Simulation of Heavy Metals Migration in Soil of Rare Earth Mining Area

Abstract

The study of heavy metal interactions with soils under specific climatic circumstances might lead to a better understanding of heavy metal migration and provide further information for local pollution control. In this work, we collected soil samples from the world's largest light rare earth mining district, Bayan Obo mine district, and assessed the heavy metal content in the soil at various depths. The extraction effectiveness of Diethylenetriaminepentaacetic acid (DTPA) and Toxicity Characteristic Leaching Procedure (TCLP) for heavy metals in surface soil were compared. Furthermore, we studied the longitudinal transport of heavy metals under precipitation conditions using simulated experiments and kinetic fitting. We discovered that pH has a significant impact on heavy metal release. Precipitation easily transports Zn, Pb, and Cr to deeper layers of the soil. The modified Elvoich equation could better describe heavy metal release patterns.

Keywords: mine soil, heavy metals, leaching, migrate, curve fitting