A micro-bacia do córrego Banguelo da sub-bacia Bom Jesus contribui, junto com outras, para formação do reservatório da Pampulha, cuja poluição é considerada um dos grandes problemas ambientais do município de Belo Horizonte. O presente trabalho teve como objetivo avaliar o efeito do uso e ocupação do solo na qualidade da água num ciclo sazonal em diferentes pontos da micro-bacia. Para o monitoramento da qualidade da água, os parâmetros analisados foram: pH, turbidez, oxigênio dissolvido, fosfato, nitrato, nitrogênio total, temperatura, DBO 5 , DQO, sólidos totais e coliformes termotolerantes. Foi realizado, ainda, um levantamento florístico e das condições de ocupação do solo nas margens do córrego. A partir dos resultados do monitoramento, foram calculados os índices de qualidade da água (IQA NSF ) e identificados os pontos com maior grau de poluição. A análise do IQA indicou que a qualidade da água oscilou entre média e ruim no período seco, tendo-se observado a melhoria da qualidade da água para boa e média no período chuvoso. A deterioração da qualidade das águas ocorreu devido ao lançamento de efluente industrial e esgoto das áreas urbanizadas, com ocorrência de níveis baixos de oxigênio dissolvido, alta concentração de matéria orgânica e nutrientes. Nas áreas com vegetação, observou-se diminuição na concentração de poluentes (principalmente nitrato e fosfato), indicando a importância da manutenção da vegetação ripária como medida de melhoria da qualidade das águas na região. A minimização da poluição neste córrego pode melhorar a qualidade da água da sub-bacia e, consequentemente, contribuir para deseutrofização do reservatório da Pampulha. Palavras-chave:Qualidade da água, uso e ocupação do solo, índice de qualidade da água. ABSTRACTThe Banguelo creek micro-basin, in the sub-basin Bom Jesus contributes for the formation of Pampulha reservoir, along with other contributors. The pollution in this reservoir is considered one of the major environmental problems of the city of Belo Horizonte. This paper evaluated the effect of land use and occupation in Banguelo Creek on its water quality, considering the seasonal cycle in several points of the micro-basin. The PONTES, P. P.; MARQUES, A. R.; MARQUES, G. F. Efeito do uso e ocupação do solo na qualidade da água na micro-bacia do Córrego Banguelo -Contagem. Ambi-Agua, Taubaté, v. 7, n. 3, p. 183-194, 2012. (http://dx.doi.org/10.4136/ambi-agua.962) 184 analyzed parameters for monitoring the water quality were: pH, turbidity, dissolved oxygen, phosphate, nitrate, total nitrogen, temperature, BOD 5 , COD and thermotolerant coliforms. The results were analyzed based on a floristic survey and on land occupation conditions in the micro-basin. Water quality index (WQI NSF ) was calculated and the points with the highest degree of pollution were identified. Analysis of WQI indicated that the water quality fell in the classes "average" and "bad" during dry season, with improvement for "good" and "average" in the rainy season. The deterioration of water quality was attrib...

This paper presents the characterization of specific organic constituents (carbohydrates, proteins and lipids) in raw sewage and in the anaerobic and aerobic effluents of a demo-scale (500 inhabitants) UASB- trickling-filter system. The evaluation of such parameters was carried out for two operating conditions, either without sludge recirculation (experiment I) from the trickling filter to the UASB reactor or with sludge recirculation (experiment II), for sludge thickening and stabilization, in the anaerobic reactor. The results showed that the contribution of acetic acid, carbohydrates, proteins and lipids amounted for approximately 70% of the total COD fed to the UASB during experiment I, whereas during experiment II these constituents amounted for only around 40% of the total COD. Although very high BOD and COD overall removal efficiencies were observed for the treatment system (around 90% and 80%, respectively), it was possible to infer that these efficiencies were mainly related to the removal of carbohydrates and lipids (around 80% removal), and of other non-identified constituents. The removal of proteins was much lower (around 50% removal), and the relative contribution of proteins to the total COD increased along the treatment course, being responsible for most of the residual COD of the treatment units. In the present system configuration, the UASB reactor played a major role in the removal of carbohydrates, whereas the trickling filter was very effective in the removal of lipids. The return of aerobic sludge for thickening and stabilization in the UASB reactor did not affect its performance.

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This work aimed at evaluating the influence of the excess sludge produced in a trickling filter (TF) on the performance of a UASB reactor used for the combined treatment of domestic sewage and aerobic sludge. During phase 1 of the research, the UASB reactor/TF system was fed with domestic sewage pumped directly from the sewer collector of Arrudas stream, in Belo Horizonte-Brazil. During phase 2, besides feeding the reactor with domestic sewage, the UASB reactor was also fed with the aerobic sludge from the trickling filter. The UASB reactor, with a volume of 420 litres, was operated at a mean hydraulic detention time of 5.6 hours in both operational phases. After 133 days of continuous monitoring, no detrimental effect was noticed on the performance of the UASB reactor regarding the return of the aerobic sludge produced in the TF. On the contrary, the COD results indicated a higher percentage of compliance with the discharge standards set forth by the Brazilian environmental legislation. During phase 2 of the research, when the UASB reactor was used for combined treatment of domestic sewage and excess aerobic sludge from the TF, the anaerobic effluent presented mean concentrations of 108 mgCOD x L(-1), 57 mgBOD x L(-1) and 18 mgTSS x L(-1).