Browsing the papers in my local news agent the day before the recent election I picked up a copy of the Times because it contained a magazine called 'Eureka: Science. Life. The Planet'. It featured a short article on the Moringa or Ben Oil Tree Moringa oleifera Lam. and refers to an article in Current Protocols in Microbiology (Feb 2010) that published a downloadable, step by step extraction and treatment procedure to produce "90.00% to 99.99%" bacterial reduction.
The crushed seeds of the tree, or the remaining cake after useful oil has been extracted, contain basic polypeptides that are an effective natural flocculating agent that significantly reduces turbidity and colour of untreated surface water. Pathogenic microorganisms are bound together in a colloidal suspension and fall to the bottom of the vessel. Treated water can be decanted or siphoned off.
The paper is careful to point out that using the process does not guarantee the elimination of pathogens and that further treatment may be necessary.
The tree itself originates from the Indian Himalayas, is tolerant of poor soil conditions and is drought resistant and has multiple nutritional and supposed medicinal uses.
Well done to Current Protocols for publishing the method.