Assessment of trace metal contamination in the Kol wetland, a Ramsar site, Southwest coast of India

Abstract

The present study quantified the agrarian quality and assessment of 16 sediment samples in two seasons from the identified three representative zones (North, Center and south) of Kol wetlands in Vembanad system, situated in the west coast of Kerala, India. Estimated the pollution quality indices (Enrichment Factor, Geoaccumulation index and Contamination Factor), sediment quality (Organic matter, texture and nutrients) and their ecological risk . Water Quality parameters (pH, salinity, DO) of the residing habit were also examined. The overall seasonal analyses of sediment trace metal’s mean concentration of these three zones exhibited in the following order: Fe>Zn>Pb>Cr>Mn>Ni>Co>Cu>Cd. The nutrient quality parameters inferred high concentration with spatial disparity. The Enrichment factor of Co, Cr, Zn, Cu and Ni varies from moderate to severe; and the potential ecological index of Cd in the studied Kol sampling sites were likely to result in a dangerous situation in the near future. Water Quality of the surface water noticed a putrefied condition with negligible Dissolved Oxygen (DO) at Tholur (8) in the non monsoon season. While comparing the Sediment Quality Guidelines (SQGs) and the recommended food and Agriculture Organization (FAO) standard values, the Cd, Zn and Cu concentration were exceeded the recommended limit. These scenario alter the ecological and environmental feasibility of the habitat including the sediment dwelling organisms. Multivariate statistics Analysis infers the anthropogenic and domestic source input of Cd, Ni, Mn, Co and Cu in the central basin and the correlation pattern with respect to Pb, Zn, Total Sulfur (TS), NO2-N and NH4+-N indicates an agriculture input. Among these three distinct zones the cluster results shows that the central agriculture sites confronts elevated trace metal concentration.