الفهرس 
General Introduction
Preparation and characterization of AdsorbentsOnly 14 pages are availabe for public view
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Abstract
The aim of the present investigation is to prepare activated carbon from water hyacinth and using it in separation and pre-concentration of certain inorganic pollutants (lead ,cadmium and mercury) and organic pollutants (Methylene blue and Rhodamine B) from aqueous solution. It includes the preparation and characterization of different adsorbents:
1. Dried stems and leaves( DS, DL) were prepared by soaking the leaves and stems of water hyacinth in 0.25M EDTA at pH 10 overnight, washing with distilled water for several times and drying in oven at 110 ºC for 48 h .
2. Activated carbon samples (ACS, ACL) were prepared by soaking dried stems and leaves in 50 wt. % analytical grade phosphoric acid (1:3) for 48 h following by carbonization at 550- 600 ºC for 3h, washing and drying.
3. Modified activated carbon samples(MACS, MACL) were prepared by refluxing ACS or ACL in nitric acid solution(1:1 dilution from 67% concentrated HNO3 acid) at a ratio of 1 g AC to 5 ml nitric acid solution for 3 h at 100 ºC, washing and drying.
4. characterization of the investigated carbons was made by determining surface pH, point of zero charge, FTIR spectra, surface porosity (SEM) and surface area (BET equation).
5. studying the effect of pH, initial pollutant concentration, contact time, ionic strength, adsorbent dosage and temperature on the adsorption of different pollutants onto different samples. The adsorption of pollutants increased with increased pH, initial concentration, contact time, and bio-sorbent dosage. The adsorption capacity pollutant decreased with the increase in ionic strength. The experimental data were fitted well with the linear form of Langmuir model. Adsorption kinetics followed a pseudo-second-order model. Thermodynamic parameters, including ΔHº, ΔGº, and ΔSº for the adsorption process of different pollutants from aqueous solution onto different adsorbents indicated that adsorption was endothermic and spontaneous process. Desorption were investigated using HCl the results revealed that the percent recovery of pollutant increased with the increase of HCl from 0.3 to 0.6 M and then remained constant.