Assessment of effect of raw wastewater application on concentration heavy metals in olive tree (Olea europaea)

Use of municipal or domestic raw wastewater in order to irrigation is very important in arid and semi-arid regions. Application of municipal effluent، which was one of the pollution sources، as micro and macro elements has been used for a long time. The most factors for making difficulties in irrigation of soil with municipal effluent is the presence of heavy metals like Cd، Pb، Cr، Ni، Fe، Zn، Mn and Cu in municipal effluent and transformation of this pollution in food chain and threaten of healthy. The aim of the present study was to determine effect of irrigation with raw domestic wastewater effluent on concentration of young Olive plant (Olea europaea) and accumulation of heavy metals (Cd، Pb، Cr، Ni، Fe، Zn، Mn and Cu) in roots، and leaves of Olea europaea. In order to study the soil – plant complex effects as the transformation of these pollutants and nutrients in soil as a result of irrigation with raw domestic wastewater، a series of lysimeter (120 cm height and 70 cm diameter) studies were carried out in Khoramabad region during 2008- 2009). The experiment was carried out factorial based on CRBD with three factors and six replications. Factors were considered as three irrigation treatment including drip irrigation with raw domestic wastewater (DI)، subsurface drip irrigation with raw domestic wastewater (at depth of 15 cm، SDI15)، subsurface drip irrigation with raw domestic wastewater (at depth of 30 cm، SDI30). The results indicate that treatment application significantly increased concentrations of heavy metals. Maximum shoot concentrations of Fe، Cu، Ni and Pb were achieved by treatment SDI30.