Augmented Efficacy of Rubber Wood Sawdust Biochar and Polypyrrole Composite for the Sequestration of Ciprofloxacin from Aqueous Solution

ABSTRACT Fluoroquinolone (FQs) antibiotics are emerging organic contaminants in aquatic environments, with significant toxic effects on ecosystems and human health due to their residual presence in marine environment. This study aims to create a novel alkali‐modified natural rubber wood sawdust biochar/polypyrrole (NARSB/PPy) composite for the sequestration of ciprofloxacin (CIP), a FQ from an aqueous matrix. Agglomerated pseudo‐spherical, crystalline NARSB/PPy particles act as effective adsorbents. The surface area and pore volume of NARSB/PPy were determined as 97.63 m 2 /g and 0.23 cm 3 /g, respectively. Under optimal conditions (pH 6.0, adsorbent dose of 1.0 g/L, and initial CIP concentration of 10 mg/L, contact time of 120 min), NARSB/PPy composite exhibited a removal efficiency of 96.72% for CIP, surpassing NARSB, which achieved 85.97% removal at pH 6.0. The adsorption process follows pseudo‐second‐order kinetics, and the Langmuir isotherm provides an excellent fit ( R 2 = 0.990) with a maximum capacity of 76.34 mg/g. The adsorption of CIP onto NARSB/PPy is primarily governed by electrostatic attraction, hydrogen bonding, and π–π stacking. Isotherm and kinetic studies indicate monolayer chemisorption, confirming its strong potential for CIP removal from aqueous solutions. Stability analysis further demonstrated that the NARSB/PPy composite can be effectively reused for multiple cycles of CIP adsorption.