الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
In recent decades, environmental issues have been highlighted due to their great importance. One of these issues is the optimal and practical use of plant and animal waste, which are among the most important atmosphere pollutants when incinerated. The preparation of new natural resins from these wastes has been studied, for example, by converting unused or plant pollutants such as cotton stalks, rice straw and wood residues into highly absorbent materials for unwanted metals (impurities).
Cellulose is one of the most oldest chemical raw materials and, until now, has been the most crucial renewable resource of the chemical industry. The chemistry of cellulose has been vigorously promoted in recent decades. On the other hand, it is unfavorable for heavy metals working from aqueous solutions to be adsorbed across the hydrophobic porous carbon surface. Thus, the latter’s surface should be operational or modified.
The procedures and the methodology of this study can be summarized in the following topics: -
The first part: it involves synthesis of some new organic compounds as ion exchanger (different resins) derived from natural microcrystalline cellulose.
The second part: it involved the study of several batches using synthesized resins, which were conducted to determine the relevant factors affecting the removal of impurities such as Cr6+, Cd2+, Pb2+, and V5+ ions by adsorption using a synthetic standard solution. The relevant factors are thus studied, namely, concentration of acid, temperature, adsorbent dose and contact time.
The third part: it involved preparation of purified titanium oxide pigment from ilmenite mineral concentrate using modified cellulose adsorbent under optimum conditions.
Part 1
Chemicals improve adsorption and mechanical strength in this regard. For the adsorption of metal ions, the introducing of a new functional group into the structure of cellulose R1 resulted in several cellulose derivatives.
In this study, the cellulosic material was modified via phosphorus oxychloride, chlorosulfonic acid and mixture of phosphorus oxychloride acid with chlorosulfonic acid to increase the activity of the cellulose surface and improve the adsorption capacity of Cr6+, Cd2+, Pb2+, and V5+ ions from a diluted sulphuric solution of titanium liquor to gain the purified titanium dioxide.
Cellulose has a low adsorption capacity as well as variable physical stability. Therefore, chemical modification of cellulose can be performed to achieve adequate structural durability and adsorption capacity for effluent treatment. Chemical modification can be used to change certain properties of cellulose such as the ability to absorb or ion-exchange capability. Therefore, treatment of microcrystalline cellulose R1 with sodium hydroxide 6% (w/v) afforded soda pretreated swelling ion exchanger resin as light brown crystals (pretreated cellulose) R2.
Treatment of microcrystalline cellulose R1 with phosphorus oxychloride in the presence of pyridine as an alkaline catalyst furnished cellulose phosphoric or (cellulose phosphate) R3, while the reaction of pretreated cellulose R2 with phosphorus oxychloride diluted with dichloroethane in boiling pyridine as a weak base medium afforded pretreated cellulose phosphate R4.
Also, microcrystalline cellulose (MCC) R1 reacted with chlorosulfonic acid diluted with dichloroethane in boiling pyridine as an alkaline catalyst to furnish cellulose sulfate R5, while heating of pretreated cellulose R2 with chlorosulfonic acid which was diluted with dichloroethane in pyridine under reflux afforded pretreated cellulose sulfate R6.
Add to that, the treatment of cellulose (MCC) R1 with chlorosulfonic acid and phosphorous oxychloride in the presence of dichloroethane under reflux using pyridine as an alkaline catalyst gives (cellulose sulfate/phosphate) R7, while treated cellulose derivative R2 has been allowed to react with chlorosulfonic acid and phosphorous oxychloride in the presence of dichloroethane under reflux with pyridine to afforded pretreated cellulose derivative R8.
Part 2
In this part and by using various series of adsorption tests (using the batch technique) with synthesized adsorbents (10–400 mg), individual Cr6+, Cd2+, Pb2+, and V5+ (25–800 mg.L− 1), acid concentration (0.25–2 M/L), and contact time (5–120 min.) were conducted to examine their removal efficiencies within temperature ranges of 298–328 ◦K. Altogether, these tests were made in triple calculations to ascertain the procedure’s accuracy and ±2% of adsorption errors were found. Besides, equilibrium isotherms, kinetics, and parameters of thermodynamic (298–328 ◦K) were performed. from any experiment of adsorption, some concerning individual metal ions (qe, mg/g), which adsorbed on synthesized adsorbent, distribution coefficient (Kd), and removal efficiencies (E, %) assumed. It was observed that the maximum Cr6+, Pb2+, V5+, and Cd2+ adsorption capacity and the removal efficiency were 132.5, 141.7, 121.5, 113.7 mg/g and 88.3, 94.5, 81.0, 75.8%, respectively when using cellulose impregnated phosphorus oxychloride R4 (COP) as adsorbent under the optimal conditions.
Part 3
For the purposes of this section, a purified titanium dioxide pigment has been obtained from titanium sulphate leaching liquor, which has been obtained from ilmenite concentrate using cellulose impregnated with phosphorus oxychloride R4 (COP) as an adsorbent for removing impurities of metal ions such as Cr6+, Pb2+, V5+, and Cd2+ ions under the optimal conditions.