Geochemical Characterization of the Spoil Heaps of the Ain Aouda Mine and its Impact on the Soil (Morocco)

Abstract

The exploitation of the Ain Aouda zinc lead mine in the Tazekka massif (Morocco) has abandoned spoil heaps stored directly on a karstified carbonated ground, in the middle of nature, without any means of precaution. The heaps were exposed to the weather agents such as water infiltration and air circulation, which would generate a real source of pollution for the ecosystem. These pollution will inevitably produce effluents that can be loaded with metals and metalloids, which will have a significant negative influence on the soil and the environment. In this regard, the objective of this study is to confirm the existence of contamination/pollution of soils by the technique of atomic emission spectrometry with inductively coupled plasma, and of spoil heaps by X-ray diffractometry, which confirmed contamination by zinc, arsenic, lead and copper. Their maximum concentration are respectively 19858.800 (ppm), 1280.700 (ppm), 495.750 (ppm), and 328.65 (ppm). Nevertheless, we note that the pH of the majority of soils always remains basic, due to the significant presence of carbonates, the majority of soils are calcareous (15% to 30%) to very calcareous (> 30%). We notice that the phenomenon of neutralization occurs.

Keywords

• calamine
• contamination
• content of zinc
• neutralization
• pollution