Rachel Beth Phillipson
Robustness of our plate settler design is defined as the ability of the plate settlers to produce 1 NTU water over a variety of non-ideal conditions. One set of non-ideal conditions was building a floc blanket with underdoses and overdoses of alum to measure performance through effluent turbidity from the tube settler.
Alexander Campbell Duncan, Rachel Beth Philipson
The Plate Settler Spacing team is currently investigating the Floc Roll-Up Phenomenon in the tube settler. By developing a velocity gradient model, we hope to both analytically and experimentally determine the critical velocity floc particles experience when they begin to roll up the settler tube and into the effluent rather than settling back down the tube and into the floc blanket. The critical velocity is determined using a force balance for a floc particle. In addition to determining this critical velocity, we hope to understand how properties of the flocs themselves affect floc roll-up.
Christine Lauren Catudal, Matthew William Hurst
This experiment explored the impact of water supersaturated with respect to atmospheric pressure on floc blanket formation and performance. This experiment involved collaboration with the Floating Floc Research Team, who supplied the saturated water that served as the influent water to the process.
The Effect of Floc Roll-up on Clay-Aluminum Hydroxide Flocs
Matt Hurst, Monroe Weber-Shirk*, Tanya Cabrito, Cosme Somogyi, Michael Adelman, Zachary Romero, Richard Pampuro, Rachel Phillipson, Sarah Long, Colette Kopon, Ying Zhang, Ashleigh Sujin Choi, Adela Kuzmiakova, Jae Lim, Alexander Duncan, Christine Catudal, Elizabeth Tutunjian, Ling Cheung, Kelly Kress, Tiara Marshall, and Leonard W. Lion
Inclined plate and tube settlers are commonly used to create compact sedimentation tanks. Conventional design guidelines are based on obtaining a desired sedimentation design capture velocity. Theoretically, this capture velocity can still be achieved while greatly reducing conventional plate spacing or tube diameter. The greatest concern with small plate spacing is the danger of settling sludge being swept out with the finished water. This research presents the basis of this failure mechanism as high velocity gradients present at small tube settler diameters and small plate settler spacings.
Ryan Anthony, Elyssa Dixon, Zac Edwards
The purpose of a venturi is to create a low pressure zone in the contraction of a pipe that can be used to pullfluid from another location into the existing ow against the force of gravity. AguaClara can use this technology to implement floc recycle and decrease the necessary size of the flocculator. A pipe will transport heavily flocculated and turbid water from the floc hopper in the sedimentation tank to the horizontal section of the rapid mix pipe that leads into the flocculator. A venturi constructed in this horizontal portion of the rapid mix pipe will pull this turbid water from the floc blanket into the incoming plant flow and thereby increase the incoming turbidity. The flow of the turbid water transported from the floc blanket to the rapid mix pipe is dependent upon difference in head at the end of the system compared to the head in the throat of the venturi. By recycling the turbid water, a greater floc volume fraction will be present at the beginning of the flocculator to increase collisions and thereby reduce the amount of time that the water must spend in the flocculator; this, in return, will reduce the size of the flocculator and reduce material and construction costs.
Surya Kumar, Christine Leu, Amlan Sinha, Cindy Dou
Floc blankets, which are suspended layers of highly concentrated flocs, have the potential of being a more efficient option for removing arsenic, fluoride, and certain dyes in terms of energy and water consumption than currently employed techniques. For floc formation, a coagulant needs to be added to the water, allowing particles to adsorb to each other when they collide. Previous research has shown that the coagulant, polyaluminum chloride (PACl), has properties that allow arsenic, fluoride, and certain dyes to adsorb to its surface. The first iteration of this research used three floc blankets in series with a counter-current flow of contaminated water and flocs. By feeding flocs from the last reactor into the second, and from the second into the first, the PACl’s surface area can be saturated. To test this theory and apparatus, a dye, Remazol Brilliant Blue R (RBBR), was chosen to be the contaminant due to its less toxic nature and visual component. With this apparatus and contaminant, this semester’s goals were to test dye removal efficiency from water with varying concentrations of clay, PACl, and dye. With a 1:1 ratio of PACl to dye, a dye removal efficiency of roughly 80% was achieved. However, the transportation of flocs from the third reactor to the second and first was not sustainably achieved.
