UASB - Spring 2017

Zac Chen, Subhani Katugampala, Serena Takada, Linping Xu

Abstract:

Upflow Anaerobic Sludge Blanket (UASB) Reactors are a conventional primary wastewater treatment technology. Improvements to UASB reactors are required for the development of affordable small-scale wastewater treatment systems. This semester, the feasibility of two design modifications to conventional UASB reactors were explored: (1) a submerged gas capture lid (SGCL) to increase gas capture capacity, and (2) plate settlers to improve solids (granules) retention. The results of the SGCL prototype testing showed that the SGCL was gas-tight, which is not achieved in traditional UASB reactors. Additionally, granule settling tests demonstrated that plate settles do not improve settling capacity for small-scale UASB reactors. In the immediate future, AguaClara should fabricate a full-scale UASB reactor that incorporates the SGCL design and other design modifications detailed in the January 2017 EPA P3 Proposal. Eventually, AguaClara should explore post-treatment options to couple with the UASB reactor to develop a complete small-scale wastewater treatment system.

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.

Fluoride - Fall 2017

August Longo, Victoria Zhang, Michelle Cheng

Abstract:

The Fluoride subteam seeksto dvelop a sustainavble, inexpensive fluoride removal system for implementation in upcoming AguaClara plants located in India. After earning an EPA Phase II grant for the Spring 2016 fluoride remocal reactor, the subteam continued to improve fluoride purification by testing lab-scale systems consisting of either a single reactor or two reactors in series. During the experimentation process, clay was incorporated into the influent stream to abate PACl buildup at the bottom of the reactors. As the subteam seeks to transplant their system to India, it is currently working to optimize fluoride removal by minimizing use of resources. Thus, the team is currently trying to eliminate the use of clay and lower PACl dosages by increasing upflow velocity and further redesigning its reactor. Initial tests suggested insufficient fluoride removal for potable effluent, but the team is looking to repeat its previous experiments using the summer 2017 High Rate Sedimentation subteam’s reactor design

Sensor Development - Spring 2017

Cheer Tsang, Luna Oiwa, Jingfei Wang

Abstract:

This semester, the Sensor Development subteam modified and recalibrated the fluidized bed solids concentration sensor. This sensor enable the High Rate Sedimentation (HRS) team to determine the concentration of suspended clay particles in a running flocculation recirculator. In addition, the team fabricated a submersible sensor to determine the depth and concentration of the sludge layer in a sedimentation tank. This sensor functions in the same way as the fluidized bed solids concentration sensor, with the added characteristic that the photometer is fixed to the end of a PVC tube.

Chemical Dose Controller - Spring 2017

Annie Cashon, Cynthia Chan, Susan McGrattan, Karan Newatia

Abstract:

The Chemical Dose Controller (CDC) system was designed to maintain a constant chemical dose to the treatment train as the plant flow rate and influent turbidity change. This semester, the CDC team worked on expanding the modular design from previous semesters in order to improve ease-of-use during operation, better access to the system for plant operators, and greater system efficiency overall. The team designed and fabricated a new and improved constant head tank and calibration columns systems. This semester the CDC team also collaborated with the 1 L/s plant sub-team to create a CDC system for low flow rates.

High G Flocculation - Fall 2017

Roswell Lo, Tanvi Naidu, Luna Oiwa

Abstract:

The High G Flocculation team this semester designed an experimental set-up to test the effects of velocity gradient (G) in a flocculator and to determine the optimal G value based on flocculator performance in terms of effluent turbidity. The G value was varied in different trials by varying flocculator flow rate while controlling for coagulant dosage, influent turbidity, flocculation tube length, and upflow velocity through the sedimentation tank. G_theta was kept constant as around 20,000. The constant sedimentation tank upflow velocity was achieved using a waste stream between the flocculator outlet and sedimentation tank. It was found that for a standard coagulant dose, lower G values were associated with lower effluent turbidity, with 100 Hz being the lowest value tested. The same general relationship was observed for a higher coagulant dose, except that the lowest G values resulted in higher effluent turbidity due to floc blanket collapse. Data from this study will be used in the future to inform the geometry of the flocculator, i.e. the optimal distance between baffles in a full-scale water treatment plant.

Water Quality Monitoring for Diarrheal Pathogens - Fall 2017

Ji Young Kim, Steven Lopez, Fletcher Passow

Abstract:

AguaClara plants effectively remove turbidity and fecal indicator bacteria (FIB) from drinking water sources in Honduras. However, no study has documented the plants’ ability to remove specific diarrheal pathogen species. This study identified best practices for collecting and shipping pathogen DNA from sampling locations in Honduras back to Cornell University. A literature review identified options for filtration systems, chemical DNA preservation solutions, and shipping protocols. Tests of the clogging behavior of 5um and 0.1um pore size membrane filters demonstrated that this filtration method’s 60 h projected run time for a 10L samples outweighs its gains in simplicity.

Sensor Development - Fall 2017

Grace Zhang, Lois Lee, Srilekha Vangavolu

Abstract:

The Fall 2017 Sensor Development team worked on redesigning and calibrating the fluidized bed solids detector to be used for testing concentration of suspended particles in floc blankets as well as the submersible sensor designed to measure the height of the sludge blanket in the sedimentation tank.

Please note, no research report could be located for this team and the final presentation is linked instead

Ram Pump - Fall 2017

Priya Aggarwal, Will Lopez, Ana Ruess

Abstract:

The Fall 2017 Ram Pump subteam worked on mathematically modeling the ram pump’s mechanical behavior. Experiments conducted the previous semester proved that the ram pump does not operate as anticipated or desired. Ideally, modeling will explain this unpredicted behavior. With this knowledge, the team will be able to produce a more efficient and effective design. The team found a way to derive the forces involved in the pump, but more work needs to be done to determine what the optimal spring force is for the system.

Ram Pump - Spring 2017

Abigail Brown, Christopher Galantino, Ana Ruess

Abstract:

The purpose of the Ram Pump team is to fabricate a properly functioning hydraulic ram pump, or hydram, for implementation in AguaClara plants. The hydram is designed to deliver outgoing water initially flowing towards the distribution tanks back to the facility for utilization in chemical stick tanks or to collect water at higher elevations for other plumbing needs (toilets in the plant etc.) The team’s main goals for the semester are to determine which parameters are effective in allowing the system to work at minimal driving head as well as developing an audio-based diagnostic system for plant operator use in order to identify specific issues and apply correct solutions.

StaRS Filter Theory - Fall 2018

Barbara Oramah, Lainey Reed, Emily Spiek

Abstract:

Stacked Rapid Sand 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. This semester, the Stacked Rapid Sand (StaRS) Filter Theory team constructed 3 StaRS filters with sand of varying sizes. These filters will be used in future experiments to analyze how specific parameters, including sand grain size and coagulant dosage, affect filter performance. The StaRS Filter Theory team has spent the semester compiling a manual so that future teams can run experiments and reconstruct experimental filters if necessary.

Fluoride - Summer 2018

Ching Pang, Kevin Sarmiento, Cheer Tsang

Abstract:

Fluoride is a major contaminant in drinking water in many parts of India. The fluoride team's overarching goal is to create low cost, compact, and sustainable solutions to fluoride contamination in drinking water. The Summer 2018 team aims to continue and expand upon the work of previous teams by running experiments with both the pump-controlled system and the gravity powered system. The goal for the summer is to optimize the amount of coagulant needed to reduce the effluent fluoride concentration to 1 mg/L, as per the fluoride standard in India and design an easily adjustable gravity powered system. In addition, the team aims to develop a simple user guide for the fluoride probe in order to maximize future teams' efficiency.

Fluoride Auto - Fall 2018

Fluoride Automated System

Tigran Mehrabyan, Janak Shah, Samba Sowe

Abstract:

The Fluoride Auto subteam seeks to develop a sustainable, inexpensive fluoride removal system for implementation in upcoming AguaClara plants in India. Using the apparatus developed in previous semesters, the team continued running experiments testing how various concentrations of PACl affect fluoride removal. The team then analyzed the variability of the Langmuir isotherm generated by the summer 2018 Fluoride team. This analysis factored into the overarching goal of developing a model to predict an optimal coagulant dosage given both influent and target effluent fluoride concentrations.

Ram Pump - Spring 2018

Maile McCann, Will Lopez, and Steven Lopez

Abstract:

The goal of the Ram Pump subteam is to optimize the pumping efficiency of the hydraulic ram pump, where efficiency is measured in energy of water entering the pump over the energy of the water pumped. The hydraulic ram pump pumps clean water through the plumbing system of an AguaClara water treatment plant, which provides treated water for use in the chemical dosing system as well as sinks and toilets, and saves operators time and energy transporting treated water up by hand. The ram pump system is entirely electricity-free.

A major goal of Spring 2018 was to examine maximum energy efficiency. The value of calculating experimental energy efficiency is that the team is then able to compare the values to calculated theoretical energy efficiency. From there, we can exclude terms in the theoretical calculations to determine the main contributors to inefficiency.

This manual outlines procurement, fabrication, testing, and cleaning of the current hydraulic ram pump model as of Spring 2018.

Sensor Development - Fall 2018

Dana Owens, Lawrence Li, Lois Lee

Abstract:

The objective of the Sensor Development subteam is to develop sensors to monitor water quality during the water treatment process in Aguaclara plants. In previous semesters, the subteam developed a working prototype for an in-lab fluidized bed solids detector and also made progress towards prototyping a submersible sludge blanket detector. This semester the subteam also worked on finalizing a product-level version of the in-lab fluidized bed solids detector with a more intuitive user interface.The subteam will also work on finishing and determining the best prototype for the sludge blanket detector.

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.

UASB - Spring 2020

Emily Liu, Emily Wood, Lydia LaGorga, Katrina Chen, Winnie Chan

Abstract:

The Upflow Anaerobic Sludge Blanket (UASB) team has been designing, fabricating, and testing a gravity-powered wastewater treatment system for communities seeking an alternative to releasing waste directly into streams and rivers. A reactor with pulsed flow was installed at the Ithaca Area Wastewater Treatment Facility (IAWWTF) in Fall 2019, and sludge granules were added to initiate organic decomposition. The Spring 2020 subteam began monitoring pH, biogas accumulation, and sludge blanket height on a regular basis, and implemented a system to control reactor temperature. When the reactor completes its startup phase, the subteam will begin monitoring its performance with Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) tests.

StaRS Filter Theory - Spring 2020

Wenjie Lu, Claire Kenwood, Kelly Ly, Valentina Dai

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.

Sensor Development - Spring 2020

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 Spring 2020, the subteam tested two projects from Fall 2019 - the Submersible Sludge Blanket Detector, which is meant for the floc hopper, and the low-cost turbidimeter to measure dissolved organics.