Bioadsorption of suspended and dissolved particles from coal washery effluent onto fluted pumpkin seed shell biomass

Fluted pumpkin seed shell, an abundant and inexpensive natural resource in Nigeria, was used as a precursor to adsorbent production for the removal of suspended and dissolved particle (SDP) from initially coagulated coal washery effluent (CWE). Key parameters such as contact time, adsorbent dose, pH and temperature were investigated using batch mode. The adsorption equilibrium, thermodynamics and kinetics of SDP on H₃PO₄ treated shell (FPA) and NH₄Cl treated shell (FPS) were examined at specified temperatures. Equilibrium data sufficiently fit the Langmuir isotherm model (R² > 0.99; SSE < 0.09). The pseudo-second order kinetic model provides the best correlation (R²>0.99;SSE<0.1) with the experimental data. The evaluated ΔG○ and ΔH○ indicate the spontaneous and endothermic nature of the process. This study demonstrates that pumpkin seed shell could be utilized as low cost, renewable, ecofriendly bioadsorbent for the removal of SDP from CWE.