Development and Evaluation of a Purely Pelletized Adsorbent for Remediating Real Polluted Urban Runoff via Continuously Operated Column Studies

The current work aims to develop and evaluate the capability of a new natural composite, pelletized adsorbent made from activated carbon, zeolite, and bentonite clay for remediating real polluted urban runoff via continuously operated column studies. Continuous-flow column studies, designed by using up-flow and gravity-flow systems, were carried out for the adsorption experiment. The adsorbent was characterized in terms of physicochemical characteristics. Kinetic adsorption data were analyzed using four kinetic models: the Pseudo-first order (PFO), fractional power (FP), Pseudo-second order (PSO), and Syafiuddin (SYF), which were then compared by using six statistical indicators and residual analysis. The adsorbent made from activated carbon (10%), zeolite (20%), and bentonite clay (70%), heated at 400 °C, provided the best physical stability (without deformation) compared to other adsorbent compositions. In addition, adsorption by gravity flow effectively removed turbidity by 83.35%, while up-flow removed turbidity by 64.64%. FTIR analysis of the adsorbent showed the presence of Si–O–Si functional groups of siloxane compounds, which contribute to pollutant adsorption. Kinetic analysis revealed that the PFO model was identified as the most suitable model for predicting the up-flow adsorption data, while the FP model performed well for gravity-flow adsorption.