Effect of denitrification type on pH profiles in the sequencing batch reactor process
Yong-zhen Peng1, Shao-po Wang, Shu-ying Wang
1College of Environmental and Energy Engineering, Beijing University of Technology, China.
Summary
Partial denitrification yields higher pH than complete denitrification. Higher nitrite proportions during denitrification lead to increased pH peaks, offering real-time system monitoring insights.
Area of Science:
- Environmental Microbiology
- Water Treatment Engineering
Background:
- Biological denitrification is crucial for removing nitrogen pollutants from wastewater.
- Understanding pH dynamics during denitrification is key to optimizing treatment processes.
- Different nitrogen species (nitrate, nitrite) influence alkalinity production and pH shifts.
Purpose of the Study:
- To investigate pH profiles during partial and complete denitrification.
- To determine the impact of initial nitrogen substance proportions on pH.
- To identify characteristic pH points for real-time monitoring of denitrification.
Main Methods:
- Laboratory batch experiments using five stirred tank SBR reactors.
- Operation in denitrification mode with varying initial nitrate and nitrite proportions.
- Monitoring of pH profiles and alkalinity during denitrification.
Main Results:
- Partial denitrification achieved higher final pH than complete denitrification at similar initial NOx- concentrations.
- A higher proportion of nitrite in the initial NOx- concentration resulted in a higher pH peak.
- Partial denitrification produced more carbonate alkalinity compared to complete denitrification.
Conclusions:
- pH profiles provide valuable indicators for monitoring nitrate and nitrite removal.
- Characteristic pH points can be identified for rapid, real-time assessment of biological denitrification status.
- Optimizing nitrite proportion can enhance pH monitoring and process control in wastewater treatment.
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