Comprehensive characterization for efficient adsorption of Tetracycline from wastewater from the synthesis of nanoparticles by batch and fluidized bed column

Abstract

A novel cost-effective reactive adsorbent, WS/MgONPs, composed of walnut shells (WS) and magnesium oxide nanoparticles (MgONPs) prepared from magnesium acetate tetrahydrate, as verified by FE-SEM, EDX, BET, FTIR, and XRD studies. Was synthesized and shown excellent removal of tetracycline (TEC) from wastewater. The synthesized WS/MgONPs performed various batch and fluidized bed column studies to ascertain the optimal employed parameters. Results showed that WS/MgONPs adsorption capacity increases with the concentration gradient. A 0.07 g of the adsorbent was proven sufficient to remove >87.4% of TEC initial dose of 50 mg/L in 1000 mL of deionized water with an agitation speed of 200 rpm for 70 min. The adsorption isotherms conformed to both the Langmuir and Freundlich models, but the Langmuir model exhibited a more accurate fit to experimental data, with loading capacity determined to be 216.511 mg/g at pH 7 and 25°C, while the pseudo-second-order model most accurately characterized the absorption kinetics, obtaining a rate constant of k₂ = 0.0025 g/mg min. Fluidized bed columns with various operational conditions were used, the minimum fluidization velocity (V_mf) of the bed was influenced by flow rate (Q), bed height (H_S), and initial concentration (C_o). Experiments work revealed that decreasing flow rate and concentration of TEC, while enhancing the sorbent mass, substantially extended the effective lifetime of the synthesis sorbent inside the fluidized bed column. The observed breakthrough curves were optimally fitted using the Thomas (TH) model, which yielded the greatest R² values with the minimal sum of squared errors (SSE). Finally, the results obtained highlight the novel synthesized WS/MgONPs exceptional effectiveness and eco-friendly in addressing TEC in pharmaceutical wastewater, establishing it as a viable option for sustainable and economical wastewater treatment solutions. This study provides significant insights into the creation of improved adsorption materials for pharmaceutical adsorption in wastewater treatment.