A carregar...
Publicação
OTIMIZAÇÃO DO PROCESSO DE TRATAMENTO DOS EFLUENTES CIANETADOS DA OFICINA DE TRATAMENTOS ELETROLÍTICOS DA TAP
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 32.89 MB | Adobe PDF |
Orientador(es)
Resumo(s)
A ETAR da TAP, destina-se ao tratamento dos efluentes de lavagem provenientes da
oficina de tratamentos eletrolíticos, onde são efetuados vários tratamentos aos componentes
das aeronaves. Um dos três tratamentos aos efluentes, consiste na oxidação dos cianetos, com
H2O2 e CuSO4, combinada com a utilização de radiação ultravioleta.
Com o propósito de garantir o cumprimento do disposto no Licenciamento Ambiental,
relativamente à [CN-] Totais, onde se encontra expresso que esta não pode ser superior a 0,2
mg/L, realizaram-se vários ensaios industriais, de forma a averiguar quais as melhores con-
dições para alcançar um tratamento eficiente no processo de oxidação de cianetos. Para tal,
fizeram-se variar os caudais de reagentes adicionados, o tempo de residência nos tanques de
tratamento e a densidade energética aplicada nos reatores ultravioleta, analisando, assim, em
cada uma das fases definidas do tratamento, o impacto destas alterações no final do processo,
na [CN-] Totais , na cor, no pH, na CQO e nos SST.
Deste modo, obteve-se uma eficiência de tratamento no Tanque 1 de 98 % com a apli-
cação de um caudal de H2O2 de 8,5 L/m3, um caudal de CuSO4 de 2,0 L/m3 e um tempo de
residência de 120 minutos. Por sua vez no Tanque 2, foi utilizado um caudal de 1,5 L/m3 para
o H2O2, um caudal de 0,5 L/m3 de CuSO4 e uma densidade energética de 35 kWh/m3, verifi-
cando-se, neste estudo, uma eficiência máxima de 92 %. Uma vez que o efluente já se encontra
parcialmente tratado, a eficiência do segundo tanque não será tão elevada quando comparada
à do primeiro, pois tal como foi estudado, o tratamento, nas fases individuais, não é tão efici-
ente com baixas concentrações de cianetos.
Assim, no processo completo de tratamento dos efluentes cianetados, foi possível obter
eficiências dos tratamentos entre 98 % e aproximadamente 100 %, garantindo assim a eficiência
praticamente total do mesmo, bem como o cumprimento dos VLE’s.
The WWTP in TAP facilities is dedicated to treating effluents generated from the elec- troplating workshop, where various treatments are applied to aircraft components. One of the three processes for treating cyanide effluents involves the oxidation of cyanides using hydro- gen peroxide and copper sulfate, combined with the use of ultraviolet radiation. To ensure compliance with the Environmental License, which stipulates that the concen- tration of total cyanides can’t exceed 0,2 mg/L, several industrial assays were conducted to determine the optimal conditions for achieving efficiency in the cyanide oxidation treatment module. This involved varying the flow rates of added reagents, residence time in treatment tanks and the energy density applied in the ultraviolet reactors. At each defined phase of treat- ment, the impact of these changes on the final effluent, including the concentration of total cyanides, sample color, pH, COD, TSS, was analyzed. As a result, a treatment efficiency of 98 % was achieved in Tank 1 with the application of a H2O2 flow rate of 8,5 L/m3, a catalyst flow rate (CuSO4) of 2,0 L/m3, and a residence time of 120 minutes. In Tank 2, a flow rate of 1,5 L/m3 for hydrogen peroxide, a flow rate of 0,5 L/m3 for copper sulfate, and an energy density of 35 kWh/m3 were implemented, resulting in a respective maximum treatment efficiency, of 92 %. Since the effluent is already partially treated, the efficiency of the second tank is not as high when compared to the first, as demon- strated by the current study, which showed that individual phases of treatment are less effi- cient with low concentrations of cyanides. All in all, in the complete process for treating cyanide effluents, treatment efficiencies between 98 % and approximately 100 % were achieved, thus ensuring almost total efficiency as well as compliance with the emission limit values.
The WWTP in TAP facilities is dedicated to treating effluents generated from the elec- troplating workshop, where various treatments are applied to aircraft components. One of the three processes for treating cyanide effluents involves the oxidation of cyanides using hydro- gen peroxide and copper sulfate, combined with the use of ultraviolet radiation. To ensure compliance with the Environmental License, which stipulates that the concen- tration of total cyanides can’t exceed 0,2 mg/L, several industrial assays were conducted to determine the optimal conditions for achieving efficiency in the cyanide oxidation treatment module. This involved varying the flow rates of added reagents, residence time in treatment tanks and the energy density applied in the ultraviolet reactors. At each defined phase of treat- ment, the impact of these changes on the final effluent, including the concentration of total cyanides, sample color, pH, COD, TSS, was analyzed. As a result, a treatment efficiency of 98 % was achieved in Tank 1 with the application of a H2O2 flow rate of 8,5 L/m3, a catalyst flow rate (CuSO4) of 2,0 L/m3, and a residence time of 120 minutes. In Tank 2, a flow rate of 1,5 L/m3 for hydrogen peroxide, a flow rate of 0,5 L/m3 for copper sulfate, and an energy density of 35 kWh/m3 were implemented, resulting in a respective maximum treatment efficiency, of 92 %. Since the effluent is already partially treated, the efficiency of the second tank is not as high when compared to the first, as demon- strated by the current study, which showed that individual phases of treatment are less effi- cient with low concentrations of cyanides. All in all, in the complete process for treating cyanide effluents, treatment efficiencies between 98 % and approximately 100 % were achieved, thus ensuring almost total efficiency as well as compliance with the emission limit values.
Descrição
Palavras-chave
Indústria Aeronáutica Tratamento de Águas Residuais Oxidação de Cianetos Doseamento de Reagentes Processos Oxidativos Avançados Radiação Ultravioleta