Filter Flow Control - Spring 2017

Matt Cimini, Alex King, Tanvi Naidu

Abstract:

The objective for the Filter and Treatment Train Flow Control team (FTTFC team) this semester was to design and construct a weir module that would allow the plant operator to easily redirect sucient flow for filter backwash without shutting o↵ other filters’ flow. The goal of the design was to be easily constructible, easy to operate, strong enough to withstand water pressure and require no calculations for plant use. The team designed several removable weir options and ultimately chose a hinged design. The design is similar to a dog door that will be shut during normal flow and open during backwash. The model was fabricated and tested under conditions simulating a 20 L/s plant. The weir module was strong enough to withstand the flow, was easy to construct and was simple to open and close even with the water pressure against it and therefore was a success. There was some significant leakage around the weir flap. Therefore, construction and design should focus on recommendations for watertightness of the flap if this design is to be used in an AguaClara plant in the future.

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 1L/S - Spring 2017

Sidney Lok, Sung Min Kim, Sean King

Abstract:

The Spring 2017 semester 1 L/s Plant Testing subteam's objectives were to improve upon the previous work done on the design of the 1 L/s pilot plant in Honduras. This semester, the primary goals of the 1 L/s Plant Testing subteam were to complete the 1 L/s plant and to design and fabricate a tapered flocculator. This tapered flocculator design would be used to decide whether tapered flocculation would improve overall water treatment in the 1 L/s plant.

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.

Arsenic Sensor - Spring 2017

Kevin Juan, Dylan Vu, Kelly Stefanski

Abstract:

Final research report was not available for this team, so the final presentation is linked instead. If you know where this research report can be found please reach out the RIDE Committee, so this can be updated.

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.

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.

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.