Levels of heavy metals in subtidal sediments in the vicinity of thermal power/desalination plants: a case study

Sediments can accumulate various pollutants and are widely used for environmental monitoring of human impact. The central purpose of this study was to examine the levels of eight heavy metals in subtidal sediments in the vicinity of two thermal power/desalination plants in Oman: (1) the Barka power/desalination plant and (2) the Al-Ghubrah power/desalination plant. The samples of bottom sediment were collected with a grab sampler. The samples were analysed for cadmium (U), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), vanadium (V) and zinc (Zn). Sediment samples were collected at different stations. Some of these stations were located near the intake of the two plants, others were located at different distances and directions from the vicinity of the outfalls (outlets of the discharge). In addition to heavy metal analysis, other physical and chemical parameters measured simultaneously in the water include temperature, salinity, conductivity, and dissolved oxygen. The results indicated that the sediments were not polluted by heavy metals. The levels of Cu, Zn, Ph and Cd in sediment appear to be derived from the discharge whereas the levels of the other metals (Cr, Fe, Ni,V) appear to have a geochemical source.