Abstract:

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

Key words: lead, acid mine drainage, heavy metals contamination, environmental geochemistry, Dabaoshan mine, Guangdong