With the aim of mitigating the problem of salinity of purified waste water of the STEP (waste water treatment plant) of Ouargla,
one proposed to study the possibility of integration of solar energy to solve the problem of this water intended for the irrigation of
the agricultural surfaces and in particular the palm trees, which underwent major damage because of the salinity of this water. A
physicochemical and biological study was carried out on a sample of 20 L, whose pH is of 8.03, a salinity of 5.2g/l, and a
conductivity of 9170 μ S/cm, we note that distillation was spread out over 5 days.