Filter Media Treatment – Fall 2011

Po-Hsun Lin

Abstract:

The post sedimentation addition of polyaluminum chloride (PACl) was investigated as a means to enhance particle removal efficiency in rapid sand filtration. The process modification was evaluated in laboratory studies and at the Cornell Water Filtration Plant (CWFP). PACl was continuously metered into CWFP filter influent to increase concentrations by 0.06 to 4.2 mg/L (as aluminum) during the filter-to-waste stage of the filter operation cycle to accelerate filter ripening. Lower influent PACl concentrations ranging from 0.056 to 0.43 mg Al/L were also continuously applied during filtration. In comparison to a control filter that received no PACl addition, the ripening time required decreased with PACl dose, and the incremental improvement in particle removal during filtration increased with PACl dose. The addition of 0.056 mg Al/L of PACl (the lowest concentration tested) significantly reduced initial filter ripening time at the CWFP from 10 hours to 2.5 hours, and effluent turbidity in the test filter over the 77 hour filter run was lower than the control filter by an average of 17%. Incremental head loss increase caused by the PACl feed was dose dependent and was negligible for the lowest dosage tested.

String Digester - Spring 2019

Kiki Lo, Antonio Martinez, Gaby Sibel, Zsofia Szegletes

Abstract:

The objective of String Digester for the Spring 2019 semester was to continue research on revamping a wastewater treatment system to eliminate problems associated with current trickling filters. To improve consistency in wastewater treatment, experiments were conducted using metallic and plastic chains to optimize surface area. The long-term goal of this team is to create an efficient wastewater treatment system that will perform secondary and tertiary treatment on domestic wastewater. These tests involved testing different chain types and synthetic materials for their hydrophillic properties, fabricating and testing reactors for efficiency, and researching biofilm growth to help define design parameters for the construction of a functioning string digester.

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.

StaRS Filter Theory - Fall 2019

Wenjie Lu, Claire Kenwood, Kelly Ly

ABSTRACT:

StaRS (Stacked Rapid Sand) Filtration is crucial to the water treatment process. As one of the last steps in AguaClara’s water treatment, StaRS filters are responsible for removing the last of the unwanted particles. In order to operate effectively under EPA standards, the filters must reduce the turbidity to 0.3 NTU or less. In efforts to better refine the AguaClara filters, variables such as grain size, the height of the active zone, coagulant dosage will be tested in order to increase the failure time. At the beginning of experimentation, the Fall 2019 StaRS sub-team will focus specifically on the grain size.

StaRS Filter Theory - Spring 2019

Barbara Oramah, Lainey Reed, Pablo Alonso Alguacil and Ronya Strom

ABSTRACT:

Stacked Rapid Sand (StaRS) Filtration is the last stage in an AguaClara treatment plant. The filters are used to further reduce the turbidity of water to meet EPA standards of 0.3 NTU or less. As a whole, the StaRS sub-team is working to develop a mathematical model to describe sand filtration. This semester, the StaRS Filter Theory team worked towards running experiments with the three newly constructed StaRS filters with varying sand grain sizes. This research will show the extent to which sand grain size has an effect on filter performance.

String Digester - Spring 2019

Kiki Lo, Antonio Martinez, Gaby Sibel, Zsofia Szegletes

ABSTRACT:

The objective of String Digester for the Spring 2019 semester was to continue research on revamping a wastewater treatment system to eliminate problems associated with current trickling filters. To improve consistency in wastewater treatment, experiments were conducted using metallic and plastic chains to optimize surface area. The long-term goal of this team is to create an efficient wastewater treatment system that will perform secondary and tertiary treatment on domestic wastewater. These tests involved testing different chain types and synthetic materials for their hydrophilic properties, fabricating and testing reactors for efficiency, and researching biofilm growth to help define design parameters for the construction of a functioning string digester.

Ram Pump - Spring 2019

Ching Pang, Cheer Tsang, Alyssa Ju, Iñigo Cabrera

ABSTRACT:

The AguaClara Vertical Ram Pump (ACVRP) is an innovation that will enable water to be pumped from lower elevations to higher elevations using the driving force of falling water. The ACVRP improves on a conventional ram pump design by increasing its space efficiency and decreasing its capital cost. Although a prototype had been built, it did not reach its target pumping efficiency. The goal of this semester was to optimize the ram pump efficiency by finding the necessary forces to open and close the valve at the ideal times.

Ram Pump - Summer 2019

Ching Pang, Alyssa Ju

Abstract:

AguaClara plants contain chemical dosage tanks that require water to make liquid chemical stocks. The AguaClara Vertical Ram Pump (ACVRP) is an innovation that elimantes the need for plant operators to manually displace water up to the dosage tanks. Water is pumped from a lower to higher elevation by harvesting kinetic energy from the treated water flowing out to the community's water distribution system. The design is a modification of the conventional ram pump that allows the waste water to be contained within the pump system due to the inline feature of ACVRP. Compared to a conventional ram pump, the ACVRP is more operator-friendly and requires lower capital cost. Teams from past semesters have determined that the previous version of the ACVRP was inefficient due to a significant amount of head loss. The goal of this summer was to reduce head loss in the design and to determine the efficiency of the improved ACVRP.

Fluoride Automated System - Spring 2019

Fluoride Auto – Dominic Grasso, Melissa Louie, Desiree Sausele, Emily Spiek

Abstract:

The Spring 2019 Fluoride Auto subteam aimed to determine the optimal dosage of polyaluminum chloride (PACl) needed to precipitate fluoride ions out of influent water to meet the World Health Organization’s drinking water standard for fluoride concentration (1.5 mg/L). The team accomplished several fabrication tasks, including lengthening the flocculator used by the Fall 2018 subteam and constructing a new sedimentation tube. The team tested the new apparatus with PACl and red dye to visually determine that it worked properly and that aggregated particles (flocs) were exiting the tube through the floc weir. The team then aimed to run experiments with fluoride but experienced difficulty calibrating the fluoride probe. Upon acquiring a new probe in the future, the team will analyze fluoride removal efficiency using the Langmuir Adsorption Model.

Fluoride - Fall 2019

Fluoride Auto — Sarah Huang, Cindy Jin, Melissa Louie, Emily Yueh

Abstract:

The World Health Organization estimates that globally over one million people face adverse health consequences due to fluoride contamination of drinking water. The current state of fluoride removal technology is not suitable for water treatment plants, and continuous fluoride removal systems do not exist. The Fluoride team aims to develop a cheap and efficient apparatus to reduce ionic fluoride from contaminated water to a safe level. The Fall 2019 team hopes to redesign the flocculation process to optimize the adsorption of fluoride to polyaluminum chloride (PACl) coagulant and the sedimentation process to minimize PACl-fluoride complexes in the effluent, ultimately producing potable water.

Ram Pump - Fall 2019

Ching Pang, Alycia Storch, Payton Hunter

Abstract:

Previous Ram Pump teams have created mathematical models describing velocities, forces, flow rates, headlosses, etc. in the AguaClara Vertical Ram Pump (ACVRP); performed experiments to learn more about what actually happens in the system; and have made redesigns to the setup and ACVRP itself to further improve its efficiency, likeliness to an AguaClara plant, and to increase the ease of assembly and adjustment. This semester the team plans to fabricate a new lab setup that integrates the setup into the work bench for a redesign of the ACVRP, and to further explore ways to improve its efficiency. The team has decided on a new design that eliminates the bottom check valve of the ACVRP and the threaded rod and compression spring that it housed and instead includes an extension spring that will be at the top of the head tank. The extension spring will be connected to a hook on the top of the plate with metal wire rope. It is expected that the functionality and process of the ACVRP will not change but making fine-tune adjustements to the initial and final forces of the spring will be easier to make because there will be easier access to the spring. The team created a materials list for the new parts needed and is currently updating the CAD model to reflect the changes. The team plans to construct the new lab setup and ACVRP design and then to perform experiments as well as improve theoretical equations to further optimize the ACVRP.

String Digester - Summer 2019

Madeline Garrell, Emily Wood

Abstract:

The String Digester Summer 2019 subteam continued research on designing a new trickling filter to eliminate problems associated with conventional designs. Experiments this summer focused on designing a water distribution system that does not encourage preferential flow, and creating a matrix of strings using "loopy yarn" as the filter media. An ideal string digester would distribute water uniformly onto a large number of densely packed strings from a spray. Initial testing demonstrated that a "good" spray can be achieved with flow rates on the order of 10 μL/s, which is the amount needed to ensure proper cleaning by a biofilm. Initial testing found the string density resulting in the least preferential flow to be between 25 and 30 strings/cm, although more trials are needed to confirm this result. Further experimentation is also needed to improve the spray pattern geometry, and to determine if the "loopy yarn" is suitable for biofilm growth. The long-term goal of this team is to create an efficient wastewater treatment system that will perform secondary and tertiary treatment on domestic wastewater.

Sensor Development - Spring 2019

Lois Lee, Lawrence Li, Srilekha Vangavolu, Sonu Kapoor

Abstract:

The Sensor Development subteam’s goal is to develop low-cost sensors with readily available materials to monitor and report water quality in the water treatment processes in AguaClara plants and labs. In Spring 2019, the subteam worked on four different projects. The subteam started developing a calibration curve for the Fluidized Bed Solids Detector that was fabricated in the previous semester, and also prototyped a Sludge Blanket Detector for the upcoming Honduras trip. Additionally, the subteam began developing the Mobile Application-Processed Endoscope. The subteam also started designing a low-cost turbidimeter that would measure both the transmittance and absorbance of light.

Sensor Development - Fall 2019

Sonu Kapoor, Saul Bernaber, Rishik Zaparde

Abstract:

Sensor Development's goal is to develop affordable sensors with readily available materials to monitor and report water quality in the water treatment processes in AguaClara plants and labs. In Fall 2019, the subteam worked on two different projects that were slight modifications from the previous semester. The subteam worked on a second prototype of the submersible Sludge Blanket Detector. Additionally, the subteam also started designing a low-cost turbidimeter that would measure the amount of dissolved organics as well as turbidity.

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

Fluoride Removal - Summer 2019

Fluoride Auto - Cindy Jin, Melissa Louie, Mike Rees

Abstract:

The Summer 2019 Fluoride team investigated issues related to the Automated and Gravity systems, with the goal of determining ideal conditions for removing fluoride. Initial qualitative tests prompted fabrication changes, such as an increase in the plate settler angle in the sedimentation tube. Jar testing was also done to examine if a floc blanket is needed for fluoride removal. Several changes in the sedimentation tube were tested to develop an optimal system for fluoride removal. Fluoride concentrations were measured with an ion electrode to determine removal efficiency and to continue developing the Langmuir Adsorption Isotherm model.