Improvement of biochemical systems directly affects nitrogen and phosphorus removal

Improving the nitrogen and phosphorus removal effect of the biochemical system is one of the key objectives in wastewater treatment. The following are some common optimization means:
1. Oxygen environment control
Realize the reasonable distribution of aerobic zone, anoxic zone and anaerobic zone to ensure the microenvironment required in the biological nitrogen and phosphorus removal process. Adjust the amount of aeration to control the dissolved oxygen (DO) level in the aerobic zone to promote the nitrification reaction. Ensure sufficient residence time in the anoxic zone to facilitate the denitrification reaction.
2. Sludge age (SRT) control
Appropriate prolongation of sludge age facilitates the growth of nitrifying bacteria and the nitrification process. For phosphorus removal, it is necessary to balance the sludge age to maintain sufficient phosphorus-polymerizing microorganisms.
3. Nutrient balance
Ensure sufficient and balanced carbon, nitrogen and phosphorus sources to meet the needs of microbial nitrogen and phosphorus removal. Adjust the dosage of external carbon sources, such as methanol and acetic acid, according to the quality of influent water to promote the denitrification process.
4. Return and discharge strategy
Optimize the internal recirculation and sludge return flow to improve the removal efficiency of nitrate and phosphate. Control sludge discharge to maintain microbial balance in the system.
5. Inlet Pretreatment
Remove suspended solids and some nutrients from influent water by physical or chemical methods (e.g., sedimentation, flotation) to reduce the burden on the biochemical system.
6. Microorganism inoculation and selection
Inoculate microbial strains for efficient nitrogen and phosphorus removal to improve the treatment capacity of the system. Promote the growth of specific functional microorganisms through biological selection or biological regulation.
7. Sludge concentration control
Maintain proper sludge concentration (MLSS) to improve the treatment efficiency of the system.
8. Monitoring and analysis
Regularly monitor indicators such as nitrogen and phosphorus, as well as important parameters such as pH, DO, temperature, etc., to adjust the operation strategy in time. Mirror inspection of sludge to observe changes in the microbial phase to assess system operation.
9. Optimize the process flow
Consider adopting advanced treatment processes such as sequencing batch reactor (SBR), oxidation ditch, membrane bioreactor (MBR), etc. to improve the effect of nitrogen and phosphorus removal.
10. Cope with fluctuation of feed water load
For the fluctuation of feed water load, take corresponding measures, such as dilution of high load feed water, to protect microorganisms from impact. Through the comprehensive application of the above optimization means, the nitrogen and phosphorus removal effect of the biochemical system can be significantly improved to achieve more efficient wastewater treatment.