الفهرس 
Cover EnglishOnly 14 pages are availabe for public view
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Abstract
Chitosan interact with polyphosphate ions to form nanoparticles with different diameters depending on the mutual ratio among them. Three nanoparticles have been prepared and were characterized by spectral and X-ray diffraction tools. TEM analysis revealed there diameters. The nanoparticles were thoroughly studied for wastewater treatment such as the removal of Total Suspended Solid (TSS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and removal of six heavy metal cations (Cr, Cu, Fe, Mn, Pb, and Zn) from wastewater. These investigations were carried out to minimize the cost and obtain the optimum performance in wastewater treatment. The result showed that the dosage of nanoparticles increases the % efficiency of wastewater treatment, and the smaller the size of the nano chitosan the higher is its activity The results of the present investigation showed that, the dosages of 16 & 24 mg/l of chitosan nanoparticles were the optimum dosages for maximum removal in all treatment. This behavior could be explained based on charge density character of the nano chitosan. Compared to the other coagulants, chitosan nano particles have a high charge density. The charge density of the polymer increased when polymer adsorption increased. Therefore, this signifies the rapid destabilization of the particles. On the other hand, there was a drastic DROP for the percentage of wastewater treatment up 32 & 40 mg/l dosages of the chitosan nanoparticles. This poor performance was due to the phenomenon of excess polymer is adsorbed on the colloidal surfaces and producing restabilized colloids Thus, there were no sites available on the particle surfaces for the formation of interparticle bridges. The restabilized colloidal particles can become positively charged and cause the electrostatic repulsion among the suspended solids It is noted also that, the smallest size of nano chitosan (~ 10 nm) has the greatest surface area of effective sites which exhibited maximum uptake capacity and so highest treatment percentage of wastewater. Chitosan nano particles can serve as an environmentally friendly material for waste water treatment.