The Impact Of Wastewater On Water Quality In The Moulouya River, Morocco

Physico-chemical characterisation of water quality in several urban tributaries discharging into the Moulouya River, Morocco, and at 15 stations on the river itself, was done in 2004. The urban streams had a high organic matter load, marked by high mean values for BOD5 (180 ± 39.32 mg/l), suspended matter (630 ± 79.55mg/l), orthophosphate (3.1 ± 0.46mg/l) and sulphate (408 ± 21.67mg/l), although their average loads of heavy metals (iron, copper and bromide) were very low. The Moulouya River showed a clear deterioration at the confluences of the urban tributaries, with low dissolved oxygen and increased organic load. Self-purification quickly returned these parameters nearly to their natural values some distance below the region of urban disturbance. Keywords : Organic matter, urban tributaries, self-purification, Moulouya River, Morocco. Tropical Freshwater Biology Vol. 16 (2) 2007: pp. 1-8