Regional Planning - Spring 2016

Lauren Frazier, Yu Jin Hur, Disha Mendhekar

Abstract:

The scope of the semester was to analyze the feasibility and need for an AguaClara plant in India. The team decided to focus on India asa country of potential implementation as India already has AguaClara LLC workers on the ground building connections. The team approached the analysis through large-scale research, gathering data on India’s water sources, demographics, geography, and economy. There are ten ideal characteristics that would suggest a potential site. The team conducted research on India to determine locations with these characteristics. The team also created an optimization model using Matlab to visually display the deliverable in the form of a color-coded map.

Granular Sequencing Batch Reactor, Spring 2016

Nisarg Gohil, Amiel Middelmann, Claudia Vesga, Victoria Zhang

Improving aerobic granulation wastewater treatment processes with PACl dosing.

High Rate Sedimentation - Plate Settlers, Spring 2016

Albert Cheng, Sidney Lok, Yuqi Yu, Lishan Zhu

Abstract

This semester, the goal of the High Rate sedimentation - Plate Settlers team was to maintain a suspended layer of colloidal particles (flocs) at upflow velocities higher than 1 mm/s. The suspended layer, referred to as the floc blanket, circulates flocs, enhances flocculation, and is self-cleaning. As the floc blanket grows in height, it spills over a weir into a sludge collection chamber to prevent sludge build-up inside the sedimentation tank. increasing the upflow velocity in the sedimentation tank decreases the necessary plan-view area and cost of construction. A high density floc blanket is necessary to prevent flocs from escaping the sedimentation tank at higher velocities. The High Rate Sedimentation - Plate Settlers team explored different plate settler geometries in the sedimentation tank to concentrate the floc blanket.

High Rate Sedimentation (Floc Blanket), Spring 2016

Ogechukwu (Oge) Anyene, Isha Chaknalwar, Josiah Hinterberger, Ziwei (Vanessa) Qi

Abstract

The High Rate Sedimentation - Floc Blanket team built a sedimentation tank model with the goal of increasing the upflow velocity and decreasing the plan view area, without degrading the performance of the floc blanket inside the tank reactor. Under high turbidity conditions, a stable floc blanket was maintained under upflow velocities from 1-4 mm/s. Two method of encouraging floc re-circulation, viz., in-reactor lamella plates and sludge recycling, were tested to observe effects on effluent turbidity. Results indicated that neither method had a strong enough effect to fully recommend increased upflow velocity, but future testing in improved apparatus with low turbidity influent has potential.

Microbiological Water Safety Monitoring, Spring 2016

Jacqueline Dokko, Janak Shah

Abstract

The ultimate goal for the microbiological water safety monitoring (MWSM) team is the development of a test that detects pathogens in water. The test must be of low cost (under ten dollars for each test), have a reduced incubation time from the standard 48 hours, and be able to be used in a low-resource setting such as Honduras. The team tested methods indicating the presence or absence of bacteria compared to quantitatively determining bacterial presence. Upon understanding the cost and efficiency of each method, it was possible to narrow down the methods that could be used as a model for microbial detection for AguaClara purposes.

Prefab 1 L/s - Spring 2016

Kimberly Buhl, Claire DeVoe, Meryl Kruskopf, and Felix Yang

Abstract:

The goal of the Prefabrication 1 L/s team was to research, test, and provide fabrication methods to be used when constructing the 1 L/s plant design in Honduras. The team worked on an approximate 1/10th flow rate scale model to design novel geometries for a low-flow flocculator and sedimentation tank while implementing known AguaClara fluid mechanic techniques. The cost per capita associated with these plants was calcu- lated to be much lower than plants built using traditional construction methods. Recommendations on design and fabrication methods were re- layed to future teams working on full-scale plant production.

Fluoride - Spring 2016

August Longo, Pooja Desai, Katie Dao

Abstract:

In many developing countries, high levels of fluoride in groundwater have been found to have chronic effects on bone health. Though some countries intentionally add fluoride to water in order to strengthen teeth, overexposure to fluoride has grown as a problem worldwide. The Fluoride team has been working to solve this very issue, by testing and developing a fluoride removal system fit for AguaClara plants in India and Honduras. In spring 2016, the Fluoride team built on the previous work of the Fluoride and Countercurrent Stacked Floc Blanket Reactor team to create a more optimal and efficient fluoride removal system. In the fall, the Fluoride team worked to understand the efficiency of fluoride removal using polyaluminum chloride (PACl) while the CSFBR team developed a reactor system to remove undesirable soluble particles. This semester, a new system was built consisting of a single floc blanket formed using PACl and clay. In the future, this system will be optimized by changing flow rates and dosages to better understand fluoride treatment and optimize AguaClara plants for fluoride removal.

CSFBR - 2016 Spring

Surya Kumar, Christine Leu, Amlan Sinha, Cindy Dou

Abstract

Floc blankets, which are suspended layers of highly concentrated flocs, have the potential of being a more efficient option for removing arsenic, fluoride, and certain dyes in terms of energy and water consumption than currently employed techniques. For floc formation, a coagulant needs to be added to the water, allowing particles to adsorb to each other when they collide. Previous research has shown that the coagulant, polyaluminum chloride (PACl), has properties that allow arsenic, fluoride, and certain dyes to adsorb to its surface. The first iteration of this research used three floc blankets in series with a counter-current flow of contaminated water and flocs. By feeding flocs from the last reactor into the second, and from the second into the first, the PACl’s surface area can be saturated. To test this theory and apparatus, a dye, Remazol Brilliant Blue R (RBBR), was chosen to be the contaminant due to its less toxic nature and visual component. With this apparatus and contaminant, this semester’s goals were to test dye removal efficiency from water with varying concentrations of clay, PACl, and dye. With a 1:1 ratio of PACl to dye, a dye removal efficiency of roughly 80% was achieved. However, the transportation of flocs from the third reactor to the second and first was not sustanaibly achieved.

StaRS Filter Theory - Spring 2016

Theresa Chu, Lucinda Li, Jonathan Harris

Abstract

A mathematical model describing sand filtration would promote the understanding of stacked rapid sand filter performance. Variables affecting filter performance include coagulant dosage, influent turbidity, and sand filtration depth. The collected data from a model filter informed a mathematical model explaining the effect of coagulant mass on the filter’s effluent turbidity, head loss, and failure time. Experiment runs demonstrated that increasing coagulant dosage led to an increase in head loss and decrease in time until filter failure as well as vary effluent turbidity. Head loss curves for the various PACl dosages had the same trend after filter failure and converged to the same value after a 24 hour run time.

Ram Pump - Spring 2016

Priya Aggarwal, Juan Guzman

Abstract

The Ramp Pump team was created to design, construct, test, and ultimately implement a hydraulic ram pump for AguaClara plants. The Ram Pump is located at the lowest level of the plant and is used to pump water either to a storage tank or directly to chemical stock tanks located at the top level of the plant. The team’s goal for the semester was to finalize designs for a self-contained pump, which is intended to maximize space efficiency. The team confirmed the viability of an enclosed vertical ram pump design over the course of several iterations. The team also redesigned the spring manipulation system and has a design that is ready to be implemented in AguaClara plants.

Fabrication: Open Stacked Rapid Sand Filtration (OStaRS) - Spring 2016

Mengqi Jiang, Subhani Katugampala

Abstract:

The construction of Open Stacked Rapid Sand Filters, or OStaRS, has been determined to be a difficult and labor-intensive process. the absence of a uniform installation procedure and proper construction methods leads to the overall inefficiency of the OStaRS assembly process. The Spring 2016 OStaRS Fabrication Sub-Team was tasked with developing three design modifications to ease with installation, which include a spacer system to be installed between filter modules, a movable platform for operators to stand on during assembly, and a holder system to fixate the dead end of the filter trunk line. The team has designed and fabricated the spacer and the platform systems. These designed were successfully stress tested, approved for field implementation, and are currently set for installation in one AguaClara treatment plant.

Fabrication: Floc Hopper Probe - Spring 2016

Miguel Castellanos

Abstract:

The floc hopper probe is a devise that is meant to locate the height of the sludge blanket in the floc hopper of AguaClara water treatment plants. Teams in the past have conducted research and eventually fabricated a working probe prototype that was transported down to Honduras in January 2016. The probe was tested at different treatment plants in Honduras and showed promising results with minor complications. This semester, one of the main objectives is to re-size the probe in order to ensure that it is able to enter the PVC pipe port that is in the sedimentation tank channel system. Furthermore, the team will look into making the design more professional while keeping it cost effective.

Note: The final report for this subteam for this semester was not available and the final presentation is linked instead.

Fabrication: Constant Head Tank - Spring 2016

Anna Doyle, Valerie Shao, Serena Takada

Abstract:

The main problem with the plastic Tupperware Constant Head Tank (CHT) containers currently used in the the AguaClara water treatment plants is that they are not chlorine resistant so they have to be replaced frequently. This issues was addressed by the fabrication team this semester. New CHTs were designed, fabricated ,and evaluated to determine the best to be implemented at AguaClara treatment plants. The first design was fabricated from clear PVC sheets and constructed using PVC welding; the second was constructed out of a PVC pipe and cap. The two designed were then compared in terms of ease of construction, functionality, and costs. Based on this analysis and the recommendations from the AguaClara engineers, the second design was determined to be the best and will be implemented in future AguaClara water treatment plants.

Enclosed Stacked Rapid Sand Filtration (EStaRS) - Spring 2016

Natalie Mottl, Michelle Bowen, Lilly Mendoza, Erica Marroquin

Abstract:

Manometer research & head loss modeling for greater efficiency and ease of use in Honduras and India.

No research report was available for this team for this semester. The final presentation is linked instead

Expanded Granular Sludge Bed (EGSB) - Spring 2016

Qiu Shen, Stephen Galdi, Zoe Maisel

Abstract:

The Expanded Granular Sludge Bed (EGSB) team was created to work within the wastewater subteam to design and run new, bench-scale, high rate anaerobic reactors. New reactors were designed to create a system with increased upflow velocity of influent, a fluidized bed, and decreased hydraulic retention time without decreased granular retention. Reactors were designed with simple operation in mind, with narrow modules in series rather than a single large reactor with recycle. The reactors were inoculated following abiotic testing of pumping rates, connection seals, and methane sensors. Immediately after inoculation, the granules began to form blockages and back up the reactor. Various forms of agitation seem to alleviate the problem, and automated solutions to the blockage problems has been proposed. In addition to blockages, the first module of the reactor was acidifying due to the low hydraulic residence time and relatively high specific organic loading rate. However, the following three modules were observed producing significant amounts of methane via the sensors, and at the end of an uninterrupted week of operation a COD test indicated about 40 percent total COD removal. With improved methane sensor calibration and a blockage prevention system, the bench-scale setup for high rate anaerobic treatment could potentially become a very versatile tool for testing the limits of anaerobic wastewater treatment and methane bioenergy reclamation.

Floc Size and Count App - Spring 2016

Christian Rodriguez, Anthony Verghese, Deniz Yilmazer

Abstract:

Turbidity measurements provide the primary source of performance monitoring at many water treatment plants. However, turbidity readings of floc suspensions do not provide any insight into the performance of subsequent treatment processes. The Floc Size and Count App team’s aim is to create and easy-to-use personal computer application that could measure floc size distribution using a digital camera with appropriate magnification. The app will be written in LabVIEW. The aim for this semester is to develop coding expertise in the LabVIEW environment and start working on the app that will be used in the AguaClara labs and eventually in AguaClara drinking water treatment plants.