Biological nutrient removal by applying modified four step-feed technology to treat weak wastewater

- A modified four step-feed process for treating weak municipal wastewater is proposed.
- Nutrient removal mechanism in the process to be completed by material balance method.
- The inflow distribution ratio had no impact on COD and NH4+-N removal but TN and TP.
- We got the optimal effluent by adjusting inflow distribution ratio of 20:35:35:10%.
- 74% of COD was efficiently utilized for denitrification and phosphorus release.