The Lagunage For The Purification Of Waste Water In The ‎sahara: An Approach Integrated Into The Environmental ‎conditions

The water resources currently exploited in the Algerian Sahara, ‎are in majority underground. . Contrary to the northern zone ‎where the discharge system of water of the rivers is done ‎towards the sea, carrying with them waste water purified or not; ‎in the South, the rivers at the time of the risings, run towards the ‎interior of the grounds, involving with them waste water, ‎contaminating the sebkhas and the tablecloths. It is the case in ‎the valley of M’zab and the zone of Ouargla, wedged mediums ‎where the rejections pollute the ground water directly. The ‎treatment of waste water became a requirement and a social ‎and environmental stake impossible to circumvent. The process ‎of treatment by lagunage is used in the purification plants of the ‎towns of Ghardaïa and Ouargla It is ecological insofar as it ‎does not use any chemicals to treat waste water and to evacuate ‎them without risk towards the receiving natural environment. ‎Fragile environmental balance and the ecosystem of the ‎Saharianunit, must be safeguarded and for this reason it is ‎important to remove the harmful effects in residential areas; to ‎protect the receiving medium and the ground water; to make ‎possible the re-use of waste water purified at agricultural ends.‎