Abstract
The hydrodynamics of wastewater land treatments system has a direct influence on the removal efficiency of pollutants. By studying the effect of net-pipes, a solid basis will be provided for design and optimization purposes. On the basis of residence time distribution (RTD) theory, the flow pattern in a land treatment reactor was analyzed using tracer-response technology. Computational fluid dynamics (CFD) software Fluent was utilized to simulate the flow pattern of water. By combining the results of tracer experiment with CFD simulation, the bear-layer was clearly shown to have the function of distributing water and the water-layer was clearly capable of collecting water from the whole water-carrying section. After flowing horizontally through the bear-layer, the water passed through the packing vertically before finally reaching the collection net-pipe in the water-layer. The net-pipe distribution was shown to have a negligible influence on the flow pattern in the absence of bear-layer and water-layer. However the water distribution of net-pipe holes was uneven. Even though the volume efficiency was all above 90%, there were parts of useless or stagnant zone. The highest volume efficiency was obtained in the reactor with half distribution and collection net-pipe, where the flow pattern was different from the plug flow. The dimensionless mean residence time was 1.09, and the degree of dispersion was only 0.037.
| Original language | English |
|---|---|
| Pages (from-to) | 1298-1305 |
| Number of pages | 8 |
| Journal | Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae |
| Volume | 33 |
| Issue number | 5 |
| Publication status | Published - 2013 May 1 |
Keywords
- CFD
- Flow pattern
- Residence time distribution (RTD)
- Simulation
- Wastewater land treatment
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Chemistry
- Environmental Engineering