Principal Investigator: Zhou Lixiang 

Funding Received: 2.91 Million RMB

Sponsored by: National Natural Science Foundation of China

Project Period: January, 2017─December, 2021

Brief Introduction:

  Toxic metal-containing acid mine drainages (AMD) generated in many mines are hardly purified by traditional passive limestone ditch treatment system (PLDTS) due to high concentration of dissolved iron and sulphate. In the program, we attempt to use Acidiphilic iron-reducing bacterial (Acidiphilium sp.) to reduce the remaining non-biomineral Fe³⁺ in AMD to Fe²⁺ and then the resulting Fe²⁺ are re-oxidized by Acidithiobacillus ferrooxidans to form schwertmannite with almost 100% of biomineralization efficiency for dissolved iron in AMD through the oxidizing-reducing cycles. Almost all of the dissolved iron and most of the sulfate can be removed and transformed into schwertmannite, a useful environmental material, by virtue of such biomineralization. The effectiveness and mechanism concerning the removal of toxic metal especially for As in AMD by this biomineralization process are also investigated. Furthermore, microorganism adhesion, crystal seed formation and the microorganism-mineral relationship will also be explored for understanding their roles in improving crystal growth of biogenic schwertmannite. Moreover, the effectiveness of PLDTS receiving the effluent of AMD biomineralization unit will be further studied for technology of enhancing the water quality of the final effluent. Finally, a new passive treatment system with biomineralization-limestone ditch neutralization will be designed and constructed.