The aims of the present study were to measure the concentrations of As, Cr, Co, Fe, and Zn in soils from two heavily industrialized areas and to assess the degree of heavy metal pollution by using the indices enrichment factor and the geo-accumulation index, as well as assessing the potential ecological risk. The concentrations of the selected elements in the environmental samples were determined by the neutron activation analysis. The pollutant concentrations in the studied areas showed that the soils were characterized by a high pollution from As and Cr due to the industrial facilities in the area. The concentrations in the Tuzla industrial area were 79–1215 mg/kg of Cr, 17–84 mg/kg of As, 22,000–54,000 mg/kg of Fe, 101–258 mg/kg of Zn, and 8–23 mg/kg of Co. The results for the Cerkezkoy industrial area were found to be 46–196 mg/kg of Cr, 6–24 mg/kg of As, 17,000–25,000 mg/kg of Fe, 67–136 mg/kg of Zn, and 7–10 mg/kg of Co. The contamination in the soils from heavy metals was assessed based on enrichment factor, geo-accumulation factors, and ecological risk indices. The results were compared with the data from other industrial areas in Turkey. It was found that the metals As and Cr showed higher concentrations in Tuzla than in other examined industrial areas. The results for Cerkezkoy industrial area indicate that the area is not as contaminated as the other industrial areas in Turkey.

The present study involves selenium (IV) adsorption onto organic pillared bentonite using batch experiments and kinetic modeling, at two different temperatures. selenium (IV) remediation in an aqueous environment, such as contaminated drinking water, groundwater, and industrial wastewater, is the aim of this study. The experimental data were tested with both surface reaction-based and diffusion-based kinetic models to clarify the controlling mechanism of the adsorption process from both microscopic and macroscopic point of view. Among all the investigated models, the most appropriate was the pseudo-second-order surface reaction-based kinetics model. The obtained results proved that the adsorption process at a selenium dioxide concentration of 300 mg L⁻¹ is controlled by the diffusion rate of penetrated selenium (IV) into the reacted layer.