Nitrogen removal from coke making wastewater through a pre-denitrification activated sludge process.
Sci Total Environ
; 666: 31-38, 2019 May 20.
Article
em En
| MEDLINE
| ID: mdl-30784820
ABSTRACT
Under the Industrial Emissions Directive (IED), coke production wastewater must be treated to produce an effluent characterised by a total nitrogen (TN) <50â¯mg/L. An anoxic-aerobic activated sludge pilot-plant (1â¯m3) fed with coke production wastewater was used to investigate the optimal operational requirements to achieve such an effluent. The loading rates applied to the pilot-plant varied between 0.198-0.418â¯kg COD/m3.day and 0.029-0.081â¯kg TN/m3.day, respectively. The ammonia (NH4+-N) removals were maintained at 96%, after alkalinity addition. Under all conditions, phenol and SCN- remained stable at 96% and 100%, respectively with both being utilised as carbon sources during denitrification. The obtained results showed that influent soluble chemical oxygen demand (sCOD) to TN ratio of should be maintained at >5.7 to produce an effluent TN <50â¯mg/L. Furthermore, nitrite accumulation was observed under all conditions indicating a disturbance to the denitrification pathway. Overall, the anoxic-aerobic activated sludge process was shown to be a robust and reliable technology to treat coke making wastewater and achieve the IED requirements. Nevertheless, the influent to the anoxic tank should be monitored to ensure a sCODTN ratio >5.7 or, alternately, the addition of an external carbon source should be considered.
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Base de dados:
MEDLINE
Assunto principal:
Esgotos
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Eliminação de Resíduos Líquidos
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Desnitrificação
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Águas Residuárias
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Resíduos Industriais
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Nitrogênio
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article