Assessment Impacts of Irrigation Using Treated Wastewater on Plants Growth, Soil Properties and Metals Accumulation in Soil and Tomato Plants

The objective is to study the impact of treated wastewater on the physico-chemical parameters of soil and amended soil with compost or sewage sludge, their effects on plant development as well as the accumulation of heavy metals in cultivated plants. The study was conducted using the wastewaters of the Sfax North treatment plant and the Agareb treatment plant. Experiments were undertaken to evaluate the phytotoxicity of metals present in treated wastewater: the implementation is carried out in a greenhouse under controlled conditions, with a regular monitoring of plant morphology, physiology and followed by physico-chemical soil parameters. Sewage sludge and compost resulted in the addition of micronutrients and organic matter in the soil parameters which are considered important for the development and maintenance of a vegetative cove. Following these experiments, optimum tomato plants growth is observed in substrates amended with sewage sludge and irrigated by the Agareb treated wastewater (122 cm). The most interesting observation is the importance of the contribution of sewage sludge that minimizes the phytotoxicity of the effluent.