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| Author(s): |
André Augusto Gutierrez Fernandes Beati
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Mecânica |
| Defense date: | 2010-02-23 |
| Examining board members: |
Marcos Roberto de Vasconcelos Lanza;
Raquel Fernades Pupo Nogueira;
Susanne Rath;
Christiane de Arruda Rodrigues Ragnini;
Paulo Olivi
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| Advisor: | Rodnei Bertazzoli; Marcos Roberto de Vasconcelos Lanza |
| Abstract | |
In this study the identification of degradation products ametrina (AME), pesticides used on a large scale in the sugar industry. The improvement in the treatment of environmental conditions is of paramount importance to the agricultural regions, since the contamination of soil and groundwater contamination is almost inevitable. In relation to industries producing/formulate pesticides, an alternative treatment is interesting because the Advanced Oxidation Processes (AOPs), and among these, the use of Electrochemical Technology. Once the parameters set can generate combustion total organic content, or general degradation products, which can be identified, and thus better understand the degradation process of AME. Thus were partial oxidation reactions of the herbicide using the addition of H2O2 in a solution containing 100 mg L-1 of AME and catalyzed with Fe2+ at different pH and temperature. The products were identified by mass spectrometry, Ion-Trap electrospray ionization (ESI.) The product 4-amino-6-(methylamine)-1,3,5-triazine-2-ol (m/z 141) was identified, almost all trials. The best experimental condition to oxidize chemically AME, occurred at a rate of 20% (v/v) H2O2, pH 7 and temperature of 65°C. Another way to study the degradation of AME was controlling the generation of electrogenerated H2O2, thus the electrochemical degradation of the herbicide were performed using 200 mg L-1 of the active principle from a commercial solution (Herbipak®). Constant potential electrolyses were performed from -0.7 V ? E ? -1.2 V vs. Ag / AgCl for generation of H2O2, reaching the maximum concentration of 508 mg L-1 for the potential of -0.9 V vs Ag/AgCl. The monitoring of AME analyzed by HPLC, showed a rate of decay of the concentration of 55% via H2O2 generation, with 45% reduction of TOC when used at eletrossíntese H2O2/Fe2+. These tests also monitored the degradation via AME IC, identifying the formation of NO3- and NO2-. The identification of the formation of degradation products was performed by AME CG-MS/MS. (AU) | |