Seavn

General contamination of heavy metals in the environment is a major global concern, which has provoked the emergence of phytoremediation technologies for cleaning aquatic environment. Heavy metals are released into the environment from a wide range of natural and anthropogenic sources. Macrophytes are known as good indicators of heavy metal contamination in aquatic ecosystems and they act as biological filters by accumulating heavy metals from the surrounding environments. Concentrations of heavy metals such as Hg, Cd,
Co, Cu, Mo, Ni, Pb, Tl and Zn were measured in macrophytes and water samples from the mouth of five rivers namely; Gavaraget, Argichi, Makenis, Masrik each of them meeting the Lake Sevan, Armenia. The collected plants were Batrachium rionii, Myosotis palustris, Lythrum salicaria, Scrophularia alata, Calamagrostis epigeios, Lepidium latifolium, Glyceria plicata, Veronica anagallis-aquatica, Butomus umbellatus, Sparganium erectum. The highest concentration of Ni (5.5 mg/kg) was observed in Glyceria plicata whereas concentrations (mg/kg) of all other metals were highest (Hg, 0.02; Cd, 0.46; Co, 3; Cu, 18.9; Pb, 6.9; Tl, 0.13 and Zn, 113) in Batrachium rionii. Range and trend in concentrations of Co (<0.5μg/l), Cd (<0.5μg/l), Tl (<0.1μg/l) and Hg (<0.3μg/l) in water samples were similar at all the sites. Occurrence of heavy metals was much higher in macrophytes and water from Gavaraget and Masrik than that of the Argichi and Makenis due to the discharge of sewage into the river Gavaraget and industrial wastewaters into the river Masrik. The fact that the concentrations of different heavy metals in these macrophytes were far higher than in their respective water column indicates to their role in the biogeochemical cycles of heavy metals. This study aimed at understanding the importance of macrophytes in accumulation of heavy metals and suggesting remedial measures for the preservation and restoration of the lake ecosystem.