Using a phytoremediation approach to treat Egyptian watercourses with heavy metal contamination

Abstract

In this study, Potamogeton nodosus has a powerful ability of nutrient concentrations, and heavy metals uptake from the surrounding contaminated sediments and water in River Nile and Ismailia Canal was investigated. Ismailia Canal distributed stations uniformly (Shubra El-Kheima: S1–S3), and River Nile (El-Qursaya Island: S4–S6) of Egypt was selected. In each field station sampling, two sampling collection stations were selected; where P. nodosus sample collection along with contiguous sediments and water samples was conducted. The biomass of P. nodosus decreased with increasing distance from the discharge points S1 and S2 in Ismailia Canal to S3 and also in River Nile at El-Qursaya Island (S4) to S6. No significant difference was recorded between the biomass of P. nodosus in S2 and S3 on the one hand and S4 and S5 on the other hand. Significantly higher nutrients (N, P, K, Zn, and Cu) River Nile concentrations were recorded at El-Qursaya Island (S4) than at Ismailia Canal (S1 and S2) stations. Plant heavy metal accumulation rates (Fe and Mn), (Zn and Cu), and (Ni and Cd) in plant samples examined showed the same concentration pattern in the studied stations. Besides, the bioaccumulation factor (BAF) was above one for all the considered heavy metals; this confirms the high efficiency of metals uptake from the environment. Significantly positive correlations were recorded for all the plants, heavy metal, and sediments. The recorded high BAFs values may refer to the high ability of the studied plants to concentrate heavy metals, which suggested its use as an accumulator plant.