الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
1. Chapter I:
Water importance, water supply approach in Egypt, sludge as a waste of the water treatment process and its effects on the environment and the proposed uses and handling methods which include the recovery of aluminum coagulants from water treatment sludge using acidification.
2. Chapter II:
Water importance, water treatment, coagulants and different uses of waterworks sludge with a focus on its use as coagulant after acidification.
3. Chapter III:
This chapter includes experimental work, materials, solutions, their preparation techniques, instruments and the analytical methods used in this work and the practical procedures that have been carried out in this study to achieve its goal.
4. Chapter IV:
This chapter presents and discusses the results obtained through the study done to prepare aluminum coagulants from water treatment sludge by acidification and testing these coagulants on the raw water of ESZ-WTP and the steps done to achieve that are as follow:
a. Aluminum metal recovery and coagulant preparation and characterization:
Aluminum recovery studied in this section through testing six different factors affecting the leaching rate using sulfuric and hydrochloric acid which are: acid concentration (N), sludge weight (g), acid / sludge ratio (g/g), mixing speed (RPM), mixing time (min) and temperature (°C). Then aluminum concentration was determined in the supernatant in each experiment to determine optimum conditions for recovery through the percentage aluminum recovery by comparing it to the total aluminum concentration in sludge. Two aluminum coagulants were prepared using sulfuric and hydrochloric acids under the optimum conditions obtained, which were at acid concentration 1.5 N, sludge weight 5 g, mixing speed 60 RPM, temperature 60 °C and mixing time 40 minutes using sulfuric acid that achieve maximum aluminum recovery of 94.2 %. In addition best aluminum recovery was 82.4 % using hydrochloric acid concentration 2.0 N, sludge weight 5 g, mixing speed 80 RPM, temperature 40 °C and mixing time 40 min. Recovered coagulants are characterized through analyzing aluminum, iron, manganese, chromium, calcium, magnesium, potassium, sodium, barium, cobalt, copper, lithium, nickel, lead, strontium, vanadium and zinc.
b. Evaluation of using recovered and commercial coagulants with raw water in ESZ-WTP:
In this section a break point chlorination test was done to the raw water and the optimum chlorine dose was 4.5 mg/l, and the optimum dose of commercial aluminum sulfate was 30 mg/l but using recovered aluminum sulfate the optimum dose was 46 mg/l and recovered aluminum chloride was 39 mg/l, optimum doses were used to compare the three coagulants and their efficiency in treating the raw water of ESZ-WTP using jar test, the work concludes that aluminum species in the virgin coagulant is more effective than in the recovered aluminum coagulant using sulfuric acid and the lowest efficiency was for the aluminum recovered using hydrochloric acid the turbidity removal percentages were 82.5%, 80.0% and 76.25% for commercial, recovered coagulant using sulfuric and hydrochloric acid respectively and that may be due to the organic content in the recovered aluminum coagulants which binds to the coagulant and reduce the net charge on it reducing its efficiency.
c. Evaluation of sequential aluminum recovery with raw water in ESZ-WTP
To complete the picture about using recovered coagulants in water treatment safely without affecting the produced water quality sequential (repeated) aluminum recovery was carried out applying optimum conditions for recovery using sulfuric and hydrochloric acid then the produced water was analyzed. However repeated recoveries don’t show significant change in the overall quality of result waters but it shows remarkable increase in the total trihalomethanes (THMs) showing maximum concentration at the third recovery which could tell that maximum possible times for coagulant recoveries is three times then a virgin coagulant should be used to refresh the sludge and repeat the recoveries. Accumulation of THMs is not due to THMs in sludge because it’s decomposed during the drying process, but it may be due to the organic content in sludge.