ABSTRACT
The trace element is used to denote a group of otherwise unrelated chemical elements present in the natural environment in low concentrations. In small quantities, many elements are essential to biological growth. This chapter reviews the fate of trace elements applied to soil during wastewater irrigation. It focuses on the quantity of irrigation water that would commonly be applied to irrigate crops in arid and semi-arid regions, which is 4 ft/year. The occurrence of trace elements in the wastewater is related to the source water and activities in the urban environment. Trace elements are widely used in industrial processing and in manufacturing consumer goods. The actual concentration of trace elements in the wastewater, however, may vary considerably with time within a particular treatment plant as well as among treatment plants in various communities. When wastewater effluents are used for crop irrigation, the concentration of trace elements in the water is not high enough to cause any short-term acute harmful effects.
