الفهرس 
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Abstract
The aim of this study was to track some radioactive (uranium and thorium) elements in mines (old and reclaimed soils) and their remediation , using 3 plants of Helianthus annuus L, Phragmites australis and Cyperus plants over periods of 30, 45 and 45 years 60 days after starting farming to check uptake of uranium and thorium by plants .
This could be achieved by growing cultivating the previous plants in pots using three types of studied soils, This happened in November 2020 to leased land in the Abu Rawash area of Giza Governorate. This is achieved by cultivating the existing plant species in pots ( 2 kg) using the three soil types examined , Two of the were taken from the east and west of the Nile. The phosphate mines of Nasr Mining Company represented the reclaimed soil in Aswan governorate that has been cultivated east of the Nile (Wadi al-Shagb) for more than 10 years, and the soil (the reclaimed soil) has been cultivated for more 10 years ,3 years in the Sebiya area, west of the Nile near the phosphate breakers. The third in from the permanent experiment at Bahteem Agricultural Research Station in Qalyubiya Governorate ( old soil fertilized with P fertilizer since 1912).The plants were harvested after three periods. i.e,30, 45 and 60 days after cultivation through bout 75 pots per sample.
In the study areas we find that the sandy loam soil derived from the parent material is highly in fluenced by the soil composition by the parent material. It is an inherent property of the soil that does not degrade over a short period of time.
where the sandy loam structure is predominant in the soil of Wadi Al-Shagb (East Nile) and Al-Sabiya(West Nile), but contains sufficient clay and sediment to ensure some structure and soil , while the clay structure in the permanent soil prevails experiment in agricultural research station.
Bahteem In general, most Egyptian soils have a pH greater than 7.0. The pH range of the examined soils was between 7.75 and 8.05.
The P content of the examined soils was between 0.11 and 11.96 %. It represents a sufficient value for plant growth and can be attributed to the continuous application of P based fertilizers.
The total K content in the soils examined varied between 0.024 to 21.29 % , especially in the soil of Bahteem which is considered high and sufficient for grown plants.
The analysis was performed to estimate the elements uranium and thorium at the Nuclear Materials Authority’s Uranium and Thorium Central Laboratory. Cairo, Egypt. using an ICP-OES device with an RF power 1200W and Nebulizer gas pressure 36 L / min.
In drying plants the moisture content is typically higher at the beginning of drying and then decreases to the lowest value at all temperature levels at the end of drying.
The parts of each plant were weighed separately before drying and placed in an oven at a temperature of 70 °C one hour to check the percentage weight loss according to the following equation:
Loss % = Dec. (fresh weight - dry weight) / fresh weight x 100.
There are large differences in fresh and dry yield content between the examined plants and for the plant parts which is due to the calculion of the % decrease .In general the (decrease in % ) varied with period of harvesting time and plant age in the soils studied..
In this work, the concentration of uranium and thorium in the three soils studied was as follows. The concentration uranium in Wadi al-Shaghb (East Nile) is 70 (ppm), while the thorium concentration is 18 (mg kg).The uranium concentration in Sebiya (West Nile) is 54 (mg kg ), while the thorium concentration is 13 (mg kg). The concentration of uranium in the soil of the permanent experiment at Bahteem research station was 50 (mg kg ), while it was not intended for thorium.
The high concentrations of uranium and thorium are considered in the areas of Al-Nasr Phosphate east of the Nile, which were 70 (mg kg ) for the uranium and 18 (ppm) for the thorium, and in the areas west of the Nile, which was not was 54 (ppm) for the uranium and 13 (mg k g) for the element thorium, and the areas east of the Nile are among the most important areas for the occurrence of phosphorite in Egypt .
Depending on soil and plant type, the ratio of concentration levels or TF can vary by several orders of magnitude.
Soil uranium content and plant tissue concentration are assumed to be linearly related in the TF calculation.
Transfer factor (TF) (ratio%) of the plants plant types examined grew on Wadi Al-Shaghb soil ( East Nile ) as follows:
It was found the transfer factor values between the plant species examined varied greatly during the throughout the studied harvest times examined : The transfer factor values of U lay after the 1st harvesting period (30 days) between 0.11 and 81.91 .
Transfer factor (TF) (ratio%) of the plants the studied plant types grown in Sebaiya Soil ( Wast Nile ) as follows:
Showed transfer factor of U and Th in grown in Sebaiya Soil. It is noticed that the transfer factor of U varied between 29.99 - 50.46, 3.30 and 192.35, 3.68 - 206.69 (ratio %) throughout the harvesting periods 30,45 and 60 days respectively. It is noticed ,generally is specific ,clear trend for the obtained values with time as harvesting especially for Helianthus annuusL thus plants ,while the there is as ending ander for the other two investigated plants. Also, it is noticed that Phragmites australis plants appeared the higher values as U transfer factor, while Helianthus annuusL plants shows the least values, Recording to Th .the transfer factor varied between 0.231 and 13.06 (ratio %) after the 1st harvesting time, (30 days) while being nil throughout the other two harvesting periods.
Transfer factor (TF) (ratio% ) of the plants the studied plant types grown an Bahteem soil as follows :
Recoding to plant. grown in Bahteem soil. The transfer factor of Th are neglable for all plants. However transfer factor of U a renged between 1.42 -98.58 ,1.86 -198.27 ,1.94–213.21 ( ratio %) throughout the harvesting times as 30,45 and 60 days respectively .It is noticed that the transfer factor of U increased consequently with increasing time of harvesting . Also, it is noticed that Phragmites australis plants Shaw least values of transfer factor compared to the other investigated plants.
The results also showed that in the three types of studied soils (Wadi Al-Shaghb, Al- Sebiya and Bahteem Research Station), there was an increase in the absorption of uranium and thorium elements from the soil in which the studied plants were grown, which were grown in greenhouses under conditions of temperature of 28 0C Abu Rawash, affiliated to Giza Governorate, the soil pH in Wadi Al-Shaghb area was 8.05, while the soil pH for Al-Sebaiya area was pH 8.01, and the soil pH 7.75 for Bahtim agricultural research station.
The results were as follows :
1- The highest concentration of uranium element in Shoots of Helianthus annuus was 211.3 (mg kg) at 60 days of age in the soil of Bahteem research station, while the lowest concentration in shoots of Helianthus annuus was 8.37 ( mg kg) aged 30 days of age in the areas areas of Wadi Al-Shaghb east of the Nile .
2- The thorium concentration of in the root of Cyperus was 28.8 (mg kg ) at the age of 30 days in the lands of Wadi Al-Shaghb east of the Nile, while the lowest concentration in the roots was 1.11 (mg kg ) at root of the Helianthus annuus at the age of 30 days in the soil of Wadi Al-Shaghb east of the Nile.
3- Residual concentrations of uranium and thorium (mg kg ) in the three soils after harvest periods (30, 45 and 60) days It reached the highest uranium absorption value in the soil of the Wadi Al-Shaghb over a period of (60 days) and Phragmites australis had a value of 4.00 (mg kg) at a rate of (19.05 % in soil,while the uranium content was lowest. The absorption rate was in Cyperus over a period (30 and 60 days) value of 1.00 (mg kg) with a rate of (4.76%) remaining in the soil . Also the highest value of uranium absorption in the soil of Sebaiya in a period of (60 days) was the Helianthus annuus L value of 1.50 (ppm) with a rate of (18.75%) in the soil during,while the lowest percentage of uranium absorption in soil was at the Cyperus value of 0.30 (mg kg) over a period of (30 days) the Cyperus value of 0.30 ( ratio%) with a rate of (3.75% ) remaining in the soil. During the highest percentage of uranium absorption in the Bahteem soil during the period (60 days) at Helianthus annuus L value of 1.35 (mg kg) at rate of (22.50 %) remaining in the soil,while the lowest percentage of uranium absorption in soil during the period (30 days) at Cyperus value of 0.15 (mg kg ). and with a percentage remaining in the ground (2.50%).The highest absorption percentage of thorium in WadiAl-Shaghb soil was period of (60 days) in Helianthus annuus L value an 1.10 ( mg kg ) with a rate of (27.50). remaining in the soil,while the lowest percentagepercentage of absorption for thorium in the WadiAl-Shaghb soil for was at the Cyperus value of 0.10 (mg kg ) for a period of (45 days) and achieved a percentage (2.50%) remaining in the soil . In general, the actinide series of elements includes uranium and thorium. Both elements have ions with comparable radii that can occur in nature in the tetravalent oxidation state.
Thus, the two elements can significantly substitute for each an other, which explains their geochemical coherence. The uranyl ion (UO2+2),in which uranium is present as U(VI) , is formed when uranium is exposed to oxidizing conditions. The uranyl ion often converts to water soluble materials. This means that thorium, which only exists in the tetravalent form and whose compounds are normally insoluble in water, separates from uranium, which is often mobile under oxidizing conditions.
Through this study, could recommend the following :
1-Phosphate mining has harmful effects on human and the environment ifnot properly managed. In order to minimize the harmful effects of phosphate depletion, several precautions must be taken.
2-This research can be augmented by monitoring the activity concentrations of various chemical fertilizers and studying their effects.
3- The activity concentrations of uranium and thorium in soil samples should be tested reguly to see how they are changeing.
4- There is an urgent need to techniques to decontaminating radioactive areas ,the principle of phytoremediation is that different plants have the potential to eliminate different dangerous toxins that are present in the environment.