الفهرس 
interoduction and literatureOnly 14 pages are availabe for public view
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Abstract
Surface waters contain certain level of phosphorus in various compounds, which is an important constituent of living organisms. In natural conditions the phosphorus concentration in water is balance i.e. accessible mass of this constituent is close to the requirements of the ecological system. When the input of phosphorus to waters is higher than it can be assimilated by a population of living organisms the problem of excess phosphorus content occurs. The excess content of phosphorus in receiving waters leads to extensive algae growth (eutrophication). The phenomenon of eutrophication usually decreases the water quality and as a result it may increase significantly the cost of water treatment at treatment plants for surface water. The load of phosphorus discharged to receiving waters comes from various groups of sources of which the main sources are agriculture use of fertilizers, domestic and industrial wastewater. Domestic wastewater is the dominating source of phosphorus in municipal discharges in densely populated regions. Therefore the aim of present study was the removal of phosphorus from sanitary wastewater because in Delta region (Egypt) the major phosphorus input on receiving waters comes from municipal wastewater.
Processes of available for phosphorus treatment are generally classified into three general categories: chemical, physical or biological-based treatment systems. Among physical-chemical
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methods, phosphorus removal is achieving using ion exchange, dissolved air flotation, and membrane filtration. Among the various physical-chemical methods, coagulation with chemical precipitation and adsorption are the most common techniques being used for removing phosphorus. The major drawback of the chemical precipitation is that during phosphorus removal an additional amount of sludge is produced. Physical-chemical methods can also accommodate recycling sludge to reduce further costs involved in handling sludge. However, finding an effective and feasible material is a significant challenge in physical chemical approach. The key problem is to find a suitable material, which is easily available and effective to remove phosphorus from wastewater.
The overall goal of this study is to discuss and to evaluate the effectiveness of low-cost Drinking Water Treatment Alum Sludge DWT-AS) and red mud as available materials for removal of phosphate from aqueous media. DWT-As produced at water treatment plants is an unavoidable by-product. Red mud, bauxite wastes of alumina manufacture, emerges as an unavoidable by-product during alkaline leaching of bauxite in the Bayer process. For every tone of alumina produced, between 1 and 2 tones (dry weight) of red mud residues are produced. Huge amounts of red mud residues are discharged from EGYPTALUM Aluminum Industry Corporation in Ngaa Hamady, Qena, Egypt.
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In general, the present thesis includes three main chapters.
The first chapter deals with the aim of the study and general introduction about phosphorus in surface water and wastewater, and literature survey of the previous studies of the same study field. The second chapter includes the experimental work which involve preparation of the standard phosphate solutions and adsorbents used and the instruments and apparatus which used in adsorption process and measurements. Adsorption experiments were carried out using batch technique. The influences of initial solution pH, shaking time, initial phosphate concentrations, and adsorbent dose on the removal efficiency have been investigated.
The third chapter involves review of the results and discussion, tables and figures which illustrate the results. The results obtained showed that the adsorbed phosphorus amount by using (DWT-AS) and (RM) is slightly increases with the increase in pH value reaching the maximum removal at about pH 5 and then with increasing decrease of pH values. The results showed also, that high temperature (up to 60 °C) is advantageous for phosphorus adsorption on adsorbents. Results of shaking time effect showed that most phosphate is captured during the first 20 min. The phosphorus uptake increased with increasing initial phosphorus concentration. It was observed that lower initial concentration (25 mg P-PO43-/l) resulted in higher removal efficiency compared to the higher concentrations. By increasing initial concentration of
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phosphate, the removal efficiency was decreased. The Freundlich and Langmuir models were used to simulate the sorption equilibrium. from the experimental data, the results indicate both models are clearly best fitting isotherms with correlation coefficients greater than expected. The present study demonstrated that DWT-As and Red Mud can be employed as a highly effective natural adsorbents for phosphorus removal from aqueous solutions and sanitary wastewater.