Modeling simultaneous carbon and nitrogen removal (SCNR) in anaerobic/anoxic reactor treating domestic wastewater. (15th July 2016)

• Record Type: Journal Article
• Authors: Mendes, Carlos; Esquerre, Karla; Queiroz, Luciano Matos
• Is Part Of: Journal of environmental management. Volume 177(2016)
• Page Start: 119
• Page End: 128
• Publication Date: 2016-07-15
• Subjects: Simulation -- Denitrification -- Anaerobic Digestion Model No. 1 -- Domestic wastewater; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2016.04.016
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: This paper presents a mathematical model based on the Anaerobic Digestion Model No. 1 (ADM1) to simulate the effects of nitrate concentration and hydraulic retention time (HRT) on the simultaneous carbon and nitrogen removal (SCNR) in anaerobic/anoxic reactor treating domestic wastewater. The model was calibrated using previously published experimental data obtained from anaerobic batch tests for different COD/ NO 3 − ratios. Model simulations were performed to predict the SCNR in a completely mixed reactor (CSTR) operating under mesophilic conditions (35 °C). Six different scenarios were evaluated to investigate the performance of the SCNR based on typical influent characteristics of domestic wastewater. The variables analyzed were chemical oxygen demand (COD) removal, nitrate concentration, methane production, nitrogen gas, volatile fatty acids (VFA) concentration, pH and percentage of COD used by the denitrifying and methanogenic microorganisms. The HRT was decreased stepwise from 15 to 4 h. The results indicate that Scenario (S5) with a COD/ NO 3 − ratio equal to 10 and an HRT equal to 15 h ensures the occurrence of the stable SCNR. Furthermore, the accumulation of denitrification intermediates and a significant reduction in the biogas production when the organic matter is limited was verified. Highlights: Simultaneous carbon and nitrogen removal is simulated in a CSTR. ADM1 parameters are modified to considered a low strength domestic wastewater. The best scenario for treating domestic wastewater is identified. ADM1 was adapted to consider simultaneous denitrification and anaerobic digestion.