Calculation of N2O Emission in the Wastewater Treatment Process of Paper Mill

Nishonov Akbarjon, Feini Huang and Wenhao Shen* State Key Laboratory of Pulp & Paper Engineering, South China University of Technology, China *Corresponding author Abstract—Aiming at the quantification of the N2O production from wastewater treatment plants (WWTPs) of papermaking industry, we provided a practical mathematical model. Primarily, the TNs (influent and effluent) were off-line measured with the ultraviolet spectrophotometry, and the flowrate of wastewater was the field data from on-line monitoring system. Subsequently, combining with the two variables, the determinate emission rate factor of N2O was applied to the estimation of the N2O emission. The results showed that the averaged 15.234 mg/m3 of N2O was emitted during the biological nitrogen removal process in a paper mill. In addition, we analyzed some influencing factors during the operation in this article, including the dissolved oxygen (DO), pH, nitrite concentration and COD/N ratios. And the nitrite concentration in the wastewater directly increased the N2O generation, except that other parameters have the modest influence. Compared with the researches on N2O emissions, the proposed model is simplified to be dedicated to the wastewater treatment of papermaking industry.