Efficient and rapid removal of typical phenolic compounds from water with biobased porous organic polymers

Abstract

Removing phenolic compounds from water resources is urgent as they have seriously damaged aquatic ecological equilibrium. In this study, divanillin-based porous organic polymers (DPP) and 2,5-furandicarboxaldehyde-based porous organic polymers (FPP) were prepared from sustainable lignocellulose-derivatized monomers using a one-step synthetic method. The characterization highlighted the large Brunauer–Emmett–Teller (BET) surface area (SBET 513.9 and 772.8 m2∙g−1), mainly mesoporous property (3.4 and 6.5 nm) and high nitrogen content (over 25%) of the obtained DPP and FPP, which rendered them high adsorption affinity toward phenolic pollutants. Specifically, DPP and FPP exhibited the highest adsorption capacity for p-nitrophenol (PNP) (254.2 and 339.4 mg∙g−1) calculated by the Langmuir isotherm model. The porous networks of DPP and FPP enabled fast sorption kinetics for PNP with adsorption equilibrium times of only 8 and 4 min, respectively. Thermodynamic investigation revealed adsorption followed spontaneous and exothermic chemisorption processes. The interaction between the PNP and DPP/FPP mainly involved the synergism of hydrogen-bonding interactions, electrostatic force, and π-π stacking interactions. Furthermore, DPP and FPP exhibited outstanding durability and retained over 78.9% and 81.9% removal efficiency for PNP after ten cycles. Therefore, these biobased materials with high adsorption capacity and rapid adsorption rate show promising application in wastewater treatment.