Coupling the SHARON process with anammox: model-based scenario analysis with focus on operating costs.

Area of Science:

• Environmental Engineering
• Biotechnology
• Wastewater Treatment

Background:

• The SHARON-Anammox process combines partial nitritation (SHARON) and anaerobic ammonium oxidation (Anammox) for high-ammonia wastewater treatment.
• SHARON is often used for sludge digestion rejection water to reduce ammonium load on main treatment plants.
• Maintaining an optimal nitrite:ammonium ratio is critical for efficient Anammox reactor performance.

Purpose of the Study:

• To investigate methods for optimizing the nitrite:ammonium ratio in the SHARON reactor effluent.
• To evaluate the effectiveness of different control strategies in ensuring stable operation of the combined SHARON-Anammox process.
• To assess the economic performance of various control strategies.

Main Methods:

• Simulation study of a SHARON reactor under realistic influent conditions.
• Implementation and testing of cascade pH control and cascade oxygen (O2) control strategies.
• Economic assessment using an operating cost index to quantify strategy performance.

Main Results:

• Simulation revealed that uncontrolled operation can lead to significant deviations in the nitrite:ammonium ratio, jeopardizing Anammox reactor stability.
• Cascade feedback control of the effluent nitrite:ammonium ratio by adjusting the O2 set-point proved most effective.
• The cascade O2 control strategy demonstrated superior performance in maintaining the desired ratio.

Conclusions:

• Effective control of the nitrite:ammonium ratio is essential for the successful implementation of the SHARON-Anammox process.
• Cascade oxygen control offers a robust and economically viable solution for optimizing SHARON reactor operation.
• This strategy enhances the reliability and efficiency of treating high-ammonia wastewater streams.