The transport of elements from soils around Kaiga to the Kali river, southwest coast of India

The behaviour of alkali, alkaline earth and transition elements during weathering, their consequent delivery into the adjoining river system and their surficial and subsurficial distributions in the soils around Kaiga, southwest coast of India, have been investigated. The mean concentrations of the elements studied are: Rb 50 ppm, Sr 31 ppm, Ba 156 ppm, Mn 1163 ppm, Pb 19 ppm, Cu 60 ppm, Zn 86 ppm, Co 32 ppm, Ni 108 ppm, Mo 1 ppm, Na 0.5%, K 0.9%, Mg 0.5%, Ca 0.4%, Fe 5.9% and Al 9.2%. The mean enrichment factors (EF) of Fe, Al, Mn, Cu, Co, Ni are > 1. The rest of the elements have an EF of < 1. These data and the metal/Al ratios indicate that alkali and alkaline earth elements are mobile and transported in the dissolved phase, whereas transition elements are predominantly present and transported in the particulate phase. All the elements studied (except Pb and Mo) are depleted in the surface horizon indicating their removal during soil erosional processes. Lead and Mo enrichment in surficial soils could be due to atmospheric input and by the sequestering nature of the organic matter respectively. Geoaccumulation indices for the elements studied fall within the ranges prescribed for unpolluted soils. This study has provided baseline data on metals in soils around Kaiga which will be the centre of industrial activities in the years to come.