Scale-Up of Moringa Coated Sand Filters to Produce Clean Drinking Water
Open Access
- Author:
- Espinoza Soto, Paula
- Area of Honors:
- Chemical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Stephanie Butler Velegol, Thesis Supervisor
Themis Matsoukas, Thesis Honors Advisor - Keywords:
- Moringa oleifera
water
binary mixtures
collector size
activated carbon
total organic matter
water filters
Moringa seeds - Abstract:
- Clean drinking water is a global issue particularly in developing countries, affecting more than 844 million people around the world. The objective of the project is to scale-up and redesign a Moringa oleifera seed coated sand filter (f-sand) to remove bacteria from wastewater with locally accessible and affordable materials. Moringa seeds contain a cationic protein that will adhere to negatively-charged sand. This sand can then be used to can remove the pathogens present in the water due to electrostatic forces between negatively charged microbes and the positively-charged protein on the sand. For the purpose of scaling up these filter columns, the glass columns packed with 106 um glass beads used previously were replaced by glass columns packed with binary mixtures of larger sand sizes. These materials included recycled materials and more available and cost-effective materials from the field. The column diameter and effluent flow rate were adjusted according to the Clean Bed Filtration Model to obtain the EPA standard approved pathogen removal. To prove the functionality of the filters for bacterial removal, fluorescent E. coli bacteria was first utilized as the influent. The results showed that the higher the percentage of 106 um sand size, the higher the removal of bacteria the filter achieves. However, in a more realistic scenario, it was noted that when treating water spiked with E. coli and organic matter (TOC), the TOC competes with the bacteria for protein sites, impeding the proper removal. To address this problem, an activated carbon pre-filter was implemented. The results showed that, when this pre-filter is applied, the TOC is contained within the activated carbon particles, allowing the f-sand filter to function properly and remove bacteria above the EPA standard approved removal.