Slow Sand Filters in Mwenezi, Zimbabwe

Creating engineering education resources on water filtration techniques and coordinating resources to build slow sand filters

Acquired skills: Project management, curriculum creation, frugal engineering

The DeBoer Lab, the engineering education lab that I worked for, uses a specially developed model called Localized Engineering in Displacement (LED) to work on long-term implementation of solutions in the communities that we collaborate with. The curricula designed are contextualized to local assets and cultures.

One of the projects that we worked in was in collaboration Plan USA and all-girls schools in Mwenezi, Zimbabwe, to address local water insecurity issues. In this project, I created several lessons for local teachers to teach about different water filtration techniques. We worked with a Purdue start-up called Maji Safi and its cofounders Dr. John Maiyo and Dr. Chad Jafvert, a professor of Civil Engineering at Purdue. We utilized their expertise on slow-sand filters to teach the girl students on the functionality and the construction of these filters.

Diagram of Slow Sand Filters, designed by Dr. Chad Jafvert at Purdue

After creating lessons on the functionality of the slow sand filters, I worked closely with Dr. Jafvert to create lessons on how to construct them. We also added an extra step of alum flocculation to get rid of inorganic compounds since groundwater was the students’ primary water source. There were several steps involved in this process:

  • Collating an inventory list for the filters and flocculation process, and coordinating with local liasons to acquire them
  • Recording videos of the assembly of the slow sand filters
  • Coordinating with Dr. Jafvert on manufacturing and transporting Maji Safi’s proprietary porous plate kits for the slow sand filters

By the end of the project, 240 girl students were able to construct 8 slow sand filters. These filters were very advantageous, as they require little mechanical power, are low maintenance, easy to assemble, and greatly improve the quality of the water by reducing its turbidity and organic contaminants.