[Effect of Temperature on PAO Activity and Substrate Competition]

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Engineering
• Biochemical Engineering

Background:

• Enhanced biological phosphorus removal (EBPR) is crucial for nutrient management in wastewater treatment.
• High-temperature operations present unique challenges for microbial community function.
• Understanding thermophilic organisms is key to optimizing EBPR under varying conditions.

Purpose of the Study:

• To determine the impact of temperature on high-temperature phosphate accumulating organisms (PAO_HT) activity.
• To assess the competitive substrate uptake ability of PAO_HT at different temperatures.
• To quantify the kinetic parameters of PAO_HT relevant to phosphorus removal.

Main Methods:

• Utilized sludge from a stable 30°C EBPR reactor.
• Investigated PAO_HT activity across a temperature range (15°C to 30°C).
• Measured anaerobic phosphorus release, aerobic phosphorus uptake, and acetate uptake rates.
• Applied a simplified Arrhenius equation to model temperature effects.

Main Results:

• PAO_HT activity and substrate competition significantly increased from 15°C to 30°C.
• At 30°C, anaerobic P release, aerobic P uptake, and acetate uptake rates were 239.46, 79.90, and 357.47 mg·(g·h)^-1, respectively.
• The P/HAc ratio reached 0.628, exceeding previously reported values for PAO. Temperature coefficients were 1.08, 1.07, and 1.05 for the respective processes.

Conclusions:

• Temperature positively influences PAO_HT performance and substrate competition within the studied range.
• Optimizing temperature to 30°C enhances phosphorus removal efficiency in EBPR systems.
• The findings provide valuable kinetic data for designing and operating high-temperature wastewater treatment processes.