Résumé:
Water is essential to life and human activity. Given the scarcity of conventional water
resources, the poor management of water resources and the pollution caused by wastewater
discharges into the natural environment, wastewater treatment is essential to protect the
natural environment and to create new water resources for reuse and reclamation for
agricultural irrigation. The aim of our study is to evaluate and determine the physicochemical
and microbiological quality of treated wastewater from the Hadjadj lagooning (Mostaganem)
plant before and after treatment, and to determine the effect of irrigation with treated
wastewater from this plant on the physicochemical quality of olive oil.
According to our results, the physicochemical analyses of the treated wastewater were as
follows : Purified volume= 1991,33 (m³) ; COD= 79,52 (mg/l) ; BOD5= 25,83 (mg/l) ; TSS=
26,66 (mg/l) ; DO= 3,49 (mg/l) ; pH= 7,76±0,25 ; CE= 1559.83 (μs/cm) show that the values
obtained comply with the standards required by the WHO and Algerian regulations (JORA,
2012) and can be used for agricultural irrigation without any risk. The results of the
microbiological parameters show that these waters are characterized by fecal contamination
(presence of total and fecal coliforms ˂1000 CF/100ml), the total absence of pathogenic
germs according to Algerian standards (JORA, 2012).
According to our results, the samples show physico-chemical values within acceptable ranges,
notably for acid value, acidity, peroxide value, iodine value, and other parameters. Levels of
carotenoid pigments, chlorophyll, polyphenols, and flavonoids vary but remain within
reasonable limits. The oil samples also showed high fat levels and notable antioxidant
activity. Our study highlights the importance of closely monitoring irrigation water quality,
particularly when treated wastewater is used. The results indicate that irrigation with treated
wastewater can have a significant impact on olive oil quality.
