Experimental investigation of pyridine removal using vulcanized oil shale

Abstract

The study systematically conducted orthogonal and univariate experiments to determine the optimal parameters for pyridine removal using vulcanized oil shale. The findings revealed that the key determinants of pyridine adsorption onto vulcanized oil shale included the pH level of the pyridine solution, contact time, initial pyridine concentration, and the quantity of vulcanized oil shale introduced into the system. Under optimal adsorption conditions, the vulcanized oil shale achieved a 48.00% adsorption efficiency and an equilibrium adsorption capacity of 4.83 mg·g⁻¹. In contrast, the untreated oil shale exhibited a comparatively reduced adsorption efficiency of 22.88% under its respective optimal conditions. The research further examined the adsorption kinetics and isothermal adsorption models for both types of oil shale. The kinetic data indicated that pyridine adsorption followed a pseudo-second-order model. The pyridine adsorption isotherms for both oil shale and vulcanized oil shale were best described by the Freundlich model, compared to the Langmuir model. These findings provide significant insights into the utilization of vulcanized oil shale for the efficient treatment of low-concentration pyridine wastewater, potentially contributing to environmental remediation and pollution control strategies.