Rudimentary Ceramic Water Purifier (CWFs) were originally manufactured by hand with the same basic materials used in current models. These filters were hand formed from a mixture of minimally processed local clay combined with a burnout material such as pine sawdust or dung. Efforts by early CWF technicians Ron Rivera, and Fernando Mazariegos working with the Asociacion Guatemalteca para la Familia de las Americas (AFA) led to the development of a more consistent form by lining a metal pail with plastic and forming the filter on the inside surface.
During this time the large scale filter industry was already manufacturing micro-porus ceramic filters treated with colloidal silver. These filters used diatomaceous earth in place of sawdust, and were formed as “candle” type filters, small cylinders adopting plastic housing and mounting systems. Although this compact format resolved issues of transport, the complex assembly coupled with leakage problems made their local manufacture and adoption unreasonable.
As the basic qualities of an effective filter were being examined it was realized that in order for the filter to produce reliable results, issues regarding consistency of form would have to be addressed. Adaptable forms were already being produced in the low-fired ceramic flower pot industry. Mass produced terra cotta flower pots are being manufactured in India, China, and Italy using electric over hydraulic presses and aluminum molds. It was decided to re-produce these production methods in a more appropriate manner for localities with very basic infrastructure. The first CWF presses to utilize aluminum molds and hand operated hydraulic jacks were made in Central America.
As the technology continues to develop the primary challenge continues to be: how do we improve on the manufacturing process by making it more simple? Certainly industry is familiar with the challenge of producing a better product by adding layers of expensive and complex technology.The challenge in our case is to keep the manufacturing locally sourced and accessible to areas lacking basic utilities. To that end significant effort is being made towards improvements in basic equipment and manufacturing best practices. The greatest achievements in CWF technology will involve batch consistency and simple ways to improve the three primary objectives: Flow rate, Filter strength, and Bacterial removal efficiency.
http://es.wikipedia.org/wiki/Fernando_Mazariegos