الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Heavy metals present a problem when present in water streams above certain since they may be lethal to human and aquatic environment. Accordingly, their is a necessity before the water is used especially drinking water. The need for . cat, effective and safe methods for removal of heavy metals has resulted in the for alternative methods other than the standard popular techniques which include
’caI precipitation, oxidation-reduction, electrolytic recovery techniques, adsorption
membrane processes, etc. Biosorption has emerged as a potential option for heavy removal that is simple and cost effective. It involves the adsorption of heavy metals microorganisms (such as bacteria and fungi e.g.; yeast (Saccharomyces cerevisiae) synthetic leaves (such as algae, aquatic and emerged plants). Recently, these have been used for the removal of heavy metal pollutants in water streams due high efficiency in the sorption process and their availability and low cost. gly, in the present work a study has been conducted to test the ability of removing ions from aqueous solutions by biosorptive flotation using yeast. Initially, batch flasks adsorption experiments were conducted to test the ability of yeast (both s and medical yeast) to adsorb Cu(II) from aqueous solutions. The effect of some ’ables such as type of yeast, initial Cu(II) ions solution concentrations, solution temperature and amount of yeast were studied as to their effect on the % extraction and
, equilibrium, Freundlich and Langmuir isotherms were conducted and it was found that the !,equilibrium isotherms were mostly of type (III) for which the Freundlich and Langmuir ” iIotberms were obeyed meaning that mono-layer adsorption took place, which in other ” cues adsorption followed type (II) isotherms in which neither Freundlich nor Langmuir ” iIoIhenns were obeyed .
. In the second part of this investigation biosorption experiments were carried out in
~ ..• betch baffied stirred tank reactor in which biosorptive flotation experiments were
: ’ . Numerous variables were investigated for their effect on the extent of removal
ions either through biosorption and flotation together or each conducted separately. variables included initial Cu(II) ion solution concentration, ratio of Cu(II) ions to . solution temperature, air flow rate during flotation, time of biosorption, additives to IOlution (type and quantity), type and size of impeller (propeller or turbine) and er speed. It was found that % extraction increased inversely to the initial Cu(II)ions
tration and that increase in temperature decreased the % extraction. In addition, propeller impeller was the most preferable one an10ng the three cases studied, and Iddition of 5 drops of a nonionic surface active agent resulted in the highest % of Cu(II) ions compared to 2 and 7 drops; and that the addition of ethyl alcohol effect on the % extraction. Also, higher air flow rate gave better results and • yeast and medical yeast had the same performance. Finally, using activated
:10 adsorb the soluble portion of the yeast following biosorption, was shown to be Ie and other means should be tested for extracting the soluble portion e.g.; by tDembranes for separation of the yeast from the water.