<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> Sediment characteristics of Poonthura estuary (southwest coast of India) in relation to pollution </smarttagtype></smarttagtype>

Abstract

Texture, redox potential and organic carbon of sediments in Poonthura estuary, Thiruvananthapuram, presently exposed to sewage pollution were evaluated over a period of one year. Textural study revealed the presence of highest percentage of finer particles at the sheltered upstream stations. Oxidation-reduction potential varied between -211 and +156. Strong negative potentials recorded from the most polluted stations while freshwater and oceanic stations always recorded positive values. Organic carbon widely varied between 2.4 to 83.3 mg/g, and showed enrichment always at the polluted zone. Organic carbon content was more than the prescribed limit for unpolluted estuaries at some stations and reflects the level of pollution in the estuary. Significant variation in organic carbon and redox potential during the monsoon season shows that better dilution can diminish the high organic load to a great extent.