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Abstract(s)
Este estudo, tem como objetivo a refinação do efluente da Estação de Tratamento de Águas Residuais (ETAR) de uma fábrica de curtumes – empresa JR Fontes – via utilização de membranas e oxidação química com reagente de Fenton. Numa fase inicial, procedeu-se à avaliação do efluente final da ETAR, disponibilizado pela empresa JR Fontes, nomeadamente no que diz respeito aos parâmetros carência química de oxigénio (CQO), crómio (Cr), pH e sólidos suspensos totais (SST). Os valores obtidos foram comparados com os Valores Limite de Emissão (VLE) que constam no anexo II do Aviso n.º 5505/2015 e com os indicados pela empresa JR Fontes, para a CQO e SST, 1100 mg O2/L e 650 mg/L, respetivamente. Chegou-se assim à conclusão que a CQO era o parâmetro que não cumpria o VLE, uma vez que, apresentava valores entre 1700 – 1900 mg O2/L. Foi então estudada a aplicação de dois tipos de tratamento terciário ao efluente da ETAR da empresa JR Fontes, nomeadamente a utilização de membranas de ultrafiltração e o processo de oxidação química usando o reagente de Fenton, com o objetivo de fazer respeitar os valores limite de descarga impostos à empresa. Os ensaios de ultrafiltração foram efetuados com membranas 100 kDa, 30k e 10k de Celulose Regenerada (CR), sendo que os resultados obtidos não foram satisfatórios. Os ensaios de oxidação com o reagente de Fenton foram realizados para as condições operatórias correspondentes a pH=3,50, temperatura ≈ 24 ºC, concentração de peróxido de hidrogénio equivalente à concentração estequiométrica, razão (Fe2+:H2O2) = 1:5 e razão (Fe2+:H2O2) = 1:3, sendo que para estas condições a percentagem de redução da CQO foi 95 %., alcançando-se, portanto, o objetivo pretendido.
The aim of this study is to refine the effluent from the Wastewater Treatment Plant (WWTP) of a tannery - company JR Fontes - using membranes and chemical oxidation with Fenton's reagent. Initially, the evaluation of the final effluent from the WWTP, provided by the company JR Fontes, was carried out taking into account the following parameters: chemical oxygen demand (COD), chromium (Cr), pH and total suspended solids (TSS). The obtained values were compared with the Emission Limit Values (ELVs) that appear in annex II of Notice No. 5505/2015 and with those indicated by the company JR Fontes, for COD and TSS, 1100 mg O2 / L and 650 mg / L, respectively. It was thus concluded that COD was the parameter that did not comply with the ELVs since their values were between 1700 - 1900 mg O2 / L. The application of two types of tertiary treatment to the effluent of the WWTP company JR Fontes was then studied, namely using ultrafiltration membranes and chemical oxidation process using Fenton's reagent with the objective of ensuring compliance with the discharge limit values imposed to the company. The ultrafiltration tests were carried out with 100 kDa, 30k and 10k Regenerated Cellulose (RC) membranes, and the results obtained were not satisfactory. The oxidation tests with Fenton's reagent were performed at the following operating conditions: pH = 3.50, temperature ≈ 24 ºC, hydrogen peroxide concentration equivalent to the stoichiometric concentration, ratio (Fe2 +: H2O2) = 1: 5 and ratio (Fe2 +: H2O2) = 1: 3. For these conditions the percentage of COD reduction was 95%., therefore, the intended objective was achieved.
The aim of this study is to refine the effluent from the Wastewater Treatment Plant (WWTP) of a tannery - company JR Fontes - using membranes and chemical oxidation with Fenton's reagent. Initially, the evaluation of the final effluent from the WWTP, provided by the company JR Fontes, was carried out taking into account the following parameters: chemical oxygen demand (COD), chromium (Cr), pH and total suspended solids (TSS). The obtained values were compared with the Emission Limit Values (ELVs) that appear in annex II of Notice No. 5505/2015 and with those indicated by the company JR Fontes, for COD and TSS, 1100 mg O2 / L and 650 mg / L, respectively. It was thus concluded that COD was the parameter that did not comply with the ELVs since their values were between 1700 - 1900 mg O2 / L. The application of two types of tertiary treatment to the effluent of the WWTP company JR Fontes was then studied, namely using ultrafiltration membranes and chemical oxidation process using Fenton's reagent with the objective of ensuring compliance with the discharge limit values imposed to the company. The ultrafiltration tests were carried out with 100 kDa, 30k and 10k Regenerated Cellulose (RC) membranes, and the results obtained were not satisfactory. The oxidation tests with Fenton's reagent were performed at the following operating conditions: pH = 3.50, temperature ≈ 24 ºC, hydrogen peroxide concentration equivalent to the stoichiometric concentration, ratio (Fe2 +: H2O2) = 1: 5 and ratio (Fe2 +: H2O2) = 1: 3. For these conditions the percentage of COD reduction was 95%., therefore, the intended objective was achieved.
Description
Keywords
ETAR Efluente de curtumes Ultrafiltração Membranas Reagente de Fenton WWTP Effluent tannery Ultrafiltration Membranes Fenton's reagente