Table 2.

Challenges and applications of treatment technologies to superbugs and SARS-CoV-2.

Treatment technologies	Challenges	Application of treatment technologies to superbugs or the novel coronavirus (SARS-CoV-2)
Sodium hypochlorite disinfection	• Disinfection byproduct formation with a high dosage of sodium hypochlorite • Incomplete removal of the novel coronavirus (SARS-CoV-2) with WHO disinfection strategy [26]	Novel coronavirus (SARS-CoV-2) [26]
Multifunctional fluorescence-magnetic biochar	• Large-scale development of multifunctional biochar for long-term performance [34]	Methicillin-resistant Staphylococcus aureus (MRSA) superbugs [34]
UV irradiation	• Large-scale application • Limitation of cost-effectiveness	Novel coronavirus (SARS-CoV-2) [29]
ZnO-nanobeads (encapsulation of ZnO nanoparticles in an alginate biopolymer)	• Large-scale development • Long-term performance • Potential inhibition from other contaminants in water	Antibiotic-resistant bacteria (i.e. E. coli DH-5α and pseudomonas aeruginosa) [35]
Graphene- and carbon-nanotube-based nanohybrids	• Potential release of metal ions • Lack of field applications	Antibiotic-resistant bacteria (i.e. E. coli DH-5α) [36]
Factors for development of treatment technologies • No toxic byproducts • Cost-effectiveness • Large-scale treatment and long-term performance • Effluent quality • Energy balance • Final sludge production