ENVR 159 |
| Silica obtained from rice hull ash can be used to prepare beta-Ca2SiO4, a component of hydraulic cement. This methodology may avoid several environmental problems such as the burning of rice hull at fields. This common practice may cause respiratory problems and soil impoverishment. Furthermore, in commercial cement plants, temperatures around 1,500°C are necessary. When rice hull is used, the synthesis is accomplished at 800°C. On the other hand, cement-based materials such as mortars and concrete are largely used to encapsulate heavy metals. The main idea is that insertion of heavy metals inside stable cement matrix can isolate such contaminants from the environment. Here we present the synthesis of several cements (based on the structure of beta-Ca2SiO4) containing metals such as cadmium, cooper, chromium and zinc. Considering that these metals are chemically bonded to cement matrix, the encapsulation process will be much more effective when compared to the traditional method. |
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General Papers
6:00 PM-8:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster
Division of Environmental Chemistry |