Biological Sand Filters: Low‐Cost Bioremediation Technique for Production of Clean Drinking Water

Michael Lea1

1 Safe Water International, Carpinteria, California
Publication Name:  Current Protocols in Microbiology
Unit Number:  Unit 1G.1
DOI:  10.1002/9780471729259.mc01g01s33
Online Posting Date:  May, 2014
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Abstract

Approximately 1.1 billion people in rural and peri‐urban communities of developing countries do not have access to safe drinking water. The mortality from diarrheal‐related diseases amounts to ∼2.2 million people each year from the consumption of unsafe water. Most of them are children under 5 years of age—250 deaths an hour from microbiologically contaminated water. There is conclusive evidence that one low‐cost household bioremediation intervention, use of biological sand filters, is capable of dramatically improving the microbiological quality of drinking water. This unit will describe this relatively new and proven bioremediation technology's ability to empower at‐risk populations to use naturally occurring biological principles and readily available materials as a sustainable way to achieve the health benefits of safe drinking water. Curr. Protoc. Microbiol. 33:1G.1.1‐1G.1.26. © 2014 by John Wiley & Sons, Inc.

Keywords: biofiltration; bioremediation; biosand filter; water treatment; microbiological contamination; water quality; developing countries

     
 
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Table of Contents

  • Introduction
  • Strategic Planning
  • Reading Source Water Turbidity
  • Basic Protocol 1: Quantitative Estimate of Turbidity
  • Support Protocol 1: Building a Simple Turbidity Gauge
  • Options for Pretreating Source Water
  • Basic Protocol 2: Alleviating High Turbidity
  • Basic Protocol 3: Adapting the Biosand Filter for Arsenic Removal
  • Constructing the Sand Biofilter
  • Basic Protocol 4: Preparing Media for Use in a Biosand Filter
  • Basic Protocol 5: Installing the Media
  • Operating the Biosand Filter
  • Maintaining the Sand Biofilter
  • Basic Protocol 6: Periodic Disinfection (Cleaning) of Filter Container
  • Basic Protocol 7: Recovering the Flow Rate
  • Safe Water Storage
  • Disinfecting Effluent Water
  • Basic Protocol 8: Bleach (Free Chlorine) Disinfection of Effluent Water
  • Basic Protocol 9: Solar Disinfection (SODIS) of Effluent Water
  • Basic Protocol 10: Boiling Disinfection of Effluent Water
  • Commentary
  • Literature Cited
  • Figures
     
 
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Materials

Basic Protocol 1: Quantitative Estimate of Turbidity

  Materials
  • Turbidity gauge (see protocol 2Support Protocol)
  • Additional reagents and equipment for turbidity treatment ( protocol 3)

Support Protocol 1: Building a Simple Turbidity Gauge

  Materials
  • 1‐in. (2.5 cm) diameter PVC end cap
  • Waterproof marking pen
  • Glass or clear plastic tubing, 1‐in. (2.5 cm) diameter, 28‐in. (70 cm) length
  • PVC cement (glue)
  • Measuring tape

Basic Protocol 2: Alleviating High Turbidity

  Materials
  • Collected water
  • Filter container
  • Sari cloth or other fabrics

Basic Protocol 3: Adapting the Biosand Filter for Arsenic Removal

  Materials
  • Water (from the best source possible)
  • 11 lb. (5 kg) of nongalvanized iron nails, length <¾ in. (20 mm)
  • Filter containing diffuser box (see Strategic Planning)
  • Small broken brick chips or stones, 2‐ to 4‐in. (5 to 10 cm) diameter

Basic Protocol 4: Preparing Media for Use in a Biosand Filter

  Materials
  • Mixed sand and gravel
  • Water (from the best source possible)
  • Materials for building three wooden sieves including:
    • 1‐in. × 4‐in. (2.5 cm × 10.00 cm) lumber to construct three sieves, three 8 foot (2.4 m) lengths
    • 1‐in. × 1‐in. (2.5 cm × 2.5 cm) wood strapping, three 8‐foot (2.4‐m) lengths of ½‐in. (12 mm) screen, ¼‐in. (6 mm) screen, and 0.03 in. (<0.7 mm) mosquito screen; screens must be metal, not nylon or fiberglass
  • Tape measure
  • Hammer
  • Nails
  • Saw
  • Shovels
  • Tarp
  • 5‐gallon (20 liter) buckets

Basic Protocol 5: Installing the Media

  Materials
  • Water
  • Household chlorine bleach solution (see protocol 10)
  • Filter (see Strategic Planning)
  • Materials for correct media installation including:
    • 2 in. (5 cm), 2.7 quarts (∼3 liters) of washed ½‐in. (12 mm) drainage gravel
    • 2 in. (5 cm), 3 quarts (3.25 liters) of washed ¼‐in. (6 mm) separation gravel
    • 21.6 in. (550 mm), 27 quarts (30 liters) of washed filtration sand
    • Stick, 40 in. (100 cm) long
    • Measuring tape
    • Black magic marker pen
    • Diffuser box (see Strategic Planning)
  • Materials for testing filter flow rate including:
    • Measured container (1 liter soda bottle is adequate)
    • Stop watch

Basic Protocol 6:

  Materials
  • Raw (untreated) water
  • Biosand filter including a diffuser box (see Strategic Planning)
  • Buckets

Basic Protocol 7: Periodic Disinfection (Cleaning) of Filter Container

Clean the entire outside surface of the filter regularly (only when dirty) with soap and water or a chlorine cleaning solution.

Basic Protocol 8: Recovering the Flow Rate

  Materials
  • Soap
  • Water
  • BioSand filter with a diffuser box (see Strategic Planning)

Basic Protocol 9:

  Materials
  • Household bleach
  • Clean water
  • Clean empty 11.5‐oz. (340‐ml) container

Basic Protocol 10: Bleach (Free Chlorine) Disinfection of Effluent Water

  Materials
  • Biosand filtered water
  • 1‐ to 2‐liter clear bottles (e.g., soda bottles)
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Figures

Videos

Literature Cited

   Bruzunis, B.J. 1995. Intermittently Operated Sand Filtration: A New Water Treatment Process. Master of Engineering Thesis, Department of Civil Engineering, University of Calgary, Calgary, Alberta, Canada.
   Catherman, R. 2006. Using Ultraviolet to Disinfect Household Drinking Water. MEDRIX, Woodinvale, Wash.
   Centers for Disease Control and Prevention (CDC). 2012. Slow Sand Filtration. The Safe Water System. http://www.cdc.gov/safewater/sand‐filtration.html.
   Centre for Affordable Water and Sanitation Technology. 2012. Biosand Filter Construction Manual: Design, Construction, and Installation. CAWST. Calgary, Ontario, Canada.
   Conant, J. 2005. Water for Life: Community Water Security. Hesperian Foundation, Berkeley, Calif. Available at http://hesperian.org/wp‐content/uploads/pdf/environmental/ehb_water_EN_watermark.pdf.
   Ellms, J.W. 1928. Water Purification, 2nd ed.. McGraw‐Hill, New York.
   Fisher, M.B. , Keenan, C.R. , Nelson, K.L. , and Voelker, B.M. 2008. Speeding up solar disinfection (SODIS): Effects of hydrogen peroxide, temperature, pH, and copper plus ascorbate on the photoinactivation of E. coli . J. Water Health 6:35‐51.
   Muhammad, N. , Ellis, K. , Parr, J. , and Smith, M.D. 1996. Optimization of slow sand filtration. Reaching the unreached: Challenges for the 21st century. Proceedings of the 22nd WEDC Conference, pp. 283‐285. Water, Engineering and Development Centre (WEDC), Loughborough, U.K.
   Nath, K.J. , Bloomfield, S.F. , and Jones, M. 2006. Household water storage, handling and point‐of‐use treatment. A review commissioned by IFH. Available at http://www.ifh‐homehygiene.org.
   National Small Flows Clearinghouse. 1997. Pipeline: Sand Filters Provide Quality, Low‐Maintenance Treatment. 8:1‐7.
   Ngai, T. , Dangol, B. , Murcott, S. , and Shrestha, R.R. 2006. Kanchan Arsenic Filter. Massachusetts Institute of Technology (MIT) and Environment and Public Health Organization (ENPHO). Kathmandu, Nepal.
   Rau, R. 2003. Complex simplicity: A slow sand filter for drinking water. Home Power 93:52‐56.
   Smethurst, G. 1992. Basic Water Treatment: For Application World‐Wide. Thomas Telford, London.
   Sobsey, M.D. 2002. Managing water in the home: Accelerated health gains from improved water supply. WHO/SDE/WSH02.07. World Health Organization, Geneva, Switzerland. Available at http://www.who.int/water_sanitation_health/dwq/wsh0207/en/.
   World Health Organization. 2003. Emerging Issues in Water and Infectious Disease. WHO, Geneva, Switzerland.
   World Health Organization. 2007. Combating Waterborne Disease at the Household Level. WHO, Geneva, Switzerland.
Key References
   Centre for Affordable Water and Sanitation Technology. 2008a. Source of Square Concrete Biosand Filter Construction Manuals. CAWST. Calgary, Ontario, Canada.
  Provides the most comprehensive concrete filter construction materials.
   Centre for Affordable Water and Sanitation Technology. 2008b. Source of “Summary of Field and Laboratory Testing for the Biosand Filter. CAWST. Calgary, Ontario, Canada.
  Provides the most comprehensive summary of research results. Available from http://www.cawst.org.
Internet Resources
   http://www.sodis.ch/methode/anwendung/factsheets/turbidity_waterdepth_e.pdf
  EAWAG and SANDEC, undated. SODIS Technical Note No. 7, Duebendorf, Switzerland.
   http://wedc.lboro.ac.uk/knowledge/booklets.html
  Water, Engineering and Development Centre (WEDC) booklet entitled “An Engineers's Guide to Domestic Water Containers.”
   http://www.who.int/household_water/network/en/
  The International Network to Promote Household Water Treatment and Safe Storage.
   http://manzwaterinfo.ca/
  Dr. David Manz's Internet‐based cooperative discourse for the Biosand Water Filter.
   http://www.who.int/water_sanitation_health/monitoring/jmp2005/en/
  Link to the report Water for Lfe: Making it Happen. This report, prepared by the WHO/UNICEF Joint Monitoring Program, makes it clear that achieving the International Decade for Action Water for Life 2005 to 2015 target of access to safe drinking water and basic sanitation will bring health and dignity to millions of the world's poorest people.
   http://www.medrix.org/
  Medical Education and Development of Resources through International Exchange (MEDRIX)—provides a UV‐lamp water‐treatment (with optional sand filter) system handbook available upon request.
   http://www.biosandfilter.org
  BushProof, Biosand Filter home page, Retrieved March 15, 2007. Presents comprehensive online reference material for construction of round concrete and metal drum biosand filters.
   http://web.mit.edu/watsan/Docs/Other%20Documents/KAF/KAF%20booklet%20final%20Jun05.pdf
  Kanchan Arsenic Filter (KAF).
   http://www.hydraid.org/
  International Aid's new plastic HydrAid BioSand Water Filter initiative.
   http://www.cawst.org
  The Centre for Affordable Water and Sanitation Technology (CAWST) is a Canadian humanitarian organization that provides training, education, and technical consulting in water and sanitation to organizations working with the poor in developing countries.
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