Effective Adsorption of Diclofenac Sodium from Wastewater by Nanocellulose/Alum/Chitosan/Polyethyleneimine Biohybrid Aerogel Beads Adsorbent

In this work, a novel nanocellulose/alum/chitosan/polyethyleneimine biohybrid aerogel (NACPBA) beads adsorbent was successfully prepared to remove diclofenac sodium (DS) from wastewater. The NACPBA beads adsorbent was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometer, and Brunauer–Emmett–Teller. A possible adsorption mechanism was also discussed. The experimental results showed that the adsorption process was followed by a pseudo-second-order kinetic model and Sips isotherm model with the calculated maximum adsorption capacity of 321.3 mg/g on DS. It was much higher than most of the previously reported works. The adsorption capacity of NACPBA beads on DS was increased rapidly within 120 min, especially in the first 60 min. Furthermore, after five regeneration cycles, NACPBA still retained a good adsorption capacity of 103.7 mg/g with a removal efficiency of 50%. Moreover, 95.4% of DS was removed from river water (simulated 5 mg/L DS-contaminated wastewater). The possible adsorption mechanism was primarily governed by electrostatic attractions and hydrogen bond interactions.