Alternative Coagulants

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Point of Use Coagulation and Flocculation


Turbidity Terminators Morgan Rog Shubha
Bhar Melanie Tan Lindsay Ellis
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Comparing Chemical Coagulants
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Alternative Coagulants Plants

• Study done by Kenneth Yongabi, Tafawa Balewa
  University, Bauchi Nigeria
• Medicinal plants could have coagulative
  properties

• Experiment
• Samples from each plant were dried, ground and
  stored
• Alum was added to each sample
• Coagulation mixtures added to turbid water
  samples
• Alum was used as a control
• The samples sat for 24 hours
• Coagulative effect and bacterial counts were
  recorded
• Extracts were tested for E. coli as a fecal
  contamination indicator

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Jatropha Curcas

• Common plant found in western and southern
  Africa
• Roots and leaves highly medicinal
• Seeds dried and ground up to determine
  coagulative properties

• Results
• Coagulated 60-80 of particles
• Decrease bacterial counts
• Less effective than Moringa, but still more
  effective than Alum

5
Hibiscus subdariffa

• Plant cultivated in Northern Nigeria
• Contains red calyx extract dried and tested for
  coagulation

• Results
• Effective coagulation
• Effective disinfectant
• Reduced E. coli and coliform bacterial counts
  better than Alum
• Leaves water tinted red

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Pleurotus tuberregium

• Grown in Cameroon and parts of Nigeria
• Mushrooms have medicinal value

• Results
• Least effective coagulant
• No antimicrobial properties
• Still just as effective as Alum

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Moringa oleifera

• Originally from India, found in tropics in Asia,
  S. America, and Africa
• Tough plant, easy to grow and cultivate
• Drumstick, use dried seeds from pods
• One tree cleans enough water for 5-6 people
• Also contains pterygospermin, antibacterial

• Results
• Coagulated 90 of particles
• Much better than treatment with just alum
• Antimicrobial properties
• Bacterial counts reduced from Too Numerous to
  count to 2700 CFU

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Preparation of Moringa Oleifera

• Process
• dry and crush seeds
• make into a paste
• filter
• add paste to turbid water
• stir fast for ½ minute
• stir slowly 5 minutes
• settle 1 hour

Dosage Demand lt 50 NTU 10-50 mg/L 50-150 NTU
30-100 mg/L gt150 NTU 50-200 mg/L
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Pros and Cons of Moringa Oleifera

• Advantages
• Cheap, readily available
• doesnt alter pH, pH independent
• doesnt change taste
• biodegradable sludge

• Disadvantages
• still needs to be disinfected
• possibility of recontamination, no residual
• needs to be fresh

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POU Coagulation Flocculation in Guatemala

• diarrhea 2nd highest cause of death
• water generally kept in open containers
• use bleach to treat water

• The Experiment, by Proctor and Gamble
• Households assigned home flocculation-disinfection
  system
• 4 controls using flocculation disinfectant and
  bleach
• Stir water 30 seconds quickly, stir 5 minutes
  slow, let sit ½ hour, filter

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Effectiveness of Proctor and Gamble Experiment

• How it Works
• Cheap flocculation disinfectant contained
  ferric sulfate, bentonite, sodium carbonate,
  chitosan, polyacrylamide, potassium permanganate,
  and calcium hypochlorite
• causes clumps to form and settle with stirring
• chlorine residual 3.5 mg/L

• Results
• Flocculation-disinfection (top) reduced diarrhea
  by 24
• Flocculation-disinfection with special container
  reduced diarrhea by 30

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Helpful Websites

• http//www.blackwell-synergy.com/links/doi/10.1111
  /j.1365-2672.2004.02309.x/pdf
• http//murungaexports.ebigchina.com/sdp/181012/4/c
  p-1011556.html
• http//www.treesforlife.org/project/moringa/uses/u
  ses_water_lgscale_article.en.asp
• http//www.biotech.kth.se/iobb/news/kenneth04.doc
• http//www.ajtmh.org/cgi/content/abstract/69/4/411