الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Sanitation problems and risks at the global level are regarded as the largest source of pollution in terms of volume, due to the increase in drainage from developing countries as a result of rapid urbanization and population growth, as well as the lack of capacity, planning, and funding required to establish a sewage network and water treatment plants.One of the most important ways to prevent pollution of water and land sources is to treat sewage water according to objective standards. This is because sewage water can be used to make up for a shortage of potable water and is put to good use in agriculture, such as the irrigation of parks, gardens, and forests.
Chapter I
Introduction
The study area is about 10 km away from Matrouh city. It is constrained by longitudes of 270 15/ and 270 25/ E, latitudes of 310 8/ and 310 25/ N with a total area of approximately 400 km2. Three drainage basins were chosen for the present study; these basinsfrom the northwest to the southeast are Wadi Samla, Wadi Khair, and Wadi Naghamsh with the area of 26, 36, and 116 km2, respectively. The chosen basins are important because of their agricultural operations, which require more water supplies to be sustainable and not transitory. The sewage treatment plant in the study area at an altitude of approximately 60 m from sea level with a capacity of 25,000m3/day. The plant has 14 oxidation basins used in aerobic and anaerobic treatment. The wastewater is treated and directed to three untreated dirt reservoirs used for water storage and tree forest irrigation. The wastewater treatment plant provides 9 million m3/year of water to irrigate 4 Km2 of tree plantations.
The sewage treatment plant was established with a capacity of 25,000 m3/day at an altitude of approximately 60 m from sea level and due to the population increase and the urban development movement and the increasing tourist demand in the city of Marsa Matrouh, the station receives 14,000 m 3/day of sewage water in a period Winter increases to nearly 60,000 m3/day during the summer months, which exceeds the absorptive capacity of the wastewater treatment plant, which leads to the disposal of wastewater and its drainage on the tree forest without proper treatment of wastewater.
Chapter II
Literrature review
This chapter provides a summary of previous research on the following:
• Review on Groundwater quality assessment using water quality index and multivariate statistical analysis.
• Review on preparation and characterization of Er3+- doped TiO2 nanocomposite synthesized in a sol-gel method for application in photocatalytic reactions.
• Review of the impact of operating settings on the photocatalytic degradation of diverse water contaminants, using a variety of photocatalysts exposed to visible, solar, and ultraviolet light.
• Review on applications of the integrated system.
Chapter III
Experimental
A field trip has been carried out in June 2019 with an inventory survey of 31 existing water samples from the study area (25 groungwater and 6 surfacewater). All laboratory analysis was conducted for all samples to estimate the concentrations of the major and minor components in addition to heavy metals.
This work focused on the preparation and characterization of nanoparticles by sol gel method. In the present study, an integrated system was used to analyze the reuse and recycling of waste treatment facilities in the study region. It was proposed to optimize the hybrid system to examine various combinations of pretreatment, photocatalytic process, and membrane filtering. The efficiency of the processes was verified by comparing samples before and after each stage. In light of this, the main goal of this study was to explore the practicality of a comprehensive, advanced treatment system using the above innovative technologies for wastewater treatment plant reuse and reclamation and to optimize system layout.
Result and discussion
Chapter IV
Hydrogeochemistry in the study area
The main results of the study were as follows:
1. The hydrogeochemical results indicate a wide range of groundwater salinity. The total dissolved solids (TDS) values ranged from 5041 to 11741 mg/l in the Pleistocene aquifer, from 2360 to 4742 mg/l in the Miocene groundwater and. All groundwater samples exceed the drinking water guideline of 1000 mg/l (WHO 2017).
2. Major ions are observed in Na+ and Cl− correspondingly as prominent cation and anion species in both the groundwater and surface water sample concentrations. The concentration of Na+ varies from 1450 to 3500 mg/l in the Pleistocene groundwater, from 580 to 1380 mg/l in the Miocene groundwater.The ionic concentration of Cl− is highest among all the ions and the concentration of Cl− in Pleistocene groundwater is between 2211 and 6076 mg/l, in Miocene groundwater. The groundwater display significantly higher Na+ and Cl− concentrations, indicating that seawater most likely affects the water quality in the area under investigation and this indicates the mixing of groundwater with the matrix of marine aquifers.
3. The values of TDS, Cl-,SO42-, TH, TOC, PO43-, BOD, COD, and Na+ were found to be above permissible limits in the groundwater and Surface water according to WHO (2017). The high levels of contamination shown by the physiochemical parameters point is due to the mixing of groundwater with the matrix of marine aquifers, municipal sewage discharge from waste treatment plant in the study area and land runoff.
4. Cd2+, Cu2+, Mn2+, and Pb2+ were found to be over the permissible limit. Heavy metal concentrations seen in the research region could be due to municipal sewage water and wastewater from a waste treatment plant.
3. According to Piper 1944, and Stiff 1951, groundwater samples of Pleistocene and Miocene aquifers are located in the sub-area 7, Where; the groundwater are dominated by noncarbonated alkali and strong acids (Primary salinity) exceeds 50 percent. This reflects the main groundwater salinization is mainly attributed to leaching and dissolution processes of aquifer matrix rich with minerals.from stiff digram may be determined that there is a lot of mixing of different water types in the study region, which is caused by marine intrusion that comes through groundwater resources and the mixing of groundwater with the matrix of marine aquifers
4. The hydrochemical facies evolution Diagram shows that most samples are appropriate for a phase of marine intrusion, which confirms the hypotheses regarding salinization. The Na-Cl facies signifies that the aquifer’s state is probably controlled by water-rock interaction.
5. Statistical analyses can show there was also a strong positive correlation between sodium and chloride. Sodium was generally present in the form of sodium chloride, which was mostly caused by mixing with seawater intrusion. Cu2+, Pb2+, Cd2+, Mn2+, COD, TOC, and BOD all exhibit a significant positive correlation, indicating that these contaminants in water may have common origins such as industrial effluents and municipal wastewater discharge. Principal component analysis (PCA) identified several variables and varifactors, giving forward a hydrochemical meaning. First, at the Pleistocene aquifer, minerals and nutrient pollution were identified for varifactor 1, and heavy metal and biological pollution for varifactor 2. Second, at the Miocene aquifer, minerals and nutrient pollution were identified for varifactor 1, and biological pollution for varifactor 2. Organic contamination, which results from the regular flow of residential wastewater into groundwater, is represented by varifactors 3 and 4.
6. The heavy metal pollution index exceeds 100 in the majority of the samples. Wells are shown to be contaminated by heavy metals. It was estimated that the research region would be affected by heavy metal leakage from the water treatment plant. The water treatment plant has not treated the inorganic matters, especially the heavy metals.
7. According to the result of the ecological risk index, it was found that 66.7% of the Pleistocene aquifer samples have low ecological risk, 22.2% have moderate risk, and 11% are considerable risks. However, 42.8% of the Miocene aquifer has low ecological risk, 42.8% has moderate risk, and 14.4% are a considerable risk.
Different methods have been conducted to evaluate the using of groundwater for the purposes such as drinking, and irrigation. The study shows that:
a. All groundwater samples in the study area are unsuitable for drinking, where the total salinity ranging from 5041 to 11741 mg/l in the Pleistocene aquifer, from 2360 to 4742 mg/l in the Miocene groundwater and i.e. more than the permissible limit (1000 mg/l), in addition to high concentrations of some heavy metals such as cadmium, manganese, cupper and lead.
b. Most of the groundwater samples were doubtful for agriculture. Irrigation water is classed according to its soluble sodium level because irrigation water with higher sodium content has lower permeability. Increased sodium and salinity hazards cause the quality of irrigation water to deteriorate.
c. High sodium adsorption value values of samplaes indicate a tendency for water to replace adsorbed Ca2+ and Mg2+ with salt, affecting irrigation quality and harming soil structure. This will also lead to a decrease in infiltration and permeability of the soil to water leading to problems with crop production.
from the chemical study of groundwater samples, it is clear that the study area is suffering from higher saline groundwater that is unsuitable for drinking, irrigation uses. It was estimated that the research region would be affected by heavy metal and organic pollution from the water treatment plant. The water treatment plant has not treated the inorganic matters, and organic matter.
Chapter V
Prepartion and characterization
of nanocomposite
Consequently, in the following part of this study, many trials to overcome this problem were done by optimize the hybrid system to examine various combinations of pretreatment, photocatalytic process, and membrane filtering. The current study synthesized a series of (Er3+/TiO2) NCs catalysts using the sol-gel method. The sol-gel method was utilized to dope erbium ions into TiO2 structures with variable amounts, resulting in pure TiO2 and a range of erbium-doped TiO2 nanocomposites (Er3+/TiO2) NCs catalysts. TiO2 doped with erbium metal has shown to be an efficient technique to improve the photocatalytic properties and reduce the crystallite size and increase the surface area, which will enhance the degradation ability of organic contaminants.
The synthesized (Er3+/TiO2) NCs were characterized by using Fourier transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HR-SEM), elementary dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectra (XPS), specific surface area (BET), zeta potential, and particle size., the results indicate that:
a. The X-ray diffraction patterns of all investigated nanoparticle materials showed a high degree of crystallinity and confirmed the synthesis process efficiency and appeared the high-intensity peaks. It can be concluded that doping anatase TiO2 with erbium ions increases its thermal stability, inhibits crystallite growth, and increases its surface area.
b. Using FTIR spectroscopy, it is found that, the spectrum indicates the appearance of characteristic peaks of TiO2 NPs and erbium metal. Finally, these peaks indicate the successful incorporation of TiO2 NPs with erbium through a chemical interaction between TiO2 NPs and erbium.
c. The changing surface morphology of the prepared nanoparticles has been investigated using scanning electronic spectroscopy (SEM). The SEM shows pure TiO2, it was revealed that the particles crystallized into irregular forms and agglomerated. Even after varied quantities of Er3+ ions were added to TiO2, the particle-like features remained.
d. EDX elemental maps were used to establish the occurrence and dispersal of Ti, Er, and O elements.The result shows that titanium (Ti) and oxygen (O2) atoms are present in the undoped sample, whereas erbium (Er) atoms are present in the doped samples, demonstrating that Er3+ ions have been incorporated into TiO2.
e. The surface electronic states of Ti, Er, and O elements in pure TiO2 and (Er3+/TiO2) NCs were determined by XPS analysis. As the concentration increased, there was a shift in the peaks toward greater binding energies. These shifts could be due to Erbium interaction with oxygen molecules.
f. The zeta potential is an important factor in mediating particle-particle interaction. The result shows that all samples have negative zeta potentials. This indicates that the dispersion medium has good stability and great dispersion of nanoparticles. This also demonstrates that the nanoparticles resisted one another and did not flocculate.
g. from specific surface area (BET) analysis, we concluded that the typical samples exhibit strong mesoporosity and pore size uniformity.
h. The Uv-vis-diffuse reflectance spectrum is used to evaluate the optical properties of pure TiO2 and (Er3+/TiO2) NCs. Reveal that Erbium doping affects the band gap energy value of titanium nanoparticles in this study. Because of the Er3+ doping, the band gap is reduced, and less energy is required to move an atom from one side of the valence band to the other.
Chapter VI
PERFORMANCES OF THE PREPARED NANOPARTICLES ON THE PHOTOCATALYTIC PROCESS
This study investigates the impact of operating settings on the photocatalytic degradation of various water contaminants, including hazardous organic compounds (cationic and anionic dyes), using a variety of photocatalysts exposed to visible, solar, and ultraviolet light. TiO2 nanoparticles were synthesized by the sol-gel method and then modified with rare earth element (Er3+) to enhance the photocatalytic properties. The influences of various process parameters, i.e., the effect of catalyst dose, contact time, dye dose/concentration, pH effect, and light intensity.
It was found that pure TiO2 only revealed higher photocatalytic activity than the doped ones under UV light. As a result, degradation efficiency increased at pH 5. In the deterioration process, flow rate is evidently important. For low flow rates, the flow of feed water is very small. Oxygen species are much more likely to get into contact with the surface of the catalyst. Additional to this, a sufficient flow of feed water contributes to a sufficient amount of solar light intensity. The results showed that raising the dye concentration from 5 mg/L to 30 mg/L decreased degradation efficiency. The rate of photodegradation reaction improves with increasing catalyst quantity and reaches a maximum value at 2%. The performance was enhanced by increase the oxygen content by using the aeration pump .The elimination efficacy of pollutants increases with increasing the speed of the air pump that is responsible for increasing the amount of oxygen bubbled into the feed solution was enhanced to be preferred for dye degradation. When compared to pure TiO2, the photocatalytic activity of the prepared photocatalyst (Er3+/TiO2) NCs for the degradation of dye significantly higher. This is due to the synergistic effect that exists between the rare earth ions and the anatase TiO2, which can increase the light adsorption while inhibiting the recombination of photogeneration electron–hole pairs during the photocatalytic reaction.
Chapter VII
Application of the integrated system
in water purification
The study focuses on the hybrid treatment of wastewater, which involves the use of ultrafiltration, photocatalytic degradation, and membrane filtration. Effluent from the sewage treatment plant was collected as a sample in the study area. This study collected and used raw water to evaluate the design of the treatment setup. A pretreatment stage was implemented to remove turbidity, and suspended solids from sewage. The results of the pretreatment effluent tests convincingly confirmed the unit’s high turbidity and suspended particles removal effectiveness. Additionally, OMs, FC, phosphate, and ammonium nitrogen were partially removed. During the photocatalytic degradation process, the concentrations of COD, BOD, and TOC reduced to 82.3%, 91.6%, and 86.9%, respectively. Erbium-doped TiO2 nanocomposites (Er3+/TiO2 NCs catalysts) were able to degrade or absorbed high percent of these materials when they were exposed to visible light. The acidity of the wastewater, which had a pH of 6.3, caused the adsorption of anionic pollutants on nanoparticles and the destruction of those contaminants via visible irradiation, respectively. In addition to this, due to the pH level of the effluent. If the wastewater requires demineralization in addition to heavy metal removal, RO may be the optimal choice. Two important characteristics, water permeability and salt rejection, were tested to evaluate the performance of commercial RO membranes. Through RO membrane, the total dissolved solids (TDS) of the pretreated water, which was used as the feed water for the membrane treatment, decreased from 8,400 mg/l to 3000 mg/l and 1700 mg/l for 4 bar and 8 bar, respectively, which is significantly less than the conductivity of feed water and demonstrates the excellent performance of RO membrane in terms of soluble solids removal. This study concluded that the combination of the three stages for treating wastewater from sewage treatment plant in order to obtain high-quality water for used in irrigation purposes. In the end, despite the fact that the presented study was a necessary step for assessing the quality of the integrated system.
Recommendations
1. To achieve sustainable development in the study area. This research recommends the treatment of contaminated groundwater before human consumption. In addition, groundwater protection strategies should be implemented because the aquifers are rather shallow.
2. Chemical analyses must be carried out periodically for groundwater to determine any water quality changes.
3. Monitoring of the seepage of groundwater from the contaminant drains in such area will be necessary, as well as the development of a treatment plant that includes the inclusion of a triple-stage filtration and disinfection process, which includes the use of chlorine gas for sanitation before and fter filtration to assure the elimination of all contaimaints, and worms, and that the water must meet the standard set by the Ministry of Health.
4. Establishment of a triple treatment plant in order to treat water and use it in planting plants and food crops, while defining the appropriate places for the establishment of the plant according to geological and geomorphological studies and in line with the actual expected population increase according to the statistics of the Mobilization and Statistics Authority.
5. Community provision to accept the cultivation of plants using treated sewage water, through the establishment of a model farm in the region under the supervision of the Directorate of Agriculture, as well as conducting guide convoys to educate the people of the region to deal optimally with that p