h1. Floating Flocs
h2. Abstract
{float:right|border=2px solid black|width=400px}
[!floating floc.jpg|width=400px!|Dissolved Air Flotation of Flocs]
{float}
Floating floc in the sedimentation tanks of AguaClara plants in Tamara, Ojojona, and Marcala results in polluted effluent water. The cause of the problem is thought to be bubbles forming on floc particles due to supersaturation of influent water. The Floating Floc team is conducting research with a back-washed sand filter to remove excess gas from the water in the grit chamber before it reaches the sedimentation tank. The sand provides a surface area on which bubbles can form to leave the water in the grit chamber. The goal is to remove enough excess gas, so that the water entering the sedimentation tank has a lower bubble forming potential. WeCurrently, areresearch currentlyis performingbeing researchconducted with different sand grain sizes to observe and quantify the effectiveness of the method for removing the excess gas from supersaturated water. Our main objective is to find an optimal sand size and flow rate to maximize gas removal and minimize the amount of sand carried away by bubbles.
{float:left|border=2px solid black|width=250px}
[!sludgeTop.jpg|width=250px!|Dissolved Air Flotation of Flocs]
{float}
h2. Introduction and Objectives
Rising flocs inIntroduce your approach to solving the sedimentationproblem tanksyou havewere beenworking pollutingon theby effluentexplaining waterwhat atneeds theto plantsbe indone Tamara,to Ojojona,meet andyour Marcala. Initially, Alum overdosing was thought to be the cause of the problem; however, the issue persisted even after the dosage was changed. The speed at which the flocs rise suggests that air bubbles are lifting them to the surface.
goal. What did you hope to learn? How did you expect your work to guide the construction of water treatment plants or to improve drinking water quality in the Global South?
The goal of AguaClara is to provide safe drinking water through sustainable, replicable water treatment systems. Currently, Floating flocs caused by supersaturation of influent water into many treatment plants are polluting the effluent water. Gas bubbles form in water when the total dissolved gas pressure is greater than the local solution pressure (when the water is supersaturated with gas). Supersaturation of the water flowing into the plants may be caused by a pressure drop to below atmospheric pressure due to high rates of mixing caused by turbulence at the plant entrance and churning in the grit chamber. Cracks in the transmission lines combined with high pressure regions would also result in gas being infused into the influent water. SupersaturationExcess gas ofin the water causes gas bubbles to form on dirtfloc particles in the watersedimentation tank, resultingfloating in flocsthem floating to the surface and contaminating the effluent water.
. The goal of the Floating Floc Teamteam is to find an efficient and cost-effective remedyapproach to remove theexcess floatinggas flocfrom problemwater and to implement that method in current and future AguaClara plants to improve the sedimentation process. We are
The Floating Floc team is currently lookingexperimenting intowith a back-washed sand filter approach,column. whichIn involvesthe decreasingactual theplants, gasa contentlayer of sand would thebe watersuspended in the grit chamber before it enters to provide a surface area for gas bubbles to form and leave the flocculation tanksolution.
Floating Floc Team [Semester Goals|Floating Floc Goals]
Floating Floc Team [Meeting Minutes|Floating Floc Meeting Minutes]
h2. Current Research
[Floating Floc Sand Filter Method|Floating Floc Sand Filter Method]
* The sand filter approach involves forcing water upward through a layer of sand, as if backwashing a sand filter. The sand filter method provides a substance besides the sediment in the water on which the bubbles can form. When the bubbles grow large enough, they will rapidly rise to the surface.
h2. Additional Information
[Floating Floc Aeration Method|Floating Floc Aeration Method]
* This page discusses past research on the aeration approach to dissolved oxygen removal. The aeration approach attempted to use bubbles as a catalyst to increase the rate of dissolved oxygen transfer out of solution by allowing dissolved oxygen to diffuse into the bubbles. This would increase the bubble size and cause the bubble to rise faster.
[Theoretical Modeling of Aeration Method|Floating Floc Research]
* This page discusses the research into the floating floc phenomenon that is being conducted.
Floating Floc Team [Annotated Bibliography|Floating Floc Annotated Bibliography]
[Quiz|Floating Floc Quiz]
This quiz checks that you have a basic understanding of the principles behind this research. | 