泡沫化预处理对污泥干燥特性的影响  

Effect of foaming pretreatment on drying behavior of sludge

作　　者：王慧玲[1,2] 杨朝晖[1,2] 黄兢[1,2] 闫景武 汪理科[1,2] 宋佩佩[1,2] 杨坚 

机构地区：[1]湖南大学环境科学与工程学院,长沙410082 [2]环境生物与控制教育部重点实验室(湖南大学),长沙410082 [3]长沙市人防工程质量监督定额管理站,长沙410000

出　　处：《环境工程学报》2015年第2期907-912,共6页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51378189)

摘　　要：采用泡沫化预处理与污泥干燥相结合的方法提高脱水污泥的干燥效率。采用密度变化的间接测定法,研究了脱水污泥的起泡性能和泡沫稳定性。采用薄层干燥实验法探讨泡沫化污泥的干燥特性,并引入干燥曲线,深入分析泡沫化污泥快速干燥的机理。结果发现,脱水污泥中加入一定量Ca O后经搅拌可以形成泡沫化污泥,且泡沫的稳定性很强。当泡沫化污泥的质量和表面积相同时,在不同的干燥温度下,密度为0.70 g/cm3的泡沫化污泥均表现出最好的干燥性能。泡沫化处理后污泥与干燥空气的接触面积增大,泡沫化污泥中自由水含量增多以及干燥过程中泡沫化污泥内部形成的大量孔洞使得水分迁移和热量传递的阻力减小,这些是泡沫化污泥干燥速率得以加快的主要原因。In this study,the combination of foaming pretreatment and drying process was used to be an alternative method to improve the drying performance of dewatered sludge.The foaming performance and foam stability of dewatered sludge were assessed indirectly by measurement of density variation over a specified time.The thin-layer drying experiments were carried out in drying oven to study the drying characteristics of foamed sludge.Meanwhile,the drying curves were used to discuss the reasons of high drying rate for foamed sludge.The results indicated that Ca O addition followed by mechanical whipping could be employed for foaming the dewatered sludge,and the foams were stable.When the masses and surface areas of foamed sludge were same,the foamed sludge at 0.70 g/cm3 had the best drying performance at each level of temperature.The shorter drying time of foamed sludge resulted from the larger surface area exposed to drying air,more water from bound type into free type,and the lower internal resistance to moisture and heat transfer of the foamed sludge.

关 键 词：脱水污泥 泡沫化预处理 起泡特性 污泥干燥 

分 类 号：X703[环境科学与工程—环境工程]