Point of Use Coagulation and Flocculation Turbidity Terminators: Morgan Rog Shubha Bhar Melanie Tan Lindsay Ellis

Comparing Chemical Coagulants

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

Jatropha Curcas Results: –Coagulated 60-80% of particles –Decrease bacterial counts –Less effective than Moringa, but still more effective than Alum Common plant found in western and southern Africa Roots and leaves highly medicinal Seeds dried and ground up to determine coagulative properties

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

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

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

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: < 50 NTU mg/L NTU mg/L >150 NTU mg/L

Pros and Cons of Moringa Oleifera Advantages: Cheap, readily available doesn’t alter pH, pH independent doesn’t change taste biodegradable sludge Disadvantages still needs to be disinfected possibility of recontamination, no residual needs to be fresh

POU Coagulation & Flocculation in Guatemala 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 diarrhea 2 nd highest cause of death water generally kept in open containers use bleach to treat water

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 Effectiveness of Proctor and Gamble Experiment Results: Flocculation-disinfection (top) reduced diarrhea by 24% Flocculation-disinfection with special container reduced diarrhea by 30%

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