الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Alexandria is considered as the second industrial city in Egypt where it accounts for around 40% of the whole Egyptian industries. The pressing problem is that these industries discharge there wastewater to Lake Maryut and the Mediterranea Sea, or to the general sewage system. (Meybeck et al., 1989)(l)
The amount of industrial water wastes entering water bodies is increased by untreated runoff. These wastes commonly contain petroleum products, hazards wastes, organic matters, trace metals and heavy metals, these cause health, economic, socioeconomic and environmental impacts. In the past decades fish production in Lake Maryut declined by some 80% because of these direct discharge of untreated wastewater. Similar environmental degradations are taking place along the seafront as a result of this problem (Alex 4 all, web site)(2).
These impacts can be reduced or avoided by the treatment of this industrial wastewater. Treatment systems differ according to waste type discharge destination and potential reuse, such uses can be quite different as stated in UNEP study (1993)(3)
1- Landscape Irrigation: Reclaimed w’ater can be distributed for irrigation of parks, golf courses, football fields, highway medians, and even residential lawns.
2- Industrial Uses: Industrial facilities and power plants can use reclaimed water for cooling equipment, parts washing and cleaning, equipment operation and various other manufacturing processes.
3- Construction Uses: Reclaimed water can be used at construction sites. It can also be used for washing aggregate and making concrete.
4- Miscellaneous: Water can be used as a water supply for commercial laundries, for vehicle washing, and flush sanitary sewers as stated at New Jersey division of water quality Technical Manual (2005)(4).
Wastewater treatment includes several systems, e.g.: Aerobic granular reactor, Anaerobic clarigester, Anaerobic digestion, Anaerobic lagoon, Cesspit, Combined sewer, Composting toilet, Constructed wetland, Expanded granular sludge bed digestion, Sequencing batch reactor, Up flow anaerobic sludge blanket digestion and Wet oxidation (Chrobak and Ryder, 2005 )(5).
One of these treatment Systems is the anaerobic digestion which is a biological process ideally suited for the pretreatment of high-strength wastewater that is typical of many industrial facilities. The anaerobic process utilizes naturally-occurring bacteria to break