Abstract
This study explored the effect of temperature and carbon source on the denitrification process. Batch experiments were conducted within the 10–30 °C range, using either acetic acid, propionic acid or an 1:1 mixture (by weight) of the same acids as an external carbon source. A 5 M NaNO 3 solution was added to yield nitrate-nitrogen concentrations of 50, 100 and 200 mg/L, and carbon to nitrogen (C:N) ratios of 2:1 and 4:1, respectively. It was observed that denitrification was feasible under all conditions investigated, provided that the initial reactor pH was adjusted to approximately 6.5. Overall, a temperature change from 10 to 20 °C exerted a greater effect on both the specific denitrification and carbon consumption rates than a further temperature increase from 20 to 30 °C, which was also evident in the corresponding temperature coefficient values. At a given temperature, the specific denitrification rate appeared to depend on the initial nitrogen concentration, while the specific carbon consumption rate was a function of the initial carbon content. Furthermore, a C:N ratio of 2:1 was sufficient for complete denitrification at all temperatures and types of carbon investigated. During the mixed VFA experiments, acetic acid was utilized faster than propionic acid, indicating a preferential utilization pattern. Finally, substantial alkalinity recovery was also observed in all runs, in accordance with the theoretically calculated values.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.