Applying response surface methodology to optimize partial nitrification in sequence batch reactor treating salinity...

Area of Science:

• Environmental Engineering
• Wastewater Treatment Technologies
• Biochemical Engineering

Background:

• Partial nitrification (PN) is crucial for nitrogen removal from wastewater.
• Saline wastewater presents unique challenges for biological treatment processes.
• Optimizing PN parameters is essential for efficient ammonia and nitrite management.

Purpose of the Study:

• To optimize partial nitrification (PN) in saline wastewater using Box-Behnken design via response surface methodology (BBD-RSM).
• To develop a novel three-stage strategy for controlling carbon/nitrogen (C/N) ratio, alkalinity/ammonia (K/A) ratio, and salinity.
• To enhance ammonia removal efficiency (ARE) and nitrite accumulation rate (NAR) in a sequence batch reactor.

Main Methods:

• Implementation of a novel three-stage control strategy for PN in a sequence batch reactor.
• Application of Box-Behnken design via response surface methodology (BBD-RSM) for parameter optimization.
• Monitoring of ammonia removal efficiency (ARE) and nitrite accumulation rate (NAR) under varying operational conditions.

Main Results:

• Stable PN was achieved within 50 days, with an initial ARE of 98.37% and NAR of 85.93%.
• BBD-RSM identified optimal C/N, K/A, and salinity at 0.84, 2, and 5.5 g/L, respectively.
• Optimized reactor performance yielded significantly higher ARE (99.9% ± 0.04) and NAR (95.25% ± 0.32) compared to the non-optimized reactor.

Conclusions:

• The developed three-stage control strategy effectively enhances PN performance in saline wastewater.
• BBD-RSM is a powerful tool for optimizing PN process parameters, leading to superior treatment efficiency.
• This study offers a promising approach for robust PN process control and improved wastewater treatment outcomes.