Determination of Cadmium and Lead Species in the Water Column of the Jose Antonio Alzate Reservoir, Mexico

Contamination by dissolved cadmium and lead was studied at two different depths at four sites of the Jose Antonio Alzate Reservoir in central Mexico. Total dissolved levels were found to be between 0.3 and 0.6 μg/L for cadmium and between 2.1 and 4.8 μg/L for lead. Chemical dissolved speciation showed primarily inorganic lead species, whereas cadmium species were detected in both inorganic and organic fractions. Most of the lead and cadmium species were removable by cationic exchange. No specific distribution trend was noted for the metal species in the reservoir, although a difference between the surface and bottom samples resulted from physical and chemical factors. Sedimentation and adsorption seemed to help with the natural scavenging process of reservoir water metals.