Ideas
- Find a way to improve screening before water enters the plant (we were thinking about coffee bean shells in the diffuser pipes in the plant in La Brea).
The problem at La Brea is that they didn't have a trash screen and the water was bypassing the grit chamber.
- Flocculator design for 1 - 5 L/s flocculators. These flocculators may be most cost effectively built using pipes. The number of pipe fittings required to make these flocculators (at least in the design as used for the 1 L/s plant) raises the flocculator cost significantly. Fittings for larger pipes are substantially more expensive. Might there be another way to fabricate small prefabricated flocculators that would cost less?
- Decrease height of flocculation tank and decreasing spacing between baffles in order to have multiple smaller flocculators to conserve space.
This would require more baffles and increase the plan view area of the plant and both changes result in an increase in cost.
- Irregular baffle spacing in the flocculators, from more to less spacing (?)
Tapered flocculation uses energy less efficiently and thus produces fewer collisions for the same energy input. Tapered flocculation only makes sense if the goal of treatment is to produce big flocs (That isn't our goal!).
- Changing the angle of the baffles in the flocculator. Changing the angle could have the potential to increase particle collisions, thereby creating more flocs, and contributing to "no particle left behind". As a deliverable, a team could compare the head loss of AguaClara's current design with a variation in baffle angle.
The amount of fluid deformation is a function of the total head loss and the uniformity of the energy dissipation rate. It isn't clear how changing the angle of the flocculator baffles would improve on the current design. Vertical is the best angle for preventing floc sedimentation.
- Floc recycle system for sedimentation tanks. Because sedimentation tanks are the slowest and therefore most expensive unit process, we want to find a way to speed up the process. However, at higher upflow velocities the floc blanket thins severely. We want to find a way to introduce a floc recycle system to keep floc blanket dense at higher upflow velocities (similar to the recycle of active sludge in wastewater treatment plants).
This is best done as a laboratory experiment.
- More compact plate settler system and explore alternative fabrication methods. Now that we have strong evidence that deeper floc blankets would improve performance we need to see if we can reduce the sed tank depth occupied by plate settlers. This is a high priority for our prefabricated plants.
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From survey data, design a water distribution system, including tanks, pressure break tanks, pipe size, pipe material, etc.
- Flow quantity present and required
- Tank storage required and proper location of the storage
- Peak flows and velocities
- Design appropriate pressure gradients
- Population data and projected growth
- Community information and history
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Design disinfection process, calculating quantity of chemical needed per time period, delivery method, and physical process.
Do we need a comparison of available technologies? The AguaClara doser has the economic advantage in that it can use the cheapest source of chlorine (calcium hypochlorite) that doesn't have the danger of chlorine gas. Perhaps a comparison of available chlorinators given that there are several technologies and given that for some unknown reason the AguaClara doser isn't being adopted by other organizations.
- Determine treatment required based upon water quality information. What water quality parameters go into the thought process of needed treatment and would an AguaClara system be appropriate?
- Grit removal via de-sander (Desarenador) highly probable
- Flocculation/Floc blanket/Sedimentation process possibly needed
- Disinfection definitely required. (1.b.)
- Scaling potential in piping system?
- Is filtration needed?
A decision matrix is needed and is likely very simple. The only question is whether particle removal is ever needed and whether direct filtration is ever better than floc/floc blanket/sedimentation.
Developing Python code and Onshape to improve the process of designing aerial crossings in distribution systems. In distribution systems in Honduras one often has to cross a river, stream, or very rugged terrain with an overhead crossing system. It would be very beneficial to have a more efficient method of producing the designs given a set of criteria. < This would be an excellent project for a structures class. If there are students that have taken structures courses, then this could be a great project. The idea would be to use the AguaClara Infrastructure Design Engine approach to design scalable aerial crossings.
Problem- Filter use in agriculture is very common. What we observed in Honduras was that farmers were using sand filters purchased commercially to filter the stream water before it went into their drip irrigation systems. Filtering water before drip irrigation is very important because sand, clay, and silt can cause abrasions to the hoses and clog the orifices in the drip irrigation system.
Goal- create a cheaper and more effective filter for use in agriculture, particularly when using drip irrigation techniques.
This likely needs a small floc/floc blanket/sed system. This may be better to tackle as a laboratory research project.
Goal- Through current talks with ACODAL in Colombia we have found out that there are 40-50 plants that are going to be constructed in Cundinamarca. They have expressed interest in having 1-2 of these plants be AguaClara plants. Our goal is to identify which of their proposed sites has the greatest potential for success.
We have to first continue to talk to those in Colombia to see if these 40-50 sites have already been pre-selected. If they have we can study those sites and evaluate our decision but if they have not then we will have to identify the communities ourselves.
It isn't clear if we can have access to site data in time for this project.
Design a compact AguaClara plant in a container. Consider fold out walkways and a tent style roof. This would be for the US market and for rapid deployment.
The flocculation model equations currently predict performance as a function of coagulant dose. Create the reverse solution and solve for coagulant dose. This is what the plant operators need based on the turbidity, Natural Organic Matter surface area, and flocculator characteristics. This is probably too simple for a capstone because it likely only requires use of a scipy root finding method.
- Use a manifold between flocculation and sedimentation and between sedimentation and filtration so that any unit can be taken out of service.
- Invent a method to flocculate to waste, settle to waste, and filter to waste. These waste methods must maintain water levels and operation of upstream processes. Use hydraulic systems that are similar to what is used in Built in Place AguaClara plants.
- Determine whether a single flocculator is replaced whenever the plant is upgraded with another PF300 unit or if each PF 300 has its own flocculator.
- Ensure that your design thoroughly mixes the coagulant with the flow before the flow is split.
For plants with flows above 120 L/s it will be very attractive to simplify the internal geometry of the sedimentation tanks. Devise a system that would ensure floc blanket formation, hydraulic sludge removal, and uniform flow through the sedimentation tank. Explore options for fabricating the bottom geometry that would start with a flat concrete tank floor. Draw your proposed design using Onshape and develop equations for the important dimensions using Python.
Contact AguaClara alumni working for consulting firms to see they have any comparisons. See Evaluation of ultrafiltration and conventional water treatment
See Table 4-1 Comparison of Clarification Processes for a good start. Identify the advantages and disadvantages of the AguaClara treatment scheme relative to the other available technologies. Provide recommendations for how AguaClara technologies should be improved to enhance their competitive advantage.