<p>Even after mine closure, continuous chemical treatment of mine water and proper sludge management remain necessary. Previously, a pilot-scale rapid sand filter (RSF) system was applied to treat manganese-containing circumneutral mine water (21&#xa0;mg/L Mn<sup>2</sup>⁺, pH 7.0) at a mine site, achieving up to 40% Mn removal. In this study, adjusting the inlet water pH to 8.5 and 9.0 increased Mn removal rates to 89.5% and 95.0%, respectively. Although microbial contribution to Mn<sup>2</sup>⁺ oxidation under alkaline conditions is presumed to be minimal, dominant bacterial species on the sand filters were investigated using nanopore sequencing. <i>Stenotrophomonas maltophilia</i>-related bacteria were highly dominant, with relative abundances ranging from 8.83% to 24.5%. After isolating the strain designated AS50Mn from sand filters, its growth and Mn-oxidizing ability were examined under alkaline conditions. As Mn-oxidizing activity was not confirmed at pH 8.5 and 9.0 under the experimental conditions, the strain’s dominance is likely due to traits such as alkaline tolerance and heavy metal resistance.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Characterization of Dominant Bacterial Species on Sand Filters Used for Treating Manganese-Containing Mine Water Under Alkaline Conditions

  • Hiroshi Habe,
  • Tomohiro Inaba,
  • Takuro Nishimura

摘要

Even after mine closure, continuous chemical treatment of mine water and proper sludge management remain necessary. Previously, a pilot-scale rapid sand filter (RSF) system was applied to treat manganese-containing circumneutral mine water (21 mg/L Mn2⁺, pH 7.0) at a mine site, achieving up to 40% Mn removal. In this study, adjusting the inlet water pH to 8.5 and 9.0 increased Mn removal rates to 89.5% and 95.0%, respectively. Although microbial contribution to Mn2⁺ oxidation under alkaline conditions is presumed to be minimal, dominant bacterial species on the sand filters were investigated using nanopore sequencing. Stenotrophomonas maltophilia-related bacteria were highly dominant, with relative abundances ranging from 8.83% to 24.5%. After isolating the strain designated AS50Mn from sand filters, its growth and Mn-oxidizing ability were examined under alkaline conditions. As Mn-oxidizing activity was not confirmed at pH 8.5 and 9.0 under the experimental conditions, the strain’s dominance is likely due to traits such as alkaline tolerance and heavy metal resistance.