WiSci blog encourages you to download these pdf’s and send them or the links (below) to anyone who is involved in water treatment in the developing world.
Mindbogglingly useful: Inexpensive water purification in the developing world using Moringa oleifera tree seeds
In the Hitchhiker’s Guide to the Galaxy, Douglas Adams described his fictional creation, the all-language-translating Babel fish, as being something “so mindbogglingly useful’” that it seemed almost inconceivable that it could have evolved by chance. This description might equally apply to the drought-resistant Moringa oleifera tree, which can yield–among many other things–oil for cooking and lighting, soil fertilizer, as well as highly nutritious and tasty food in the form of its pods, leaves, seeds and flowers. In addition, as is set out in this unit published in Current Protocols in Microbiology, its seeds can be used as part of an inexpensive drinking water treatment technique that could help significantly reduce the incidence of waterborne disease in the developing world.
Around a billion people in parts of Asia, Africa and Latin America rely on untreated surface water sources for their daily potable water needs. Of these, some 2 million are reckoned to die from waterborne diseases every year, with the majority of deaths being those of children under 5 years of age. This works out to something like 250 deaths an hour, which in population terms is like losing a large town every month, or one Mexico City every decade. To help combat this appalling toll of avoidable mortality, Michael Lea of Clearinghouse–an organization that researches and implements low-cost water purification technologies– has outlined a procedure that can reduce levels of harmful bacteria in water by between 90-99%, as well as reducing cloudiness, making the resulting drink both microbiologically and aesthetically more acceptable for human consumption.
Water purification methods using seeds from the Moringa tree have been known about for centuries, but their use has been limited geographically. Cultivation of this tree as a food source is now increasing–amazingly the tree grows well in those regions where it can be most useful–-but not enough people know how the crushed seed powder can help them clean their water and thereby avoid disease. It is Lea’s hope that having these protocols freely available online from a trustworthy source will be a massive aid in boosting in their distribution to where they are needed, by community leaders, health workers and educational programs.
The Moringa’s usefulness doesn’t end with the provision of cleaner water and food–incredible though that might seem–it can even bring small economic benefits and other health benefits: included in the pdf is a protocol for purification that can be used for extracting a multi-purpose vegetable oil from the seeds (in a process that leaves a ‘presscake’ that can cleanse water just as effectively as the powder). An advantage of this technique is that that any oil that is not needed for home cooking, lighting or mosquito repellent can then be sold, as can any of the surplus seed powder or presscake.
Michael Lea is at pains to stress that the use of these techniques will not be a panacea against waterborne disease. However, given that increasing the use of the Moringa tree would bring benefits in the shape of nutrition and income, as well as of purer water, there is the possibility that thousands of contemporary families could find themselves largely liberated from what should really be considered 19th century causes of death or debilitating disease. The idea that such change–even if it is not all-encompassing–might come by using the by-products of just one (almost implausibly useful) tree is something that should truly be classed as “mindbloggling”.
Bioremediation of Water Using Sand Filters
Current Protocols in Microbiology also features a second method for water purification, using a readily available and inexpensive material, which is also authored by Michael Lea. This uses biosand filters, which are based on a centuries-old bioremediation concept: water percolates slowly through a layer of filter media (sand), and microorganisms form a bacteriological purification zone atop and within the sand to efficiently filter harmful pathogens from microbiologically contaminated water. This low-cost household bioremediation intervention is capable of dramatically improving the microbial quality of drinking water, and should enable at–risk populations to use naturally occurring biology and readily available materials as a sustainable way to achieve the health benefits of safe drinking water.
- Bioremediation of Turbid Surface Water Using Seed Extract from Moringa oleifera Lam. (Drumstick) Tree
Biological Sand Filters: Low‐Cost Bioremediation Technique for Production of Clean Drinking Water
More Resources from Wiley Wastewater Microbiology, 4th Ed.
by Gabriel Bitton
Water and Sanitation Related Diseases and the Environment: Challenges, Interventions and Preventive Measures
by Janine M. H. Selendy
1. Michael Lea (2010). Bioremediation of Turbid Surface Water Using Seed Extract from Moringa oleifera Lam. (Drumstick) Tree Current Protocols in Microbiology DOI: 10.1002/9780471729259.mc01g02s16
2. Michael Lea (2008). Biological Sand Filters: Low‐Cost Bioremediation Technique for Production of Clean Drinking Water Current Protocols in Microbiology DOI: 10.1002/9780471729259.mc01g01s9