In heel message Ph.D

Thesis (M.Sc.) - Cairo University - Institute of African Research and Studies - Department of Natural Resources

The long term (e.g., 15 to more than 50 years) effects of primary treated wastewater (PTWW) irrigation on soil properties and heavy metal concentrations at Abou-Rawash farm, Giza Governorate, and its surrounding agricultural land were investigated. Soil profiles represented five definite locations (I, II, III, IV and V) including different landscapes features from either Abou-Rawash farm (I, II and III) or its surrounding area (IV, V). In addition, control soil profile (VI) was investigated from crop cultivated area irrigated with Nile freshwater (FW). At each location, soil samples were collected from subsequent layers (0-20, 20-40, 40-60 and 60-80 cm) for determination of various physico-chemical parameters. The total and DTPA extractable contents of heavy metals (Ba, Cd, Cr, Co, Cu, Fe, Pb, Mn, Ni, Zn) were also determined. The X-ray diffraction (XRD) analysis was undertaken to qualitatively investigate the composition of the soil samples mineralogy. The analysis of PTWW indicated that most of the physicochemical parameters and heavy metals concentrations were within the limits proposed by national and international guidelines for irrigation water. The bacteriological counts such as total and fecal coliforms indicated that the wastewater was not suitable for irrigation purposes and denotes the potential public health hazards.Soil analysis revealed that the dominant fractions were the sand across the six locations investigated and soil bulk density was redistributed under PTWW irrigation which deceased the bulk density values and thus increased soil total porosity. Furthermore, measurements revealed that pH and CaCO₃ values were high in PTWW irrigated soils compared to Nile FW irrigated soils

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