Raper, EleanorFisher, R.Anderson, D. R.Stephenson, TomSoares, Ana2019-03-042019-03-042019-02-14E Raper, R Fisher, DR Anderson, et al., (2019) Nitrogen removal from coke making wastewater through a pre-denitrification activated sludge process. Science of The Total Environment, Volume 666, May 2019, pp. 31-380048-9697https://doi.org/10.1016/j.scitotenv.2019.02.196http://dspace.lib.cranfield.ac.uk/handle/1826/13957Under the Industrial Emissions Directive (IED), coke production wastewater must be treated to produce an effluent characterised by a total nitrogen (TN) <50 mg/L. An anoxic-aerobic activated sludge pilot-plant (1 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 0.198–0.418 kg COD/m3.day and 0.029–0.081 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 <50 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 sCOD:TN ratio >5.7 or, alternately, the addition of an external carbon source should be considered.enAttribution-NonCommercial-NoDerivatives 4.0 InternationalCoke making wastewaterNitrificationDenitrificationsCOD:TN ratioNitrate-respiring bacteriaArticle