Accumulation of Heavy Metals in Soils Irrigated by Treated Wastewater: A Case Study from the Northwest of the Haut Chelif Plain, Algeria

Long-term irrigation by treated wastewater (TWW) can lead to the accumulation of heavy metals (HM) in the soil inducing negative effects on the pedo-environment. In this study, plots irrigated with TWW were studied to estimate the accumulation trends of HM and their impact on the physicochemical properties of the soil over a period of four years under a gravity irrigation system on turf with no fertiliser input. Soil samples were taken at two depths (0 to 20 cm: H1 and 20 to 40 cm: H2). The results of this study show that TWW are a main source of increase in HM in the soil by well-identified conditions, the degradation of the environment in general and on the physicochemical quality of soils in particular. It was concluded that the use of TWW in long-term irrigation enriches the soils with heavy metals, by main factors such as TWW composition, climatic conditions, soil type, and irrigation frequency