الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 228 |  |  |
| | | from | 228 | | |
Abstract
In this study, the geopolymer concrete was produced from two by-product wastes as an alternative for environmentally green construction and building materials without using Ordinary Portland Cement (OPC). Water treatment sludge (WTS) was taken from Sheikhzaied, Marg and Obour Water Treatment Plants at Cairo, Egypt. Meta-Kaolin (MK) and De-Aluminated Meta-Kaolin (DaMK) wastes were collected from Aluminum Sulfate Co. of Egypt. The mineralogical and chemical compositions of the WTS, MK and DaMk were done using X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) analyses. Sodium hydroxide (NaOH) solution was used as an alkaline activator. The effect of the various influential factors on the geopolymer compressive strengths for different mixtures of WTS, DaMK and MK based was investigated. The 40% DaMK/MK mixtures were achieved the highest compressive strength (50 MPa). Moreover, the WTS and DaMK wastes that traditionally disposed into landfills or drainage canals can be sustainably used in developing and producing cement-free geopolymers with economic and environmental significance. The immobilization behaviors of Cd2+, Pb2+ and Hg2+ ions in a geopolymer based on the WTS and DaMK solid wastes from the Alum industry were investigated in this study. WTS/DaMK based geopolymer mortar has been tested for leaching to study its immobilization behavior of selected heavy metals under the optimum condition. The Cd2+, Pb2+ and Hg2+ ions were used and effectively immobilized in this study. The heavy metals with concentrations of 100, 200 and 300 ppm were used in the geopolymer matrix giving about 98% of immobilization efficiency. The study showed that Pb2+ has the best immobilization efficiency followed by Hg2+ and Cd2+ at high concentrations.