Removal of Ammonia-Nitrogen from Wastewater in Dragon Steel Corporation
|Publication Author||: Chan-Po Chen, Cheng-Nan Tsai|
|Publication Year||: 2018|
|Publication Theme||: SQJ Vol 47 No.2|
Ammonia-nitrogen (NH3-N) pollutant can be detected in many kinds of industrial wastewater. Considering ammonia has a very high oxygen demand and is highly toxic for aquatic ecosystem, Taiwan Environmental Protection Administration has added the NH3-N criteria in Effluent Standards since 2011. Currently, the NH3-N concentration in the effluent from various kinds of industries must be under 20 mg/L.
The production of coke would produce the coking wastewater, whose NH3-N concentration is
about 500 to 1000 mg/L. Dragon Steel Corporation (DSC) is an integrated steel plant with an
annual production capacity up to six million tons of crude steel and two million tons of coke.
To comply with the NH3-N criteria, DSC has submitted the NH3-N pollutant reduction plan in March 2014 and received the approval by the local authority. The plan has been successfully completed in October 2017. At present, the NH3-N concentration in DSC’s effluent is steadily less than 20 mg/L.
This article would introduce the public policy-making process for NH3-N criteria in Taiwan
and how DSC reacts to comply with the standard. The action of DSC includes three parts. First, DSC has evaluated several possible solutions for NH3-N removal from wastewater. Second, DSC has added the ammonia removal facilities in by-product plant to reduce NH3-N pollutant in coking wastewater. Third, DSC has improved nitrification reaction in activated sludge system, and built a backup system for abnormal ammonia wastewater.
Keywords: Wastewater Treatment, Ammonia, Coking Wastewater, Nitrification