Download Free Water Purification Techniques from Current Protocols in Microbiology

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



    May 2011

    Water and Sanitation Related Diseases and the Environment: Challenges, Interventions and Preventive Measures
    by Janine M. H. Selendy

    Made freely available as part of the John Wiley & Sons Corporate Citizenship Initiative.

    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

Interview with R. Ian Freshney, Author and Cell Culture Expert

R. Ian Freshney, PhD, is an honorary Senior Research Fellow in the Centre for Oncology and Applied Pharmacology at the University of Glasgow. He is a world-renowned expert on cell culture technique and has authored and edited numerous successful books, including the hugely popular Culture of Animal Cells (now in its 6th Edition), and Culture of Human Stem Cells.

Here, he answers a few questions on his own techniques as an author and on the continuing role of books in modern scientific research.

  1. Culture of Animal Cells: A Manual of Basic Technique and Specialized Application, 6th Ed has been very well received by the scientific community, as have many of your other titles. What do you think sets your books apart and makes them so successful compared to other titles in the field?
    I would say there are three major components: (1) The books are designed as practical guides with detailed single-step instructions which should be sufficient without further recourse to the literature. (2) The preparation and sources of materials are explained in detail. (3) Most of the basic protocols are illustrated with easy-to-follow diagrams.
  2. What challenges did you face while putting together Culture of Animal Cells: A Manual of Basic Technique and Specialized Applications, 6th Edition?
    I struggled with the need to update but at the same time preserve basic procedures which have not changed markedly from the previous edition. This, of course, led to the dilemma of deciding what to retain and what to leave out. I also thought long and hard about what specialized protocols to add without compromising the basic technique role of the book.
  3. What do you find rewarding about authoring and editing books in the sciences?
    It forces me to keep up-to-date with developments in cell culture, and in turn helps me to be a better teacher of cell culture. I also get satisfaction from converting what are sometimes complex instructions into one simple straightforward procedure.
  4. What inspired you to write your first book?
    I was invited to prepare a textbook on cell culture for a college course. Previously, I had used John Paul’s book, Cell and Tissue Culture, and knew it needed to be updated.
  5. What advice would you offer to scientists writing or editing their first book?
    • Determine the precise niche that you wish to fill.
    • Plan the structure carefully beforehand but do not be afraid to deviate, within reason, to meet new demands.
    • Ensure the text is well illustrated with tables and diagrams.
    • Make sure the book is properly cross-referenced.
    • Prepare the index yourself. Even if it is to be professionally indexed you will find terms that the indexer does not.
  6. How would you compare the experiences of writing a book and writing a journal article?
    Both require a clear concise style, but the author has more freedom to express ideas and opinions when writing a book. Another major difference is that a scientific paper must address a specific topic and provide proof to substantiate the conclusions that are drawn, while a book draws on the author’s and other scientists’ experience to provide a more general review and specific guidelines or instructions.
  7. Do you find that the role of books in the scientific research community has changed over the years? Are they valued more or less today than they were 10-20 years ago?
    Rapid changes in technology mean that some books will become outdated without regular updates, which are not always feasible in printed copy. Yet, while there is an increasing tendency to provide instructions and protocols online, many people will still find reassurance from using a textbook with an established reputation.
  8. How do you envision the evolution of science writing over the next 5-10 years?
    Certain journals will still tend to be regarded as more reliable than others, as indicated by their citation indices. However, the number of free public access journals will probably increase, presumably with payment to submit articles. There will be a continuing need for editorial control of journal content due to the proliferation of unedited, non-reviewed material appearing online.
  9. What do you feel has been the most significant scientific discovery that has been made during your lifetime?
    I can really only speak for biology where the elaboration of the genetic code is probably the most significant development. The ability to regulate gene expression and the resultant plasticity of the cell phenotype will create major opportunities in cell culture and its relevance to tissue in vivo.
  10. What are you reading right now?
    This questionnaire! Otherwise, mostly novels and current journals for which I have alerts.

Video Games Enhance Visual Attention

Video games might cause aggressive behavior,1 and they may contribute to childhood obesity,2 but recent research by Daphne Bavelier and her colleagues at the University of Rochester suggests that playing video games can have at least one benefit: they enhance visual attention

Visual attention is the mental mechanism we use to select relevant visual information and suppress irrelevant information in our visual field. This ability is particularly important during activities that require selective focus amidst an overwhelming amount of incoming visual material. Driving a car or flying an airplane are two such circumstances . . . as is playing a video game.

In action-packed video games such as Halo or Call of Duty, players must aim and shoot accurately while simultaneously tracking enemies and other rapidly moving objects—thus emphasizing visual attention. In studies comparing the visual attention of gamers and non-gamers, Bavelier and her colleagues found that gamers consistently outperformed non-gamers.3 Furthermore, non-gamers who practiced playing video games demonstrated improved visual attention. This means that playing the video games increased gamers’ visual attention (as opposed to the alternative possibility that people with superior visual attention tend to play video games).

The implications of this research are important in both medicine and the military. EyeMario, a system developed by National Labs, is a vision-controlled video game that is being used to treat amblyopic patients. Amblyopia, or “lazy eye,” is treated by forcing the patient to exercise their lazy eye, often by patching the healthy one. Video games such as EyeMario work as “eye exercises”: sensors attached to the player’s face detect retinal movements and use these to control the character Mario’s actions in the game.

In addition to helping patients with visual deficits, Bavelier and her colleagues suggested in their review that fighter pilots would benefit greatly from enhanced visual attention. In 2008, the U.S. Army invested $50 million over 5 years to develop games and gaming systems to train soldiers, and the Program Executive Office for Stimulation, Training, & Instrumentation (PEO-STRI) has already developed the Additional Blackhawk Flight Simulator—amongst other programs—to help train army pilots.

Read Bavelier et al.’s research in WIREs Cognitive Science.

Watch a demonstration of EyeMario.

Find more PEO-STRI programs.

Resources from Wiley on This Topic
Computer Assisted Exercises and Training: A Reference Guide

by Erdal Cayirci and Dusan Marincic

1. Anderson, C., & Carnagey, N. (2009). Causal effects of violent sports video games on aggression: Is it competitiveness or violent content? Journal of Experimental Social Psychology, 45 (4), 731-739 DOI: 10.1016/j.jesp.2009.04.019

2. Vandewater EA, Shim MS, & Caplovitz AG (2004). Linking obesity and activity level with children’s television and video game use. Journal of adolescence, 27 (1), 71-85 PMID: 15013261

3. Hubert-Wallander, B., Green, C., & Bavelier, D. (2010). Stretching the limits of visual attention: the case of action video games Wiley Interdisciplinary Reviews: Cognitive Science DOI: 10.1002/wcs.116