| 摘要 |
<p>Removal of divalent Fe from underground or surface water is effected by partially oxygenating the water and passing it through a bed of specific autotrophic bacteria supported on a filter medium, with the improvement that the amt. of O2 dissolved in the water is controlled in inverse proportion to the pH of the water. The improvement prevents physicochemial pptn. of basic ferric salts, which is less efficient than biological oxidn. The maximum dissolved O2 content should be 7 mg/l. at pH 7, 2 mg./l at pH 7.1, 0.5 mg/l. at pH 7.2, and 0.1 mg/l. at pH 7.3 or higher. These O2 levels can be achieved by percolating the water through the biological filter bed, aerating the effluent water to satn. point, and recycling the O2-satd. water for mixing with the incoming water in an amt. controlled in response to the pH of the incoming water.</p> |
