Levels of some heavy elements in water, sediments and two aquatic plants in Al-Garraf river at Shatra district/ southern Iraq

Abstract

The present study was conducted in the Al-Garraf river in Thi-Qar governorate (October 2018 to March 2019) and aimed to investigate the pollution in the Al-Garraf river and the possibility of using some aquatic plants as bioindicator at three selected stations along the river. The study was achieved by measurement of air and water temperature, pH, and salinity, as well as the measurement of the concentration of some heavy elements (Cd, Pb, Ni, and Cu) in both dissolved and particulate phases in water and an exchangeable and residual phase in sediments and the tissues of two aquatic plants species, Ceratophyllum demersum L. and Phragmatis australis (Can.). The mean concentrations of the heavy elements (Cd, Pb, Ni, and Cu) in the dissolved phase in water were (0.07, 1.19, 3.17, and 0.03μg/l) respectively, while their concentration in the particulate phase was (15.73, 24.71, 65.63 and 22.86 μg/g) respectively. The mean concentrations of the heavy metals in sediments in an exchangeable phase were 15.73, 24.71, 65.63, and 22.86 (μg/g), respectively, while in the residual phase were 0.07, 0.85, 74.62, and 14.00 (μg/g) respectively. Results confirmed increased mean concentrations of heavy metals in aquatic plants tissues compared to their means in water. The maximum mean of heavy metals was recorded in Ceratophyllum demersum L. The Bioconcentration factor (B.C.F) values were more than their values of Biosedimentation factor (B.S.F) in all aquatic species.