Simple water purification

Where water is scarce, irrigation is a luxury. One way to extend precious resources is to use waste water but, for hygiene reasons, only after purification. Classical purification plants are expensive and require skilled personnel. A new technique, known to its protractors as epuvalisation, simply and economically combines water purification and hydroponics (growing plants with no soil). Polluting effluents can be used to help certain plants grow, as long as they have a well developed and non-pivoting root system, as well as purifying properties. Researchers at the Horticulture Development Centre of the Agricultural Research Institute of Senegal (ISRA Dakar), working with researchers from the Gembloux Agricultural faculty in Belgium, have run tests on celery, watercress and canna (Canna indica). Results have been encouraging: the waste water has been cleaned naturally, and the vegetables grown hydroponically have been sold on the local market. Tests in other countries on value-added crops such as melon and carnations have also been encouraging. Epuvalisation can also be used for treating slurry and effluents from household wastes. Philippe Dumont and Dimitri Xanthoulis Unité hydraulique agricole Faculté universitaire des sciences agronomiques 2, Passage des Déportés5030 Gembloux, Belgium Tel.: 32 81 62 21 87 Fax: 32 81 62 21 81 Web: www.fsagx.ac.be http://www.agricta.org/Spore/spore83Where water is scarce, irrigation is a luxury. One way to extend precious resources is to use waste water but, for hygiene reasons, only after purification. Classical purification plants are expensive and require skilled personnel. A new technique,..