International Academy of Ecology and Environmental Sciences
Abstract
the present study water, sediment and soil samples of Cauvery basin was undertaken to evaluate the spatio-temporal variations in heavy metal concentrations between 2007 and 2009. The Line diagrams for individual heavy metals of the seasonal samples with standard deviation at p=0.05 were plotted to comprehend the seasonal and spatial fluxes and variations. The seasonal heavy metal concentration in river water was maximum for Fe, Zn, Mn, Cu, Co and Cd during pre-monsoon and Pb, Ni and Cr during post-monsoon season whereas, in the sediment samples higher concentration of Ni, Cr, Mn, Cu, Co and Cd was found during pre-monsoon and Fe Pb and Zn in post-monsoon. In the case of soil samples maximum concentrations of Fe, Pb, Zn, Cr and Co noticed during pre-monsoon, while Ni, Mn, Cu and Cd during post-monsoon. An exponential increasing trend from water to soil and to sediment was evident throughout the river stretch. The mean concentration for all the heavy metals in water was within the limits of BIS and WHO standards. In sediment samples heavy metal concentrations were below the limit of sediment quality guidelines except Ni and Cd. Correlation analysis revealed higher degree of inter-metallic and intra-metallic association among water, sediment and soil samples indicating identical behavior of metals during its transport into the river environment. The spatial trends of heavy metal enrichment in river sediments reflected the sources/activities of the corresponding catchments in the study area. As such the downstream stations of Cauvery are enriched with heavy metals due to the influx of pollutants
