A Novel Biosorbent Based on Amorphous Nanocellulose Synthesized by Comamonas Terrae YSZ Chemically Modified for Enhanced Copper Ions Removal

ABSTRACT

Copper (Cu) is a highly toxic heavy metal that is released into the environment and requires an efficient removal method. In this study, we report the incorporation of calcium carbonate (CaCO ₃ ) into amorphous bacterial nanocellulose (BNC) to study its effectiveness in the adsorption of Cu ²⁺ . The Fourier Transform Infrared Spectroscopy (FTIR) results of the modified BNC (BNC‐M) showed the stretching at 1403.26 cm ⁻¹ and bending at 874 and 743 cm ⁻¹ of carbonate groups, confirming the successful incorporation of CaCO ₃ into the BNC. The BNC‐M attained better Cu ²⁺ removal, with a maximum of 50.3% compared to native BNC with 5.0% at an initial concentration of 100 mg/L in 2 h. Thermodynamic analysis confirmed a spontaneous and exothermic process (ΔH° = −10.20 kJ mol ^{− 1} ). The Cu ²⁺ adsorption fitted well with the Langmuir isotherm and pseudo‐second‐order model for both BNC and BNC‐M, respectively. Optimization of BNC‐M under different parameters resulted in a 1.7‐fold increase in Cu ^{2 +} ion removal efficiency compared to nonoptimized BNC‐M, achieving a maximum removal of 86.4% at an initial concentration of 100 mg/L. The regeneration‐desorption study of the optimized BNC‐M adsorbent demonstrated good recyclability. This study reveals that BNC with CaCO ₃ modification can potentially be a new adsorbent for Cu ²⁺ removal.