Village Supply System - Household – Fall 2014

Pooja Desai, Paula Gomez­Nunez, Mary John

Abstract:

The Fall 2014 Household Infrastructure Team designed a storage tank, sink and a flow regulation system at the household level in a rural Indian village. The ultimate goal of the semester’s designs was to provide equitable flow to each house, to be stored and used in a sanitary environment. The designs determined that a 600L HDPE storage tank at each household is necessary to store a days worth of water to the family, attached to double level sink that provides an upper basin for washing of dishes 1m above the ground and a ground level platform for washing clothes. Tanks are elevated on top of a brick stand that is approximately 1m tall. Inside the tanks, ball cock float valves with an inner diameter of 1⁄2” regulate water flow.

To provide equitable water flow to each household in the village, no matter where the house is located, flow regulation to within 10% of the target household flow, 0.021L/s was forced in our design by adding headloss elements into the distribution system before the storage tanks. Extensive research into pressure regulators as a means of flow regulation was done, but it was determined that they are impractical for villages that have only a few meters of elevation difference. The design expanded further upon previous semesters work with small diameter coiled flexible tubing that greatly restricts flow. Depending on the available tubing diameters, it was found that 1m­6.7m of tubing is required at the household level to force equitable flow throughout the village.

Village Supply System - Distribution Subteam – Fall 2014

Maria Veronica Cordova, Tianchen Yu

Abstract:

The Team Village Supply has three sub teams working on the photovoltaic pump, distribution and household design. The Village Supply­Distribution System Subteam has worked based on last semesters code 2canzzzz’ and improved it so that it has more accurate final results and it can be set continuous, meaning that this code can be updated with any characteristics of other villages. The overall design of the subteam consist in the network of pipes that distribute water coming from the tank to every house in the village. The new code has taken into account the flow variation into each tier of pipes, and thus the result in the sizing of the pipes has changed significantly. As a result we obtain the critical path and the correspondent head loss through the pipes, considering major and minor losses and differences in height elevations. The cost of the total network design including pipes and tees has been calculated with updated costs for the optimal solution.

Village Supply System - PV/Pump – Fall 2014

Qingjing Gong, Anqi Wang, Erika Axe

Abstract:

The PV/Pump Subteam section has worked on how to modify and improve upon the ideas and models already in place for design of pumps in villages for the Fall 2014 Semester; this group is a subset of the entire Village Supply Team in the AguaClara Student Project Team at Cornell University. In general, this subset has worked toward having single electric pumps that send water to the town and lifts water from the well at ground level to an AguaClara facility/distribution system, deliberating types of pumps and pressure requirements for equal distribution, balancing cost and efficiency of pumps, and evaluating the different options for the design of the photovoltaic and pump system. Among the different designs for the photovoltaic and pump system, this section will be looking at two main options. The first option will be to divide the power between the two pumps, create a simple control system for easily maintenance, and to design the photovoltaic system to be able to handle cloudy, winter days. The second option to be looked into will be to divert all the power to the first pump on cloudy days and to allow the control system to automatically divert all of the power to the well pump when the chlorine contact tank isn't full—thereby allowing the second option to be more easily implemented.

Chemical Dose Controller - Fall 2014

Annie Cashon, Jeanette Liu, Christine Leu

Abstract:

The Chemical Dose Controller is a device that maintains a constant chemical dose as the plant flow rate changes. This semester, the Chemical Dose Controller team has started doing research on chlorine compatibility with the constant head tank. Part of this assignment includes exploring alternative CHT designs in hopes of maximizing durability and efficiency while minimizing costs. The team is also considering scaling the CDC system down by looking into the single lever arm design. The team has begun recording these adjustments in a CDC assembly manual for future CDC teams that includes photos and item lists. Finally, the team has reached out to the team in India, in hopes of working out a cost effective and reliable system for future shipments.

Ram Pump - Fall 2014

Abigail Brown, Annie Ding, Pablo Nistal, Kadambari Suri

Abstract:

The Fall 2014 ram pump team is working on expanding and improving upon the work of previous ram pump teams, which includes fabricating and implementing a working ram pump design in a plant in Honduras. The team has completed literature research, fabrication of the ram pump designs to be tested, basic experimentation, and data collection. The literature review has determined that while experimentation done on ram pump components like the spring check valve indicate that these parts will last for decades, the non-ideal conditions of the use of the spring valves in AguaClara plants means that more experimentation is needed to determine how long the valves will last while in use in AguaClara plants. Additionally, the team has found other points of wear within the valve during testing this semester. Ideas for potential improved designs have resulted in the fabrication of air chambers of varying sizes and drive pipes of different lengths and diameters. The most efficient pump model was determined by taking data for different models with varying numbers of weights on pressure within the system and flow rates at various head loss values. The team found that the optimal system for the ram pump is to use as few weights as possible without causing the ram pump to stop, along with either one of the two tested outlet possibilities, and as large an air chamber as desired or available. However, this system does not result in an adequate output flow rate, due to losses within the system. More work still remains to be done - the team is currently working on a vertical system alternative which may eliminate the need for a horizontal drive pipe and may reduce the number of losses within the system that is affecting the output flow for the system currently in use.

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Ram Pump - Spring 2014

Ruben Ghijsen, Kelly Huang, Ruju Mehta

Abstract:

The team this semester focused mainly on rebuilding and improving the ram pump and its lab set-up. Major changes to the system from last semester include a more compact head loss system, higher overhead drive tank (to better simulate Honduras parameters), and an attempt to improve the air chamber design, In the end, the team was able to con- struct a working prototype that successfully pumped and delivered water through the entire head loss system. However, due to time constraints, the future team will have to make additional improvements to the system. They include a larger, encased recycling system, and more structural sup- ports to minimize instability. Although the initial run proved successful, additional testing could not be conducted due to computer malfunctions and again, time constraints. Had given the time, experimentation would be conducted regarding the 􏰃ow rate, head loss, reliability, and scaling. Future teams can now focus on these experiments since the prototype is basically complete.

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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.

Wastewater Treatment, Spring 2014

Ge Gao, Maithili Gokarn, Walker Grimshaw, Ethan Keller, Caitlin McKinley, Amiel Middelmann, Luke Zhu

LFSRSF, Summer 2014

Richa Gwalani, Guneet Sandhu, Tom Schultz, Savannah Wing

Abstract

People in many parts of the world are still devoid of basic human necessity like clean drinking water. Many drinking water treatment systems in the global south face limited economic viability because of the unreliable source of electricity and expensive operation costs. Stacked Rapid Sand Filters (SRSF) were invented by the AguaClara team to eliminate the need for pumps or control equipment, thus making it more robust and reliable than conventional rapid sand filters. The low-flow stacked rapid sand filter (LFSRSF) is an adaptation of the SRSF for flow rates < 3.0 L/s and is currently being deployed in India for flow rates of 0.8 L/s serving communities of about 500 people. The previous LFSRSF research teams have been working on fabricating the laboratory version (version 1) of the filter with continuous improvements to the design aimed at simplifying the operation and maintenance of the filters. This version of the full-scale filter in the lab fabricated by the previous team has 0.2mm slotted pipes throughout and top and bottom manifolds consisting of single slotted pipes. The initial version 1filter is nearing completion in two villages in India, Rohne and Gufu. Our work was to fabricate the next version full-scale filter, version 2, which was built upon the previous teams version 1filter. In the 2nd version of the full-scale filter, we tried to mitigate problems faced by the previous version, such as overflowing of the inlet tank and the inability to backwash at designed ow rates. We also wanted to move towards the ability to handle and filter turbid water. This 2nd version of the full-scale LFSRSF will be used as a prototype for mass production by the Tata Water Mission in India. A major part of optimizing the operation of the filters included accounting for head loss incurred in the system and incorporating these changes in the final design of the critical components of the filter.

Distribution System Contamination Prevention, Fall 2014

Alicia Peters, Chen Weier, David Gold, Lucia Garcia-Iturri Gallego

Abstract

Contamination of treated water in the distribution system has the potential to negate the improvements to water quality provided by an AguaClara plant. Intermittent distribution systems may create the conditions for the mechanisms which cause this contamination to occur. The most likely mechanisms of distribution system contamination are pipeline intrusion, cross contamination and inadequate household storage. Through proper operator training, effective regulation and installation of secure storage facilities and backflow prevention valves, these mechanisms can be prevented and safe water delivered to all AguaClara households.

EStaRS, Fall 2014

Sarah Bolander, Skyler Erickson, Subhani Katugampala, Mary Millard, Savannah Wing

Abstract

The ultimate goal of the EStaRS (Enclosed Stacked Rapid Sand) Filter team was to develop an appropriate configuration for the stacked rapid sand filter system that could be implemented to treat groundwater in India. The stacked rapid sand filter is an excellent choice for treating water near the city of Ranchi, India, as the primary water source there is groundwater. The low turbidity of groundwater means that the full AguaClara treatment process is not required and filtration with dosing will suffice. After testing the current apparatus, the goal was to improve the design so that modular EStaRS filters can be run in parallel efficiently and sand bed fluidization can be detected. This team set up a system to allow for extended backwash times, proposed a weir design to run multiple EStaRS Filters in parallel, and set up a manometer system to analyze bed fluidization during backwash.

Arsenic Team, Spring 2014

Tanapong Jiarathanakul, Jason Koutoudis, Mingze Niu

Abstract

The modification of AguaClara sand filtration unit by coating the media surface with PACl was investigated in this research in order to remove arsenic from contaminated influent. This process is called adsorptive media filtration, which is one of the emerging technologies in water treatment processes. In order to ensure accurate arsenic analysis, the graphite furnace atomic absorption spectrometer (GFAAS) was aligned and calibrated extensively. Since the pre-programmed sampling procedure by the GFAAS had been proven ineffective in measuring low arsenic concentration, two specialized analytical methods called multiple injection method and large injection method were created to detect arsenic at low concentrations. These methods lowered the detection limit of arsenic concentration by the GFAAS down to 2 µg/L. In the experimental preparation, an upflow sand filter column was fabricated using a 1.20 m transparent PVC pipe with 0.622-inch inner diameter. The sand bed depth was 87 cm. Two peristaltic pumps were connected to stock solutions: coagulant (PACl) and groundwater with diluted arsenic concentration at 100 µg/L. In this experiment, both pre-treatment and co-treatment methods were employed. Using an approach velocity of 1 mm/s, the results showed the arsenic removal efficiency during the first 80 minutes of the experiment was at least 97%, which validated the removal efficacy of adsorptive media filtration technique.

Demonstration Plant, Spring 2014

Alice Reis, Erin Loughlin, Lauren Frazier

Abstract

The demo plant team is responsible for design, construction, and troubleshooting of the AguaClara Demo Plant. The successful operation of this plant is crucial in order to demonstrate the process of AguaClara plants to all stakeholders, including students, faculty, staff, community members, business partners, and potential sponsors. This spring semester, our research team focused on fixing issues with the current demo plant design, such as an unreliable flocculator and dose controller, unstable frame, and concerns with differences in hydraulic head. Our research includes conceptualizing and testing a more efficient and stable plant assembly and start-up for those unfamiliar with the technology; resolving issues with improper coagulant dosing and head loss differences; designing and implementing a new flocculator design; testing new fittings for the stacked rapid sand filter; and providing thorough documentation of the demo plan so that future teams would have less difficulty familiarizing themselves with the AguaClara demo plant. The redesigned demonstration plant is more stable with the addition of a middle bream and a contiguous bottom support. Overflow issues in the flocculator were addressed through the manufacture of a new flocculator, which contains an overflow weir and outlet. Inconsistencies with head loss were resolved by creating a Mathcad calculation file to determine the necessary lengths of a “long, straight” tubing from the constant head tanks. Increasing the capacity of the raw water stock tank from less than one liter to two liters allowed for an increase in continuous operation without interruption.

Fabrication - Spring 2015

Stephen Galdi, Natalie Mottl

Abstract:

The team’s task is to test, troubleshoot, and complete the scale model of the weir system developed by last semester’s team. By the end of the semester, the team will create as et­up and video that accurately portrays the behavior of the water through the full scale weir system. The Fabrication Team aims to create a plant that is easier to operate, troubleshoot, and build.

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.

Countercurrent Stacked Floc Blanket Reactor, Fall 2016

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 sustainably achieved.