Solution：Applied MicroMotion®-N and MicroMotion®-Den to address the collapse of the nitrification and denitrification systems caused by high concentrations of 2,3-dichloropyridine nitrogen and other toxic influent components.
Processing Scale：1500m³/d
Treatment Effect：Effluent from the biological treatment tank achieved total nitrogen < 70 mg/L and ammonia nitrogen < 50 mg/L.
Characteristics
2,3-Dichloropyridine, Oxadiazon API, D-threo-p-methylsulfonylphenylserine ethyl ester, 2,5-Diamino-4,6-dihydroxypyrimidine hydrochloride, and (1R,4S)-1-Amino-4-hydroxymethyl-2-cyclopentene hydrochloride, among other pharmaceutical intermediates and active pharmaceutical ingredients (APIs).
① High salinity
② High organic nitrogen content
③ High total nitrogen
④ High ammonia nitrogen
⑤ Complex influent composition
⑥ Shock loads
Plant Profile
Description
名称 | 单位 | 进水 | 出水 | 处理目标 |
氨氮 | mg/L | 425 | 426 | 50 |
总氮 | mg/L | 513 | 441 | 70 |
COD | mg/L | 547 | 438 | 500 |
Based on the data above, ammonia nitrogen removal was minimal. Since nitrate and nitrite levels in the influent were nearly undetectable, it is estimated that organic nitrogen accounts for approximately 14% of the total nitrogen, indicating that the system had a weak initial ammonification capacity.
Option
1. Data analysis and bench-scale testing indicated that high concentrations of toxic substances (such as 2,3-dichloropyridine and free ammonia) were inhibiting nitrifying bacterial activity.
2. Low-concentration influent was pumped into the system, and the return flow rate was increased to accelerate the dilution of toxic compounds in the mixing tank. Non-compliant wastewater was temporarily diverted to the emergency tank for further treatment.
3. Ensured sufficient system alkalinity (alkalinity > 7.14 times the ammonia nitrogen concentration), maintained dissolved oxygen in the aerobic zone above 2 mg/L, and kept pH between 8.0 and 8.5.
4. Dosed 800 kg of MicroMotion®-N.
Result
Following the corresponding adjustments, the ammonia nitrogen removal rate reached 99%, with effluent ammonia nitrogen consistently maintained below 10 mg/L, well below the discharge limit of 50 mg/L, meeting the requirements.
The total nitrogen removal rate ranged from 90% to 93%, with effluent total nitrogen stably maintained below 40 mg/L, which is also lower than the discharge limit of 70 mg/L. The system successfully resumed stable and compliant operation.
Periodic Service
