Fluoride - Spring 2018

Philip Akpan, Tigran Mehrabyan, Desiree Sausele, and Victoria Zhang

Abstract

The Fluoride subteam seeks to develop a sustainable, inexpensive fluoride removal system for implementation in upcoming AguaClara plants located in India. Using the apparatus developed by previous semesters, the team continued running experiments testing how various concentrations of PACl affect fluoride removal. However, complications with the ability to measure fluoride concentrations required the team to shift its goals to designing a lab scale, gravity-powered system. The team finalized a design and completed construction of the new, electricity-free apparatus. The team plans to run experiments to test its fluoride removal capabilities after ensuring that there are no remaining water leaks.

Fluoride - Spring 2017

August Longo, Briana Li-Vidal, Michelle Cheng, Victoria Zhang

Abstract

The Fluoride subteam seeks to develop a sustainable, 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 removal reactor, the subteam seeks to improve fluoride purification by testing lab-scale systems to compare a single reactor with reactors in series. At the beginning of this semester, the subteam identified potential issues with floc buildup at the bottom of the reactor. Thus, a sloped plane bottom geometry was incorporated into the reactor system to encourage recirculation of the flocs. Additionally, experiments with high concentrations of PACl resulted in clogging of the apparatus due to PACl buildup. Clay was incorporated into the influent stream to abate this PACl buildup. Initial testing of fluoride removal with the updated one and two reactor systems provided results that seem to indicate slightly better fluoride removal efficiency with two reactors, but more data collected by future testing is required to make a concrete conclusion.

Floc App - Spring 2017

Christian Rodriguez, Anthony Verghese, Deniz Yilmazer

Abstract:

Turbidity measurements provide the primary source of performance monitoring at many water treatment plants. Turbidity provides an excellent way to measure overall plant performance, but it fails to provide insight into the specific processes that make up the plant. The earliest reduction in turbidity in an AguaClara plant occurs after the sedimentation tank with a time delay of 30 to 45 minutes. This delay makes feedback control challenging especially when raw water turbidity varies rapidly. The floc size and count app comes in to fill this shortcoming by providing an easyto-use desktop application to measure floc distribution in various parts of the plant. The floc app can measure floc size distribution of the flocculated water to characterize flocculation efficiency. Flocculation residence time is expected to be less than 5 minutes in the next generation of AguaClara plants and this will significantly reduce the feedback time to provide guidance for setting the plant coagulant dose.

Prefab 1 L/S - Fall 2017

Felix Yang, Lilly Mendoza, Ken Rivero-Rivera

Abstract:

The 1 Liter per Second (LPS) Plant testing team is continuing the work done by previous semester's Pre-Fabrication team by attaching the ESTaRS to the 1LPS plant and flocculator. By doing this AguaClara will have a complete 1 LPS Plant running in the lab so that experimental data can be gathered. This data will be used to optimize and improve current designs as well as further iterations of the technology.

Fluoride Floc Blanket - Spring 2017

Fluoride Auto — August Longo, Briana Li-Vidal, Michelle Cheng, Victoria Zhang

ABSTRACT:

The Fluoride subteam seeks to develop a sustainable, 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 removal reactor, the subteam seeks to improve fluoride purification by testing lab-scale systems to compare a single reactor with reactors in series. At the beginning of this semester, the subteam identified potential issues with floc buildup at the bottom of the reactor. Thus, a sloped plane bottom geometry was incorporated into the reactor system to encourage recirculation of the flocs. Additionally, experiments with high concentrations of PACl resulted in clogging of the apparatus due to PACl buildup. Clay was incorporated into the influent stream to abate this PACl buildup. Initial testing of fluoride removal with the updated one and two reactor systems provided results that seem to indicate slightly better fluoride removal efficiency with two reactors, but more data collected by future testing is required to make a concrete conclusion

Filter Constrictions - Spring 2017

Jillian Whiting, Janak Shah, and Samantha He

Abstract:

The goal of the Filter Constrictions Team was to test the hypothesis that particles are captured preferentially at flow restrictions in sand filters. There was evidence for this from work done by the Milli-Sedimentation Team and the Stacked Rapid Sand (StaRS) Filter Theory Team. The goal of the team was to create a flow constriction in a 0.5 mm channel in a flow cell reactor, and take a video of the particles at the constriction. The video was taken using Point Grey FlyCapture Software, and provided evidence about the hypothesis that flow constrictions serve as particle collection sites.

Anaerobic Fluidized Bed Reactor - Spring 2017

Clare O’Connor, Evan Greenberg, Peter Martin

Abstract:

The initial focus of the Spring 2017 Anaerobic Fluidized Bed team (AFB) was to continue developing declogging mechanisms for the reactors, however it was learned that side-stepping declogging was possible by focusing on steady-state operation of the reactors. Thus, the middle of the semester included design of two reactor set-ups designed to determine the fastest hydraulic residence time (HRT) that could feasibly be used. The new designed showed that not enough was known about the treatment process to move forward productively, so an extensive literature search was performed to gather more information necessary for a possible redesign in the fall.

Enclosed Stacked Rapid Sand Filtration (EStaRS) - Spring 2017

Anna Doyle, Juan Guzman, Lilly Mendoza, Felix Yang

Abstract:

The Low Flow Stacked Rapid Sand Filter (LFSRSF) team was originally tasked with building a small, stan-alone sand filter to be implemented in communities in India. This semester the Enclosed Stacked Rapid Sand Filtration (EStaRS) team fabricated a new filter based on the design the Fall 2016 team created. The new design modifies the original LFSRSF; the filter column itself is shorter, the manifolds are sized differently, and the entrance and exit plumbing is now rigid PVC instead of flexible PVC. Next semester, the new EStaRS filter will be connected to the 1 L/s plant that has been built in the lab.

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.