cafe filter

CAFE stands for Clean Aqua For Everyone. The filter can be a Rapid Gravity Filter (RGF); this is how drinking water in cities is treated. The water flows by gravity through a filter bed of sand.

The other options can be a self cleaning low head filter such as the one on the left, which can provide 50,000 litres of water per day, or a standard pressure sand filter similar to the ones used for swimming pools.

The difference is that we do not use sand, instead, there is a special filter media called AFM active filter media that I developed as part of my PhD research on water treatment. I formed a company called www.DrydenAqua.com off the back of this research, which I have now sold.

AFM is a direct replacement for sand in sand filters, but it makes the filters work up to 10 times better. Instead of filtering down to 20 microns with sand, AFM will filter down to 1 micron. AFM will eliminate parasitic infections, which is the number one disease suffered by humans. Over 10 billion people suffer from gastric parasitic infections. In Central and South America, 50% of the population carries one parastine and 25% carries two.

AFM filter media that can be used is a simple sand filter. Idealy, it should be fabricated in accordance with German DIN standards for best performance.

AFM an activated filter media

AFM replaces sand in sand filters, be it for the treatment of drinking water or the tertiary treatment of wastewater. AFM is manufactured by upcycling coloured glass bottles. The product is at least 10 times better than sand at removing sub-20-micron particles from the water. While it is more expensive than sand, AFM will last for the life of the filter. AFM could effectively eliminate parasitic infections from drinking water and save a huge amount of energy and chemicals that would otherwise be used for coagulation and flocculation of the sand. The ROI return of investment can be measured in months to about 3 years, but in preventing pollution and human disease, it is invaluable.