Sahinkaya E, Ozkaya B, Kaksonen A H, Puhakka J A
Institute of Environmental Engineering and Biotechnology, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland.
Water Sci Technol. 2007;55(10):269-75. doi: 10.2166/wst.2007.331.
The applicability of fluidised-bed reactor (FBR) based sulphate reducing bioprocess was investigated for the treatment of iron containing (40-90 mg/L) acidic wastewater at 65 degrees C. The FBR was inoculated with sulphate-reducing bacteria (SRB) originally enriched from a hot mining environment. Ethanol or acetate was supplemented as carbon and electron source for the SRB. A rapid startup with 99.9, 46 and 29% ethanol, sulphate and acetate removals, in respective order, was observed even after 6 days. Iron was almost completely removed with a rate of 90 mg/L.d. The feed pH was decreased gradually from its initial value of 6 to around 3.7 during 100 days of operation. The wastewater pH of 4.3-4.4 was neutralised by the alkalinity produced in acetate oxidation and the average effluent pH was 7.8 +/- 0.8. Although ethanol removal was complete, acetate accumulated. Later the FBR was fed with acetate only. Although acetate was present in the reactor for 295 days, its oxidation rates did not improve, which may be due to low growth rate and poor attachment ability of acetate oxidising SRB. Hence, the oxidation of acetate is the rate limiting step in the sulphidogenic ethanol oxidation by the thermophilic SRB.
研究了基于流化床反应器（FBR）的硫酸盐还原生物工艺在65℃下处理含铁（40 - 90 mg/L）酸性废水的适用性。该流化床接种了最初从热采矿环境中富集的硫酸盐还原菌（SRB）。添加乙醇或乙酸盐作为SRB的碳源和电子供体。即使在6天后，也观察到乙醇、硫酸盐和乙酸盐的去除率分别迅速达到99.9%、46%和29%，实现了快速启动。铁几乎被完全去除，去除速率为90 mg/L·d。在100天的运行过程中，进水pH从初始值6逐渐降至约3.7。废水pH为4.3 - 4.4，通过乙酸盐氧化产生的碱度被中和，出水平均pH为7.8±0.8。虽然乙醇被完全去除，但乙酸盐积累。随后仅向流化床反应器中加入乙酸盐。尽管乙酸盐在反应器中存在了295天，但其氧化速率并未提高，这可能是由于乙酸盐氧化SRB的生长速率低和附着能力差。因此，乙酸盐的氧化是嗜热SRB进行产硫化物乙醇氧化的限速步骤。
