Pilot field comparison of traditional Pilot field comparison of traditional alum flocculation, chlorination, and alum flocculation, chlorination, and combined flocculation- -chlorination chlorination combined flocculation point- -of of- -use water treatment on use water treatment on point drinking water quality in Western drinking water quality in Western Kenya Kenya John A. Crump 1 1 , George O. Okoth , George O. Okoth 2 2 , Laurence Slutsker , Laurence Slutsker 2 2 , Bruce H. Keswick , Bruce H. Keswick 3 3 , Stephen P. Luby , Stephen P. Luby 1 1 • • John A. Crump • • Foodborne Foodborne and and Diarrheal Diarrheal Diseases Branch, Division of Bacterial and Diseases Branch, Division of Bacterial and Mycotic Mycotic Diseases, National Center for Infectious Diseases, Centers for Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA 1 1 Disease Control and Prevention, Atlanta, Georgia 30333, USA , Kenya 2 2 • • Kenya Medical Research Institute/United States Centers for Disea Kenya Medical Research Institute/United States Centers for Disease Control and Prevention se Control and Prevention Kisian Kisian Field Station, PO Box 1578, Field Station, PO Box 1578, Kisumu Kisumu, Kenya USA 3 3 • • Procter & Gamble Health Sciences Institute, 8700 Mason Montgomery Road, Mason, Ohio 45040, Procter & Gamble Health Sciences Institute, 8700 Mason Montgomer y Road, Mason, Ohio 45040, USA • • John A. Crump, MB, ChB, DTM&H John A. Crump, MB, ChB, DTM&H • • Foodborne and Diarrheal Diseases Branch Foodborne and Diarrheal Diseases Branch • • Division of Bacterial and Mycotic Diseases Division of Bacterial and Mycotic Diseases • • National Center for Infectious Diseases National Center for Infectious Diseases • • Centers for Disease Control and Prevention Centers for Disease Control and Prevention • • Atlanta, GA 30333 Atlanta, GA 30333 • • United States of America United States of America • • Tel +1 Tel +1- -404 404- -639 639- -2206 2206 • • Fax +1 Fax +1- -404 404- -639 639- -2205 2205 • • E E- -mail jcrump@cdc.gov mail jcrump@cdc.gov TM
Woman collects drinking water from a turbid pond Woman collects drinking water from a turbid pond Asembo, Western Kenya , Western Kenya Asembo
Background Background • 1.1 1.1 billion persons lack access to improved water billion persons lack access to improved water • • Diarrheal Diarrheal disease kills >2 million persons disease kills >2 million persons annually annually • • ‘ ‘Point Point- -of of- -use’ approaches to improving drinking use’ approaches to improving drinking • water water - Require little infrastructure Require little infrastructure - - Are suited to rural settings Are suited to rural settings - - Empower individuals to make water safe for Empower individuals to make water safe for - their families families their • ‘ ‘Point Point- -of of- -use’ disinfectants (e.g., sodium use’ disinfectants (e.g., sodium • hypochlorite) are likely to perform poorly for ) are likely to perform poorly for hypochlorite highly turbid source highly turbid source water water
Aim Aim • To To compare the effect on water quality compare the effect on water quality • indicators of traditional alum flocculation, indicators of traditional alum flocculation, chlorination, and combined flocculation- - chlorination, and combined flocculation chlorination (P Pu ur r A and A and P Pu ur r B) point B) point- -of of- -use use chlorination ( water treatment on drinking water quality in water treatment on drinking water quality in Western Kenya over a range of source water over a range of source water Western Kenya turbidities turbidities
Methods and Materials Methods and Materials • 30 water sources 30 water sources • 10 low turbidity (<10 NTU) 10 medium turbidity (10-100 NTU) 10 high turbidity (>100 NTU) • Six treatments Six treatments • - Combined flocculation Combined flocculation- -chlorination product yielding ~3.5 chlorination product yielding ~3.5 - mg/L free chlorine (P Pu ur r A) A) mg/L free chlorine ( - Combined flocculation Combined flocculation- -chlorination product yielding ~2.0 chlorination product yielding ~2.0 - mg/L free chlorine (P Pu ur r B) B) mg/L free chlorine ( - Locally produced water disinfectant yielding ~5.0 mg/L Locally produced water disinfectant yielding ~5.0 mg/L - free chlorine (Klorin Klorin) ) free chlorine ( - Locally available alum Locally available alum flocculant flocculant ~100 g for 60 seconds ~100 g for 60 seconds - - Alum + Alum + Klorin Klorin - - Untreated control Untreated control -
Outcomes Outcomes • Turbidity Turbidity measured by measured by Hach Hach 2100P Portable 2100P Portable • Turbidimeter ( (Hach Hach Company, Loveland, CO) Company, Loveland, CO) Turbidimeter • Free and total chlorine concentration measured Free and total chlorine concentration measured • by Hach Hach Portable DR/890 Colorimeter ( Portable DR/890 Colorimeter (Hach Hach by Company, Loveland, CO) Company, Loveland, CO) • pH measured by pH measured by IQ 150 Handheld pH Meter (IQ IQ 150 Handheld pH Meter (IQ • Scientific Instruments Inc, San Diego, CA) Scientific Instruments Inc, San Diego, CA) • E. E. coli coli concentration measured by concentration measured by Colilert Colilert • Quantitray 2000 system (IDEXX Laboratories 2000 system (IDEXX Laboratories Quantitray Incorporated, Westbrook, ME) Incorporated, Westbrook, ME)
Combined Combined flocculation- - flocculation chlorination product chlorination product Alum ‘dawa dawa’ ’ Alum ‘ Sodium Sodium hypochlorite 1% hypochlorite 1% Point-of-use water treatments evaluated
Turbid water after treatment with Pur
Results Results Before treatment, turbidity and Escherichia Before treatment, turbidity and Escherichia coli concentrations were highest in pond concentrations were highest in pond coli water, followed by stream, river, lake, spring, water, followed by stream, river, lake, spring, and borehole water and borehole water Turbidity by untreated source water E. coli coli concentration by untreated source concentration by untreated source Turbidity by untreated source water E. type, , Asembo Asembo and Gem, 2002 and Gem, 2002 water type, type, Asembo Asembo and Gem 2002 and Gem 2002 type water 10,000 1,000 Mean CFU/100 mL* 1,000 Mean NTU 100 100 10 10 1 1 Pond Stream River Lake Spring Borehole Pond Stream River Lake Spring Borehole *WHO guideline <1 E. coli CFU/100 mL
Turbidity by untreated source water Turbidity by untreated source water type, Asembo Asembo and Gem, 2002 and Gem, 2002 type, 1,000 100 Mean NTU 10 1 Pond Stream River Lake Spring Borehole
Untreated Klorin Pu ur r B B Pu ur r A A Alum Alum + Untreated Klorin P P Alum Alum + control Klorin control Klorin Visual impact of water treatments on highly turbid source water
Effect of water treatments on turbidity Effect of water treatments on turbidity by turbidity, turbidity, Asembo Asembo and Gem, 2002 and Gem, 2002 by Low turbidity (n=10) Low turbidity (n=10) Medium turbidity (n=10) Medium turbidity (n=10) High turbidity (n=10) High turbidity (n=10) 1,000 Mean NTU 100 10 1 Pur A* Pur B* Klorin Alum Alum + Untreated Klorin control *Includes two water sources where one sachet of Pur failed to form floc
Although Klorin Klorin delivers a higher chlorine dose delivers a higher chlorine dose Although compared to P Pu ur r A, free chlorine levels measured A, free chlorine levels measured compared to 30 minutes after water treatment were higher for 30 minutes after water treatment were higher for Pu P ur r A compared to A compared to Klorin Klorin alone alone Effect of water treatments on free Effect of water treatments on free chlorine, , Asembo Asembo and Gem, 2002 and Gem, 2002 chlorine 1.5 * L / g 1.0 m - l C e e 0.5 r f n a i d e M 0.0 Pur A Pur B Klorin Alum Alum + Untreated Klorin control *Measured 30 minutes after treatment
Alum- -based treatments lower pH substantially based treatments lower pH substantially Alum Effect of water treatments on pH Effect of water treatments on pH Asembo and Gem, 2002 and Gem, 2002 Asembo 8 pH 7.0 6 Mean pH 4 2 0 Pur A Pur B Klorin Alum Alum + Untreated Klorin control
Effect water treatments on E. E. coli coli Effect water treatments on concentration, Asembo Asembo and Gem, 2002 and Gem, 2002 concentration, 10,000 Mean CFU/100 mL* 1,000 100 10 1 Pur A Pur B Klorin Alum Alum + Untreated Klorin control *WHO guideline <1 E. coli CFU/100 mL
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