Table 1. Available techniques and technique integration for removing antibacterial potency from antibiotic production wastewater.

Available technologies	Description	Advantage and disadvantage
Abbreviation: ARGs=antibiotic resistance genes; AMR=antimicrobial resistance; OTC=oxytetracycline; SOA=synchronized oxidation-adsorption; MVR=mechanical vapor recompression.
Pretreatment techniques (16–19,26,27,32)
Enhanced hydrolysis	Pretreatment method used for production wastewater of fermentative antibiotics (for example, tetracyclines and macrolides). It can selectively remove antibiotics from wastewater by eliminating their active antibacterial groups. The removal of antibiotics could reach 99%, and the reduction of AMR discharge is about 80%.	Selective hydrolysis of functional groups of antibiotics with low cost and decrease of inhibition on biological treatment and dissemination of ARGs in the environment.
Biological technique using yeast	Pretreatment method used for oil-containing antibiotic production wastewater. Oil residue removal rate was 61.4%–74.2% in full-scale operations, and oil is the substrate for the fermentation production of antibiotics. No ARG from bacteria produced since yeast play the role in the biological treatment.	Avoiding the emergence of ARGs in bacteria during biological treatment.
Coagulation, sedimentation and adsorption-based techniques	Traditional pretreatment methods used for wastewater with high content of suspended solid. Some kinds of antibiotics can be partially removed, while the removal is very limited.	Low removal of antibacterial potency.
Oxidation-based techniques	For example, ozone oxidation and Fenton oxidation. Doses of 1.2 mg O3 per mg of initial OTC permitted 92% OTC removal from OTC production wastewater (OTC, 702 mg/L).	High cost and low selectivity for antibacterial potency removal.
Advanced treatment (3,28)
Oxidation-based techniques	For example, SOA, ozone oxidation, Fenton oxidation, electrochemical oxidation.	End protection before discharge. High cost.
Membrane separation	For example, ultrafiltration, reverse osmosis.	Good removal of antibacterial potency and ARGs in effluent. High cost.
Technique integration (5,20-24,33)
Pretreatment +biological treatment	The effluent needs to be discharged to a municipal wastewater treatment plant.	With the pretreatment such as enhanced hydrolysis, the antibacterial potency could be removed.
Pretreatment + biological treatment + advanced treatment	It can meet the standards for direct emission.	With the pretreatment such as enhanced hydrolysis, the antibacterial potency could be removed.
MVR + harmlessness of solid waste and waste gas	Maximizing the recovery of water from wastewater using vapor.	No wastewater discharge. High cost. Disposal of solid waste is difficult.