State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, N.O.163, Xianlin Avenue, Qixia District, Nanjing, 210023, Jiangsu, People's Republic of China.
Jiangsu Zhongyijinda Institute of Environmental Industry Technology CO., LTD., Yixing, 214200, Jiangsu, People's Republic of China.
Bioprocess Biosyst Eng. 2019 Oct;42(10):1701-1710. doi: 10.1007/s00449-019-02166-x. Epub 2019 Jul 16.
Denitrification deep-bed filter has been widely applied in the field of advanced wastewater treatment, yet its efficient operation is highly dependent on the filter bricks-controlled water and air distribution system. Considering the restrictions of existing bricks such as poor hydraulic properties and large non-working area during backwashing, a cuboid novel filter brick with two internal distribution chambers was designed and its hydraulic behaviors under three conditions (air washing, water and air joint backwashing, water washing) were simulated using computational fluid dynamic (CFD) analysis. Results showed that the uniformity of fluid velocity distribution was better than that of the conventional brick under two hydraulic conditions, especially in water and air joint backwashing process with a 10% promotion of water and air distribution uniformity. Furthermore, a 30-day engineering validation test was also carried out to testify the actual performance of the novel filter brick. Better performance was testified in the filters with novel bricks. The present study showed that the novel filter brick had a better uniformity of water and air distribution and smaller dead zone area than those of the conventional brick, implying a good feasibility of application in denitrification deep-bed filter.
反硝化深床滤池已广泛应用于高级废水处理领域，但它的有效运行高度依赖于滤砖控制的水和空气分配系统。考虑到现有滤砖存在水力性能差和反冲洗时非工作面积大等限制，设计了一种具有两个内部分配室的长方体新型滤砖，并采用计算流体动力学（CFD）分析模拟了在三种条件（气洗、水气联合反冲洗、水洗）下的水力行为。结果表明，在两种水力条件下，新型滤砖的流体速度分布均匀性均优于传统滤砖，尤其是在水气联合反冲洗过程中，其水和空气分布均匀性提高了 10%。此外，还进行了为期 30 天的工程验证试验，以验证新型滤砖的实际性能。装有新型滤砖的滤池表现出更好的性能。本研究表明，新型滤砖的水和空气分布均匀性更好，死区面积更小，这意味着在反硝化深床滤池中具有良好的应用可行性。
