Chemical Dose Controller - Fall 2014

Zeyu Yao, Saugat Ghimire

Abstract:

The Chemical Dose Controller is an important of component of a AguaClara plant. The CDC delivers the coagulant (Polyaluminum Chloride (PACl) or Aluminum sulfate (Alum)) to the influent water and disinfectant Calcium hypochloride to the effluent filtered water. The Chemical Dose Controller is a simple mechanical response device which maintains a linear relationship between the plant flow and the chemical dose. It consists of a calibrated lever arm which the operator can use to adjust the dose of the chemical based on the turbidity of the influent water. The Fall 2013 team started o􏰂 by putting together three half size doser units for stacked rapid sand􏰃filters constructed in India. All the parts were shipped to India with a detailed instruction manual to aid the assembly. The dosers sent to India contained CPVC ball valves with fluoroelastomer seals that are more resistant to chlorine than the previously used PVC ball valves. The ball valves in all the AguaClara plants will now be replaced with these CPVC ball valves. Similarly, a lock-and lock container will now be used as the Constant Head tank for both chlorine and coagulant suspended with a chain and a turnbuckle for height adjustment. Although the lock-and-lock container degrades when in contact with chlorine, it is locally available and can be easily replaced. In addition to this, the design of a new half-size doser with single arm which only doses chlorine has been completed. A 3D sketch-up file has been created and sent to Hancock Precision for fabrication. This new doser will primarily be used in low 􏰄ow plants in India which only require chlorine delivery.

Water Treatment Technology Selection Guide – Spring 2014

Subhani Katugampala, Neelesh Bagga

Abstract:

This is the final research report of the Water Treatment Technology Selection Guide Team for Spring 2014. Our goal this semester was to design a selection guide that provides a clear rubric for evaluating and comparing water treatment technologies. A major part of this involved developing the framework and decision-making methodology for such a decision-support system. Current technology selection guides tend to focus on providing information on treatment technologies based on contaminant removal requirements, while ignoring the realities of resource-constraints and skill-constraints of communities, and without considering sustainable engineering practices. An expert guidance tool is needed to empower water supply professionals to make better decisions and to learn the constraints determine which technologies are appropriate.

Water Treatment Technology Selection Guide – Fall 2014

Yao Lu, Larissa Sakiyama, and Sarah Sinclair

Abstract:

The Water Treatment Technology Selection Guide Team seeks to build an attractive and functional web application that will allow parties interested in the construction of an AguaClara plant to compare various available treatment technologies and receive an estimate of plant costs. This semester’s team was tasked with integrating plant cost calculator (PCC) and water treatment technology selection guide (WTTSG) tools, improving the regression equations which provide cost estimates to the PCC, and synthesizing and incorporating information about various treatment plants into the application. The team worked to completely overhaul previous semesters’ web development work in order to pursue a design that embodies UI/UX (User Interface/User Experience) principles. The new tool is highly interactive with a sleek, modern design, and is in the process of being deployed live as part of AguaClara’s web presence. The team has developed several regression equations useful for cost estimation, engaged in research related to plant cost and available treatment technologies, and made significant progress in the implementation of the WTTSG tool over the course of the semester.

Plant Cost Calculator – Spring 2014

Andrew Bales, Chris Mills, Derrik Yee

Abstract:

AguaClara designs low-cost water treatment facilities and desired a tool to estimate and present the capital and operational costs of an AguaClara plant. The goal of the Plant Cost Calculator team is to create such a tool to provide an accurate estimate of the costs associated with construct- ing and operating an AguaClara water treatment plant. The objective of the calculator is to allow users to easily obtain accurate design and operational cost estimates that can be compared to alternative water treatment options, and to make users better aware of the factors that contribute to the final plant cost. At the end of our first semester, the plant cost calculator team has completed the back-end for a working and easy-to-use calculator based in part on data from existing plants in Honduras. Future objectives will include developing a more attractive front-end interface, closer collaboration with WTTSG, and integrating India plant costs into the data used for prediction.

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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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.

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.

Laminar Tube Flocculator - Summer 2014

Shreya Jain, Tanya Peifer, Nadia Shebaro, and Luke Zhu

Abstract:

Over the summer of 2014, the laminar tube flocculation team has worked to test AguaClara's new residual turbidity monitoring system, SWaT, as compared with prior teams that used FReTA. The group has also implemented PID control for the laminar tube flocculator to regulate the amount of clay added to the system. In order to achieve these goals, the laminar tubing system was simplified and reconfigured to eliminate the feedback loop with the turbidimeter. The team plans to continue optimizing the system and confirming the self regulating controls were working before starting experiments using varying dosages of coagulant.

Laminar Tube Flocculator - Spring 2014

Victoria Chou and Yining Dai

Abstract:

Flocculators are an integral part of the water treatment process. The􏱕focculation process turns the colloidal matter within water into flocs that will eventually be removed through the sedimentation process. The creation and eventual settling of flocs formed in the flocculator results in cleaner, clearer water. According to Swetland et al.'s hypothesis, flocs that reach a certain size are no longer effective in removing colloids be- cause the shear on the surface of the flocs becomes too high for the colloids to attach. Thus, by breaking large flocs, they may regrow and scavenge additional small colloids that were not able to settle out from the suspension. The purpose of this series of experiments is to continue testing the Floc Breakup Theory and, if valid, to determine the most effective way to break up flocs in order to have the highest removal rate of colloidal particles. The settled water turbidity analyzer (SWaT), a new turbidity measurement system, was designed and implemented for the Spring 2014 research, in which the effluent water first travels through an angled tube settler with continuous 􏱕ow before being analyzed by the effluent turbidimeter. A base case test was run to serve as a control showing residual turbidity with the new turbidity measurement system. Adjustments to the new setup were made to accommodate for issues that arose from the new turbidity measurement system.

Foam Filtration - Spring 2014

Kristin Chu, Skyler Erickson, Melissa Shinbein, Jeffrey Suen, Kadambari Suri

Abstract:

The Spring 2014 foam filtration team will focus on improving the water treatment system designed in Fall 2013 and incorporating the knowledge learned on the trip to Honduras in January, 2014. This includes: redesign- ing the cleaning techniques to improve efficiency in removing dirty water off of the top of the foam, investigating foam re-expansion in a drum with vertical sides, designing the LFOM, and implementing a coagulant doser. The goal for this semester is to design, build, and test a compact system that can be easily transported and eventually implemented in small communities. In order to achieve this long-term goal, the Foam Filtration team will need to investigate multiple design options and create an operational system in the AguaClara lab. The foam filter will then be tested in Honduras.

Foam Filtration - Summer 2014

Abby Brown, Ethan Keller, Skyler Erickson, Ji Young Kim

Abstract:

The Summer 2014 Foam Filtration team will continue to improve the water treatment system, aiming to send a complete filter design to Honduras in July 2014. The goal of the summer is to verify the safety of the foam filter itself and to improve the design of the filtration system for better performance, easy fabrication and transportation. The foam filter will be additionally tested in Honduras.

Foam Filtration - Fall 2014

Kristin Chu, Marlana Hinkley, Ethan Keller, Valerie Pietsch

Research report not available. Research presentation attached below.

Enclosed Stacked Rapid Sand Filter - Spring 2014

Dhaval Mehta, Ariel Seidner, Sarah Sinclair, Lishan Zhu

Abstract:

The Low Flow Stacked Rapid Sand Filter (LFSRSF) is a scaled-down version of the AguaClara Stacked Rapid Sand Filter (SRSF). Similar in theory of operation to the SRSF, the LFSRSF is optimized to treat smaller flow rates of 0.8 L/s. The current LFSRSF design in India uses multiple valves to switch from filtration to backwash; the LFSRSF research subteam at Cornell seeks to reduce the number of valves by designing a filter that uses hydraulic controls. In detailing the teams work this semester, this report seeks to accomplish three main goals: to document the design process for such a filter, to document the fabrication process to facilitate easy technology-transfer to India, and to document filter performance as tested to date.

This semester, the team calculated appropriate design specifications for slotted manifold, trunks, plumbing systems and sand for the filter, as well as created a unique flexible-tubing derived sand drain. The team completed all fabrication, and also set up a water-recycle and leak containment system to support testing, as well as a pressure sensor array to test ow-distribution between sand layers. The team then solved multiple water- and air-leak issues. Ultimately, the team was successful in ensuring that the LFSRSF backwashes easily, efficiently and whenever an operator may so desire.

Teams working on the project further must tackle three major issues: the current filter cannot handle backwash flow rates greater than around 0.6 L/s, its entrance and exit tanks need to be raised, and the filter also faces significant challenges of larger-than-expected head loss during backwash. Once these issues are solved, the hydraulically-controlled LFSRSF shall be truly ready to be deployed in the field

Chemical Dose Controller - Spring 2014

Andrea Cashon, Saugat Ghimire, Jeanette Liu

Abstract:

The Chemical Dose Controller team completed the design and fabrication of the single lever arm assembly. This assembly will be utilized in low flow plants that only require a chlorine doser. The new Chemical Dose Controller maintains the same functionality of the previous model. It will also be chemically resistant and require fewer materials, lowering fabrication and shipping costs. The team also created a float valve for the constant head tank that has fewer corrosive metal components and has the floatin line with the orifice. The team has created a new height adjustment system for the constant head tank and a dosing tube air removal system that utilizes a wye channel. Additionally, the entrance tank float was redesigned to be smaller and lighter, for easier and cheaper shipping. Finally, the team created an items catalog that contains every single component - and it’s corresponding McMaster-Carr identification number - used in a Chemical Dose Controller system. This catalog will help future Chemical Dose Controller teams order components and construct new systems.

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