气升式氧化沟流动特性的中试研究  

Flow characteristic of a pilot scale airlift oxidation ditch

作　　者：庞洪涛[1] 施汉昌[1] 施慧明 杨超[2] 殷益明[2] 

机构地区：[1]清华大学环境科学与工程系,环境模拟与污染控制国家重点联合实验室,北京100084 [2]江苏一环集团有限公司,江苏无锡214261

出　　处：《中国环境科学》2008年第12期1057-1061,共5页China Environmental Science

基　　金：国家“863”项目(2004AA601061)

摘　　要：在清水实验中研究了中试气升式氧化沟单侧廊道流速分布及进气量对升流区和直段流速的影响.中试装置容积54m3,当进气量按42,79,170m3/h增大时,升流区水平方向流速略有增加,沿水深方向流速增幅较大;直段流速随气量的增加变化不大;进气量大于79m3/h后直段流速几乎没有变化,底部平均流速约为0.25m/s.通过测试不同进气量下的污泥浓度确定了保证流动的最小流速.进气量为20m3/h时,沟内最大流速仅有0.07m/s,此时仍未出现污泥沉降.结合后续的污水处理效果研究,实际工程中可将沟底流速大于0.15m/s作为防止污泥沉降的流速要求.The influence of air flow rate on liquid velocity and velocity distribution of a pilot scale airlift oxidation ditch were studied with clean water. The capacity of the pilot scale airlift oxidation ditch was 54m^3. As the air flow rate varied from 42 to 170m^3/h, the horizontal velocity had a small increase and the axial velocity grew up largely. Liquid velocity had a relatively small change in the straight part with the increase of air flow rate. The average velocity in the bottom was about 0.25m/s when the air flow rate was over 79m^3/h. In order to investigate the minimum velocity for preventing the settlement of activated sludge, the sludge concentrations under different air flow rate were measured. When air flow rate was 20m^3/h, a minimum velocity of 0.07m/s was sufficient to prevent sludge sedimentation in the ditch. According to the result of wastewater treatment, horizontal velocity higher than 0.15m/s in the bottom was suggested as the design criterion for a large scale airlift oxidation ditch.

关 键 词：气升式氧化沟 流动特性 中试 污泥沉降 

分 类 号：X703[环境科学与工程—环境工程]