Mrs. Julie Anne Wildschut

<p>Access to clean drinking water has long been an issue in the developing world, and the <br />impacts of unclean water on these communities cannot be overstated. A crucial component to <br />saving lives as well as improving quality of life is water disinfection. However, this problem is <br />made difficult by the fact that for water systems in developing countries, particularly rural ones, <br />there is a lack of access to the same funds, testing equipment, and electricity that make water <br />disinfection feasible in developed nations. As a result, a creative solution must be utilized to <br />achieve water disinfection in these communities. This is where the Calvin Clean Water Institute <br />comes in: combining knowledge across a wide variety of disciplines to help solve these <br />problems. We bring our academic understanding and work with knowledgeable locals to help <br />develop creative solutions to complex problems.</p>
<p><br />The goal for this year&rsquo;s research was to investigate, with the future goal of implementing, <br />a passive (non-electric) chlorinator that could be used in a small (less than 500 home) <br />Ecuadorian community. Preliminary research indicated the suitability of the CTI-8 chlorinator for <br />this undertaking.</p>
<p><br />The CTI-8 chlorinator was chosen because it could be constructed easily out of PVC, <br />was inexpensive, and could dispense chlorine consistently. As a result, we began our research <br />by building the chlorinator and a model system to test it in. Afterwards, we began collecting <br />large quantities of data about the chlorinator to understand its operation and capabilities. To do <br />this, the flow rate of water through the model system was varied, as were other parameters to <br />determine the behavior of the CTI-8. The effluent chlorine concentrations were measured using <br />a DPD pillow and a visible spectrometer. We learned that by varying the chlorinator bypass an <br />operator can effectively exert control over the chlorine concentrations. For implementation in a <br />community, this can prevent microbial contamination while maintaining low enough <br />concentrations to prevent community rejection. This was a crucial lesson that will most likely be <br />used in the future implementation of chlorinators, including a possible passive chlorinator <br />installation in Spring of 2024.</p>
<p><br />A secondary component of my research was the use of electrolysis to create bleach,<br />and to design a procedure for container disinfection with the synthesized bleach solution. This <br />ended up being the less successful portion of the project but still led to important developments <br />for future research.</p>
<p>The electrolysis system was comprised of an electric current that was run through a saltwater <br />solution for 24 hours, which results in a concentrated bleach solution. Several trials were run, <br />with the intent to create a concentrated bleach solution. Although none of the trials produced the <br />original target concentrations, modifications in the process resulted in a marked improvements <br />as the summer progressed. </p>
<p>Although I succeeded in meeting the goals that my advisors and I set for summer research, <br />there were significant setbacks along the way. It took days to begin collecting reliable data for <br />the chlorinator due to an unexplained spike in chlorine concentrations, and the electrolysis <br />produced unexplainably low bleach concentrations.<br />Overall, research was an incredible experience. The most important lesson I learned from this <br />project is that the solution to any real-world problem is extremely complex. As engineers, we are <br />prone to the sin of pride, where we think we have the answers necessary to solve every <br />problem. In reality, real world problems are necessarily complex and multifaceted, and problems <br />that are worth solving can require weeks, months, or even years to develop adequate solutions.</p>

In 2002, WHO reported that nearly 1.7 million deaths worldwide were caused by unclean  water. The risk of death by unclean water is elevated for young children, for which the second  cause of death worldwide is diarrheal disease, which is largely caused by microbes; these  microbes, when unaddressed, can proliferate in drinking water. Health risks are further elevated  in rural communities, which often lack access to the technology necessary to treat water for  microbial contamination. This can be seen in Ecuador, in which only 52.8% of rural households have access to safe drinking water.

The problem of infected drinking water in rural communities begs the question: how does   one effectively eliminate the risk of microbial contamination without the use of electricity and   complex, expensive components? A solution: passive chlorination. Passive chlorination systems   use the flow of the water itself to release chlorine into the water. The chlorine then disinfects   the water, leaving it safe to drink.

The research that I conducted this summer, in conjunction with related research   conducted by a team of professors and engineering students, primarily involved assembling and   testing a chlorinator that was determined by literature review to be the most promising option   of several different passive chlorinators. The CTI-8, designed by Compatible Technology   International, is a low-cost chlorinator that can be made using hand tools and commercially   available PVC components. Using the provided instructions for building a CTI-8, I constructed and   tested one in a model system that was meant to mimic the flow conditions in Ecuadorian   communities. The model system was comprised of a hose-fed 50 gallon upper tank, a main pipe   line that split into two lines (one with the CTI-8 and one without it), a bypass valve, and a 50   gallon lower tank into which both lines drained. This model system provided a way to run a series   of experiments to determine the dosing capabilities of the CTI-8, and to determine how to adjust   the bypass valve that controlled the ratio of water that went through the chlorinator versus the   ratio that bypassed the chlorinator.

The ability to control this ratio proved to be a very reliable means of controlling the final   combined concentration of the two lines. If more chlorine was needed in the lower tank, the   amount of water bypassing the chlorinator was reduced, and vice versa. Additionally, the CTI-8   proved to be very effective at consistently dosing water for a wide range of flow rates. For this   reason, the CTI-8 will be implemented for an Ecuadorian community by July 2023.   Working with a team to develop and test a real-world solution has been eye-opening to   the multi-faceted nature of real-world engineering problems. In the case of Ecuador, access to   clean water is a societal, economic, and technological issue, making it a challenge to create an   appropriate solution that meets the needs of Ecuadorian communities.