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| Author(s): |
Taína Martins Magalhães
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Civil, Arquitetura e Urbanismo |
| Defense date: | 2017-03-17 |
| Examining board members: |
Adriano Luiz Tonetti;
Marcelo Zaiat;
João Paulo Bassin
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| Advisor: | Adriano Luiz Tonetti |
| Abstract | |
Nitrogen it is an essential element for growing organisms, however, in case of excess into aquatic environment, nitrogen compounds can cause eutrophication of the environment as well as fish mortality and, nitrogen as nitrate can lead to methemoglobinemia. Denitrification remains an alternative for the removal of this compound. Thus, in this research, anaerobic filter (AF) filled with synthetic material and UASB reactor, both in lab-scale operating with the hydraulic retention time (HRT) of 12 h were fed with synthetic effluent enriched with nitrate at concentrations 0.0, 25.0, 50.0, 75.0 and 100.0 mg N-NO3- L-1 (stage 2 to 6) to compare nitrogen removal efficiency between both reactors. Moreover, hydrodynamic characteristics of the reactors, biogas production and the changes in the sludge of each reactor were evaluated in each stage studied. During stages 2 to 5, both reactors showed complete denitrification despite the COD removal of 85.8 ± 3.6% in AF significantly greater than COD removal of 75.1 ± 5.1% in UASB. During step 6, with the application of 100.0 mg N-NO3- L-1 and COD/N-NO3- ratio equal to 4.4, the denitrification process was incomplete in both reactors. AF presented better efficiency, with N-NO3- removal of 87.9 ± 5.2% versus 83.3 ± 4.5% in UASB. Regarding the biogas produced during stage 2, it was produced a typical anaerobic digestion biogas with CH4concentrations close to 70% and CO2 concentration close to 13% in both reactors. However, during stage 6 the predominant composition was N2, corresponding to more than 85% of the biogas composition in AF and UASB, thus reducing its energy potential. The AF hydrodynamic profile was not significantly modified during the denitrification stages. At the UASB, it was observed an increase in the mixing behavior along stages due to the biogas production and the dispersed growth of the biomass. The denitrifying experiments performed with the stage 6 reactor sludge indicated that suspended UASB biomass had a higher potential for N-NO3- removal compared to suspended sludge of AF. Nevertheless, there is an important contribution of the microorganisms in the biofilm attached to the support medium in AF, which have been responsible for ensuring a better efficiency of the denitrification process in this reactor (AU) | |
| FAPESP's process: | 15/08751-0 - Evaluation of the denitrification on anaerobic filter and UASB reactor |
| Grantee: | Taína Martins Magalhães |
| Support Opportunities: | Scholarships in Brazil - Master |