Este estudo teve como objetivo avaliar a eficiência da eletrocoagulação na remoção da demanda química de oxigênio (DQO), turbidez e cor aparente do efluente de incineração gerado em um sistema de limpeza de gases (SLG). A modelagem e otimização das variáveis corrente elétrica (I), tempo de retenção hidráulica (TRH) e distância do eletrodo (DE) também foram realizadas em um reator em batelada utilizando eletrodos de ferro. Foi utilizado um delineamento composto central rotacional (DCCR) na 23 com um total de 19 ensaios, com correntes elétricas variando de 1A e 5A, tempo de retenção do efluente no reator de 15 a 40 minutos e distância dos eletrodos de 1 e 3 centímetros. Um algoritmo com função de conveniência foi criado para otimizar simultaneamente os parâmetros estudados. O tratamento da GCS por eletrocoagulação foi satisfatório na remoção de turbidez, cor aparente e DQO, com eficiência máxima de remoção acima de 70% para todos os parâmetros, utilizando TRH de 27,5 minutos, ED de 2 centímetros e corrente elétrica de 1 A. A análise estatística apresentou um bom ajuste do modelo com coeficiente de determinação de R2 > 0,9. A condição ótima de operação foi observada em corrente elétrica de 1A, 27 minutos de TRH e 2 centímetros de distância do eletrodo, com remoções de 82,07, 86,86 e 70,82% de DQO, turbidez e cor aparente, respectivamente. Os ensaios simulados mostraram que tempos de eletrólise mais baixos podem ser utilizados, sem prejudicar a eficiência do tratamento. Portanto, a eletrocoagulação pode ser uma ferramenta potencial no tratamento de SLG.
Palavras-chave: coagulação; eletrólise; incineração; purificador de gás
This study evaluated the efficiency of electrocoagulation in removing chemical oxygen demand (COD), turbidity, and apparent color from the incineration effluent generated in a gas cleaning system (GCS). Modeling and optimization of the variables electric current (I), hydraulic retention time (HRT), and electrode distance (ED) were also performed in a batch reactor using iron electrodes. A 23 rotatable central composite design CCRD was used, with a total of 19 trials, with electric currents ranging from 1A and 5A, a retention time of the effluent in the reactor from 15 to 40 minutes, and electrode distance of 1 and 3 centimeters. An algorithm with the desirability function was created to optimize simultaneously the parameters studied. The treatment of GCS by electrocoagulation was satisfactory in removing turbidity, apparent color, and COD, with maximum removal efficiencies above 70% for all parameters, using HRT of 27.5 minutes, ED of 2 centimeters, and electric current of 1 A. The statistical analysis showed a good fit of the model, with a coefficient of determination of R2 > 0.9. The optimum operating condition was observed at 1A electric current, 27 minutes HRT, and 2 centimeters of electrode distance, with removals of 82.07, 86.86, and 70.82% of COD, turbidity, and apparent color, respectively. The simulated trials showed that lower electrolysis times can be used without impairing the treatment efficiency. Therefore, electrocoagulation may be a potential tool in the treatment of GCS.
Keywords: coagulation, electrolysis, gas scrubber, incineration
This study evaluated the efficiency of electrocoagulation in removing chemical oxygen demand (COD), turbidity, and apparent color from the incineration effluent generated in a gas cleaning system (GCS). Modeling and optimization of the variables electric current (I), hydraulic retention time (HRT), and electrode distance (ED) were also performed in a batch reactor using iron electrodes. A 23 rotatable central composite design CCRD was used, with a total of 19 trials, with electric currents ranging from 1A and 5A, a retention time of the effluent in the reactor from 15 to 40 minutes, and electrode distance of 1 and 3 centimeters. An algorithm with the desirability function was created to optimize simultaneously the parameters studied. The treatment of GCS by electrocoagulation was satisfactory in removing turbidity, apparent color, and COD, with maximum removal efficiencies above 70% for all parameters, using HRT of 27.5 minutes, ED of 2 centimeters, and electric current of 1 A. The statistical analysis showed a good fit of the model, with a coefficient of determination of R2 > 0.9. The optimum operating condition was observed at 1A electric current, 27 minutes HRT, and 2 centimeters of electrode distance, with removals of 82.07, 86.86, and 70.82% of COD, turbidity, and apparent color, respectively. The simulated trials showed that lower electrolysis times can be used without impairing the treatment efficiency. Therefore, electrocoagulation may be a potential tool in the treatment of GCS.
Keywords: coagulation, electrolysis, gas scrubber, incineration
