表面活性剂强化污泥生物淋滤Cu、Zn的研究

通过接种经Tween-80驯化培养的污泥混合硫杆菌,研究了不同浓度表面活性剂Tween-80对污泥生物淋滤过程中重金属Cu、Zn溶出效果的影响.同时探讨了Tween-80对混合硫杆菌氧化元素硫能力的影响.结果表明,投加0.5~8.0g/L Tween-80能促进硫杆菌氧化元素硫,并随着投加量的增加,元素硫的氧化率提高.但是在污泥生物淋滤实验中,随着Tween-80投加量增加,这种促进作用先加强后被抑制.Tween-80最佳投加量为6.0g/L,这时元素硫的生物氧化率显著提高,污泥酸化加快,经过8d的淋滤,Cu和Zn的淋滤效果可达到最佳,溶出率分别为91.9%和90.4%,而对照组在第10d淋滤效果达到最佳,分别为80.1%和85.2%.但是当Tween-80浓度大于6.0g/L时,硫杆菌的生长和繁殖受到抑制,使生物淋滤反应速度减缓,去除效率较低.

Surfactant-enhanced bioleaching of Cu and Zn from sewage sludge

The effect of surfactant Tween-80 on the bioleaching of sewage sludge with indigenous sulfur-oxidizing bacteria cultured by Tween-80 was examined. The effect of Tween-80 on the sulfur oxidizing capacity of the bacteria was investigated. The dosage of Tween-80 in 0.5~8.0 g/L was favorable for the bio-oxidation of elemental sulfur. With the increaseing of Tween-80, the utilization of sulfur enhanced. Sulfur utilization grew at first and then fell with the increase in the dosage of Tween-80 in the bioleaching experiment. The optimal concentration of Tween-80 was 6.0g/L, under the condition, sulfur oxidation and sludge acidification were enhanced and the dissolution rate of Cu and Zn were 91.9% and 90.4% after 8 d of bioleaching. In contrast, only 80.1% Cu and 85.2% Zn were extracted from the control without Tween-80. However, when the concentration of Tween-80 was higher than 6.0g/L, the growth and proliferation of sulfur-oxidizing bacteria would be restrained and the metal solubilization would also slow down.