| Wastewater treatment plants were usually regarded as the repository of antibiotic resistance bacteria（ARB）and antibiotic resistance genes（ARGs）.Research based on actual strains of wastewater treatment plants has more practical significance.In this study,four kinds of ARB Enterococcus,Brevibacillus,Pseudomonas,and Escherichia coli were isolated from the secondary effluent of a wastewater treatment plant in Shandong Province,and four kinds of ARGs of tet A,bla TEM,sul I and str B were selected through drug susceptibility experiments and PCR.In addition,the colony counting method and fluorescent quantitative PCR were used to evaluate the reduction performance of traditional disinfection technology and emerging photocatalytic technology on ARB and ARGs.Meanwhile,the durability of disinfection effect and the reduction mechanism of ARB and ARGs during the disinfection process were explored through photoreactivation experiments and correlation analysis.The results can provide theoretical support and technical guidance for the control of ARB and ARGs in sewage.（1）The results of ARB inactivation showd that:UV disinfection could reduce3.76～5.13 lg of ARB for 60s,O3 disinfection could reduce 5.04～5.99 lg of ARB for25min,and UV/O3 disinfection could reduce 4.48～5.73 lg of ARB for 60s;In photocatalytic disinfection,when the reaction time was 4h,M-g-C3N4,Ti O2/M-g-C3N4and Ag/Ti O2/M-g-C3N4 reduced 4.18～4.75 lg,4.58～4.95 lg,and 7.11～7.66 lg of ARB respectively.Both traditional disinfection and new photocatalytic disinfection had good inactivation effects on ARB,but traditional disinfection was more efficient.（2）The results of ARGs reduction showd that:when the reaction time was 30 min,UV disinfection,O3 disinfection and UV/O3 disinfection had a reduction of 4.57,0.79and 4.67 lg for tet A respectively,and had a reduction of 2.48,0.48 and 2.69 lg for str B respectively.In photocatalytic disinfection,when the reaction time was 4 h,M-g-C3N4,Ti O2/M-g-C3N4 and Ag/Ti O2/M-g-C3N4 had a reduction of 0.87,0.94 and 1.58 lg for tet A,and had a reduction of 0.90,0.99 and 1.39 lg for str B.Although the ability of photocatalytic disinfection for reducing ARGs was limited,the ability to utilize visible light may made it more promising in the control of ARGs.（3）The results of photoreactivation study of ARB showed that:in traditional disinfection process,after 72 h of UV disinfection,the photoreactivation rate of strains reached 6.93%～11.58%,and the photoreactivation effect was significant.However,due to the O3 molecules could cause irreversible damage to the surface structure of bacteria,photoreactivation did not occur after O3 and UV/O3 disinfection,but the remaining strains in the water sample after disinfection could survive for a long time without nutrient source.After photocatalytic disinfection,the residual strains in the water samples gradually reduced and disappeared,which was related to the presence of a small amount of photocatalytic materials on the surface of the resistant bacteria.When exposed to light again,the photocatalytic material continue to work to kill the bacteria.Compared with traditional disinfection techniques,new photocatalytic disinfection techniques was more durable in inactivation of ARB. |
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