超声辅助生物表面活性剂去除污泥中的重金属

Removal of Heavy Metals from Sludge by Ultrasound-Assisted Biosurfactant Leaching

以城市污水污泥为研究对象,采用淋洗法研究了超声辅助生物表面活性剂(皂素)对污泥中重金属的去除率效果。通过火焰原子分光光度法测定污泥中重金属含量,考察了皂素溶液p H值、超声时间、超声功率和皂素浓度对重金属去除率的影响。结果表明:在p H=4,超声功率为100%(40 k Hz),皂素浓度为5%的条件下,处理45 min后,污泥中Cd,Ni,Zn三种重金属的去除率分别达到了58.9%,54.5%和73.0%。使污泥中原超出农用污泥标准的Cd和Zn含量降低到适合农用的范围内。可见,超声能明显强化皂素去除污泥中的重金属。

Experiments of ultrasound-assisted biosurfactant （ saponin） leaching for removing heavy metals from some municipal wastewater sludge were conducted. Contents of heavy metals were determined by flame atomic absorp-tion spectrophotometer, and the effects of saponin solution pH value and concentration, ultrasound time and power on removal of heavy metals were investigated. The results showed that the removal efficiencies of Cd, Ni and Zn in sludge were 58. 9%,54. 5% and 73. 0%, respectively, under the conditions of pH =4, 5% soponin solution, 100%（40kHz） ultrasound power for 45min. Cd and Zn contents in treated sludge were reduced to meet the control standard for pollutants in sludge for agricultural use. It was proved that ultrasound could effectively strengthen saponin leaching of heavy metals from sludge.