الفهرس 
introduction and ObjectivesOnly 14 pages are availabe for public view
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Abstract
In these days, removal of dissolved organic pollutants in water such as Trihalomethanes (THMs) and odors substances is attracting greater concerns to upgrade qualities of municipal water. Since these substances bring out unpleasantness other than negative effects on our health, water treatment plants need advanced treatment processes to supply safe water. Activated Carbon adsorption has been used to remove soluble organic contaminants from water. It can be used as a replacement for existing media in a c0!1ventional filter, or it can be installed in separate. A major advantage is that GAC bed is not all used up at once.
The aim of this research was to study the efficiency of GAC filtration process in removing organic substances, THMs compounds and heavy metals. In this study, a simple experimental set - up was installed in Oamanhor water treatment plant, different thicknesses of GAC and three types of water were used to achieve the aims of this research. ,.
The experimental work of this study was divided into two stages to study the effect of carbon layer and characteristics of the feeding water on adsorption process. Each stage consists of three phases depending on the type of the feeding water. The feeding water in the first phase was water after coagulation and sedimentation processes for Coke and GAC filter. To study the effect of absences of coagulation process on the performance of GAC filter, raw water after filtration by~.using filter paper was used in the second phase. In the third phase, filtered water with pre - chlorination and without post _ chlorination was used to study the effect of pre - chlorination on the behavior of GAC filter in removing TOC and the effect of adsorption process on THMs compounds.
Based on the observation and the results obtained from this study the following points were concluded.
1- Coke has a negative effect on TOC re/TIoval
2- Organics can be removed by adsorption process and the removal of TOC was proportional to the thickness of GAC layer
3- GAC filter has a positive effect on the reduction of pH value, Alkalinity, turbidity, chlorides, Sulfate, Calcium hardness and total hardness but has no effect on sodium concentration.
4- Heavy metals can be reduced by adsorption process
5- Using filtered raw water (without coagulation) followed by GAG filter was not an economic process, especially when TOG concentrations were high (February to May) and then bed depth of GAG filter should be increased. So, water supply should be pretreated by chemical coagulation before GAG filter.
6- At the beginning stages of GAG filter operation, using settled water followed by GAG filter gave removal efficiencies greater than that using filtered water with pre - chlorination followed by GAG filter. Therefore, the reaction of chlorine gave negative effects on adsorption process.
7- Reduction on removal efficiencies for settled water followed by GAG filter was higher than that in filtered water with pre - chlorination. Therefore, better quality of treated water will be expected by using GAG filter after conventional sand filter and low loading of pollutants to GAG filter will result in long intervals of reactivation or replacement of GAG.
8- GAG filter removed THMs comppunds completely (100% removal efficiency) and the removal of THMs was’ better than removal of TOG