This article establishes the relationship between the chemical composition, temperature and viscosity of glasses obtained from the four sludge treatment plants of urban and industrial wastewater from the Nile Delta in Egypt. In order to determine the working conditions of these glasses and their growth temperature, different techniques have been used: differential thermal analysis, hot stage microscopy and dilatometry. We used a prototype of hot stage microscopy, with the help of an image analysis programme developed in the present study. The chemical composition of major oxides sludge ranging from: SiO 2 (36-48 wt%), Al 2O 3 (9-16 wt%), CaO (5-25 wt%), P 2O 5 (1.5-11 wt%), and Fe 2O 3 (~9 wt%), this composition is close to a basalt rock, being necessary to incorporate some raw materials to adjust it to the basalt rock that has a good viscosity-temperature curve. The glass transition temperatures of the four glasses obtained vary between 650 and 725 C and the growth occurs between 938 and 1,033 C. We also obtained the viscosity-temperature curves with the aid of the hot stage microscopy that has allowed us to determine the working temperatures of the four glasses, ranging from 926 to 1,419 C, depending on the type of forming process used.
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Acknowledgements This study is a contribution of the bilateral project AECI project A/030032/10 and CICYT TIN2008-02903. The analytical work was conducted at Research Consolidated Groups 2009SGR-0044 (Mineral Resources) funded by AGAURDURSI, Generalitat de Catalunya. Wastewater treatment plants at El-Sadat City, Alexandria, Abo-Rawash and Minufiya are acknowledged for sampling authorization and facilities. We express our acknowledgement to the technical support of the Scientific-Technical Service Unit of the University of Barcelona and the additional support of the Institute for Bioengineering of Catalonia (IBEC). The English of the final draft of the manuscript was improved by C. Stonehouse.
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry