Evaluation and optimization of a new microbial enhancement plug-flow ditch system for the pretreatment of acid mine drainage: semi-pilot test. Issue 2 (3rd January 2018)

• Record Type: Journal Article
• Authors: Song, Yongwei; Wang, Heru; Yang, Jun; Zhou, Lixiang; Zhou, Jingcheng; Cao, Yanxiao
• Is Part Of: RSC advances. Volume 8:Issue 2(2018)
• Page Start: 1039
• Page End: 1046
• Publication Date: 2018-01-03
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra10765j
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Acid mine drainage (AMD) is typically characterized by low pH, a high concentration of sulfate and dissolved heavy metals. Abstract : Acid mine drainage (AMD) is typically characterized by low pH, a high concentration of sulfate and dissolved heavy metals. Therefore, it is of practical significance to promote the transformation of soluble Fe and SO4 2− into iron hydroxysulfate minerals by biomineralization of Acidithiobacillus ferrooxidans . This enhances the lime neutralization efficiency of AMD by reducing the production of ferric hydroxide and waste gypsum. In this study, a new microbial enhanced plug-flow ditch reaction system was developed for the pretreatment of AMD on a semi-pilot scale. System stability under different hydraulic retention times (HRTs) was examined and the effects of microbe enhancement-lime neutralization technology and direct lime neutralization technology were compared. The bio-oxidation efficiency of Fe 2+ (5 g L −1 ) reached 100% in some parts of the system when HRT was 3 and 2 days, and the time taken to reach steady state was 6 and 4 days, respectively. When the HRT was 1 day, the reaction system had operated for 4 days before the equilibrium was lost. At the optimum HRT (2 days) and after the system was stable, the average precipitation rate of total Fe was 53.62% and the average removal rate of As(iii ) was 17.27%. Following microbial enhanced pretreatment, the amount of lime required and waste residues generated for AMD neutralization decreased by 75.00% and 85.25%, respectively. This result supports the application of microbial enhancement-lime neutralization passive treatment technology for AMD.