title: A novel and simple mixture as point-of-use water treatment agent to produce safe drinking water.
abstract: BACKGROUND
  People in rural Bangladesh have a poor understanding of the link between use of contaminated surface water and disease. An inexpensive point-of-use water treatment agent was developed to purify surface water.
  
  
  METHODS
  Surface water was collected from various sources in Bangladesh from February 2007 to January 2008. Microbiological and physicochemical parameters of raw and treated surface water were analysed. Water was treated with a mixture of alum potash, bleaching powder and lime, or with each agent individually.
  
  
  RESULTS
  Raw water was contaminated with bacteria, the counts for total coliforms, faecal coliforms and faecal streptococci being 26,431, 14,548 and 240 colony-forming units (cfu) 100 ml(-1), respectively. These counts fell to 0 cfu 100 ml(-1) after treatment with the mixture. The count of artificially introduced Vibrio cholerae was also reduced to 0 cfu 100 ml(-1) after treatment. Treatment of raw water altered the pH from 6.90 to 6.87, turbidity from 21.61 to 3.55 nephelometric turbidity units (NTU), residual chlorine from 0 to 0.09 mg litre(-1), conductivity from 124.03 to 229.96 µS cm(-1), and total dissolved solids from 59.40 to 199.25 mg litre(-1). All these results of treatment were within the range recommended by the WHO as acceptable for drinking water.
  
  
  CONCLUSIONS
  The mixture of alum potash, bleaching powder and lime described can be safely used to disinfect contaminated surface water to make it suitable for drinking and other household purposes in Bangladesh.
authors.affiliation: Environmental Microbiology Laboratory, Centre for Food and Waterborne Diseases, International Centre for Diarrhoeal Disease Research, PO Box 128, Dhaka 1000, Bangladesh.
authors.forename: M S
authors.initials: MS
authors.lastname: Islam
authors.forename: M
authors.initials: M
authors.lastname: Ansaruzzaman
authors.forename: Z H
authors.initials: ZH
authors.lastname: Mahmud
authors.forename: M A
authors.initials: MA
authors.lastname: Matin
authors.forename: M S
authors.initials: MS
authors.lastname: Islam
authors.forename: A K
authors.initials: AK
authors.lastname: Mallik
authors.forename: S B
authors.initials: SB
authors.lastname: Neogi
authors.forename: I K
authors.initials: IK
authors.lastname: Jahid
authors.forename: H P
authors.initials: HP
authors.lastname: Endtz
authors.forename: A
authors.initials: A
authors.lastname: Cravioto
authors.forename: D A
authors.initials: DA
authors.lastname: Sack
mesh_terms: D000534:Alum Compounds; D001459:Bangladesh; D017606:Chlorine Compounds; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D004203:Disinfection / Q000379:methods*; D005243:Feces / Q000382:microbiology*; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D012423:Rural Health; D014734:Vibrio cholerae / Q000302:isolation & purification*; D014871:Water Microbiology; D014876:Water Pollution; D018508:Water Purification / Q000379:methods; D014881:Water Supply / Q000592:standards*
chemical_list: D000534:Alum Compounds; D017606:Chlorine Compounds
keywords: Bangladesh; Disinfectant; Point-of-use; Purification; Surface water