A new approach to understanding well water contamination by heavy metals at a mining extract region in Marrakech, Morocco

Abstract

Environmental pollution by heavy metals originating from functional mines can become a very important source of contamination both in soil and water. We studied the seasonal variation of physicochemical parameters of well water at the Draa Lasfar mining extract area in Marrakech, Morocco. A total of 144 samples (36 each during winter, spring, summer, and autumn) were collected during 2012-13 and analyzed for temperature, pH, total hardness, chemical oxygen demand (COD), and concentrations of nitrate and heavy metals like lead, zinc, and cadmium. Significant differences between seasons were observed for temperature, COD, and concentrations of nitrate, zinc, and cadmium. The highest temperature (28.72°±3.16) was recorded during summer. COD and zinc concentration was maximum during summer (167.25±31.05 mg/l, 131.4±12.0 µg/l, respectively). Highest nitrate (2.67±0.75 mg/l) concentrations were recorded during spring. Highest lead (632.14±82.54 µg/l) and cadmium (1.93±0.36 µg/l) concentrations were recorded during winter.