3 research outputs found
Sustained effectiveness of chlorinators installed in community-scale water distribution systems in Haiti
In 2012 and 2013, Child Relief International (CRI) partnered with Haiti Philanthropy to install “Chlorinators” in 79 gravity-fed water distribution systems in Southeast Haiti as an emergency response project, followed by a sustainability plan. We carried out an independent evaluation to assess the extent to which Chlorinators were operational and providing safe water approximately two years after installation. We completed 18 randomly selected site assessments, 180 household surveys, water quality testing for Free Chlorine Residual (FCR) and Escherichia coli on water samples from reservoirs, taps, and household stored water, and 24 key informant interviews. None of the systems were functioning 2 years after installation, 3% of household respondents had received information about the Chlorinators, and no community or household water samples had detectable FCR from Chlorinators. However, key informants were largely supportive of the systems. Reasons for non-operation and challenges associated with achieving sustainability are discussed
Evaluation of household drinking water filter distribution programmes in Haiti
Household water treatment can reduce diarrhoeal disease in populations without safe water access. We evaluated five programmes that distributed biosand, ceramic, or Sawyer household water filters in Haiti after the 2010 earthquake. We conducted household surveys, collected water samples, and tested water quality at ~50 houses from each programme. Across programmes, self-reported filter use ranged from 27-78%; confirmed use (met reported use and showed the filter with water in it) ranged from 20-76%; and, effective use (stored water quality was improved to international guideline values using the filter) ranged from 0-54%. More successful programmes: 1) distributed an effective technology; 2) provided safe storage; 3) required cash investment; 4) provided initial training; 5) provided follow-up; 6) provided supply-chain access; 7) targeted households relying on contaminated water sources; and, 8) had experience working in the local context. These findings suggest that well implemented programmes can result in sustained filter use in Haiti
Silver Dissolution and Release from Ceramic Water Filters
Application of silver
nanoparticles (nAg) or silver nitrate (AgNO<sub>3</sub>) has been
shown to improve the microbiological efficacy of
ceramic water filters used for household water treatment. Silver release,
however, can lead to undesirable health effects and reduced filter
effectiveness over time. The objectives of this study were to evaluate
the contribution of nanoparticle detachment, dissolution, and cation
exchange to silver elution, and to estimate silver retention under
different influent water chemistries. Dissolved silver (Ag<sup>+</sup>) and nAg release from filter disks painted with 0.03 mg/g casein-coated
nAg or AgNO<sub>3</sub> were measured as a function of pH (5–9),
ionic strength (1–50 mM), and cation species (Na<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>). Silver elution was controlled
by dissolution as Ag<sup>+</sup> and subsequent cation exchange reactions
regardless of the applied silver form. Effluent silver levels fell
below the drinking water standard (0.1 mg/L) after flushing with 30–42
pore volumes of pH 7, 10 mM NaNO<sub>3</sub> at pH 7. When the influent
water was at pH 5, contained divalent cations or 50 mM NaNO<sub>3</sub>, silver concentrations were 5–10 times above the standard.
Our findings support regular filter replacement and indicate that
saline, hard, or acidic waters should be avoided to minimize effluent
silver concentrations and preserve silver treatment integrity