h4. Sedimentation Tank Hydraulics
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h5. Introduction
The current design of sedimentation tanks in Agua Clara plants consists of plate settlers placed above the inlet manifold that catch flocs formed in the flocculator while allowing water to flow past the settlers into exit launders. The flocs then settle out at the bottom of the sedimentation tank and are removed regularly by a sludge drain. Because of non-uniform flow, 1) flocs accumulate unevenly in the tank which causes difficulty in removal, 2) dead zones are created in the tank that lower the efficiency of the system.
We wish to determine optimal thebottom geometry of a sedimentation tanks so that uniform flow tank for floc blanket formation. A floc blanket is achieveda anddense, deadfluidized zonesbed areof eliminated,particles whichthat wouldhelps improveto thereduce efficiencyeffluent ofturbidity theby currenttrapping tanksmall designflocs and decrease the labor needed to maintain a clean tank. Given a particular upflow velocity, under these hydraulic conditions we may also experiment with floc blanket formation, which we believe will provide a second filtration stage for upward flowing flocs in the sedimentation tank and lower the turbidity of the effluent. Flocs may then be drawn off the blanket with a weir, minimizing the effort needed to clean the tank.
While our team is specifically looking at the floc blanket, some other aspects of the sedimentation tank may also be considered for an overall optimal design such as inlet manifold and the launder. You will be able to find past research on inlet manifold on the side bar. reduces clean water waste through less frequent draining of the sedimentation tank. Floc resuspension is necessary for floc blanket formation so that flocs are recirculated through the tank instead of settling on the tank bottom as sludge. We are examining mechanisms for floc resuspension of various bottom geometries by studying the relationships between hydrostatic and hydrodynamic pressure. We are also looking at parameters such as floc blanket formation time, clarified effluent turbidity, and tube settler turbidity for various bottom geometries, which will help us to determine the optimal bottom geometry to meet a given design objective.
Our team is also working on designing a floc weir for the sedimentation tank, which will waste flocs at a constant rate from the floc hopper and serve to keep the floc blanket at a constant height.
h5. More Information
[Challenges Sedimentation Spring 2011]
[Sedimentation Team Detailed Task List]
[Sedimentation Team Research Rationale]
[Sedimentation Team Research Rationale2]
[Sedimentation Team Research Report 1]
[Sedimentation Team Final Research Report]
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h6. Members
[Mahina Wang|mgw56]
[Jill Freeman|jef246]
[Saied Khan|sak332]
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h6. [Sedimentation Tank Hydraulics Documents]
| | Challenge | Tasks | Teach in | Final Presentation | Final Report |
| Summer '11 | | | [!Research^ppt_icon.jpg|height=25!|^Teach In.pptx] | [!Research^ppt_icon.jpg|height=25!|^Final Presentation Summer 2011.pptx] | [!Research^pdf_icon.jpg|height=25!|^finalreport_sedtankhydSummer2011.pdf] |
| Spring '11 | [!Research^word_icon.jpeg|height=25!|Challenges Sedimentation Spring 2011] | | [!Research^ppt_icon.jpg|height=25!|Sedimentation Tank Hydraulics^SedimentationTankHydraulicsTeachInSpring2011.ppt.pptx] | [!Research^ppt_icon.jpg|height=25!|Sedimentation Tank Hydraulics^SedimentationTeamHydraulicsFinalPresentation.pptx] | [!Research^word_icon.jpeg|height=25!|Sedimentation Team Final Research Report] |
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h6. Past Research
[Fall 2010 Inlet Manifold Team]
[Spring 2010 Inlet Manifold Research Team]
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