UASB - Fall 2015

Zoe Maisel, Evan Greenberg, Yi Guo, Mason Minot

Abstract:

The Fall 2015 U​pflow Anaerobic Sludge Blanket (UASB) g​roup has continued the previous work of the AguaClara anaerobic wastewater groups. A literature review of technical journals was conducted to gain familiarity with the current state of anaerobic wastewater treatment technology internationally. The reports from previous wastewater groups were also reviewed to provide insight into the current state of anaerobic wastewater technology within AguaClara. The literature review served to identify common challenges to address during this and next semester including reactor leakage and creating an airtight design, combining a UASB unit with a GSBR unit in an attempt to improve overall treatment capacity, and oxygen stress testing to determine the robustness of the reactor. The beginning of the semester was spent cleaning and removing biomass from reactors, testing for leaks using a bubble solution, and performing a single ­day pressure test in an attempt to approximately quantify the volumetric leakage rate. Two UASB reactors were inoculated and began producing biogas within the first week of operation. COD analysis and gas chromatography were performed to characterize the efficiency of COD treatment and methane production within the reactors.

Whatever it is, the way you tell your story online can make all the difference.

Water Technology Treatment Selection Guide - Spring 2015

Andrew Mullen and Sarah Sinclair

Abstract:

The Water Treatment Technology Selection Guide (WTTSG) team seeks to implement a webtool capable of providing recommendations regarding the efficacy and appropriateness of various water treatment options. This tool must be dynamic, responding appropriately to user input, and robust cross-­culturally, recognizing cultural and language barriers. It must also adhere to principles of human-­centered design, remaining accessible to populations with various degrees of skill while engendering a positive user experience. The current WTTSG team has continued the work of previous teams in creating a functional and attractive website. Significant strides were made this semester in passing data between pages of the site, the design and implementation of the results page, the construction of the administration panel, and the collection and population of data in the site. The site is now equipped to calculate regressions, provide automatic translations and log user input, and has been deployed on a MySQL-­enabled server. Future challenges include the tackling logistics of providing the best recommendation possible, while continuing to make the website’s recommendations scalable to new languages and technologies.

Whatever it is, the way you tell your story online can make all the difference.

EStaRS - Spring 2015

Sarah Bolander, Skyler Erickson, Liza Johnson, Subhani Katugampala, Lilly Mendoza

Abstract:

The Spring 2015 EStaRS team built upon the work of previous semesters to optimize the original filter design as well as to develop alternative strategies to sections of the filtering process. Over the course of the semester, the team altered the process for attaching the filter cap in order to prevent future cases of blow­off, adjusted the system for controlling water level height during backwash, and ran tests on filtration efficiency. While at the beginning of the spring semester the team’s goals also included developing a method of testing and recognizing bed fluidization within the filter, looking into a method of running multiple filters in parallel, and setting parameters for backwash duration and frequency, the team changed directions and concerned itself with the implementation of a new filter injection system to combat the problems associated with using slotted pipes.

EStaRS - Fall 2015

Skyler Erikson, Lilly Mendoza, Natalie Mottl, Lishan Zhu

Abstract:

The Fall 2015 EStaRS team reworked the lab scale setup of the EStaRS filter to work without a large pool to preserve lab space. The team then finished the orifice inlet implementation that was begun in Spring 2015, and provided an operating procedure for both filtration and backwash to avoid trapping sand in the inlets during the transition. The biggest takeaway from the operating procedure is that orifices can be operated successfully as long as the backwash transition does not create a drastic pressure change. Slowly closing the gate valve on the backwash siphon provides a gradual change and does not trap sand in the inlets. This procedure was the result of numerous inlet cloggings, and thus the team also devised a method for unclogging inlets without disassembling the filter. The team also implemented a pressure sensor to track headloss accumulation through the filter bed in the entrance tank. This pressure sensor was used to measure a clean bed headloss which is very close to the design clean bed headloss.

Modular Designs - Fall 2015

Stephanie Sun

Abstract:

The Fall 2015 Modular Designs task is a continuation of previous efforts to provide AguaClara clients the ability to request individual component designs on the AguaClara website.In Fall 2012, design team member Heidi Rausch began working on creating upper levelMathCAD files that the design tool will use to create individual component designs in addition to the already available full scale plant design. The goal of the Fall 2015 Modular Designs team is to continue working on the modular designs by updating already existing component files as well as creating new upper level files for other parts of the plant.

Chemical Dose Controller - Fall 2015

Serena Takada

Abstract

This semester, the Chemical Dose Controller (CDC) Team improved the AguaClara Automated Design Algorithm by updating the CDC drawing file to reflect recent updates in the CDC system design. Updating the CDC drawing code will allow clients and team members to obtain an accurate design of the current AguaClara plant designs using the AguaClara Design Tool. When 1 the existing CDC drawing code was implemented with the most uptodate drawing at the beginning of the semester, AutoCAD outputted the design illustrated in Figure 2. As shown in Figure 2, with the existing code, the CDC system is located inside of the Flocculator even though it should be mounted on the outside wall of the Flocculator. This was the starting point of the challenge. By the end of the semester, the CDC dosing system and lever arm were mounted against the Entrance Tank and Flocculator wall.

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 included 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 compiling a system of equations to convert the CDC system into a modular, packaging item for future shipment. With design changes in mine, a major goal of the CDC team this semester will be to create an assembly manual and parts-list.

Foam Filtration Pore Size - Spring 2015

Lotta Van Leeuwen, Tianchen Yu, Caroline Caglioni

Abstract:

Abstract unavailable for this team for this semester.

Please note, the final report is not available for this team for this semester and the Final Presentation is linked instead.

Foam Filtration - Spring 2015

Marlana Hinkley, Alena Hutchinson, Ethan Keller, Alicia Peters

Abstract:

The primary goal of foam filtration is to design a low cost, locally sourced, easy to operate water filtration system. Throughout the semester, backwash cleaning efficiency experiments were performed on the small-scale filter, designed in Fall 2014 to hydraulically model the full scale filter implemented in El Carpintero. The objective of these experiments was to determine an empirical relationship between backwash pore velocity and the percent mass removal of the particles from the foam during the cleaning cycle. Experimentation with different pore sizes revealed a new mechanism for filtration: the foam acts as a sedimentation tank, providing a large surface area for the flocs to settle. This is contrary to the initial hypothesis that coagulant-covered flocs stuck to the inside of the pore walls, and that a large shear force would be required to remove the flocs during backwash. Evidently, there is still much to be understood with regards to the mechanisms behind filtration and backwash. 

Apart from work in the laboratory, the team continues to analyze data collected from experiments performed on the full-scale filter in El Carpintero by AguaClara engineer, Walker Grimshaw, to understand the discrepancies between performance in the laboratory and in the field. 

Much of the semester was spent preparing for the EPA P3 Conference held on April 10th and 11th in Washington, DC. The team fabricated a small scale model of the technology, prepared a technical report, and created a poster display for the competition, and received an Honorable Mention for its efforts in creating an “Off-Grid Solution to Drinking Water Treatment.”

StaRS Filter Theory - Fall 2015

Isha Chaknalwar, Theresa Chu, Michelle Lee

Abstract:

Modeling the physics of particle capture in stacked rapid sand filters allows for greater understanding and further innovation in filtration. A two-layer sand filter will be built to measure filtration performance parameters of effluent turbidity, head loss, and time until turbidity breakthrough or excessively high head loss. Sand filtration should be effective in removing small flocs, so flocculated influent water with coagulant and clay will enter the filter to simulate filtration and clogging.

StaRS Filter Theory - Spring 2015

Theresa Chu, Nick Coyle, Alexandra Schwab

Abstract:

The Stacked Rapid Sand Filter Theory team designed and built an apparatus to induce clogging and test the head loss across a slotted pipe, which allows the water to flow directly into the filter without sand leaving the filter. Experiments were run with high turbidity and coagulant doses to clog the slotted pipe and determine which influent conditions led to clogging and high head loss. Slotted pipes as an injection system for the stacked rapid sand filters have proven to be problematic due to clogging. Results show that floc build up of coagulant clay increased head loss and clogged the slots.