Oge Anyene, Larry Ge, Yuqi Yu
Abstract:
The Fall 2015 High Rate Sedimentation team aims to design a new sedimentation tank that will allow the tank upflow velocity to be significantly increased (by a factor or 2 to 10), without sacrificing particle removal performance (no increase in effluent turbidity). The motivating factors behind this velocity increase would be to decrease the plan view area of the sedimentation tanks, leading to smaller plants and lower the construction costs and to decrease the overall hydraulic retention time of the plant. One of the primary objectives of the new sedimentation tank will be to maintain a consistent floc blanket (i.e. one that allows for excess floc drainage into a floc hopper) similar to the ones found in current AguaClara plants, even with the increased upflow velocity. In order to achieve this goal our proposed design will feature two sets of plate settlers, one set near the bottom of the tank that will be suspended within the floc blanket, and one above them to capture finer particles. To test the feasibility of such a design, several small-scale experiments will be run in the lab. Such experiments will prove to demonstrate whether or not it is possible to maintain a fluidize bed within plate settlers and what the bulk flow of flocs will look like for a floc blanket maintained within plate settlers.
