الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
it established that:
- Cellulose can be isolated from local agricultural wastes; sugar bagasse, rice husk, and wheat straw with identical (FT-IR) analysis with commercial cellulose purchased from Sigma –Aldrich.
- We could prepare cellulose propionate with different Degree of Substitution (DS) by reflux cotton cellulose with propionic anhydride in presence of a new catalyst N-iodosuccinamid (NIS) for different time periods; (1-6) h.
- We could prepare cellulose propionate with different Degree of Substitution (DS) by reaction cellulose with propionic anhydride in presence of catalyst ZnCl2 and FeCl3.6H2O for rapid synthesis of cellulose propionate (CP) within 2-8 min under microwave irradiation.
- Cellulose nitrate-propionate mixed esters (CNPs) were prepared for the first time by nitration of the free hydroxyl group in cellulose propionate with different DS (1.20-2.74). CP and CNPs structures were characterized by IR, 1H-NMR, TGA, DSC, DTA and elemental analyses.
- Rice husk cellulose has been chemical modified with triethylenetetramine then grafted using crotonaldehyde in the presence of FeCl3 as catalyst provided a modified Cellulose-TETA-crotonaldehyde (CTC), which has been identified as an effective adsorbent to remove Cr6+ ions from various aqueous solutions. The adsorption process is pH dependent and the optimum pH was 1.55. Adsorption studies were modeled by followed Langmuir, Fruendlich and Tempkin isotherms. A high adsorption capacity of 196.08 mg/g was observed for Cr6+ ions. Furthermore, the isotherm equilibrium studies confirmed that the Fruendlich model and Tempkin models are the highest fitted models for the adsorption process of Cr6+ ions by CTC. The CTC showed high adsorption capacity under several initial chromium and sorbent dose concentrations. The Adsorbent–Adsorbate kinetic studies showed that the pseudo-second order kinetic was the applicable model. Suggested modified sorbents are effective, environment friendly and can decrease the enormous amount of toxic chromium ions introduced into aquatic environment from effluent discharges as industrial electroplating industries urbanization. Applicability of the adsorbent derived from modified rice husk cellulose with triethylenetetramine then grafted by crotonaldehyde was successfully established for Cr6+ ions removal.
Thus, CTC is found to be an efficient adsorbent for the removal of Cr6+ from aquatic environment.