| Abstrakt: |
The release of heavy metals from functional mines can result in significant environmental pollution, posing a threat to both soil and water quality. Therefore, it is crucial to characterize the chemical and physical properties of mine tailings to assess the potential risk of toxic heavy metal mobility in the environment. In this study, the chemical forms of Cd, Cu, Pb, and Zn in the tailings of Draa Sfar mine in Marrakech (Morocco) were investigated using standard sequential extraction and Atomic Absorption Spectrophotometric techniques. Results indicate that mining residues exhibit a highly acidic pH (2.9), low carbonate content (0.5%), and high electrical conductivity (7.2 mS/cm) due to significant soluble salts, particularly sulfates (3.7%). Assessing metal speciation indicated Cd's high availability in short-term mobile fractions (42%), while Cu primarily associated with soluble and exchangeable fractions (32%). Pb showed strong association with long-term mobile fractions (61%), and Zn displayed an equal distribution among mobile and lithogenic fractions. Acid-base accounting test results reveal a lower Neutralization Potential (196.4t CaCO3/kt) compared to Acid Potential (306.3t CaCO3/kt), indicating a negative Net Neutralization Potential and suggesting potential acid mine drainage. This result demonstrates that DraaSfar mining residues possess a lower acid-consuming capacity, primarily driven by their carbonate content, compared to their acid-generating capacity. This finding indicates that these mining residues have the potential to become sources of acid mine drainage, and underscore the importance of implementing sustainable mining practices and mitigation strategies to reduce environmental impact. [ABSTRACT FROM AUTHOR] |
