Nitrogen removal from coke making wastewater through a pre-denitrification activated sludge process

Under the Industrial Emissions Directive (IED), coke production wastewater must be treated to produce an effluent characterised by a total nitrogen (TN) 5.7 to produce an effluent TN 5.7 or, alternately, the addition of an external carbon source should be considered. [Display omitted] •Pre-denitrification allows effective nitrogen removal from coke making wastewater.•Carbon availability limits denitrification efficiencies.•Influent to the activated sludge process should have an sCOD:TN ratio >5.7 to obtain TN