الفهرس 
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Abstract
Jatropha curcas plants were cultivated in the drinking and sewage water treatment station in Al-Gabal Al-Asfar, Cairo, Egypt subjected to different irrigation treatments, namely tap water, sewage water, sewage water + sludge and sewage water + sludge sprayed with: tap water, 100, 200, 300 and 400 ppm of the growth retardant cycocel (CCC).
The objectives of this current study were: A. to investigate the effect of these different irrigation treatments on the physiological aspects of leaves and seed cakes of Jatropha curcas plants. B. to investigate the effect of these different irrigation treatments on the total reducing sugars content and bioethanol production from the seed cakes of Jatropha curcas plants.
A preliminary screening experiment was conducted to determine which seed cake resulting from the different irrigation treatments achieved the highest removal efficiencies of MB dye and Cr (VI) for subsequent optimization processes.
In the following, brief accounts for the main experimental results are given:
1. Analyses of Jatropha curcas leaves showed enhanced photosynthetic pigment contents [chlorophyll (a), chlorohyll (b) and carotenoids] and consequently increased total soluble sugars, polysaccharides, total carbohydrates, cellulose, total soluble protein, total free amino acids, proline, total phenol and lignin contents in response to irrigation by sewage water and sewage water + sludge as compared to the control plants.
2. The activity levels of the antioxidant enzymes SOD, CAT, PPO and POX in leaves of Jatropha curcas plants were also elevated under irrigation by sewage water and sewage water + sludge than the control plants.
3. Irrigating Jatropha curcas plants with sewage water and sewage water + sludge also enhanced the contents of total soluble sugars, polysaccharides, total carbohydrates, cellulose, hemicellulose, total soluble protein, total free amino acids, proline and total phenol as well as lignin in the seed cakes, as compared to the control.
4. Spraying the plants with different concentrations of CCC (100, 200, 300 and 400 ppm) highly affected the physiological parameters of leaves and seed cakes.
5. All CCC concentrations highly increased the photosynthetic pigment contents and consequently total soluble sugars, polysaccharides, total carbohydrates, cellulose, total soluble protein, total free amino acids, proline, total phenol and lignin contents, in addition to the activity levels of antioxidant enzymes (SOD, CAT, PPO and POX) in leaves of Jatropha curcas plants, especially at relatively low concentrations of CCC (100 and 200 ppm). There was an inversely proportional relationship between CCC concentrations and all analysed components of the leaves.
6. On the other hand,the relatively high concentrations of CCC (300 and 400 ppm) significantly enhanced the contents of total soluble sugars, polysaccharides, total carbohydrates, cellulose, hemicellulose, total soluble protein, total free amino acids, proline and total phenol as well as lignin in the seed cakes.
7. Seed cakes of Jatropha curcas plants of the different irrigation treatments were further pretreated and hydrolyzed using 4% H2SO4 and the resultant total reducing sugars were measured. The results showed that irrigation by sewage water either alone or with sludge positively increased the contents of total reducing sugars by 1.8 and 2.2 folds, respectively. Similarly, the relatively high concentrations of CCC (300 and 400 ppm) induced the maximum increase in the contents of total reducing sugars by 1.3 and 1.2 folds than the control plants. On contrary, 100 and 200 ppm of CCC decreased the levels of total reducing sugars in the seed cakes.
8. The hydrolysates containing the total reducing sugars were subjected to fermentation by the two most potent strains Candida tropicalis (Y-26) and Saccharomyces cerevisiae (Y-39) for bioethanol production. Bioethanol yields were improved than those of the control plants under irrigation by both sewage water and sewage water + sludge with 31.64% and 36.05%, respectively under fermentation by Candida tropicalis (Y-26) and 10.5% and 32.43%, respectively under fermentation by Saccharomyces cerevisiae (Y-39).
9. Spraying the plants with 300 and 400 ppm of CCC resulted in a significant increase in bioethanol yields from the seed cakes by 12.7% and 9.63%, respectively under fermentation by Candida tropicalis (Y-26) as well as 9.63% and 15.93%, respectively under fermentation by Saccharomyces cerevisiae (Y-39) than the control.
10. The seed cakes of Jatropha curcas plants resulting from the different irrigation treatments were then tested for their ability to remove each MB dye and Cr (VI) from wastewater. Seed cakes irrigated by sewage water have achieved the highest removal efficiencies with 78.8% and 41% for MB dye and Cr (VI), respectively. These selected seed cakes were then ground using 4 grinding steps in order to increase the surface area of the bio-sorbent material. After that, the selected seed cake bio-sorbent material was subjected to optimization processes to determine the optimum factors (contact time, pH, bio-sorbent material dosage and MB or Cr (VI) concentration) for maximum MB removal efficiency (MBRE) and Cr (VI) removal efficiency (CRE).
11. Contact time 4 h and 2 h, pH 7 and 5, 15 g/l and 5 g/l were the optimum factors for MBRE and CRE, respectively. Both MBRE and CRE were decreased with increasing the initial concentration of MB or Cr (VI).
12. Equilibrium and kinetic studies followed Langmuir adsorption isotherm and pseudo second order model.
13. The selected seed cake bio-sorbent material was characterized using FT-IR spectra and the functional groups present indicated the presence of proteins, lignin, cellulose, hemicellulose, lignocelluloses and hydroxyl, carboxyl, and carbonyl as well as phenol compounds in the seed cake bio-sorbent of Jatropha curcas plants that have been irrigated with sewage water.