Evaluation of Drainage Water for Suitability of Irrigation Purpose in Egypt

The study comprised of evaluation water quality of El-Wadi drain of Ismaillia, Egypt for irrigation purpose. Water samples from fifty locations along El-Wadi drain stream were collected, approximately one sample every 1 km, and analyzed for pH, electric conductivity (EC), Na, Ca, Mg, K, Cl, CO3, SO4, Cu, Fe, Ni and total phenols. Results showed a significant correlation (p < 0.01) between ions of Cl and Na (r = 0.92), Ca (r = 0.86) and Mg (r = 0.88), which were found the form of Cl-Ca/-Mg/-Na complexes in the drain water. In addition, sodium adsorption ratio (SAR), adjusted SAR (Adj SAR), adjusted sodium ratio (Adj.RNa), residual sodium carbonate (RSC) and exchangeable sodium percentage (ESP) were found average of4.35, 8.42,4.75, -1.90 and 5.13, respectively. Irrigation water classes are used for salinity (EC) and sodium hazards to assess water suitability for irrigation, and it is found that samples categorized in three classes; (i) 18 % in the class of C2S1, (ii) 76 % in the class of C3S, and (iii) 6 % in the class of C3S2 indicating good to acceptable quality for irrigation with some cautions in case of last water class. Furthermore, the trace metal analysis indicated some degree of restriction on the use of this water for irrigation due to elevated Ni concentrations that associated with intensive and moderately cultivated areas. Unfortunately, the drainage water are restricted for direct irrigation purposes because of toxic organic compounds contaminations (phenol compounds; average of 82.9 ± 32.1 µgl-1) that exceeded the Egyptian permissible limits. This finding may confirm the need of including organic and inorganic element analyses in routine work for water quality determination for irrigation purpose.