Utilisation des eaux d'une station d'épuration pour l'irrigation des essences forestières urbaines

Abstract

The objective of our work is to improve the possibility of use of the waste water of the station of purification Ibn Ziad, for the irrigation of the urban forestry trees and to put in evidence the impact of waters used on the different components of the environment, notably the physico-chemical characteristics of soil and the plantations adaptability to waste water irrigation. The results of the tests led on three urban forest species (Schinus molle, Acacia cyanophylla, Eucalyptus gomphocephala), showed that the irrigation with treated wastewaters permits a growth of the different plants and can be used without danger for the irrigation of the plantations. We noted that the best result gotten for the growth is noted at the plantations undergoing the irrigation with the treated waste water for the three studied species. On the other hand, the irrigation by ruffians’ wastewaters led at these species a reduction of the parameters measured in relation to the plantations irrigated by a drinking water. We also note that there is a gain of aerial and roots biomass to the level of the plantations submitted to an irrigation with treated waste waters for the three studied species. Our results show that the plantations of the three studied urban forestry trees are able to adapt with the irrigation with waste waters by accumulating organic solutions (proline, soluble sugars and chlorophylls). The species that accumulates more organic solutions is considered as the most resistant species. In our case it is the Schinus molle that is then the most resistant and then comes the Eucalyptus gomphocephala and finally the Acacia cyanophylla that was the most affected by the load of the waste waters.