Efficiency of a constructed wetland for wastewaters treatment
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Data
2012-09-01
Autores
Travaini-Lima, Fernanda [UNESP]
Sipaúba-Tavares, Lúcia Helena [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Limnologia
Resumo
OBJETIVO: Comparar as características limnológicas de três diferentes entradas de água no wetland construído, com dados de concentração e carga, e avaliar a eficiência de remoção de nutrientes, sólidos, DBO5, clorofila-a e coliformes termotolerantes (TC) pelo sistema de tratamento; MÉTODOS: No wetland construído, com área total de 82.8 m² e tempo de residência de 1 hora e 58 minutos na estação chuvosa e 2 horas e 42 minutos na seca, foram utilizadas as espécies Cyperus giganteus Vahl, Typha domingensis Pers., Pontederia cordata L. e Eichhornia crassipes (Mart.) Solms. Os pontos de amostragem avaliados em períodos de seca (D) e chuva (R) foram: entrada de água proveniente de aquicultura = IA; canal de entrada de escoamento da chuva = IR; entrada de resíduos provenientes de biodigestores = IB; saída de água do wetland = OUT. As variáveis analisadas foram: condutividade, pH, temperatura, oxigênio dissolvido, alcalinidade, DBO5, sólidos particulados e dissolvidos, nitrogênio, fósforo, clorofila-a e TC. Análises estatísticas multivariadas de Agrupamento e Componentes Principais (ACP) foram usadas para agrupar pontos de amostragem com características limnológicas semelhantes; RESULTADOS: Na ACP com dados de concentração foi retido 90.52% da variabilidade dos dados, correlacionando a entrada IB com altas concentrações de condutividade, alcalinidade, pH, TC, nutrientes e sólidos. Para os dados de carga a ACP reteve 80.9% da variabilidade dos dados e correlacionou os pontos IA D, IA R e OUT R com elevada DBO5, clorofila-a, STD, nitrato, nitrito, P-total, temperatura, oxigênio e vazão. As maiores taxas de eficiência de remoção ocorreram na seca, principalmente em concentração, com 78% para amônia, 95.5% para SRP, 94.9% para STS e 99.9% para TC; CONCLUSÕES: O wetland foi eficiente na remoção de nutrientes, sólidos, DBO5, clorofila-a e TC, principalmente no período seco. Reestruturações do sistema para aumentar o tempo de residência durante as chuvas e um pré-tratamento dos resíduos de biodigestores, podem aumentar a retenção de nutrientes e sólidos pelo wetland.
AIM: The limnological characteristics of three different inlets water of the constructed wetland were compared in terms of concentration data and loading rate data and evaluated the removal efficiencies of nutrients, solids, BOD5, chlorophyll-a and thermotolerant coliforms (TC) by the treatment system; METHODS: The constructed wetland, measuring 82.8 m² and with detention time of 1 hour and 58 minutes in the rainy season and 2 hours and 42 minutes in the dry one, was provided with four species, Cyperus giganteus Vahl, Typha domingensis Pers., Pontederia cordata L. e Eichhornia crassipes (Mart.) Solms. The sampling sites evaluated in the dry (D) and rainy (R) seasons were: inlet water from aquaculture farm = IA; inlet channel of rainwater runoff = IR; inlet from UASB wastewater = IB; outlet wetland = OUT. The conductivity, pH, temperature, dissolved oxygen, alkalinity, BOD5, total soluble and dissolved solids, nitrogen, phosphorus, chlorophyll-a and TC were analyzed. Multivariate analyses, such as Cluster and Principal Components Analysis (PCA), were carried out to group sampling sites with similar limnological characteristics; RESULTS: In the PCA with the concentration data was retained 90.52% variability of data, correlating the inlet IB with high concentrations of conductivity, alkalinity, pH, TC, nutrients and solids. Regarding loading rate data, the PCA was retained 80.9% of the data's total variability and correlated the sampling sites IA D, IA R and OUT R with higher BOD5, chlorophyll-a, TDS, nitrate, nitrite, total-P, temperature, oxygen and water flow. The highest removal efficiencies rates occurred in the dry season, mainly in concentration, with 78% of ammonia, 95.5% of SRP, 94.9% of TSS and 99.9% of TC; CONCLUSIONS: The wetland was highly efficacious in the removal of nutrients, solids, BOD5, chlorophyll-a and TC, mainly during the dry season. The system restructuring to increase the detention time during the rainy season and a pre-treatment of UASB wastewater, can increase the retention of nutrients and solids by wetland.
AIM: The limnological characteristics of three different inlets water of the constructed wetland were compared in terms of concentration data and loading rate data and evaluated the removal efficiencies of nutrients, solids, BOD5, chlorophyll-a and thermotolerant coliforms (TC) by the treatment system; METHODS: The constructed wetland, measuring 82.8 m² and with detention time of 1 hour and 58 minutes in the rainy season and 2 hours and 42 minutes in the dry one, was provided with four species, Cyperus giganteus Vahl, Typha domingensis Pers., Pontederia cordata L. e Eichhornia crassipes (Mart.) Solms. The sampling sites evaluated in the dry (D) and rainy (R) seasons were: inlet water from aquaculture farm = IA; inlet channel of rainwater runoff = IR; inlet from UASB wastewater = IB; outlet wetland = OUT. The conductivity, pH, temperature, dissolved oxygen, alkalinity, BOD5, total soluble and dissolved solids, nitrogen, phosphorus, chlorophyll-a and TC were analyzed. Multivariate analyses, such as Cluster and Principal Components Analysis (PCA), were carried out to group sampling sites with similar limnological characteristics; RESULTS: In the PCA with the concentration data was retained 90.52% variability of data, correlating the inlet IB with high concentrations of conductivity, alkalinity, pH, TC, nutrients and solids. Regarding loading rate data, the PCA was retained 80.9% of the data's total variability and correlated the sampling sites IA D, IA R and OUT R with higher BOD5, chlorophyll-a, TDS, nitrate, nitrite, total-P, temperature, oxygen and water flow. The highest removal efficiencies rates occurred in the dry season, mainly in concentration, with 78% of ammonia, 95.5% of SRP, 94.9% of TSS and 99.9% of TC; CONCLUSIONS: The wetland was highly efficacious in the removal of nutrients, solids, BOD5, chlorophyll-a and TC, mainly during the dry season. The system restructuring to increase the detention time during the rainy season and a pre-treatment of UASB wastewater, can increase the retention of nutrients and solids by wetland.
Descrição
Palavras-chave
wetland construído, macrófitas aquáticas, eficiência de remoção, fluxo hidráulico, carga, constructed wetland, macrophyte, removal efficiency, hydraulic flow, loading rate
Como citar
Acta Limnologica Brasiliensia. Associação Brasileira de Limnologia, v. 24, n. 3, p. 255-265, 2012.