removal efficiency and favorable specificity for coexistent ions.