Recent environmental changes in water and sediment quality of Lake Qarun, Egypt

Abstract

Lake Qarun, is currently saline, turbid (Secchi disc transparency usually <70 cm) and has no surface outflow. This study was carried out to throw the light on the present status and long term changes of lake water. Surface water and sediment samples were collected and analyzed for nutrient salts, major cations and anions besides some trace metals (Fe, Mn, Zn, Cu, Pb and Cd). Concentrations of nitrite, nitrate and ammonia in the lake sediment (average: 0.89, 9.44 and 156.39 μg g-1, respectively) were obviously higher than those reported for water (average: 0.010, 0.039 and 0.378 mg L-1). The majority of water samples contained >50 μg L-1 Zn, >20 μg L-1 Cu, >50 μg L-1 Pb and >10 μg L-1 Cd. Present study support prior contamination of the sediments with metals, which were deposited during accidental releases from drainage sewage. Long-term changes in Lake Qarun demonstrate a significant increase of nutrient in water, while salinity and major ions were fluctuated depending on the input drains water and the rate of evaporation. © 2010 Academic Journals Inc.