EFFECT OF SOIL IRRIGATION WITH WASTEWATER ON NI FRACTIONS IN SOME CONTAMINATED SOILS IN EGYPT

In this study Ni species were determined using a sequential extraction technique. The method consists of sequential extraction of the soil with different solutions, and it is designed to separate into six operationally defined fractions namely water soluble, exchangeable, carbonate bound, Fe-Mn oxides bound, organic bound and residual fractions. The objectives of this study were to investigate nickel forms in tested soils and to determine the effect of industrial wastewater effluent irrigation on the metal fractions in soil.   Data showed a remarkable increase in all tested Ni-forms in polluted soil. It could be concluded that soil composition has been changed with depth. Especially under such condition whereas, metal soluble organic compounds found in wastewater may precipitate and percolates through soil and may transport soluble Ni with the soil solution.