الفهرس 
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Abstract
Wastewater is water that has had its chemical, physical, or biological properties changed by the introduction of chemicals, making it inappropriate for specific uses like drinking and agriculture. Because water is so important to man’s daily activities, he discharges ”waste” into the water. Feces and urine as a body waste, hair, food scraps, hair shampoo, fat, fabric conditioners, pesticides, detergent, toilet paper, and microorganisms (germs) are only a few of the examples that can make population sick and harm the ecosystem. It is commonly known that a significant amount of the water supplied becomes wastewater, necessitating wastewater treatment. The expense of treating wastewater is increasing as environmental regulations become more stringent. Ionizing radiation treatment of wastewater could be a cost-effective solutio. In this thesis, laboratory studies were carried out utilizing different radiation dosage to treat primary and secondary samples of wastewater acquired from Alexandria Sanitary Drainage Company, The Eastern Wastewater Treatment Plant EWTP, Alexandria, Egypt. This work aims to evaluate the effectiveness, efficiency, and applicability of ionizing radiation for sludge treatment, by assessing the physical, chemical, and biological characteristics of sludge before and after the irradiation process.
Our results showed that
In the primary sludge samples:
The concentration of oil & greases was reduced to less than one-tenth of the control groups at 6 kGy.
The Total Solids concentration was reduced to one-third of that of the control samples at 6 kGy.
Six kGy able to reduce the BOD and COD concentrations in the primary sludge samples to that of the treated (after sludge dewatering) samples or less respectively and saved the secondary treatment stage.
In The culture of the primary sludge, E.coli, Staphylococcus aureus and Vibrio spp were isolated as heavy growth on different culture media in the samples before radiation. After exposure to increasing doses of radiation, the number of isolated organism decreased, however the growth of Proteus, Acinetobacter and vipro organisms were detected but in small numbers. No growth of any organism was noted at 5 KGy.
In the secondary sludge samples:
The concentration of oil &greases reduced from (3410.0 ± 14.14) at control to (16.30 ± 0.57) at 6 kGy. Two KGy was sufficient to reduce the oil & greases concentration to less than 1/10 the original concentration. 6 KGy of radiation is as efficient as the conventional way of treatment.
The concentration of Total Solid reduced significantly to about one-third of control concentration at 6 kGy
Summary, Conclusion and Recommendations
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Six kGy able to reduce the COD in the secondary sludge samples to about 4% when compared to that of the control samples.
In secondary sludge, it is noted that E.coli, Staphylococcus aureus, Proteus and Vibrio spp were isolated as heavy growth on different culture media in the samples before radiation. After exposure to increasing doses of radiation, the number of isolated organisms decreased, however the growth of Proteus, Acinetobacter, Moraxella spp and vipro spp organisms were detected but in small numbers. No growth of any organism was noted at 5 KGy.
secondary sludge showed the presence of rotifer adults & eggs in samples before radiation and to a lesser extent after radiation by increasing the doses.
In the primary and secondary sludge samples:
Oil &greases, Total Solids, BOD, COD Concentrations were reduced significantly (p <0.001) in a dose dependent manner.
Either primary or secondary sludge samples, total solid reduced significantly to about one-third of control concentration at 6 kGy
In The culture of the primary and secondary sludge samples, E.coli, Staphylococcus aureus and Vibrio spp were isolated as heavy growth on different culture media in the samples before radiation. After exposure to increasing doses of radiation, the number of isolated organisms decreased, however the growth of Proteus, Acinetobacter and vipro organisms were detected but in small numbers. No growth of any organism was noted at 5 KGy. On the other hand, only in the secondary sludge, Proteus and was isolated as heavy growth on different culture media in the samples before radiation. After exposure to increasing doses of radiation, the number of isolated organisms decreased, however the growth of Moraxella spp organisms were detected but in small numbers.
By increasing the radiation doses, the free-living ciliates were decreased in the primary and secondary sludge samples. The free-living ciliates disappeared completely at 3 KGy. In the primary and secondary sludge samples, free-living ciliates reduction efficiency at 0.25KGy was equivalent to the conventional treatment methods.
6.2. Conclusion
We can conclude that radiation technology using Gamma rays at a dose higher than 5 KGy with dose rate of 1.095kGy/h is an effective technology for domestic and industrial waste sludge treatment from the environmental perspective
6.3 Recommendations
Either in primary or secondary sludge samples, the concentration of oil &greases reduced significantly (p <0.001) in a dose dependent manner, that leads us to investigate later a higher radiation doses which might reduce the concentration of oil &greases to the level of the treated samples.
To minimize the cost of wastewater treatment through the application of irradiation technology, an experimental pilot plant research is necessary.