Optimizing Parthenium waste: biomass-derived carbon adsorbents for adsorbing Amido Black 10B dye analyzed through graph theory for stability and reactivity

This study investigates the feasibility of using Parthenium hysterophorus biomass as a low-cost adsorbent for the removal of Amido Black 10B dye from aqueous solutions. Raw biomass from Parthenium flowers (RPF) and activated (PFAC) was tested in batch experiments under various conditions, including adsorbent doses (0.02–0.1 g/L), pH levels (2–12), initial dye concentrations (50–500 mg/L), and contact times (5–30 min) at 298 K. Comprehensive characterization using FTIR, XRD, SEM, EDS, and pH_PZC confirmed the adsorbent’s properties and its potential for corrosion inhibition. The adsorption process was analyzed using isotherm models (Langmuir and Freundlich) and kinetic models. Electrochemical tests assessed the untreated and treated biomass’s adsorption capabilities on metal surfaces with efficiencies (η %) 66.08 and 78.82 for RPF and PFAC respectively. Von’t Hoff plots show that the ΔG is − 3.34, 3.98, and − 3.91 kJ/mol respectively at three different temperatures; ΔS is − 28.22 kJ/mol; and ΔH is − 17.87 kJ/mol. The structural stability and reactivity of the adsorbent were further analyzed using graph theory maximum eigen value of RPF 2.4892 and PFAC 2.0799.

Graphical Abstract