Effect of oxygen limitation on solid-bed bioleaching of heavy metals from contaminated sediments.

摘要: Abstract The effects of oxygen limitation on solid-bed bioleaching heavy metals (Me) were studied in a laboratory percolator system using contaminated sediment supplemented with 2% elemental sulfur (So). Oxygen was realized by controlling the gas flow and concentration aeration gas. supply varied between 150 0.5 mol O 2 S o - 1 over 28 d leaching. Moderate led to temporarily suppression acidification, rate sulfate generation Me solubilization. Lowering resulted retarding acidification period three weeks poor Oxidation So occurred even under strong at low rate. High surplus necessary for almost complete oxidation added So. maximum solubilization reached an 7.5 . Thus, input during can be reduced considerably without loss metal removal efficiency. consumption rates, ranging from 0.4 × 10−8 0.8 × 10 8 kg dm s , are primarily attributed high reactivity flower tolerance indigenous autotrophic bacteria concentrations. related calculated assuming molar yield coefficient Y / 1.21. conversion degree, defined as part feed consumed oxidation, increased 0.7% 68% when