Packed bed columns for high rate nitrogen and carbon removals

Area of Science:

• Environmental Engineering
• Environmental Microbiology
• Water Treatment Technologies

Background:

• Wastewater treatment requires efficient removal of nitrogen (N) and chemical oxygen demand (COD).
• Packed bed (PB) column systems offer a potential solution for high-strength wastewater.
• Investigating different configurations of PB systems is crucial for optimizing treatment performance.

Purpose of the Study:

• To compare the efficacy of anoxic-anoxic and anoxic-oxic PB systems for treating high N and COD wastewater.
• To evaluate the removal rates and efficiencies of both PB system configurations.
• To assess the stability of denitrification in both systems.

Main Methods:

• Two packed bed (PB) column systems were operated in series: an anoxic-anoxic configuration and an anoxic-oxic configuration.
• Wastewater with high concentrations of nitrogen and COD was used as influent.
• Removal rates (kg/m3 x d) and removal efficiencies (%) for N and COD were measured for both systems.

Main Results:

• The anoxic-oxic PB system achieved higher removal rates: 7.41 kg N/m3 x d and 28.00 kg COD/m3 x d.
• The anoxic-anoxic PB system demonstrated slightly higher denitrification stability.
• Both systems exhibited high removal efficiencies, with N removal between 97.5-100% and COD removal between 97.2-99.4%.

Conclusions:

• A packed bed (PB) system with anoxic-oxic columns in series effectively removes nitrogenous and carbonaceous compounds from wastewater.
• The anoxic-oxic PB system demonstrates a high capacity for N and COD removal, even with oxygenated influent to the anoxic stage.
• The anoxic-anoxic PB system provides superior stability for denitrification processes.