The overall aim of the project was to design a sustainable water treatment system suitable for use in small rural communities in Malawi using Moringa oleifera seeds. These communities typically use and drink water from shallow wells which are regularly found to be grossly contaminated with faecal coliforms. Seeds from the M. oleifera tree, native to Malawi, contain a unique water coagulant; a protein as distinct from an inorganic ion, which acts as a natural cationic polyelectrolyte. Limited research has been undertaken either to establish an optimisation profile of M. oleifera to purify groundwater or directly compare the effectiveness of M. oleifera against chemical coagulants. Little data also exists regarding assessment of any toxic effect caused by the seeds. A significant development for Malawi would be to develop a robust, inexpensive shallow well 'add-on' water purification system that uses this process.
- The first objective was to establish the most appropriate dosing method; the optimum dosage for removal of turbidity; the influence of pH and temperature; together with the shelf life of the M. oleifera seeds.
- The ability of M. oleifera to reduce the bacterial content of contaminated water was then tested and specifically compared to the performance of aluminium sulphate (alum) and ferric sulphate (ferric) on a variety of water types.
- To assess potential health impact of water treated with M. oleifera a series of cytotoxicity tests were completed via qualitative and quantitative methods.
- A shallow well bolt-on 'coagulation chamber' was then developed to form a simplistic water purification system. The purification system concentrates on the removal of bacteriological and physical constituents, which are the main forms of contamination that emanate from shallow wells and rivers. Preliminary laboratory data indicate that an 80 to 100% improvement in water quality can occur due to this process.