Preliminary Assessment of Several Heavy Metal Ions (Fe, Cu, Ni, Zn, Cr, Pb, and Cd) in Water, Sediment, Ceratophyllum demersum, and Potamogeton pectinatus Plants from Marsh Al-Hawizeh, Iraq

Abstract

Seasonal samples of water, sediments, and two submerged plants, Ceratophyllum demersum and Potamogeton pectinatus, were collected from four sites within Al-Hawizeh marsh between December 2017 and November 2018 to assess several heavy metal concentrations (Fe, Cu, Ni, Cd, Pb, Cr, and Zn) and analyzed by using Flame Atomic Absorption Spectrophotometer. All concentrations were compared to permissible limits for aquatic life. The findings have clarified levels of metals so as the following: Sediments > plants > water. Concentrations of heavy metals in sediment decreased within the sequence Fe > Ni > Cd > Cu > Cr > Zn > Pb (mg/kg), plants as Fe > Zn > Cd > Cr > Ni > Pb > Cu (mg/kg dry weight), in water as Fe > Ni > Zn > Pb > Cr > Cd (mg/L). The concentrations of all metals in water didn’t exceed the permissible limit, thus Fe, Ni, and Pb showed a greater concentration in water samples than other metals. In sediments Fe, Ni, and Cd have exceeded the permissible limits except Cd wasn’t detected (ND) during the winter, whereas, Zn and Pb didn’t exceed the recommended limits. In-plant samples as C. demersum Fe, Cd, Zn, and Cr have exceeded the allowable limits, while Cu and Pb didn’t exceed the permissible limits, also in P. pectinatus Fe, Cd, and Zn have exceeded the permissible limits, whereas, Ni, Cu, Cr, and Pb didn’t exceed the permissible limits altogether seasons during this study. The correlation of Pearson was administered to detect the interrelationship between metal concentrations. A significant positive correlation (p ≤ 0.05) was found in sediment rather than plants and water samples.