Introduction: In the recent years, the use of municipal wastewater for irrigation has attracted the consideration of arid countries. Despite the potential use of municipal wastewater in plants irrigation as sustainable strategy, the environmental impacts need to be investigated. The aim of this study was to evaluate the use of treated wastewater in irrigation crop plants.
Methods: The present study was carried out to assess levels of iron, zinc, chrome, copper, manganese and nickel, in plants irrigated with water from different sources. Impact of different irrigation sources on metals uptake by plants were determined using Statistical tests.
Results: According to the results, the type of water source (well water, treated wastewater) had a significant effect at 5% level on the mean concentration of Cu in barley leaves, Cr, Cu and Ni in barley root and Cu and Ni in soil around barley root. In this study, nickel concentration was higher than critical value in the soil around the roots for both plants and both irrigation sources due to the presence of nickel in the ultramafic rocks. Due to the proper performance of Birjand treatment plant stabilization ponds in reducing heavy metals from municipal wastewater, the concentration of most heavy metals in plant and soil in irrigation with treated wastewater was significantly lower than in irrigation with well water. The proximity of farms to heavy-duty vehicles increased the concentration of copper in all the situations studied which were close to the critical range. The concentration of chromium in shoots of plant was lower than other metals.
Conclusion: As a result, the values of heavy metals in different parts of plants were below the acceptable levels as suggested. In comparison to plants, the soil presented higher concentration of all studied metals. However, the regular monitoring of levels of these metals from well water and treated wastewater, in plants and soil is essential to prevent excessive build-up of these metals in the food chain.