曝气强度对城市污泥重金属生物沥滤过程的影响研究

以氧化亚铁作为底物，氧化亚铁硫杆菌（Thiobacillusferrooxidans）为主要沥滤微生物，在底物投配比为10 g/L，温度为25℃，污泥浓度为123g/L的条件下，采用5种不同曝气强度对桂林城市污泥中重金属进行生物沥滤试验。结果表明，生物沥滤的经济曝气强度宜控制在每升污泥0.4L/（min·L），沥滤3 d后，污泥中超标元素Cu、Zn和Cd的去除率分别达到62.53%、67.80%和54.63%，沥滤处理后污泥中残余重金属含量符合污泥农用的国家标准。

Effect of aeration rate on bioleaching heavy metal from sewage sludge

In this research, sewage sludge taken from Guilin Wastewater Treatment Plant(WWTP) was se-lected as cultivation medium for the growth of Thiobacillus fenooxidans. Ferrous sulfate( FeSO_4·7H_2O) as ener-gy substrate was added into sludge. Bioleaching systems with five different aeration rates were controlled under the same conditions; substrate dosage 10 g/L, temperature 25 ℃ and concentrations of sewage 12. 3 g/L. The ex-perimental results showed that the aeration rate controlled at 0.4 L/(min · L)was suitable. After three days' operation, the removal rates of Cu, Zn and Cd in fresh sludge were 62. 53% , 67. 8% and 54. 63% respectively. The residual contents of the three metals in treated sludge also accorded with the national criterion for sludge land use.