Abstract:

       Mining activities have caused severe soil environmental changes in Dabaoshan Mine, Guangdong provence, Southern China. The acid mine drainage and heavy metal ions drained directly into the Hengshihe river, which contaminated the ecological environment along the river severely. The tailings, soils, sludges, water and plants are regarded as a whole ecosystem,  and the environmental responses of the whole ecosystem to the acid mine drainage and heavy metal ions were investigated. The high lead concentration in river water was caused by the tailings, and was affected distinctly by the pH value of the water. The river sludges can stably accumulate lead of water in high pH value water, but it could be released from the deposits when the pH value of water became low, which caused the secondary contamination. The lead concentration in soils is affected by the pH value and the granularity of soils. The high lead concentrations in plants is related to the total lead in soils, and affected by the pH value of soils; increasing soil pH value by improving irrigation water quality can reduce the lead concentrations in plants.

Key words:

lead; acid mining drainage; environmental geochemistry; Dabaoshan mine