Everything about Cloth Filter totally explained
Developed for use in
Bangladesh, the
cloth filter is a simple and cost-effective
appropriate technology method for reducing the contamination of drinking water. Water collected in this way has a greatly reduced
pathogen count - though it won't necessarily be perfectly safe, it's an improvement for poor people with limited options.
Method
The method used in Bangladesh is as follows: an old
sari is folded to make four or eight layers. The folded cloth is placed over a wide-mouthed container used to collect surface water.
It is usually sufficient to rinse the cloth and dry it in the sun for a couple of hours. In the
monsoon seasons, it may be advisable to use a cheap
disinfectant to decontaminate the material.
The preferred cloth is used cotton sari cloth. Other types of clean, used cloth can be used with some effect, though the effectiveness will vary significantly. Used cloth is more effective than new cloth, as the repeated washing reduces the space between the fibres
(External Link
).
Effectiveness
The cloth is effective because most pathogens are attached to particles and plankton, particularly a type of zooplankton called
copepods, within the water. By passing the water through an effective filter, most cholera bacteria and other pathogens are removed. It has been demonstrated to greatly reduce
cholera infections in poor villages where disinfectants and fuel for boiling are difficult to get.
In
sub-Saharan Africa where
guinea worm dracunculiasis infections are endemic, infection is prevented by use of a nylon mesh with pore size of approximately 150
μm to filter out the copepods that host the parasite.
An old cotton sari, folded, creates a smaller effective mesh size (approximately 20-μm). This should be small enough to remove all zooplankton, most phytoplankton, and thus a large proportion of the cholera in the water (99%, according to laboratory studies). However, the nylon net with the larger mesh size was found to be "almost equally effective."
Background
The cloth filter has been studied and reported on by
Rita Colwell and
Anwar Huq from the
University of Maryland Biotechnology Institute, together with other researchers from the
USA and
Bangladesh. They report that:
» It is common practice in villages in Bangladesh to use cloth, frequently a flat, unfolded piece of an old sari, to filter home-prepared drinks.
The researchers studied the application of this technique to drinking water, with folded cloth. They studied the pore size of the cloth, the effect of folding the cloth on the effective pore size, the ability of the cloth to remove particles and plankton, as well as the effect on rates of cholera when used in a Bangladesh village.
Footnotes and references
Further Information
Get more info on 'Cloth Filter'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://cloth_filter.totallyexplained.com">Cloth filter Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
