河流沿岸环境对粤北大宝山矿废水锰污染的环境响应

Environmental Response to Manganese Contamination of Dabaoshan Mine in Environmental System of Lower Reaches

粤北大宝山铁多金属矿床的开发给环境带来了严重的危害。采选产生的废液及固体废弃物堆积的淋滤酸水,携带大量重金属离子排入下游河道,严重危害矿区及其酸水流域的生态环境。从尾砂、水体、河底沉积物、土壤以及食用蔬菜等方面探讨整个环境系统对Mn的环境响应。结果表明,河流水中高含量Mn直接源于尾砂,并受水体pH的显著影响;在高pH时,河底沉积物能够大量聚集水体中的Mn,并稳定存在。在水体pH值降低时,Mn会被再次从河底沉积物中释放出来,形成河流二次污染;土壤中Mn含量和土壤pH值有良好正相关关系;在蔬菜中Mn含量与根系土中Mn总量关系不明显,这与植物对Mn的吸收利用有关。

Mining activities in Dabaoshan Mine have caused severe soil environment changes. The acid mine water and heavy metals ions drained directly into the Hengshihe river, which contaminated the ecological environment along the river severely. The paper regarded ore field, soils, deposits, water and plants as whole ecosystem, investigated environmental responses of whole ecosystem to acid mine drainage and heavy metals ions. The high concentration of manganese in river water came from the tailing, and was affected distinctly by the pH value of water. Manganese of water can be accumulated stably in river deposits in high pH value water, but it should be released from the deposits when the pH value of water decreases, the secondary contamination was formed. The concentration of manganese in soils is affected by pH value and granularity of soils. The manganese concentration in plants does not correlate with that in soils.