Characterization of Wastewater Quality and Denitrification Potential of Domestic Wastewater

Abstract

Developing a simulation model requires precision in the parameters of the wastewater quality components. This study investigated the fractions of chemical oxygen demand (COD) and total nitrogen (TN) in influent and effluent at a domestic wastewater treatment plant in Taiwan. As per the COD categorization, raw wastewater includes 12.6% readily biodegradable COD and 45.6% slowly biodegradable COD that can participate in the denitrification process. Meanwhile, up to 62.8% ammonia nitrogen was present in wastewater, according to the TN classification. As a result, when using raw wastewater as a carbon source, the optimal COD/NO₃-N was 6, indicating a low denitrification efficiency (merely 50% compared to 95% for acetate as a carbon source). The abundance of slowly biodegradable COD coupled with the denitrification rate of 0.73 mg N/g VSS.hr was approximately half the denitrification rate of readily biodegradable COD (1.67 mg N/g VSS.hr). Furthermore, this study has also shown the potential to use slowly biodegradable carbon sources in the denitrification process by contributing to improving the reduction efficiency by more than 50% when applying both carbon sources.