Adsorptive removal of eriochrome black T from aqueous solution by using polypyrrole Carica papaya peel nanobiocomposite

In the present study, a Polypyrrole Carica papaya Peel Nanobiocomposite (PPy/PPNBC) was synthesized via chemical oxidative polymerization and characterised using FTIR, BET, SEM, and thermal (TG/DTG/DSC) techniques. Unlike conventional adsorbents that often face limitation in cost, sustainability, and reusability, the incorporation of waste derived from waste Papaya peel with conductive polypyrrole yielded a low cost, ecofriendly composite with enhanced surface activity. Under optimised conditions pH 2, 80 mg adsorbent dose, 60 mg/L initial dye concentration and 90 minutes contact time the adsorbent achieved a maximum dye removal efficiency of 93.91%. Kinetic data conformed best to the pseudo-second-order model, while equilibrium data fitted well with Freundlich isotherm suggesting multilayer adsorption on a heterogeneous surface. Importantly, the composite maintained high removal efficiency over four consecutive cycles, demonstrating superior durability compared to typical biomass or polymer-based adsorbents. These findings highlight the potential of PPy/PPNBC as a cost effective, ecofriendly, sustainable and high performance adsorbent, bridging waste valorization for treatment of dye-contaminated wastewater contributing to green remediation strategies.