Nitrogen removal from sludge dewatering effluent through anaerobic ammonia oxidation process

Area of Science:

• Environmental Science
• Microbiology
• Wastewater Treatment

Background:

• The anaerobic ammonia oxidation (Anammox) process is a novel biological nitrogen removal technology.
• Wastewater treatment, particularly nitrogen removal, faces challenges with conventional methods.
• Sludge dewatering effluent presents a complex nitrogenous waste stream.

Purpose of the Study:

• To investigate the feasibility of transitioning from denitrification to the Anammox process.
• To evaluate the performance of a lab-scale Anammox biofilm reactor using sludge dewatering effluent.
• To assess the efficiency of nitrogen removal under specific operational conditions.

Main Methods:

• Cultivation of a denitrification biofilm for use as inoculum.
• Transitioning the established biofilm to an Anammox process.
• Operation of a lab-scale Anammox biofilm reactor with sludge dewatering effluent.
• Monitoring of key parameters including ammonia, nitrite, and total nitrogen concentrations, and hydraulic retention time (HRT).

Main Results:

• Successful startup and transition to the Anammox process were achieved within 85 days.
• The Anammox process effectively removed ammonia from sludge dewatering effluent.
• Effluent ammonia concentration (23.11 mgN/L at 28h HRT) met China's national discharge standard II (<25 mgN/L).
• A high volumetric total nitrogen loading rate of 584.99 mg TN/(L x d) was achieved at 17h HRT.

Conclusions:

• The Anammox process is a viable and efficient method for nitrogen removal from sludge dewatering effluent.
• Transitioning from denitrification to Anammox is feasible and can be successfully implemented.
• The Anammox process demonstrates robust performance and potential for meeting stringent wastewater discharge regulations.