Simultaneous Coupling Ozonation And Biodegradation For Advanced Treatment Of Penicillin Intermediate Wastewater And Its Effect On The Elimination Of Antibiotic Resistance Genes

The composition of penicillin intermediate wastewater is complex and has biological toxicity,and it is easy to induce the enrichment and dissemination of antibiotic resistance genes(ARGs)in water environment.At present,the advanced wastewater treatment mainly adopts the indirect combination process of advanced oxidation and biodegradation.However,this combination process has issues such as high operating conditions,large amount of oxidants,large footprint,and potential accumulation of intermediate byproducts.To solve these problems,this study employed the Simultaneous Combination of Ozonation and Biodegradation(SCOB)technology for the pilot-scale deep treatment of penicillin intermediate wastewater.Firstly,small-scale experiments were conducted in the laboratory to determine the operating parameters of the SCOB technology for treating the wastewater,based on which the medium scale experiment was realized,and further completed the optimization of pilot test parameters.After optimization,the optimal operating parameters were determined: ozone dosage of 5 milligrams per liter of water,hydraulic retention time of 6 hours,and ozone supply time of 2 hours.Under the optimal conditions,the the pilot equipment operated stably for nearly 100 days.Compared to traditional biological treatment systems,the SCOB technology achieved a 30.1% increase in chemical oxygen demand removal rate and a 20.2% increase in color removal rate.Additionally,the SCOB technology also improved the removal rate of aromatic compounds in wastewater by 35.4%.Secondly,the result of the study revealed the superiority of SCOB technology from the microbial response and gene level.It was found that the SCOB technology reduced the intracellular reactive oxygen species(ROSs)level of microorganisms by60.3% and extracellular polymer secretion by 50.2% by reducing the toxicity of the water.Metagenomic analysis also revealed a significant enhancement of microbial functions related to energy metabolism,amino acid metabolism,DNA replication,and repair,indicating an overall improvement in microbial activity by the SCOB technology.Finally,the result of the study explored the impact mechanism of the SCOB technology on the enrichment and dissemination of ARGs,and revealed the superiority of SCOB technology in resistance gene control.The research showed that the SCOB technology resulted in a 10.3% decrease in the total abundance of ARGs.Furthermore,by reducing the intracellular ROS content of microorganisms and regulating mechanisms such as SOS response,efflux pumps,and type IV secretion system,the SCOB technology lowered the frequency of horizontal gene transfer(HGT)of intercellular resistance genes and reduced the plasmid abundance encoding multidrug resistance genes(m ARGs)by 25.4%.In addition,as a carrier of vertical transmission resistance genes(c ARGs),the analysis found that Proteobacteria phylum and Lewinella genus were the main hosts of vertical gene transfer(VGT)of resistance genes,and the SCOB technology reduced the abundance of human bacterial pathogens(HBPs)in the microbial community by 27.4%,thereby reducing the co-occurrence frequency of ARGs and HBPs.This study conducted long-term stable pilot experiments on actual industrial wastewater using the SCOB technology,verified the degradation mechanism and biological response mechanism,and reveal the advantages of this technology in ARGs reduction and propagation retardation.This provides practical validation and technical support for the future application and promotion of this technology.