Uptake of Heavy Metals by Different Spontaneous Plant Species Grown Along Lana River, Albania

Abstract

Plants absorb a number of elements from soil, some of them are not known for their biological function and some are known to be toxic at low concentrations. The aim of this study is to assess the accumulation of heavy metals (lead, cadmium, nickel, manganese) in some plant species grown in water media. Concentrations of heavy metals were measured also in bottom sediments, near the root of plant species, in one of the most polluted rivers in Tirana i.e., Lana River. Three stations were chosen to assess the effect of growth environment in metal accumulation by each plant depending on water quality and pollution. Beside this, physico-chemical parameters of water samples were measured at time of sampling. Considerable higher contents of Ni and Cd were accumulated especially in species Typha latifolia L., (about 254.3 mg/kg Ni) whereas species Arundo donax L. accumulated more Mn (about 182.7 mg/kg). Accumulation of Pb and Cd was almost the same in all plant species. Positive correlation was found between the concentrations of Pb and Ni in sediments and in plants for species Typha latifolia as well as for Arundo donax L. The content of metals accumulated in species Salix alba L. was not in good correlation with the content in sediments. All sediment samples sites in the study area basin were generally more or less polluted when compared with the control values. Therefore, all plants can be used as biological indicators while determining environmental situation of a special environment. The results confirm the complexity of factors influencing the efficiency of heavy metal accumulation by plant species. They indicate increasing ion absorption in the case of some metals, while the accumulation of other heavy metal ions was limited.