Improvement of sludge dewaterability and removal of sludge-borne metals by bioleaching at optimum pH
Improvement of sludge dewaterability and removal of sludge-borne metals by bioleaching at optimum pH
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在最佳 pH 值下通过生物浸出改善污泥脱水性并去除污泥中的金属
DOI：
10.1016/j.jhazmat.2012.04.028
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发表时间：
2012-06-30
影响因子：
13.6
通讯作者：
Wang, Dianzhan
中科院分区：
文献类型：
--
作者：
Liu, Fenwu;Zhou, Lixiang;Wang, Dianzhan
众所周知，生物浸出过程中能量物质的生物氧化引起的生物酸化在改善污泥中金属去除方面发挥着重要作用。在这里，我们报告生物浸出还可以在合适的 pH 水平下大大提高污泥的脱水能力。为获得生物浸出过程中污泥脱水性能的最佳能量物质初始浓度和pH值，研究了Acidithiobacillus thiovioletans TS6和Acidothiobacillusiferrohabitans LX5共接种下Fe2+和S-0的生物氧化及其对污泥生物浸出过程中污泥脱水性能和金属去除的影响。结果表明，2 g/L S-0和2 g/L Fe2+的能量物质投加量可使Fe2+生物氧化效率达到100%，S-0生物氧化效率达到50%，是污泥生物浸出的最佳投加量。污泥中的铜和铬的去除率分别达到85%和40%以上，当污泥pH值通过生物浸出降至2.4左右时，生物浸出污泥的毛细管吸入时间（CST）从新鲜污泥最初的48.9秒降至约10秒。这些结果证实了生物浸出作为改善污泥脱水性和去除金属的新方法的潜力。 (C) 2012 Elsevier B.V. 保留所有权利。
Bio-acidification caused by bio-oxidation of energy substances during bioleaching is widely known to play an important role in improving sludge-borne metals removal. Here we report that bioleaching also drastically enhances sludge dewaterability in a suitable pH level. To obtain the optimum initial concentrations of energy substances and pH values for sludge dewaterability during bioleaching, bio-oxidation of Fe2+ and S-0 under co-inoculation with Acidithiobacillus thiooxidans TS6 and Acidothiobacillus ferrooxidans LX5 and their effects on sludge dewaterability and metals removal during sludge bioleaching were investigated. Results indicated that the dosage of energy substances with 2 g/L S-0 and 2 g/L Fe2+ could obtain bio-oxidation efficiencies of up to 100% for Fe2+ and 50% for S-0 and were the optimal dosages for sludge bioleaching. The removal efficiencies of sludge-borne Cu and Cr could reach above 85% and 40%, respectively, and capillary suction time (CST) of bioleached sludge decreased to as low as similar to 10s from initial 48.9s for fresh sludge when sludge pH declined to similar to 2.4 through bioleaching. These results confirm the potential of bioleaching as a novel method for improving sludge dewaterability as well as removal of metals. (C) 2012 Elsevier B.V. All rights reserved.