Challenges Fall 2009

Design

Challenges for Fall 2009

Subteam Leader:

Number of team members needed: 9-10

Important team member skills:

Challenges

Design Tool
Chemical Doser
Entrance tank
Rapid mix components

Requires review and possible upgrade to the first draft of the rapid mix design and then coding of the MathCAD to AutoCAD (MtA) code.

Chemical storage tanks
Floc Hopper Drain Valves
Horizontal Flocculator
Vertical Flocculator
Flocculator Drain System
Sedimentation Inlet and Exit Tanks
Sedimentation Tank Control Pieces
Material's List
Documentation

Plate Settler Spacing

Challenges for Fall 2009 and Beyond

Current Subteam Leader: Rachel Philipson

Number of team members needed: 3-4

Important team member skills:

Challenges

Chemical Dose Controller

Challenges for Fall 2009Subteam Leader:Number of team members needed: 4Important team member skills:MathCADProcess ControllerFluid DynamicsChallengesNon-Linear CDCDetermine whether a single or multiple orifices should be used to connect rapid mix chamber and flocculation for optimum energy dissipation, head loss, and float sizing.We have tentative results in the mathCAD file however, we did not have enough time to optimize the functions created.Construct non-linear CDC and run experiments to evaluate design and ensure experimental results align with theoretical results.For additional challenges, seesuggested challengesour team did not address this semester.

Floating Flocs

Subteam Leader:Tanya or anyone with previous knowledge of floating flocs problem
Number of team members needed:3-4 membersImportant team member skills:Process Controller (can be trained)Microsoft ExcelMathCADChallengesDetails of the experiments that have been planned can be found on theFloating Flocs Fall 2009 Tentative Experimentspage.
Possibly redesign the experimental setup to better simulate the water quality at actual AC plants by adding a clay source or surfactant source.Confirm the cause of the floating floc problem by running experiments with the Plate Settler Team's apparatus. Two experiments have been planned in order to test whether the cause of the floating floc problem is bubbles adhering to flocs or whether bubbles form on flocs and lift them to the surface. It is also possible that both of these mechanisms are responsible for floating floc.If the cause is confirmed to be bubble formation on or adherence to flocs due to supersaturated water the team's tentative experimental plans include:
Run experiments using mild surfactants to witness their effects on bubble formation. Currently, the team is considering using a dilute soap solution as a surfactant. Details as to the concentration of soap solution have yet to be determined. This will likely be based on a conversion of organic matter in the water of AguaClara plants.Run experiments using hydrophobic surfaces with or without surfactants to see the effects on bubble formation. The details of these experiments have yet to be determined. Currently, literature searches are being performed to find cost-effective hydrophobic surfaces to test. It has been found that plant surfaces may exhibit hydrophobic properties due to their waxy coating.Developing a new mechanism to either remove gas, stop bubble formation, or stop floating flocs themselves. Currently, the team is looking at a mechanism that involves using lamella or something similar to trap air pockets in the water. These air pockets would be knocked around by eddies and may collect dissolved gas in the process.One possibility to consider is whether flocs that are floating can be redirected or captured so that they are not in the effluent water.(I doubt this can be done.)Since achieving gas removal has been proven to be difficult, putting some time into considering other solutions may be worthwhile.
If the cause of floating flocs is shown to be something other than supersaturated water, the team may still focus on stopping flocs from floating; however, other approaches may be developed that are specifically tailored to actual cause of the problem.

Outreach

Challenges for Outreach Fall 2009

Fundraising

Group Leader:

Number of team members needed:

Important team member skills:

Challenges

Public Relations

Group Leader:

Number of team members needed:

Important team member skills:

Challenges

Rapid Mix

The rapid mix research project's goal is to determine if inadequate mixing in the rapid mix unit is responsible for the residual turbidity at the end of the AguaClara treatment process. This can be accomplished by adding some additional turbidity after the rapid mix process to see if those colloids have a significant effect on the settled water turbidity. If a large fraction of the colloids that didn't go through the rapid mix end up in the effluent, then it suggests that colloids that aren't properly exposed to aluminum hydroxide in the rapid mix process could also end up in the effluent. The next phase of this research would be to experiment with different rapid mix designs.