Studies on the Heavy Metal Content of Coastal Waters Adjacent to Kadiyapattanam Estuary, South West Coast of India

Abstract

Valliyar is one of the main river systems in Kanyakumari District, originates from Velimalai Hills in Western Ghats and enters into Arabian Sea through Kadiyapattanam estuary. The concentration of heavy metals was analysed from water samples collected at different location in coastal waters adjacent to Kadiyapattanam estuary in Kanyakumari District, Tamil Nadu, south west coast of India. Samples were collected continuously throughout the year during monsoon, post monsoon and pre-monsoon seasons in the year 2015–2016. To carry out present study 5 sampling stations were selected and 7 heavy metals such as lead, zinc, copper, cadmium, iron manganese and Mercury were estimated following standard methods and procedures. Study area is situated near Indian rare earth limited corporation in Manavalakurichi. Mercury was found absent in the samples throughout the year in the present study. Concentration of iron was found higher compared to other metals. The metal concentration in samples was determined using Perkin Elmer A Analyst 200 Atomic absorption spectroscopy. The order of heavy metal content in the study area was Fe > Cd > Pb > Cu > Mn > Zn > Hg. In the present study the concentration of Zinc, copper, and manganese are within the permissible limit in all seasons. Lead and cadmium shows higher values in some season. The result of the study indicates that the river Valliyar and coastal waters of kadiyapattanam estuary are polluted due to the discharge of toxic heavy metals, agro chemical waste runoff and anthropogenic activities.