Monitoring Wadi El Raiyan lakes of the Egyptian desert for inorganic pollutants by ion-selective electrodes, ion chromatography, and inductively coupled plasma spectroscopy

Wadi El Raiyan is a great depression located southwest of Cairo in the west ern desert of Egypt, one of the most arid regions of the world, In 1973, Wa di El Raiyan was connected with the agricultural wastewater drainage system of the El Faiyum province to provide a reservoir for the wastewater that e xceeded the capacity of Lake Qarun north of the province. Pollutants from a gricultural waste including pesticides and fertilizers as well as other eff luents of industrial activities and runoffs certainly will pass into the bi otic elements of the ecosystem, This report presents the status of inorgani c pollutants including anions, cations, and trace metals in the two lakes a nd the surrounding springs of Wadi El Raiyan using ion chromatography, ion- selective electrodes, and inductively coupled plasma emission spectroscopy, The report also includes the levels of selected metals in the vegetation c ommunity of the area. The result of this investigation revealed a great imp rovement in water quality of the Wadi El Raiyan lakes compared to 1988 repo rt by Saleh et nl, Mercury was not detected in any of the samples and the l evel of lead was significantly reduced, Cadmium levels were much higher tha n those seen earlier. The higher level of cadmium might be used as an indic ator to track the contamination of water by human waste. Concentrations of common anions were not significantly different from those reported earlier, However, an increase in the level of cyanide was observed. Levels of heavy metals in vegetation around the lakes were also found to be lower than pre viously reported. (C) 2000 Academic Press.