TAILIEUCHUNG - ENVIRONMENTAL IMPACT OF HEAVY METAL POLLUTION IN NATURAL AQUATIC SYSTEMS

The purpose of Pollution Probe’s Mercury Primer is to provide an overview of the presence and effects of mercury in the environment and its impacts on human health. The primer iden- tifies where mercury is being used and released, the risks asso- ciated with exposure to mercury, and ways to help prevent mercury pollution. The primer also describes what governments, businesses and individuals are doing to eliminate the use of mercury and prevent its release to the environment. Pollution Probe has done extensive work on mercury in the envi- ronment for nearly a decade. It is an important issue that requires ongoing attention by industry, governments and consumers. This primer is. | ENVIRONMENTAL IMPACT OF HEAVY METAL POLLUTION IN NATURAL AQUATIC SYSTEMS MUHAMMAD REHAN TAYAB A Thesis Submitted for the Degree of Doctor of Philosophy Environmental Pollution Science BRUNEL THE UNIVERSITY OF WEST LONDON APRIL 1991 In the Name of Allah Most Gracious Most Merciful Read and thy Lord is Most Bountiful He who taught the use of the pen Taught man that which he knew not Al Quran Sura XCVI3-5 ABSTRACT The distribution of heavy metals between soil and soil solutions is a key issue in evaluating the environmental impact of long term applications of heavy metals to land. Contamination of soils by heavy metals has been reported by many workers. Metal adsorption is affected by many factors including soil pH clay mineralogy abundance of oxides and organic matter soil composition and solution ionic strength. The pH is one of the many factors affecting mobility of heavy metals in soils and it is likely to be the most easily managed and the most significant. To provide the appropriate level of protection for aquatic life and other uses of the resource it is important to be able to predict the environmental distribution of important metals on spatial and temporal scales and to do so with particular emphasis on the water column concentrations. Regulatory levels reflected in water quality criteria or standards are based on water column concentrations. Predicting water column concentrations requires a consideration of the interactions of water column contaminants with both bed sediments and suspended particulates as critical components in the assessment. The adsorption behaviour of cadmium copper lead and zinc onto soils is studied under the various geo-environmental conditions of pH concentration of adsorbate and adsorbent and solution compositions. Experiments were conducted to determine the equilibrium contact time of various adsorbates for adsorbent in different systems. Experiments were also conducted to check the efficiency of various acid-mixtures to extract .

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