UBC Theses and Dissertations
The basis of adsorption of water pollutants by coal Fadl, Samia Massoud Mohamed
An approach for studying the basis of adsorption of water pollutants, by coal, is presented. Oxidized and non-oxidized coal samples, mined from the Hat Creek deposits of British Columbia, were evaluated. During the first phase of the research, electron microanalysis, and macrochemical techniques were used to investigate the surface properties and the pore structure of the Hat Creek coal in comparison with activated carbon. The second phase of the study was focussed on the extensive evaluation of the adsorption capacity and efficiency of the coal to remove some dissolved components from synthetic wastewaters using both batch and continuous leaching tests. Heavy metals, dissolved organics, nitrates, phosphates, ammonia, phenol and cyanide were tested either individually or mixed in some combinations. The selectivity exhibited by coal towards mixed metals is also discussed. Adsorption isotherms and break through curves were plotted and interpreted for each material. A comparative study using other adsorbents such as activated carbon, soil and construction sand was also conducted. The effect of some factors in influencing the adsorption process were statistically analyzed. During the third phase of the study two mechanisms for the adsorption of heavy metal ions and dissolved organics were investigated. Spectroscopic, electron microscopic, and chemical methods were used to confirm that metal ions are adsorbed by coal through a chemisorption type of mechanism where the adsorbed metal ions interact with the available acid groups (mostly carboxylic COOH and phenolic -OH) to form metal complexes. In the case of removal of dissolved organics by coal, there was a combining effect of physical adsorption and biological oxidation. A material balance on the coal bed systems was utilized to estimate the bio-oxidizable fraction of the organic substrate. The last phase of this work is concerned with some design applications using the actual flow from municipal and industrial sewage. Data from long term experiments on larger columns were utilized to predict the size and performance of a coal bed to treat large quantities of flow. It appears from the research conducted that low rank coals will be a satisfactory material for the removal of pollutants from wastewaters.
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