Using Nonconventional Water in Irrigation of Olive Trees and Its Effect on Olive Oil Properties

Abstract

The response of olive orchard with same age and type to irrigation with treated municipal wastewater and freshwater was investigated in three years. Physical and chemical properties of the treated municipal wastewater reuse in agriculture (the effluent) produced by the Sheikh Ejleen wastewater treatment plant in Gaza Strip, freshwater, soil, and olive oil were determined and compared with Palestinian and international standards. The biological oxygen demand (BOD) of Sheikh Ejleen effluent is 60 mg∙l−1, which indicates low quality effluent. The results indicate that most of olive oil quality parameters— including heavy metals and trace elements for both fruits irrigated with treated wastewater or irrigated with freshwater—fall within the acceptable standard limit values. Moreover, soil analysis shows that organic content and cation exchange capacity were improved in soil irrigated with treated wastewater in comparison with that irrigated with freshwater. The results also show that there is no trace elements or heavy metals accumulation in soil.