الفهرس 
ZEOLITE –NANOSCALE WATER TREATMENT RESIDUAL COMPOSITE FOR REMOVAL OF CADMIUM AND LEAD from INDUSTRIAL WASTE WATEROnly 14 pages are availabe for public view
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Abstract
Water pollution has an adverse effect on environment, and it can reflect dangerous results on human health. To overcome this emerging problem, researchers are still exploring different new technologies to improve water purification methods with low cost. The newly emerging
nanotechnology provides a potential to purify water with high efficiency and reusability.
Therefore, the main objective of this study was to evaluate the efficiency of a novel, inexpensive and eco-friendly nano-composite in removing selected heavy metals from contaminated
wastewater. To achieve such objective, synthesis of nano-composite {Zeolite (Ze)-nano water treatment residual (nWTR) was performed along with equilibrium, kinetics and thermodynamic
studies of Cd and Pb sorption by the novel nano sorbent. The obtained results are:
The nano-composite(Ze- nWTR) was successfully synthesized and characterized using X-ray powder diffraction (XRD)analysis and scanning electron microscopy spectroscopy (SEM)
equipped with energy dispersive spectrometer (EDS) for elemental analysis. The EDS analysis reveals that the major elements of nanocomposite (Ze - nWTR)are O, Mg, Al, Si and
Fe and the minor elements of bentonite- are K and Ca.
The EDS analysis reveals that the major elements of nano-composite (Ze-nWTR) are O, Si,
C, Al and Fe, K, Na and they represent ” ” ” " ~ " ” ” ”98% of total elements concentration. The minor elements of nanocomposite (Ze-nWTR) are Ca, Mg, Cu and Cr and represent 0.81, 0.51, 0.83 and 0.51 % respectively.
The Cd / Pb sorption capacity of the three sorbents studied were in the order nano-composite (Ze-nWTR) > nWTR> zeolite).The shape of Ze-nWTR nano-composite and nWTR sorption isotherms are L ‗type isotherm which reflects initial slope that doesn’t increase with
increasing contaminant concentration, while the shape of Cd sorption isotherm by zeolite was
S-type isotherms which is characterized by increasing of the slope with increasing of contaminant concentration.
Based on determination coefficient (R2
) values and standard error (SE) values, the experimental data for adsorption of Cd and Pb onto nWTR, Ze-nWTR nano-composite and zeolite fit better to Langmuir isotherm model than the other isotherm models used.
Sorption kinetics of Pb/Cd by nWTR, and Ze-nWTR nano-composite studied exhibited an immediate rapid sorption by which > 90% of Pb/Cd was sorbed in the first 5 minutes and followed by slow sorption at 298K. The amount of Pb/Cd sorbed per unit mass of sorbent
increases with increasing initial concentration of the Pb/Cd ions.
Cadmium and lead sorption by the studied sorbents was best described by power function model as confirmed by the highest R2, and the lowest SE values suggesting that the dominant sorption mechanism could be chemisorption.
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FTIR spectroscopy technique revealed the participation of OH, O-Al-O, FeOH, and Fe OOH entities in the Pb/Cd adsorption processes on the Ze-nWTR nano-composite.