Drains in North Delta, Egypt (Kafr El-Shiekh Governorate) were used for receiving waste water (drainage water of the fields, sanitary and industrial). Because of the shortage of irrigation water, such water, is used in irrigation of agricultural crops, therefore, it becomes a dangerous source of pollution as it contains different contaminants of agrochemical pollutants. The aim of the present study was to monitor the presence of some serious agrochemical pollutants (some pesticides, heavy metals and nitrate) in waste water of the main drains in North Delta, Egypt in order to assess the degree of pollution in the water of these drains for agricultural purposes.
Data revealed that salinity and sodicity values of the studied drainage water samples ranged between 1.45 to 3.05 dS/m and 5.95 to 10.18%, respectively. According to USDA diagram, the studied samples are in class C3S1 and C4S2.
Malathion concentration in drains water was ranged between 0.13 to 1.15 µgL-1 and was not depending on sampling time (winter and summer). Atrazine concentration in drains water was ranged from 0.04 to 0.19 µgL-1 and was higher in summer than in winter.
Heavy metals concentrations in drainage water were higher in summer than in winter. The concentrations of Cu, Mn, Zn, Cd, Ni and pb in winter for all drains were varied from 0.23 to 0.51, 0.20 to 0.28, 0.17 to 0.38, 0.01 to 0.09, 0.24 to 0.79 and 0.08 to 0.25 mgL-1, respectively. The corresponding concentrations in summer were 0.29 to 0.67, 0.22 to 0.36, 0.23 to 0.46, 0.05 to 0.15, 0.35 to 1.21 and 0.19 to 0.46 mgL-1, respectively. The highest concentration levels were for Cu, Mn, Ni and Cd in all drains comparing to maximum permissible levels stated by FAO, 1992, (0.2, 0.2, 0.2, and 0.01 mgL-1), respectively. While, pb and Zn levels were lowest than the maximum permissible levels stated by FAO (1992), (pb, 5 mgL-1 and Zn, 2 mgL-1).
Concentrations of NO3- were 18.5 to 112 mgL-1 in all drains for winter and summer. Nitrate nitrogen concentrations leaving surface drains in North Delta, Egypt exceed the U. S. Environmental Protection Agency (1991) maximum contaminant level for drinking water of 10 mg L-1.
Results of the present study, reveals that the water of these drains are highly dangerous on the environment and human health, when used as it is without good treatment. So these waters must be remediated from such contaminants.