| || || Heavy metals -- Environmental aspects -- Fiji -- Rewa River (Fiji)|
| || || The study of heavy metal pollution in Rewa River, Fiji|
Author: Deo, Randhir Prakash.
Institution: University of the South Pacific.
Subject: Water -- Pollution -- Fiji -- Rewa River -- Measurement, Water -- Pollution -- Toxicology -- Fiji -- Rewa River, Heavy metals -- Environmental aspects -- Fiji -- Rewa River (Fiji)
Call No.: Pac TD 427 .M44 D37 2000
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: Heavy metal pollution is among the most pervasive and serious environmental problems facing the biosphere. The possible sources of heavy metals pollution are mining and smelting of non-ferrous metals, coal combustion, refuse and sewage disposal, and manufacturing (steel production and plating, battery manufacturing, and electroplating) . Many of these heavy metals (e.g. copper, cobalt, nickel and zinc) are essential in trace amounts for living and function as enzyme cofactors or in redox-active enzymes. However, at higher concentrations these can be toxic (Cai et al., 1998). With this in mind, heavy metal pollution was quantified from Rewa River. Rewa River is the largest river in Fiji and supports the largest kai fishery in the country. The location of the river adjacent to Nausori Town, Nausori Rubbish Dump and Nausori Sewage Treatment Plant (NSTP) makes this river most vulnerable to heavy metal pollution from industrial waste, run-offs, leachates, and sewage disposal respectively. The levels were determined in water, sediment and kai (Batissa violacea). Results showed considerable pollution of iron, zinc and copper in water, sediment and kai samples. These were concentrated near the NSTP, and near the village settlements of Kasavu, Naselai and Nakaile. The highest concentrations were obtained from near Kasavu village, mostly attributed to its high depth, concentrating the metals released from non-point sources near Kasavu village and other villages located upstream. Besides the quantification of heavy metal pollution, a new technique for heavy metal determination was investigated. Closed-vessel acid digestion of organic and inorganic samples using Bombs supplied by Parr Instrument Company was tested using a 900 watt domestic microwave oven as a heat source and analysis in Flame Atomic Absorption Spectroscopy. The optimised digestion technique achieved complete dissolution for iron, lead, cadmium, copper and zinc from organic materials in as low as 26 seconds. Except for iron, 26 seconds of digestion was also shown suitable for inorganic materials.