广东大宝山矿区生态环境退化现状及治理途径探讨

Guangdong Dabaoshan Mine: ecological degradation, acid drainage and possible measures for their Remediation

根据对广东大宝山矿区的实地调查、测试和所采集土、水样品的化学分析结果,对该区生态环境退化和向下游排放污染物现状进行报道。矿坑似乎是大宝山矿最重要的污染源地,据有限土壤样品分析结果推算,当其所含无机还原态硫彻底氧化后,平均1 t矿坑表土可产出207 kg浓硫酸。大部分矿坑表土和排土场废土已经历不同程度的酸化。实验室模拟试验显示:5 g强烈酸化的矿坑表土在接力水提条件下可产出超过750 mL的酸性“矿水”(pH<3.9)。实测数据表明:排入翁江支流的矿水,其酸度大大超过国家规定的排放标准,大多数重金属元素的浓度也超过了国家规定的污水综合排放标准的最高允许值。从技术的角度来看,对大宝山矿区生态环境退化和向下游排放污染物状况的治理,宜采用环境地球化学工程与生物修复技术相结合的综合治理方法。

This article reports the ecological degradation and off-site environmental impacts of acid drainage in Guangdong Dabaoshan Mine, based on field observation and measurements, and laboratory analysis of the water and soil samples collected from the site. The results show that the open pits are major acid sources for acid mine drainage. At the time of field measurements, the mine water discharging into a tributary of the Wengjiang River had a pH of 3.36 at the Mud Containment Dam (MCD). Concentrations of most heavy metals exceeded the permitted levels of waste water discharge stated in the National (P.R. China) Standards for Integrated Waste Water Discharges (GB8978-1996) even at a point of about 3.5 km downstream of the Mud Containment Dam. From a technical point of view, remediation of this minesite requires a combination of geochemical engineering and bioremediation technologies.