Full text
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| Author(s): |
Fernanda de Matos Ferraz
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) |
| Defense date: | 2014-01-14 |
| Examining board members: |
Jurandyr Povinelli;
Pedro Além Sobrinho;
Marcus César Avezum Alves de Castro;
Valdir Schalch;
Eny Maria Vieira
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| Advisor: | Jurandyr Povinelli |
| Abstract | |
This thesis was dedicated to two alternatives for landfill leachate treatment. The first one, the aerobic co-treatment of leachate and domestic wastewater in aerobic systems, aimed to verify if the organic matter of leachate was removed by biodegradation or dilution with domestic wastewater. To answer this questioning, it was proposed the tentative method \"equivalent in humic acid\" (Eq.HA). In the experiments with bench-scale activated sludge reactors (10 L) operated in batch mode, it was evaluated the organic matter and nitrogen removal from mixtures containing raw and pre-treated leachate and domestic wastewater, at the volumetric ratios of 0, 0.2, 2 and 5%. The treatment was mostly efficient when it was used the mixture domestic wastewater and leachate pre-treated by air stripping (for ammonia removal), at a volumetric ratio of 2%. This condition was also evaluated in a pilot-scale activated sludge reactor (95 L) and a submerged aerobic biofilter (178 L), operated under continuous-flow regime with a 24-h hydraulic retention time. The pilot-scale activated sludge reactor removed 59% of DOC and nitrification efficiency was 60%; whereas the submerged aerobic biofilter removed 83% of DOC and nitrification efficiency was 77%. Using the Eq.HA approach, it was determined that pre-treated leachate organic matter removal was due to partial biodegradation with domestic wastewater, which was confirmed by Fourier transform infrared spectroscopy. The removals of COD Eq.HA were 47% for the pilot-scale activated sludge reactor and 71% for the submerged aerobic biofilter. Aditionally, organic matter could be assessed with the India ink reverse stain test, using the proposed method for tonalities classification. The second alternative proposed by this Thesis consisted in the treatment of raw and pre-treated leachate by lime addition, using activated sludge reactors. The results did not indicate the feasibility of this alternative: after 20 days of aeration, the organic matter removal was lesser than 40%, and nitrogen was mostly removed by ammonia volatilization. (AU) | |