石英砂提高城市污泥生物沥浸效率主导因素分析

The analysis of dominant factors in enhancing municipal sludge bioleaching efficiency by quartz sand

通过摇瓶实验探究石英砂提高城市污泥生物沥浸效率的主导因素.结果表明,在0~72h内,生物菌液酸化效应在提高污泥脱水性能中占据主导作用;在72h之后,次生矿物的形成对提高污泥脱水性能的贡献率超过生物菌液.随着生物沥浸持续进行,石英砂诱导次生矿物产量逐渐增加,次生矿物在生物菌液酸化效应基础上进一步强化污泥脱水性能.在二者耦合作用下,城市污泥比阻(SRF)从初始的17.13×10^(12)m/kg下降至48h时的最低值3.56×10^(12)m/kg.然而,生物菌液和次生矿物单独作用时,SRF降到最低值均需72h,且最低SRF分别为3.89×10^(12)和4.77×10^(12)m/kg.可见,二者耦合作用在进一步改善污泥脱水性能以及缩短生物沥浸时间方面都有明显的优势.

Major factors affecting the improvement of bioleaching efficiency with the participation of quartz sand were investigated.Results showed that the bioacidification of A.ferrooxidans was the dominant factor in the first 0~72h.After 72h,the formation of secondary minerals was more significant than the bioacidification of A.ferrooxidans in improving sludge dewaterability,thereby became the major factor.The gradual increment in the yield of secondary minerals could be attributed to the continuing bioleaching process,and further increased the dewaterability based on bioacidification.The specific resistance to filtration(SRF)of municipal sludge declined from the initial value of 17.13×10^(12)m/kg to a minimum of 3.56×10^(12)m/kg at 48h under the joint action of bioacidification and secondary minerals.By comparison,the minimum sludge SRF under each single factor could be observed at 72h,i.e.,3.89×10^(12)m/kg for bioacidification and 4.77×10^(12)m/kg for secondary minerals.Thus,the joint action of these two factors was more efficient in reducing the bioleaching time and further improving sludge dewaterability.