Hey, today I’m talking about E22-treatment by ceramic water filters. These are devices that make it possible to purify surface water by filtering it through a porous material. There are centralized devices for pre-treatment of surface water or from drilling with filters of this type, although most of them are manufactured for domestic use.
The present file refers only to this type of small capacity domestic filters. Depending on the type, they can be small fixed installations for family use or portable devices that allow you to filter the water wherever you are.
Who mainly uses this medium and since when?
This procedure, used for several centuries, is recommended by various humanitarian NGOs and is used in several African countries (especially in Benin and Togo), in Haiti and in Asia. It is also used by people who travel to countries where water is not potable. Different companies offer portable devices; among them is KATADYN.
This device, simple, compact and intended for the production of drinking water for human consumption in a small community (home, shop, restaurant, etc.), is especially robust, effective and easy to maintain as long as you have some training on the precautions of use.
Who are the main stakeholders?
The interested populations are all those that, being located in the vicinity of rivers or impure water points, lack access to drinking water, or that use water that runs the risk of not being or ceasing to be potable. The filters can be used in the home, either by means of small autonomous installations or, more rarely, by connecting to a water outlet or a rainwater recovery system. As for portable systems, they are mainly aimed at populations not connected to the network, nomads, and hikers. Read more, ceramic water dispenser.
What is this procedure? How do you put it into practice?
Ceramic filters are usually presented as filter cartridges in the form of a probe placed vertically in plastic containers whose capacity can reach 20 or 30 liters. The water to be treated passes from the outside to the inside of the cartridge, and once treated it is collected in the lower part (there is a more rudimentary device that consists of placing a simple filter membrane in a pot). The filter element is impregnated with fine silver colloidal particles that act as a disinfectant and prevent the proliferation of bacteria in the filter.
The use of a siphon, as shown in the following diagram, allows to increase the production capacity and proceed more easily to wash the filter by returning the treated water.
- Ceramic filter
- Siphoning tube
- Rubber bulb
- Valve and tap
The actuation of the pear creates a vacuum that attracts water to the container.
To clean the filter, the tap must be closed. This has the effect of sending the water back to the filter and cleaning it.
The procedure is based on microfiltration. The threshold varies between 0.1 and 0.2 microns, creating a barrier that retains all impurities in suspension, as well as practically all bacteria and protozoan parasites. It has also been proven effective against viruses, although this can not be guaranteed at 100%. The system allows for obtaining adequate water for human consumption.
If the water to be treated is cloudy, the ceramic membranes become clogged, reducing the flow as a consequence. For this reason, it is necessary to carry out regular cleaning of the filter cartridges with the help of a brush, accompanied by light disinfection with bleach.
The cartridges do not suffer alterations with time, the reason why they can be used during years.
Ceramic membranes do not change over time, offering a high level of security for more than 20 years if washed regularly.
Main advantages and disadvantages
- Maintenance is realizable by the user. Eliminates almost all diseases caused by standing water. Rudimentary devices can be manufactured locally in developing countries. Mobile systems can be used by travelers.
- It can not be used with relatively turbid water so as not to clog the filter too quickly. Risk of contamination of stored water if it is not slightly chlorinated.
The price of a complete system of cartridges that produces between 10 and 20 liters a day is usually around 200-250 euros.
Its useful life is many years, but the cartridges, which can cost between 5 and 10 euros, should be replaced regularly. The maintenance cost is estimated at around 4 or 5 euros /m3, that is, it is practically insignificant. Due to its reduced capacity and high cost, it must be reserved for drinking water.
Fortunately, more rudimentary systems can be manufactured at a lower price in developing countries, although their capacity may be lower.
Observations, recommendations, and possible suggestions
The good use of these filters requires certain precautions related to the preservation of the cartridges and the preservation of the bacteriological quality of the water.
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