## 4 Mitigation Methods for Disinfecting AMR Pathogens and Genes in Wastewater Treatment  
In general, wastewater treatment (WWT) involves the separation of heavier suspended solids and biological organic matter by simple gravity sedimentation/floating in a tank [81], followed by the removal of remaining organic matter (suspended, colloidal and dissolved solids) with the aid of diverse microorganisms, with varying degree of aeration [82] and further removal of traces of finer suspended solids and excess nitrogen and phosphorus that adequately promote unwanted plant growth [81; 83]. Additionally, the disinfection of viruses, bacteria and other harmful microorganisms using chlorination, UV treatment, ozone treatment and membrane filtration in the treated wastewater would be the final stage [84].  
Although these conventional treatment methods are widely applied for the removal of AMR pathogens in wastewater, the production of toxic by-products (a cause of secondary pollution in wastewater), lower treatment efficiency and high energy consumption are the major setbacks [85]. For instance, UV radiation-based inactivation, albeit being effective, is constrained by the lower penetration of the depth possible because of the regrowth of ARGs due to an incomplete inactivation. This method achieved moderate ARG reduction ranging from 1 to 3 log reductions [86; 87; 88]. Chlorination-based disinfection can be used to achieve ARG log reduction, i.e., 2-4 log units, but this method has threat of producing harmful by-products such as halaocic acids and trihalomethanes [89; 90]. Conversely, ozonation offers enhanced efficiencies ranging from 2 to 6 log reduction in ARGs, but these methods are limited due to their high operational cost and the formation of toxic by-products such as bromate [90; 91; 92; 93]. Membrane bioreactors involve the combination of biological filtration and physical filtration and achieve a 2-6 logs removal of ARGs. But these methods are hindered by membrane fouling and are dependent on operational conditions [94; 95; 16].  
Therefore, advanced oxidation processes such as photocatalysis, Fenton processes, and electro-oxidation processes that disinfect the pathogenic microorganisms or their genes at molecular level have been suggested for the effective removal of microorganisms or their AMR genes from WWT [96; 97; 98; 99; 100; 101]. Photocatalysis offers a variable range of ARG reduction from a 0.2 to 6 log reduction. When combined with other methods such as UV and ozonation, it achieves a superior ARG removal compared to UV or ozonation alone [99; 100; 102; 109]. On the other hand, Fenton processes are capable of achieving approximately up to a 6 log reduction or the inactivation of ARGs without the formation of harmful by-products [87; 105; 111; 112; 110]. The electro-oxidation methods are unique in their ability to consistently achieve significant reduction efficiency up to a 5 log reduction with a reduced dependence on chemical additives [113; 103; 114]. These modern techniques not only enhance the overall efficacy of ARG removal but also mitigate the environmental risks associated with traditional methods. By reducing harmful by-products and offering greater flexibility in treatment conditions, advanced processes like photocatalysis, the Fenton process and electrochemical oxidation represent a significant advancement in wastewater treatment technologies [115]. Table 3 consolidates the methods demonstrated for ARG reduction in wastewater.