Transport of Cr„ VI… in Soils Contaminated with Chromite Ore Processing Residue „ COPR…

This study investigates the leaching behavior of chromium from soils contaminated with chromite ore processing residue (COPR). The primary objective was to understand the factors that influence chromium (Cr) leaching in order to address environmental concerns associated with this contaminant. A series of leaching experiments were conducted using acrylic columns filled with contaminated soil, simulating rainwater as the influent solution to create oxidative conditions. The experiments were performed at temperatures ranging from 3 to 38°C, with specific attention given to the pH of 4.3. Results indicated that the mass of leached Cr(VI) was significantly affected by temperature, with an acceleration of leaching observed above 8°C. The total mass of Cr leached varied between 0.206 and 0.260 mg/g, accounting for approximately 1% of the total Cr content in the soil sample. Additionally, a one-dimensional transport model was employed to simulate the leaching process, revealing that the dynamics were governed by adsorption/desorption mechanisms and were influenced by redox reactions. This research provides valuable insights into the environmental risks posed by chromium contamination and highlights the importance of temperature and pH in the leaching process.