地学前缘 ›› 2008, Vol. 15 ›› Issue (6): 74-82.

• 论文 • 上一篇    下一篇

酸性矿山废水中生物成因次生高铁矿物的形成及环境工程意义

  

  1. 南京农业大学 资源与环境学院环境工程系,江苏 南京 210095

  • 出版日期:2008-06-20 发布日期:2008-06-20
  • 作者简介:周立祥(1965—),男,教授,博士生导师,主要从事环境矿物材料、环境微生物、环境工程等方面研究。Email: lxzhou@njau.edu.cn
  • 基金资助:

    国家自然科学基金项目(20677028)

Biogenic iron oxyhydrosulfate and iron oxyhydroxide occurring in acid mine drainage and  their environmental engineering implications

  1. Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China

  • Online:2008-06-20 Published:2008-06-20

摘要:

酸性矿山废水(acid mine drainage, AMD)是一类pH低并含有大量有毒金属元素的废水。AMD及受其影响的环境中次生高铁矿物类型主要包括羟基硫酸高铁矿物(如黄铁矾和施威特曼石等)和一些含水氧化铁矿物(如针铁矿和水铁矿等),而且这些矿物在不同条件下会发生相转变,如施氏矿物向针铁矿或黄铁矾矿物相转化。基于酸性环境中生物成因次生矿物的形成会“自然钝化”或“清除”废水中铁和有毒金属这一现象所获得的启示,提出利用这些矿物作为环境吸附材料去除地下水中砷,不但吸附量大(如施氏矿物对As的吸附可高达120 mg/g),而且可直接吸附As(III),还几乎不受地下水中其他元素影响。利用AMD环境中羟基硫酸高铁矿物形成的原理,可将其应用于AMD石灰中和主动处理系统中,构成“强化微生物氧化诱导成矿石灰中和”的联合主动处理系统,以提高AMD处理效果和降低石灰用量。利用微生物强化氧化与次生矿物晶体不断生长的原理构筑生物渗透性反应墙(PRB)并和石灰石渗透沟渠耦联,形成新型的AMD联合被动处理系统,这将有助于大幅度增加处理系统的寿命和处理效率。此外,文中还探讨了上述生物成因矿物形成在AMD和地下水处理方面应用的优点以及今后需要继续研究的问题。

关键词: 嗜酸性氧化亚铁硫杆菌;酸性矿山废水;羟基硫酸高铁矿物;砷;地下水;石灰中和法

Abstract:

Acid mine drainage (AMD) generated through the oxidation of pyrite facilitated by Acidithiobacillus ferrooxidans has a lower pH and contains relatively high contents of heavy metals as well as Fe and SO2-4. Iron oxyhydrosulfate and iron oxyhydroxide, commonly found in acid mine drainage (AMD) and in waters polluted by AMD, play important roles in the attenuation or scavenging of toxic elements. These ferric iron precipitates include jarosite, schwertmannite, goethite, ferrihydrite, etc. In the light of the formation process of biogenic ferric iron oxyhydrosulfate in AMD and its role in scavenging of Fe, SO2-4 and toxic metals, the biogenic minerals could be considered an effective adsorbent for arsenic removal of Ascontaminated groundwater because biogenic ferric iron oxyhydrosulfate especially schwertmannite is of extreme high adsorption capacity for As(III) up to 120 mg/g. For enforced AMD treatment, the ferrous iron biooxidation and ferric iron oxyhydrosulfate formation process by Acidithiobacillus ferrooxidans could be introduced into a conventional lime neutralization active treatment system to form a twostep treatment approach including enforced biooxidation and biogenic minerals formationlime neutralization, which will reduce drastically the amount of lime needed and improve the separation of precipitate and the purification of water. In addition, Acidithiobacillus ferrooxidansloaded biological permeable reaction barrier (bioPRB), in which ferrous iron oxidation and secondary biogenic minerals formation will be able to occur, is designed and applied to AMD passive treatment system with limestone drains to constitute a new treatment model. This can increase the longevity of limestone drains in treating acid mine drainage containing high concentrations of iron and heavy metal. Among others, the advantages of secondary biogenic mineras formation applied in the treatment for AMD or Ascontanminated groundwater are also discussed. Furthermore, the future research topics are proposed.

Key words:

Acidithiobacillus ferrooxidans; acid mine drainage; iron oxyhydrosulfate; arsenic; underground water; lime neutralization

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