Chemical Dose Controller - Fall 2014

Annie Cashon, Jeanette Liu, Christine Leu

Abstract:

The Chemical Dose Controller is a device that maintains a constant chemical dose as the plant flow rate changes. This semester, the Chemical Dose Controller team has started doing research on chlorine compatibility with the constant head tank. Part of this assignment includes exploring alternative CHT designs in hopes of maximizing durability and efficiency while minimizing costs. The team is also considering scaling the CDC system down by looking into the single lever arm design. The team has begun recording these adjustments in a CDC assembly manual for future CDC teams that includes photos and item lists. Finally, the team has reached out to the team in India, in hopes of working out a cost effective and reliable system for future shipments.

Coagulant Management, Spring 2013

Madeline Haas, Rudra Koul, Jack Newman

Abstract

Coagulants are an essential part of a water filtration plant as well as a signifiant operating cost. Therefore, it is very important that they be used as effiently as possible. This semester, the Coagulant Management team has calculated and analyzed the relationship between PACl density and concentration that was ultimately used in calculations necessary for centrifugal pump parameters and for hydrometer recommendations. In addition, the team brainstormed fabrication ideas for the coagulant injection point. The centrifugal pump was partially fabricated, but because of the density vs. concentration relationship calculated, the pump, once fully fabricated, can be tested using PACl. In addition, the Coagulant Management team has recommended the testing and use of a plastic (polycarbonate) hydrometer from Krackeler Scientific Inc. with a specific gravity range between 1.000 and 1.220.

Stock Tank Mixing Team, Spring 2014

Alexandra Cheng and Apoorv Gupta

Abstract

The Stock Tank Mixing team has been charged with the task of designing and fabricating a tool to effectively and efficiently mix stock solutions of coagulant and chlorine. Currently, operators in AguaClara plants utilize a long PVC pipe to mix stock solutions to achieve chemical dissolution, but this method is inefficient and limits the ability of operators to mix large stock tanks. Uniformly mixed stock solutions are required for flocculation and disinfection; this fact is the driving force for creating a mixer to aid the formation of flocs in raw water and improve plant efficiency.

Chemical Dose Controller, Spring 2015

Annie Cashon, Christine Leu, Auggie Longo

Abstract

The Chemical Dose Controller is a device that maintains a constant chemical dose as the plant flow rate changes. After working alongside the foam filtration team in El Carpintero, Honduras this past January, the CDC team has changed the lab set-up to be more reflective of the systems in the field. Specifically, the major head loss element was changed to be vertically-oriented instead of horizontal to decrease the footprint of the CDC system.During the Spring 2015 semester, the CDC team will run a variety of experiments with the new system including head loss testing, determining flow breakpoints, and testing units at stock concentrations. In addition to testing the system through a variety of experiments, several design changes will be looked into this semester. This includes tasks such as making the constant head tank from locally available items in Honduras, as well as making the constant head tank chlorine resistant. Finally the team is is compiling a system of equations to convert the CDC system into a modular, packaging item for future shipment. With design changes in mind, a major goal of the CDC team this semester will be to create an assembly manual and parts­list.

Unit Process Analysis pH - Fall 2019

Floc pH — Justin Lee, Jena Rozanski, Rafaella Bruzual

ABSTRACT:

The Unit Process Operations pH subteam wanted to explore the performance of the AguaClara sedimentation tank as a function of pH. Filtration within the sedimentation tank is complex and the performance is often a factor of floc blanket. When the coagulant dosage exceeds a certain amount, the pH probe will be coated with coagulant, leading to inaccurate pH measurements within the plant. Therefore, the team wanted to determine this coagulant dosage and use that value as the constant coagulant dosage for all experimental trials. The team hopes to use this information to uncover new insights on how filtration performance changes in different pH ranges.

Chemical Dose Controller - Spring 2014

Andrea Cashon, Saugat Ghimire, Jeanette Liu

Abstract:

The Chemical Dose Controller team completed the design and fabrication of the single lever arm assembly. This assembly will be utilized in low flow plants that only require a chlorine doser. The new Chemical Dose Controller maintains the same functionality of the previous model. It will also be chemically resistant and require fewer materials, lowering fabrication and shipping costs. The team also created a float valve for the constant head tank that has fewer corrosive metal components and has the floatin line with the orifice. The team has created a new height adjustment system for the constant head tank and a dosing tube air removal system that utilizes a wye channel. Additionally, the entrance tank float was redesigned to be smaller and lighter, for easier and cheaper shipping. Finally, the team created an items catalog that contains every single component - and it’s corresponding McMaster-Carr identification number - used in a Chemical Dose Controller system. This catalog will help future Chemical Dose Controller teams order components and construct new systems.

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Unit Process Analysis: Coagulant - Fall 2019

Ada Lian, Sarah Paquin

Abstract:

The Fall 2019 Unit Processes Analysis Coagulant (UPAC) team’s objective is to reduce capital and operating costs and improve particle removal efficiency for the AguaClara water treatment process, specifically by analyzing the response of the system to varying coagulant dosage. To analyze the system response, we will run a series of trials on a treatment plant sedimentation model, varying the coagulant dosage and recording observations regarding the effluent turbidity, floc formation, and floc blanket formation. Through this experiment, the team will be able to establish a minimum coagulant dosage, which could lower operating costs, and to learn valuable information about the interactions between coagulant and the primary particles of the influent water at high coagulant dosages.

Contact Chamber - Fall 2017

Cheer Tsang, Yeonjin Yun, Ben Gassaway

Abstract:

The introduction of coagulant into turbid water causes collisions of suspended particles with coagulant nanoparticles, which promotes the growth of flocs. However, a large portion of the coagulant dose adheres to pipe walls rather than influent particles, requiring a higher than necessary coagulant dose to account for this effect. In order to minimize coagulant waste, an apparatus called the contact chamber was fabricated to increase collisions between influent particles and coagulant. The Fall 2017 Contact Chamber team analyzed the performance of the contact chamber by comparing influent and effluent turbidity in experiments with and without a contact chamber. After several trials, it was concluded that the contact chamber did not improve the effluent turbidity. In fact, the effluent turbidity with the contact chamber was significantly greater than the effluent turbidity without the contact chamber.

Humic Acid, Kaolin, Floc/Sed Model - Spring 2019

Matthew Lee, Walter Guardado, Carolyn Wang

Abstract:

This semester, samples of HA at 5 mg/L, 10 mg/L and 15 mg/L and concentrations of clay at 10 NTU, 100 NTU and 100 NTU are tested separately to find the respective absorbances. The individual absorbances recorded are used to compare with the mixture of different concentrations of clay and HA to find the additive aspects of the mixture. The results of these tests will investigate how absorbance and spectrophotometry can be used to quantify the concentrations of humic acid and clay in water mixtures. A mathematical model that relates the concentrations of clay and humic acid to the stream's absorbance and turbidity will be developed. This model will increase the capabilities of AguaClara plants and technology in measuring the dirtiness of nearby water sources. The model will also give insight on how efficient and effective current processes are in removing humic acid from water