الفهرس 
Acknowledgments
Importance of The Present StudyOnly 14 pages are availabe for public view
 |  | from | 176 |  |  |
| | | from | 176 | | |
Abstract
Fromancient times, water polluted by heavy metals was consideredas one of the most severe problems, which directly affects the human health. Wastewater especially drained from industrial activities has high levels of heavy metals content.Thus, several methods for heavy metals removal from wastewater and aqueous solutions have been widely studied.
This study aims to investigate the ability of introducing a cheap and local membranes of ceramic filtersfor removing three common heavy metals; Pb+2‚ Cd+2‚ and As+2from aqueous solutions. To achieve this objective, an experimental work for manufacturing ceramic filters was carried out through dimensions of 20 by 20 cm and 2.0 cm thickness from localclayandsawdustatdifferentsawdustratiosof1.0%,2.5%,and4.0% weight by weight. Aqueous solutions contaminated with the concerned heavy metals were filtered through ceramic membranes. The influence of the major affecting parameters such as; the initial pH value (5.5 and 7.0), and initial concentration (5.0 and 10.0 mg/L) of heavy metals on their removal efficiency by ceramic filters at a constant driving pressure head of 30 cm was investigated. Theefficiency of ceramic filters on heavy metals removal was studied specifically at pH 5.5 and 7.0 to exclude the effect of surface precipitation. Chemical analyses were carried out on water samples just before and after the filtration process. Furthermore, a microstructural analysis using scanning electronic microscope (SEM), energy-dispersive X-ray spectroscopy (EDS, EDX, or XEDS), and X-ray diffraction(XRD) was achieved on ceramic membranes before and afterfiltration.The morphology of the manufactured ceramic membrane filters was scanned by scanning electron microscope (SEM) to check their internal morphology under different magnification scales before and after the filtration process. XRD looks at a crystalline material’s characteristic X-ray scattering, or diffraction pattern, which reveals the material’s atomic structure.
All results detect that the percentages of heavy metals removal for (Pb+2‚ Cd+2‚ and As+2) are more than 80% at pH 5.5 and more than 82% at pH 7.0. The removal efficiency of heavy metals from aqueous solutions decreases within creasing the initial metal concentrations except Cd+2andit was constant driving water head at 30 cm. This study shows that percentages of heavy metals removal are more than 90% for concentrations of 5.0 mg/L and more than 84% for concentrations of 10.0 mg/L. A small effect on the removal efficiency of heavy metals was observed by changing sawdust ratio; however, the ceramic filter with sawdust percentage 1.0% was found to be the best and it is recommended be cause of facility in manufacturing and low shrinkage cracks. The results of the present study reveal that the membranes surface has negative charges, which attract the avymetalions besideits very small poresizes.