Engineers for a Sustainable World
Dr. Say Kee Ong, Associate Professor in the Department of Civil, Construction and Environmental Engineering, engages engineering students in development projects through the CE 388x course, Sustainable Engineering and International Development, and as advisor to the student organization Engineers for a Sustainable World (ESW).
Thanks to e-mail and the Internet, Dr. Ong and both graduate and undergraduate members of ESW collaborate with Makerere University (MUK) professor Dr. Levi Kasisira and students in the Department of Agricultural Engineering. The MUK students visited Kamuli district to learn about rural farmer's needs and to collect preliminary data. Directed by the needs identified by farmers, the engineers on both continents narrowed down their project focus to water disinfection, water harvesting and biogas generation.
In 2006, Steven Diesburg and Edward Bulliner, members of ESW, traveled to Uganda to implement pilot projects with MUK students and summer interns through the national office of ESW. The group worked closely with the local non-governmental organization VEDCO (Volunteer Efforts for Development Concerns) to make sure that the projects could be installed in a culturally acceptable ways, continued, and that lessons learned from these initial projects could be used for the implementation of similar future projects.
Access to clean water for consumption and agriculture is a challenge according to farmers and families in Kamuli district. The water disinfection project uses local waste (used bottles), a photocatalytic agent, and energy from the sun to purify water for human consumption. The process can be used to disinfect surface or rain water and may provide an alternative to expensive boreholes (deep wells) as a clean water source.
Several issues remain as obstacles for implementation of this system in Kamuli district. First, it must be determined which type of bottle would be better suited for use affordable. Another issue is the supply of the catalyst and the sustainability of using a foreign chemical.
While Uganda has two rainy seasons per year, there are water shortages during the dry seasons. Boreholes are expensive to development and difficult to maintain, therefore may not be sustainable. Water harvesting is way to store water when it is plentiful and use it during dry seasons. Having access to water near fields also frees time for people to work on more important jobs or education instead of needing hours to fetch water.
Designs for the project consist of digging an appropriately sized pit for catching water from surface runoff and possibly lining the pit in some way, likely with locally available clay. Much of the work for the project was preparing a spreadsheet to be used by VEDCO to calculate the size of retention basin needed for a farmer's or community-water needs, surrounding land usage and soil type. This spreadsheet was prepared by ISU's ESW chapter in advance of the trip. The spreadsheet was discussed with the MU student and modified accordingly in Uganda to incorporate some of the assumptions made and the availability of possible lining materials for the pit. The assumptions made in the spreadsheet primarily involved soil data for Uganda, which would affect the amount of runoff collected as well as time for the collected water to remain in the retention basin.
The MU student involved presented his work on the project, which consisted of surveying data for a proposed site as well as a design for paving a football-field-sized plot of land for water runoff with a retention pond at the bottom. However, this design was deemed to be too expensive, time consuming and not durable as the concrete would not last long under the conditions. The potential site to be used in Kamuli was visited.
Creating an affordable and dependable energy source from animal waste (biogas) would eliminate the traditional practice of wood burning stoves. This will help to maintain local forests and wooded areas as well as decrease pollution and fumes in homes. Biogas is widely used in rural India and China but has not been developed much in Africa, especially in Uganda. The fermentation of animal manure in the digestion chamber of the system provides a safer place for containment and treatment of the manure. It traditionally needs to sit for a number of days before being used as a fertilizer. In a bioreactor, the manure is contained and usable gas is produced instead of sitting out on open piles.
A pilot functioning system biogas system was built at a farm to establish trust in the technology and encourage future ingenuity. ESW developed a spreadsheet for simple planning of future digesters, and that, along with the written building instructions, was left with the VEDCO office so they can facilitate future construction. MUK will continue to monitor the system to track how it functions.
