Introduction to AquaFilters
The Aquabox has been very effective in delivering clean water in emergencies, but its use of chemical tablets with a carbon filter means that it can only deliver a finite amount to cover the most basic drinking water needs of a family for first four months in the case of a Standard Aquabox or 33,000 litres in the case of Aqua30s.
We have been looking for a longer lasting solution, and a system based on membrane technology seemed to be the answer. Membrane technology is well known and used in public water supply, and a number of versions have been produced for small scale use in developing countries. None of these, though, were found to be suitable, in price, performance, or ease of use. As a result, a Rotary supported organisation, The Safe Water Trust, was set up to develop solutions which were tailored to the real needs of Aquabox users. We have been working closely with The Safe Water Trust to help develop the AquaFilter family of products to give us a cost effective replacement to our long standing, but limited, chemical based solution.
Research in the field identified two requirements; a water supply for schools, hospitals, and other organised communities; and a water supply for families.
The AquaFilter Family
Typically, water for washing and drinking is collected from the source, and stored in a container in the family house or shelter. The AquaFilter Family is fastened to the container, such as the Aquabox or a bucket, and delivers drinking water directly into the user's cup. The filter delivers up to 1 litre a minute, so the user has only to pump to get water on demand. We are anticipating that the unit will be capable of delivering at least 18,000 litres; enough for 22.5 litres/day of general use potable water for use by the family for a period two years.
A washable gauze pre filter, first removes the larger particles, before the membrane removes the smaller biological contaminants. The membrane is continually washed by an internal cross-flow system.
Periodic maintenance includes greasing the pump seal, for which a suitable grease store is built in; replacing the pump seal, for which spare seals are already attached to the piston rod; and chemical washing, for which a pot of tablets is attached.
The unit fits into a Standard or Gold Aquabox together with the rest of the humanitarian aid.
The AquaFilter Community
The AquaFilter Community was developed for schools and other organisations, and fits into an Aquabox. This makes for easy storage and transport as part of an Aquabox consignment.
It operates by a hand pump, and delivers up to 300 litres of drinking water an hour (when used by a relay of pumpers!). It has a washable gauze pre filter to remove solid particles. Membrane washing is done by reverse flushing. Periodic maintenance includes greasing the piston seal with grease supplies from a built in container, seal replacement by a new seals stored on the piston rod, and chemical washing with tablets stored on the unit. Preliminary results show a life in excess of 560,000 litres.
Note: AquaFilter Family and AquaFilter Community units remove biological contaminants, commonly found in water from ponds, streams, or shallow wells. They do not remove dissolved substances such as salt, or arsenic, typically occurring in deep wells.
The Safe Water Trust is supported by Cleadon and District Rotary Club (district 1030), and is a Company by Guarantee. It is a continuation of the good work done by The District 1030 Aqua Filter Trust, which pioneered membrane filters for Developing countries.
Contact Aquafilter
Visit the Aquafilter website - www.aquafilter.org.uk
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