Fixed-Bed Adsorption of Industrial VOCs onto Sludge-Based Spherical Activated Carbon: Performance, Operational Parameters, and Breakthrough Curve Modeling

Industrial volatile organic compounds (VOCs) pose severe threats to occupational health and ecosystems. Herein, sludge-based spherical activated carbon (SBSAC) was employed for VOC adsorption in a fixed-bed column. The impacts of inlet flow rate (100–500 L/h), inlet concentration (200–400 mg/m 3 ), temperature (15–35 °C), and bed height (80–160 mm) on adsorption performance were investigated. Kinetic, isothermal, and thermodynamic models were applied to elucidate adsorption mechanisms. At 25 °C, 300 L/h, 300 mg/m 3, and 120 mm bed height, SBSAC achieved a specific adsorption capacity of 4.28 mg/g. Distinct from conventional empirical models, an axial dispersion model was constructed and solved via MATLAB ode15s and ls q curvefit function for breakthrough simulation and performance prediction. It delivers accurate breakthrough curves and derives axial dispersion and mass-transfer coefficients for scale-up. This work provides a sustainable strategy for VOC abatement and waste sludge valorization, as well as a robust modeling framework for fixed-bed adsorption systems.