Plate Settler Spacing
Introduction
This research is focused on a deeper understanding of the sedimentation process so that plants can remove dirt particles from dirty water as efficiently as possible, allowing for successful chlorination of the outgoing water. Currently the plants all use lamella, which are corrugated parallel plates that decrease the distance that a floc must fall to be settled out. To make things simpler for a lab, we use tube settlers of various diameters, and experiment with different flow rates and turbidities, because these things fluctuate often in the plants in Honduras based on the season.
One of the main reasons for this focus is that sedimentation is the only process in which particulates are actually removed from the water. Flocculation and rapid mix may be working well, but if the particles are not being settled out, people will still be drinking dirty water. Low turbidity water is not only aesthetically pleasing, it's also safer because the disease causing pathogens are more likely to be exposed and killed when the water is chlorinated. AguaClara has had the goal of 1 NTU water since its beginning, and the Plate Settler Spacing team has been able to accomplish this in the lab, but now is trying to see how this can be transferred to our future plants in Honduras. Sedimentation is also the limiting factor for the height requirement of the plants, so if we can find a way to produce the same results with a smaller amount of space, the plant cost will decrease significantly.
Subteam Semester Goals
Weekly Subteam Progress.
Experimental Methods and Results
The following experiments are based on research completed in Fall 2008 .
Experiments with Flow Rates and Inner Tube Diameters
These experiments run our system while varying the flow rates and inner tube diameters. From that, the ideal L/d ratio is found and more experiments are run holding this ratio constant.
Experiment 3: Floc Blanket Formation
Ongoing research concerning the rate of formation and density of floc blankets.
Experiment 4: Using Straws for Tube Settlers
The research performed used different diameter straws as the tube settlers to see how it affected the effluent turbidity.
Additional Information
Annotated Bibliography of Relevant Literature