脱水污泥颗粒等温干燥特性实验研究

采用3种不同类型的脱水污泥(消化污泥、曝气生物滤池污泥和剩余污泥),制成3种粒度的污泥颗粒,并分别在65、85、105和125 ℃条件下进行恒温干燥实验.结果表明,减小污泥颗粒和增大干燥温度均可缩短污泥完全干燥时间,提高污泥的最大干燥速率;消化污泥干燥速率最高,曝气生物滤池污泥次之,剩余污泥的干燥速率最低.通过扫描电镜分析干燥后的污泥可知,消化污泥表面非常粗糙,结构比较松散;剩余污泥表面相对比较光滑,结构密实;而曝气生物滤池污泥表面比较粗糙,结构比较致密.污泥表面的粗糙程度与等温干燥速率有密切关系.

Experimental characterization of isothermal drying of dewatered sewage sludge particle

Three types of dewatered sludge with different particle sizes were dried at constant temperature of 65℃,85℃,105℃ and 125℃,respectively.The results showed that reducing sludge particle size or increasing the drying temperature had good effect on improving the drying rate of sludge.The drying rate of digested sludge was the highest,followed by biological aerated filter sludge and excess sludge.SEM analysis indicated that there were significant differences in the micro-morphologies of three types of sludge.Digested sludge had very rough surface and loose structure,while excess sludge had smooth surface and dense structure and biological aerated filter sludge had rough surface and less dense structure.There was a positive correlation between the surface roughness of sludge and the drying rate.