Dissolved Heavy Metals in the Reservoir of Shahid Rajaei Dam, Sari, Iran

Abstract

Concentrations of heavy metals (Ni, Co, Zn, Cd, Pb and Cu) in the reservoir of Shahid Rajaei<br />Dam, one of the main water reservoirs in north part of Iran, were determined using a differential pulse polarography<br />(Metrohm 797 VA) and compared with the national and international specified maximum contaminant levels<br />(MCL) for different purposes of water use. The results showed that concentrations of Cd and Pb in the reservoir<br />exceeded different MCLs and thus they could pose health problems for regional residents. Averaged concentrations<br />of heavy metals exhibited a decreasing order of: Zn>Pb>Cd>Cu>Ni>Co. The spatial distribution and seasonal<br />variation implied the significant effect of anthropogenic sources on concentration of heavy metals. These metals<br />mainly originate from the fertilizers and pesticides which are used in upstream farm lands of the flood plain;<br />however the natural sources should not be neglected. The results would help in water resource management of<br />Shahid Rajaei Dam.