Assessment and data assimilation of agricultural drainage water for reuse in irrigation purposes

Abstract

Agricultural drainage water (ADW) represented an excellent source for irrigation purposes where the water quality in terms of pH, dissolved oxygen (DO), Turbidity, total dissolved solids (TDS), chemical oxygen demand (COD), nitrate (NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -N), ammonia (NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> -N), total suspended solids (TSS), volatile suspended solids (VSS), total organic carbon (TOC), inorganic carbon (IC) and total carbon (TC) along El-Salam canal were assessed. The results revealed that all parameters were in accordance for reuse in agricultural purposes except dissolved oxygen. This was mainly due to dumping of pollutants into the canal. The COD was varied from 4.66 to 32.6 mg/l. This is mainly due to discharge of domestic wastewater which cause a serious depletion of dissolved oxygen (DO=3.98 mg/l). The NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> was quite low and varied from 0.49 to 1.89 mg/l while the ammonia concentration along the canal was largely varied from 1.43 to 6.33 mg/l. This indicates that the nitrification-denitrification could be occurred along the canal resulting a deterioration of water quality along the canal. However, the ammonia and nitrate are represented a good soil conditioner and minimizing the usage of chemical fertilizers. Relative (10 % and 40%) and constant standard deviations (0.10 and 4) for the discharge were applied in the MIKE 11 data assimilation for pump stations no. 1 and 2 which was not significant at T-test value (p>0.05).