| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 4.5 MB | Adobe PDF |
Abstract(s)
O tratamento de águas residuais (AR) visa a protecção da saúde pública, pelo que nas ETAR a
AR é submetida a uma fileira de tratamento com diversas operações e processos unitários
(exemplo decantação primária). Esta operação de separação sólido-líquido é essencialmente
aplicada na remoção de sólidos suspensos totais (SST) da AR.
O planeamento factorial é uma técnica aplicada no desenvolvimento e optimização de processos,
onde são seleccionados vários factores, com os quais se efectuam diversas combinações, de forma
a determinar qual a sua influência na(s) variável(eis) de resposta.
No presente trabalho simulou-se e optimizou-se a influência de algumas variáveis no desempenho
de decantadores primários, para tal, foram seleccionadas duas ETAR (X e Y) da região de Lisboa.
As experiências foram realizadas recorrendo ao software de simulação GPS-X, implementando a
corrente afluente, o decantador primário (circular e rectangular), a corrente efluente e a de lamas.
As cinco variáveis estudadas foram o caudal (A) e a concentração de SST à entrada (B), as alturas
de alimentação (C) e de saída (D) e a razão entre o caudal de lamas e o caudal efluente (E).
O planeamento factorial e a análise estatística foram efectuados no software Minitab17. Os
modelos do efeito das variáveis em estudo foram: eficiência de remoção de SST (%) = 73,726 -
4,025A + 6,635B - 8,127C + 2,122E e eficiência de remoção de SST (%) = 47,129 - 4,071A +
33,041B - 2,755C + 1,606E - 2,381BC, para as ETAR X e Y respectivamente. Os valores
previstos obtidos através dos modelos apresentam uma elevada concordância com os valores
simulados. Para a ETAR X foi comparada a eficiência de remoção de SST prevista pelo modelo
com a real.
Wastewater (WW) treatment aimed the protection of public health, therefore in a WWTP the WW is subjected to a treatment scheme with several operations and processes units (e.g. primary sedimentation). This solid-liquid separation operation is essentially applied in the removal of total suspended solids (TSS) from the WW. Factorial planning is a technique applied in the development and optimization of processes. Several factors are selected and combined in order to determine its influence on the response variable(s). In the present work, the influence of some variables on the performance of primary clarifiers were simulated and optimized. For this purpose, two WWTP (X and Y) of the Lisbon region were selected. The experiments were carried out using the GPS-X simulation software, implementing the influent stream, the primary clarifier (circular and rectangular), the effluent and sludge streams. The five variables studied were the flow rate (A), the TSS concentration at the inlet (B), the feed (C) and outlet (D) heights and the ratio between sludge and effluent flows (E). Factorial planning and statistical analysis were performed in Minitab software17. The models of the effect of the variables under study were: TSS removal efficiency (%) = 73,726 -4,025A + 6,635B - 8,127C + 2,122E and removal efficiency of SST (%) = 47,129 - 4,071A + 33,041B - 2,755C + 1,606E - 2,381BC, for the X and Y WWTP, respectively. The predicted values obtained through the models show a high agreement with the simulated values. For the WWTP X, the TSS efficiency removal predicted by the model and the real values were compared.
Wastewater (WW) treatment aimed the protection of public health, therefore in a WWTP the WW is subjected to a treatment scheme with several operations and processes units (e.g. primary sedimentation). This solid-liquid separation operation is essentially applied in the removal of total suspended solids (TSS) from the WW. Factorial planning is a technique applied in the development and optimization of processes. Several factors are selected and combined in order to determine its influence on the response variable(s). In the present work, the influence of some variables on the performance of primary clarifiers were simulated and optimized. For this purpose, two WWTP (X and Y) of the Lisbon region were selected. The experiments were carried out using the GPS-X simulation software, implementing the influent stream, the primary clarifier (circular and rectangular), the effluent and sludge streams. The five variables studied were the flow rate (A), the TSS concentration at the inlet (B), the feed (C) and outlet (D) heights and the ratio between sludge and effluent flows (E). Factorial planning and statistical analysis were performed in Minitab software17. The models of the effect of the variables under study were: TSS removal efficiency (%) = 73,726 -4,025A + 6,635B - 8,127C + 2,122E and removal efficiency of SST (%) = 47,129 - 4,071A + 33,041B - 2,755C + 1,606E - 2,381BC, for the X and Y WWTP, respectively. The predicted values obtained through the models show a high agreement with the simulated values. For the WWTP X, the TSS efficiency removal predicted by the model and the real values were compared.
Description
Trabalho final de mestrado para obtenção do grau de mestre em Engenharia da Qualidade e Ambiente
Keywords
Sedimentação Sedimentation Decantação primária Primary clarifier Simulação Simulation Eficiência de remoção TSS removal Optimização Optimization Planeamento factorial Factorial planning
Citation
MARTINS, Daniela Maria de Almeida - Optimização da sedimentação primária no tratamento de águas residuais : simulação e aplicação de técnicas estatísticas. Lisboa: Instituto Superior de Engenharia de Lisboa, 2017. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa