Enhanced nitrogen removal from pharmaceutical wastewater using SBA-ANAMMOX process

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Engineering

Background:

• Pharmaceutical wastewater, containing colistin sulfate and kitasamycin, exhibits severe toxicity to microorganisms.
• Conventional anaerobic ammonium oxidation (ANAMMOX) processes often fail due to cumulative toxicity from these pollutants.

Purpose of the Study:

• To develop and evaluate a novel Sequential Biocatalyst Addition (SBA) ANAMMOX process for treating toxic pharmaceutical wastewater.
• To assess the efficiency and performance of the SBA-ANAMMOX process under challenging conditions.

Main Methods:

• Biotoxicity assay using Photobacterium phosphoreum (T3 mutation) to quantify wastewater toxicity.
• Implementation of a novel SBA-ANAMMOX process combining a high-rate ANAMMOX reactor with sequential addition of ANAMMOX granules.
• Long-term operational monitoring of nitrogen removal rates and effluent quality.

Main Results:

• The pharmaceutical wastewater demonstrated high toxicity, with relative luminosity at 3.46% ± 0.45%.
• The SBA-ANAMMOX process achieved a high nitrogen removal rate of 9.4 kg N m(-3) day(-1).
• Effluent ammonium concentration was consistently below 50 mg N L(-1), complying with Chinese pharmaceutical industry discharge standards (GB 21903-2008).

Conclusions:

• The SBA-ANAMMOX process is a promising technology for efficient biological nitrogen removal from refractory, ammonium-rich, and toxic pharmaceutical wastewater.
• Sequential biocatalyst addition effectively mitigates toxicity issues, ensuring stable and high-performance wastewater treatment.