Mining area disturbed by acid mine drainage - Acid Volatile Sulphur and Sequential Extraction studies

摘要

This study investigated the sulfate bacterial reduction process in sediments from a water reservoir (Aguas Claras) and the Antas creek contaminated by metals from acid mine drainage (AMD). The Acid Volatile Sulphur indicated that the bacterial reduction is a relevant process in the natural attenuation of the contamination in the reservoir. However, biological adverse effects are expected for sample S_1 inside the reservoir, that is likely to be toxic whilst for the sediment S4 in the river, the toxicity is uncertain. The extraction procedure (mBCR) indicated that the predominance of the U (0.4%) in the labile fraction as well as the high concentrations of Zn (0.5%) and Mn (0.7%) inside the reservoir raise concerns regarding their availability to the environment. It was observed that the contamination is concentrated in Aguas Claras reservoir.