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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Removal of Ethylenediaminetetraacetic Acid by O3 ¢ÎUV Processes

Lin, Yung-Ghang 12 August 2003 (has links)
This study was to investigate the removal efficiency and the feasibility of containing-EDTA solutions by O3 and O3/UV, advanced oxidation processes (denoted by AOPs). The operation parameters conducted in semi-batch reactor were as follows: ozone dose, pH, temperature and initial concentration of EDTA. The best mineralization and COD removal was found at pH= 9 when the pH values in O3 process was controlled at 3, 5, 7, 9 and 11. Addition of UV in O3 process for treating solutions containing EDTA was found not increasing the reaction rate but raising the COD and mineralization efficiency. In O3 process, the reaction rate was proportional to the ozone dose, it caused a higher mineralization. The higher the initial concentration of EDTA, the lower reaction rate, and the decreasing the mineralization was. Changing the temperature in reaction process was not obviously affected the removal of EDTA due to the lower activated energy found in O3 process. In O3/UV process, EDTA was decomposed very fast, but it still could not be mineralized the intermediates completely. The concentration of nitrate formed in this process was low. It is probably for high energy NH-containing bonds which is not easy break down by O3/UV. Thus, the major reactions in this process are the break of C-N bond, and followed by the break of C-H bond.

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