1. Large fluctuations in influent flow
2. High concentrations of heavy metals
3. Complex influent composition
4. Vulnerable to shock loading
Solution：MicroMotion®-N was added, and technical adjustments were implemented to resolve nitrogen-related issues caused by heavy metal shock in the influent.
Processing Scale：20000m³/d
Treatment Effect：influent ammonia nitrogen 30-35mg/L, effluent ammonia nitrogen 2mg/L
Characteristics
1. Large fluctuations in influent flow
2. High concentrations of heavy metals
3. Complex influent composition
4. Vulnerable to shock loading
Plant Profile
Description
名称 | 单位 | 进水 | 出水 | 处理目标 |
一级AO氨氮 | mg/L | 30 | 28.6 | 10-12 |
二级AO氨氮 | mg/L | 28.6 | 8-10 | 2 |
An on-site investigation conducted by our technicians revealed that due to shock loading of the influent, nitrification in the first-stage AO tank was severely inhibited, resulting in almost no removal efficiency. As a result, ammonia nitrogen levels failed to meet discharge standards.
Option
1. Based on data analysis and bench-scale testing, the issue was identified as metal ions in the influent impacting the system.
2. Strengthened pre-treatment management to improve the removal efficiency of heavy metal ions from the influent.
3. Ensured sufficient system alkalinity (alkalinity ≥ 7.14 times the ammonia nitrogen concentration), maintained dissolved oxygen at 3–5 mg/L and pH at 8.0–8.5 in the aerobic zone.
4. Maintained dissolved oxygen below 0.5 mg/L and pH between 7.0–7.5 in the anaerobic zone; ensured the carbon-to-nitrogen-to-phosphorus (C: N:P) ratio met the 100:5:1 requirement.
5. Increased sludge discharge to reduce sludge concentration to below 5,000 mg/L; changed carbon source type to reduce sludge production pressure.
6. Dosed 400 kg of nitrifying bacteria to enhance system nitrification performance.
Result
After the corresponding adjustments, the ammonia nitrogen removal rate exceeded 96%, with effluent ammonia nitrogen was consistently maintained below 2 mg/L. The result met discharge standards and restored the system to normal operation.
Periodic Service
