Making drinking water safer with Moringa seeds, lime juice .

Guardian. Lagos. Nigeria. 27.4.12

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​RESEARCHERS have validated two inexpensive and effective ways to quickly improve the quality of drinking water: sunlight plus lime juice and Moringa seeds.
Commonly known in the English language as the ben oil tree, the horseradish tree, or the drumstick tree, Moringa oleifera belongs to the plant family Moringaceae.
In Nigeria, it is called Ewe ile, Ewe igbale, or Idagbo monoye (the tree which grows crazily) in Yoruba; Gawara, Habiwal hausa, Konamarade, or Rini maka in Fulani; Bagaruwar maka, Bagaruwar masar, Barambo, Koraukin zaila, Shipka hali, Shuka halinka, Rimin nacara, Rimin turawa, Zogall, or Zogalla-gandi in Hausa; and Odudu oyibo, Okochi egbu, Okwe olu, Okwe oyibo, Okughara ite, Uhe, Ikwe beke in Ibo.
A low-cost water purification technique that uses seeds from the Moringa oleifera tree can produce a 90.00 per cent to 99.99 per cent bacterial reduction in previously untreated water, according to a paper published in Current Protocols in Microbiology. The method could help drastically reduce the incidence of waterborne disease in the developing world.
Moringa tree seeds, when crushed into powder, can be used as a water-soluble extract in suspension, resulting in an effective natural clarification agent for highly turbid and untreated pathogenic surface water. As well as improving drinkability, this technique reduces water turbidity (cloudiness) making the result aesthetically as well as microbiologically more acceptable for human consumption.
Also, a team of researchers from the Johns Hopkins Bloomberg School of Public Health and the Johns Hopkins School of Medicine, United States, found that adding lime-juice to water that is treated with a solar disinfection method removed detectable levels of harmful bacteria such as Escherichia coli (E. coli) significantly faster than solar disinfection alone. The results are featured in the April 2012 issue of American Journal of Tropical Medicine and Hygiene.
Prof. Kellogg Schwab, senior author of the study, director of the Johns Hopkins University Global Water Programme and a professor with the Bloomberg School’s Department of Environmental Health Sciences said: “For many countries, access to clean drinking water is still a major concern. Previous studies estimate that globally, half of all hospital beds are occupied by people suffering from a water-related illness.
“The preliminary results of this study show solar disinfection of water combined with citrus could be effective at greatly reducing E. coli levels in just 30 minutes, a treatment time on par with boiling and other household water treatment methods.
“In addition, the 30 milliliters of juice per two litres of water amounts to about one-half Persian lime per bottle, a quantity that will likely not be prohibitively expensive or create an unpleasant flavour.”
In low-income regions, solar disinfection of water is one of several household water treatment methods to effectively reduce the incidence of diarrheal illness. One method of using sunlight to disinfect water that is recommended by the United Nations Children’s Fund (UNICEF) is known as SODIS (Solar water Disinfection).
The SODIS method requires filling 1 or 2 L polyethylene terephthalate (PET plastic) bottles with water and then exposing them to sunlight for at least six hours. In cloudy weather, longer exposure times of up to 48 hours may be necessary to achieve adequate disinfection.
To determine if one of the active constituents in limes known as psoralenes could enhance solar disinfection of water, Schwab and Alexander Harding, lead author of the study and a medical student at the Johns Hopkins School of Medicine, looked at microbial reductions after exposure to both sunlight and simulated sunlight.
The researchers filled PET plastic bottles with dechlorinated tap water and then added lime-juice, lime slurry, or synthetic psoralen and either E. coli, MS2 bacteriophage or murine norovirus. Researchers found that lower levels of both E. coli and MS2 bacteriophage were statistically significant following solar disinfection when either lime juice or lime slurry was added to the water compared to solar disinfection alone. They did find however, that noroviruses were not dramatically reduced using this technique, indicating it is not a perfect solution.
Michael Lea, a researcher at Clearinghouse, a Canadian organization dedicated to investigating and implementing low-cost water purification technologies said: “Moringa oleifera is a vegetable tree which is grown in Africa, Central and South America, the Indian subcontinent, and South East Asia. It could be considered to be one of the world’s most useful trees.
“Not only is it drought resistant, it also yields cooking and lighting oil, soil fertilizer, as well as highly nutritious food in the form of its pods, leaves, seeds and flowers. Perhaps most importantly, its seeds can be used to purify drinking water at virtually no cost.”
Lea concluded: “This technique does not represent a total solution to the threat of waterborne disease. However, given that the cultivation and use of the Moringa tree can bring benefits in the shape of nutrition and income as well as of far purer water, there is the possibility that thousands of 21st century families could find themselves liberated from what should now be universally seen as19th century causes of death and disease.
This is an amazing prospect, and one in which a huge amount of human potential could be released. This is particularly mind-boggling when you think it might all come down to one incredibly useful tree.”
Also, another study published in African Journal of Agricultural Research by researchers at the University for Development Studies, Faculty of Applied Sciences, Department of Applied Chemistry and Biochemistry, Navrongo, Ghana, concluded: “The results obtained show that powder from seed kernels of M. oleifera contains some coagulating properties at loading doses of 10 g/L and above that have similar effect as the conventional coagulum, alum.”