混合嗜酸菌浸出污泥中重金属机制判定方法

Determination of the heavy metal leaching mechanism from the sludge by acidophilic bacteria

为判断混合菌种的生物沥浸机制,采用添加沥浸混合菌种+作用底物(硫酸亚铁铵、硫粉)、只添加作用底物和仅加硫酸3组实验,估算直接氧化作用(F11),化学氧化作用(F12)和酸性浸出作用(F13)的贡献率,从而获得混合菌种的重金属浸出机制.针对某污水处理厂剩余污泥的生物沥滤实验结果表明,Cu的浸出过程中F11、F12、F13贡献率分别为92.55%、7.45%、0%,说明混合菌种作用下Cu的浸出机制主要为直接机制;Zn的沥浸作用中F11、F12、F13贡献率分别为18.86%、44.35%、36.79%,判定Zn在混合菌种的作用下为间接机制.该法可在实际环境条件下判定重金属的生物沥浸机制,对相关研究和实际应用提供理论依据.

In order to determine the biological leaching mechanism of mixed strains,three biological leaching-experiments,i.e.,adding leaching mixed strains+substrates(ferrous ammonium sulfate,sulfur powder),addingsubstrates alone andsulfuric acid alone were conducted to estimate the contribution from direct oxidation(F11),chemical oxidation(F12)and acid leaching(F13).These experiments were tested for the excess activated sludge to evaluate the leaching of Cu and Zn.Results show that for the leaching of Cu,the contribution rates of F11,F12,and F13 were 92.55%,7.45%,and 0%respectively,indicating that the primary role of the direct mechanism.For the leaching of Zn,the contribution rates of F11,F12,and F13 were 18.86%,44.35%,36.79%respectively,indicating the dominate role of an indirect mechanism.This method can determine the biological leaching mechanism of heavy metals under actual environmental conditions,and provide theoretical basis for related research and practical applications.