الفهرس 
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Abstract
SUMMARY
Wadi El Rayan depression consists of two main man-made lakes occupy the area between Latitudes of 29° 05’ and 29° 18’ N and Longitude 30° 21’ and 30° 32’ E. The desert in all directions with only source of El-Wadi drain of agricultural drainage water borders the two lakes. Depression provided the excess agricultural wastewater over the capacity of Lake Qarun. The Depression with its huge area (703 km2) was thought to be a suitable natural flood-water reservoir. After construction of the High Dam, Wadi El-Rayian project was converted to a large drainage reservoir. Since Lake Qarun is the natural place for the accumulation of the drainage water of El-Fayium Governorate.
A project was therefore implemented in order to improve the drainage of the cultivated lands, reclaim more soils in El-Fayium and finally to lower the underground water level which was inundating the arable lands and led to the collapse of homes and buildings in several villages. The project began in 1968 and has been operated in 1973. The Depression receives about 200 million m3 of agricultural water per year. This led to the formation of an immense reservoir of agricultural wastewater, which will finally contain 2 billion m3 of water.
The present work includes three chapters; a brief description of these chapters is given as follow:
The first chapter is related to introduction of the thesis where the environmental status of Wadi El-Rayan lakes is given from the historical background and the literature survey for Aquatic Environment of Wadi El-=========================
The second chapter contains the experimental parts including sampling techniques, description of the selection and investigated sampling stations and describing the methods applied to determine the physico-chemical parameters in water and heavy metals in water and sediment.
The third chapter included the obtained results and their discussion and data analysis as the following during the period of study and discussion of these results obtained which can be summarized as follow: -
A preliminary assessment of two lakes showed that physico-chemical characteristics and heavy metals in the 1st lake are controlled by the intrusion of drainage water through El-Wadi Drain. However, the rate of evaporation and the amount of water discharged from the 1st lake are the main factors control these concentrations in the 2nd lake.
1. Water analyses
1.1. Physical characteristics
1.1.1. Temperature:
Minimum and maximum temperature recorded ranged from 14.50 oC (winter) to 31.30 oC (summer), respectively. There was no significant difference between two lakes. On the other hand, the results show temporal highly significant difference. In El-Wadi Drain, temperature ranged between 16.10-29.10 oC.
1.1.2. Electrical conductivity (EC):
EC ranged between 2.63-3.01 ms/cm and 18.67- 25.84 ms/cm in 1st and 2nd lake respectively with a maximum in summer and a minimum in winter. The significant differences between two lakes are highly. In addition, there were sites significant differences in the 2nd lake. In addition, EC in El-Wadi Drain ranged between 1.49-1.84 ms/cm.
1.1.3. Total solids (TS):
TS varied in the 1st and 2nd lake between (1710.00-1898.00 mg/l) and (11325.00-15340.00 mg/l) respectively, where highest values in hot period (summer & spring) and lowest values in cold period (winter & autumn). The results were highly significant differences between the 1st and 2nd lake. In El-Wadi Drain, TS ranged between 1346.00-1526.00 mg/l.
1.1.4. Total Dissolved Solids (TDS):
TDS increased in summer, while the lowest values were recorded in winter. It varied between (1586.00-1811.00 mg/l) and (11060.00-14908.00 mg/l) in the 1st and 2nd lake, respectively. The differences were a significant between two lakes, as well as spatial significant differences in the 2nd lake. In El-Wadi Drain, TDS ranged between 1238.00-1412.00 mg/l.
1.1.5. Total Suspended Solids (TSS):
TSS ranged between (62.00-136.00 mg/l) and (146.00-432.00 mg/l) in the 1st and 2nd lakes respectively. On the other hand, there is a significant difference between two lakes. In addition, the results show temporal significant difference. In El-Wadi Drain, TSS ranged between 96.00-114.00 mg/l.
1.2. Chemical characteristics:
1.2.1. pH:
pH of Wadi El Rayan Lakes lies in alkaline side and it ranged from 8.47 in (winter) to 8.96 in (spring) and from 8.26 in (winter) to 8.71 in (autumn) in the 1st and 2nd lakes respectively. In addition, pH in El-Wadi Drain ranged between 7.95- 8.19.
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1.2.2. Dissolved oxygen (DO):
The water of Wadi El-Rayan Lakes was will oxygenated all year round. DO varied between (6.40–12.00 mg/l) and (4.80-11.40 mg/l) in the 1st and 2nd lakes respectively, with seasonally significant difference with no local difference. The lowest value was recorded during summer, while the highest one during autumn. In El-Wadi Drain, DO was ranged between 6.60-7.80 mg/l.
1.2.3. Biological oxygen demand (BOD):
BOD ranged between (3.08-7.20 mg/l) and (2.80-6.54 mg/l) in the 1st and 2nd lakes respectively, where minimum and maximum values recorded in autumn and summer seasons, respectively. On the other hand, there was temporal significant difference. In El-Wadi Drain, BOD was ranged between 4.80-6.80 mg/l.
1.2.4. Chemical oxygen demand (COD):
COD ranged from 4.80 to 12.00 mg/l and 6.40 to 12.40 mg/l in the 1st and 2nd lake, respectively with significant difference between winter and autumn. The highest value was recorded during spring, while the lowest one during winter. On the other hand, COD in El-Wadi Drain ranged between 11.60-2.40 mg/l.
1.2.5. Nutrient salts:
The nutrient salts include compounds that contain nitrogen (NH3, NO2-, NO3-), phosphours (ortho-P, TP) or silicate (SiO22-) in different forms either in available or non-available forms. The ranges of NH3, NO2- and NO3- in the 1st lake were (85.70-376.80 μg/l), (1.90- 40.80 μg/l) and (26.55 - 290.00 μg/l), respectively while the ranges of ortho-P and TP were (27.50-
75.90 μg/l) and (154.80-434.00 μg/l) respectively, with spatial significant difference. In the 2nd lake, the ranges of NH3, NO2- and NO3- were (56.50-159.00 μg/l), (1.63-16.86 μg/l) and (28.38- 97.20 μg/l), respectively while the ranges of ortho-P and TP were (11.00 - 59.40 μg/l), and (186.00-358.40 μg/l), respectively. The SiO22- ranged (5.79-12.97 mg/l) and (6.64-17.74 mg/l) in the 1st and 2nd lake, respectively. During the seasons, there were non-significant a difference in nutrient salts levels except ortho-P and SiO22- in the 2nd lake. In El-Wadi Drain, The ranges of NH3, NO2-, NO3-, ortho-P, TP and SiO22- fluctuated between 648.20-320.90, 88.60-66.46, 824.08-366.80, 288.10-202.40, 358.40-186.00 and 8230-5420 μg/l, respectively.
1.2.6. Major anions and cations ions:
The major ions include (HCO3-, CO32-, SO42-, Cl-, Ca2+ and Mg2+). The SO42-, Cl-, Ca2+ and Mg2+ have been the same distribution trend and their concentrations in the 2nd lake were very higher than the 1st lake. They ranged between 281.65-372.00, 563.24-712.00, 51.10-68.12 & 98.20-119.82 mg/l and 2155.74-3418.00, 5073.94- 6987.00, 142.14-188.00 and 405.19-594.00 mg/l for SO42-, Cl-, Ca2+ and Mg2 in the 1st lake and 2nd lake respectively, with significant difference between two lakes. On the other hand, HCO3-, CO32- showed irregular distribution and varied between 194.56-261.12 & 12.00-32.00 mg/l and 208.32- 276.48 & 4.00-18.00 mg/l in the 1st lake and 2nd lake, respectively. In El-Wadi Drain, The ranges of HCO3-, CO32-, SO42-, Cl-, Ca2+ and Mg2+ fluctuated between 266.24-256.00, Nil, 246.00-142.94, 432.00-286.00, 56.70-44.89 and 92.77-73.75 mg/l, respectively.
1.3. Trace metals in water
The concentrations of trace metals (Fe, Mn, Cu, Pb, Ni, Co, Cr and Cd) in Wadi El Rayan lakes water were increase at inlet the 1st lake during all seasons which may be attributed to the effect of agricultural influx drained into the 1st lake from El-Wadi Drain.
The trace metal results in Wadi El Rayan lakes water can be summarized as:
a. Fe ranged between 132.00-990.00 μg/l and 146.00-676.00 μg/l in the 1st and 2nd lakes respectively. However, Fe in El-Wadi Drain ranged between 2346.00-1142.00 μg/l.
b. Mn ranged between 16.00-121.08 μg/l and 2.00-79.00μg/l in the 1st and 2nd lakes respectively. However, Mn in El-Wadi Drain ranged between 422.30-116.00 μg/l.
c. Cu ranged between 10.60-27.68 μg/l and 7.60-14.25 μg/l in the 1st and 2nd lakes respectively. However, Cu in El-Wadi Drain ranged between 32.66-16.40 μg/l.
d. Co ranged between 6.28-16.23 μg/l and 4.12-14.30 μg/l in the 1st and 2nd respectively. However, Co in El-Wadi Drain ranged between 18.60-12.66 μg/l.
e. Pb ranged between 6.10-16.40 μg/l and 4.67-10.14 μg/l in the 1st and 2nd lakes respectively. However, Pb in El-Wadi Drain ranged between 24.40-12.40 μg/l.
f. Ni ranged between 8.02-24.80 μg/l and 5.80-15.80 μg/l in the 1st and 2nd lakes respectively. However, Ni in El-Wadi Drain ranged between 44.80-12.60 μg/l.
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g. Cr ranged between 6.14-21.60 μg/l and 6.22-16.35 μg/l in the 1st and 2nd lakes respectively. However, Cr in El-Wadi Drain ranged between 44.80-12.60 μg/l.
h. The concentration of Cd in Wadi El Rayan lakes and El-Wadi Drain was less than 0.20 μg/l.
2. Sediment analyses
2.1. Carbonate in sediment:
The ranges of carbonate fluctuated between 22.24-38.10and 27.22-18.60 % in the 1st and 2nd lakes respectively.
2.2. Organic matter in sediment:
The ranges of organic matter fluctuated between 3.66-13.22 and 1.25-7.11 % in the 1st and 2nd lakes respectively.
2.2. Trace metals in sediment:
The contents of trace metals (Fe, Mn, Cu, Pb, Ni, Co, Cr and Cd) in Wadi El Rayan lakes sediment were increase at inlet the 1st lake during all seasons which may be attributed to the effect of agricultural influx drained into the 1st lake from El-Wadi Drain.
The trace metals results in Wadi El Rayan lakes sediment can be summarized as:
a. Fe ranged between 1300.50-2600.00 μg/g and 764.80-1805.00 μg/g in the 1st and 2nd lakes respectively.
b. Mn ranged between 110.30-612.50 μg/g and 102.80-267.90 μg/g in the 1st and 2nd lakes respectively.
c. Cu ranged between 12.36-38.50 μg/g and 3.61-18.60 μg/g in the 1st and 2nd lakes respectively.
d. Co ranged between 10.22-37.45 μg/g and 11.50-35.10 μg/g in the 1st and 2nd respectively.
e. Pb ranged between 4.76-42.20 μg/g and 5.10-12.60 μg/g in the 1st and 2nd lakes respectively.
f. Ni ranged between 13.63-68.30 μg/g and 11.49-70.40 μg/g in the 1st and 2nd lakes respectively.
g. Cr ranged between 11.90-54.50 μg/g and 10.50-34.12 μg/g in the 1st and 2nd lakes respectively.
h. The content of Cd in Wadi El Rayan lakes sediment was less than 0.10 μg/l.