Physico-chemical characteristics and pollution level of lake Nainital (UP,India): Role of macrophytes and phytoplankton in biomonitoring and phytoremediation of toxic metal ions

Lake Nainital is the sole source of drinking water for the local people and even to majority of tourists. In background of lake utility and its import ance at national level such study is essential which is focused on toxic me tal pollution and current nutrient status of the lake and their magnificati on by algae and macrophytes. Study has shown that lake water is rich in nut rients which supports growth of many aquatic macrophytes and algal blooms. Besides, water is contaminated with metals like Cr, Cu, Fe, Mn, Ni Pb and Z n. Concentration of some of them like Fe, Pb and Ni were higher than the re commended maximum permissible limits. Concentration of these metals were al so found high in lake sediments. The level of metals amongst various compon ents of lake varied considerably in different season. Plants and algae grow ing therein accumulated appreciable amount of metals and water roots of Sal ix being more efficient than others. High metal removing potential of these plants may be significant for biomonitoring studies and could be a useful phytoremediation technology to restore water quality by harvesting submerge d and floating biomass inhabiting littoral zone of the lake. (C)1999 Elsevi er Science Ltd. All rights reserved.