Bacterial cellulose microfilament biochar-architectured chitosan/polyethyleneimine beads for enhanced tetracycline and metronidazole adsorption.

This study investigates the potential applications of incorporating 2D bacterial cellulose microfibers (BCM) biochar into chitosan/polyethyleneimine beads as a semi-natural sorbent for the efficient removal of tetracycline (TET) and metronidazole (MET) antibiotics. Batch adsorption experiments and characterization techniques evaluate removal performance and synthesized adsorbent properties. The adsorbent eliminated 99.13 % and 90 % of TET and MET at a 10 mg.L concentration with optimal pH values of 8 and 6, respectively, for 90 min. Under optimum conditions and a 400 mg.L concentration, MET and TET have possessed the maximum adsorption capacities of 691.325 and 960.778 mg.g, respectively. According to the isothermal analysis, the adsorption of TET fundamentally follows the Temkin (R = 0.997), Redlich-Peterson (R = 0.996), and Langmuir (R = 0.996) models. In contrast, the MET adsorption can be described by the Langmuir (R = 0.997), and Toth (R = 0.991) models. The pseudo-second-order (R = 0.998, 0.992) and Avrami (R = 0.999, 0.999) kinetic models were well-fitted with the kinetic results for MET and TET respectively. Diffusion models recommend that pore, liquid-film, and intraparticle diffusion govern the rate of the adsorption process. The developed semi-natural sorbent demonstrated exceptional adsorption capacity over eleven cycles due to its porous bead structure, making it a potential candidate for wastewater remediation.