Sodium hypochlorite dosage for household and emergency water treatment: updated recommendations

Wilhelm, Natalie; Kaufmann, Anya; Blanton, Elizabeth; Lantagne, Daniele

doi:10.2166/wh.2017.012

Cited by 32 publications

(16 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We tested three mechanisms to add chlorine demand to our test waters: Kaolin clay, added TOC standard, and creek-bed sediments. These mechanisms were selected to model the different types of chlorine demand producing compounds seen in field waters (clay from rivers, TOC from natural organic materials, and creek-bed sediments from river bottoms) [51]. However, as is evident in the study, two of these compounds appear to add little chlorine demand.…”

Section: Discussionmentioning

confidence: 99%

Residual Maintenance Using Sodium Hypochlorite, Sodium Dichloroisocyanurate, and Chlorine Dioxide in Laboratory Waters of Varying Turbidity

Gallandat

Stack

String

et al. 2019

Water

Self Cite

View full text Add to dashboard Cite

Sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) are commonly used for household water treatment (HWT); chlorine dioxide (ClO 2 ) is a potential new HWT option. We compared the residual maintenance of NaOCl, NaDCC, and ClO 2 over 24 hours using recommended dosages (2 and 4 mg/L) in waters of varying turbidity (0-300 NTU, from kaolin clay or creek-bottom sediments) and total organic carbon (TOC) concentrations (0-100 mg/L), for a total of 324 reactors. NaOCl and NaDCC had similar free chlorine decay rates, and ClO 2 decayed more rapidly across all of the tested conditions. Little variability was observed across clay-based turbidity levels and TOC concentrations. With a dosage of 2 mg/L, a residual ≥0.2 mg/L was maintained at 30 NTU for NaOCl and 100 NTU for NaDCC; for ClO 2 , 4 mg/L were required to maintain ≥0.2 mg/L under all conditions except at zero turbidity. Comparisons with data from the literature suggest that the three compounds would inactivate E. coli, rotavirus, and Giardia cysts within 1 hour under all conditions, except 300 NTU for NaOCl and NaDCC. All three disinfectants are similarly efficacious for this usage; however, differences are seen in decay rates that may influence disinfectant selection depending on water storage time.

show abstract

Section: Discussionmentioning

confidence: 99%

Residual Maintenance Using Sodium Hypochlorite, Sodium Dichloroisocyanurate, and Chlorine Dioxide in Laboratory Waters of Varying Turbidity

Gallandat

Stack

String

et al. 2019

Water

Self Cite

View full text Add to dashboard Cite

show abstract

“…Balandng the three criteria, we targeted a FRC concentration of 2 mg/L at the tap. This is slightly higher than Wilhelm et al (2018) recommend (1.SS mg/L) for improved or low turbidity sources for 24 h protection. The higher target concentration is due to the relatively high chlorine demand measured in the study area.…”

Section: Adequate Dosingmentioning

confidence: 59%

“…In t he study area, the average chlorine demand was l .S mg/ L over 24 h of storage in an uncleaned jerry can (n = 46, st andard deviation (SD) = 0.3 mg/L). Wilhelm et al (2018) and international guidelines (WHO, 2017; CDC, 2020) recommend ;::a: 0.2 mg/L PRC after 24 h of transport and storage. WHO (2017) recommends a maximum of 5 mg/L FRC.…”

Section: Adequate Dosingmentioning

confidence: 99%

Assessment of low-cost, non-electrically powered chlorination devices for gravity-driven membrane water kiosks in eastern Uganda

Dössegger¹,

Tournefier²,

Germann³

et al. 2021

Waterlines

View full text Add to dashboard Cite

Recontamination during transport and storage is a common challenge of water supply in low-income settings, especially if water is collected manually. Chlorination is a strategy to reduce recontamination. We assessed seven low-cost, non-electrically powered chlorination devices in gravity-driven membrane filtration (GDM) kiosks in eastern Uganda: one floater, two in-line dosers, three end-line dosers (tap-attached), and one manual dispenser. The evaluation criteria were dosing consistency, user-friendliness, ease of maintenance, local supply chain, and cost. Achieving an adequate chlorine dosage (∼2 mg/L at the tap and ≥ 0.2 mg/L after 24 h of storage in a container) was challenging. The T-chlorinator was the most promising option for GDM kiosks: it achieved correct dosage (CD, 1.5–2.5 mg/L) with a probability of 90 per cent, was easy to use and maintain, economical, and can be made from locally available materials. The other in-line option, the chlorine-dosing bucket (40 per cent CD) still needs design improvements. The end-line options AkvoTur (67 per cent CD) and AquatabsFlo® (57 per cent CD) are easy to install and operate at the tap, but can be easily damaged in the GDM set-up. The Venturi doser (52 per cent CD) did not perform satisfactorily with flow rates > 6 L/min. The chlorine dispenser (52 per cent CD) was robust and user-friendly, but can only be recommended if users comply with chlorinating the water themselves. Establishing a sustainable supply chain for chlorine products was challenging. Where solid chlorine tablets were locally rarely available, the costs of liquid chlorine options were high (27–162 per cent of the water price).

show abstract

“…Treating water with chlorine has been shown to reduce self-reported diarrheal disease [8]. WHO recommends a free chlorine concentration of 0.2 mg/L [5]; when water is dosed properly, this concentration can be maintained for up to 24 h [9, 10]. The majority (97%) of primary drinking water samples tested in PCV households had an FCR < 0.2 mg/L.…”

Section: Discussionmentioning

confidence: 99%

“…Researchers have recognized the difficulty that public health organizations face in the real-world implementation of water retreatment every 24 h [9]. Recontamination can be reduced by storing water in containers with small openings and taps that prevent users from introducing potentially contaminated items into the stored water and by regularly cleaning storage containers [10].…”

Section: Discussionmentioning

confidence: 99%

An assessment of household water quality among Peace Corps volunteers in Guatemala

Murphy¹,

Poe²,

Murphy³

et al. 2019

Trop Dis Travel Med Vaccines

View full text Add to dashboard Cite

BackgroundGastrointestinal (GI) illness is the most commonly reported health concern among Peace Corps Volunteers (PCVs) serving in Guatemala. This project identified water types and treatment and storage practices used by PCVs and measured select water quality parameters in their household water.MethodsA survey about water types and practices was conducted of PCVs in Guatemala. The water type most frequently consumed in the household (“primary drinking water”) and other water types present in the household (“secondary water”) were tested for free chlorine residual (FCR) and for the presence of Escherichia coli and total coliforms. A negative binomial regression model was used to analyze data on incidence of self-reported GI illness.ResultsTambo (commercially purified water in a 5-gal bottle) was the water type most frequently (64%) reported as primary drinking water in 39 PCV households. Most (74%) PCVs reported drinking water other than primary drinking water ≥1 day per week; the incidence rate of GI illness per PCV per month was significantly lower among PCVs who reported never consuming water other than primary drinking water compared to those who did (0.4 and 1.6 GI illnesses per PCV per month, respectively) (p < 0.05). E. coli was not detected in any primary drinking water sample, but was detected in 35% of secondary water samples. Total coliforms were detected in more than two-thirds of primary drinking water and secondary water samples. Nearly all water samples had an FCR of < 0.2 mg/L.ConclusionsConsuming primary drinking water exclusively likely contributes to reducing the rate of GI illness among PCVs. However, most PCVs reported drinking multiple water types, which may include contaminated secondary water types in the household. All water intended for consumption, including secondary sources within and outside the household, should be properly treated and safely stored.

show abstract

Sodium hypochlorite dosage for household and emergency water treatment: updated recommendations

Cited by 32 publications

References 13 publications

Residual Maintenance Using Sodium Hypochlorite, Sodium Dichloroisocyanurate, and Chlorine Dioxide in Laboratory Waters of Varying Turbidity

Residual Maintenance Using Sodium Hypochlorite, Sodium Dichloroisocyanurate, and Chlorine Dioxide in Laboratory Waters of Varying Turbidity

Assessment of low-cost, non-electrically powered chlorination devices for gravity-driven membrane water kiosks in eastern Uganda

An assessment of household water quality among Peace Corps volunteers in Guatemala

Contact Info

Product

Resources

About