Novel magnetic nanocomposite FeO@CS@PHMG as an effective and recyclable antimicrobial material for hospital wastewater disinfection.

Hospital wastewater (HWW) is a major pollutant that presents significant risks to both environmental and human health. In this study, we developed a novel, inexpensive and highly antibacterial magnetic nanocomposite composed of FeO nanoparticles synthesised from spent pickling liquors, coated with chitosan and then integrated with polyhexamethylene guanidine hydrochloride (FeO@CS@PHMG) using sodium tripolyphosphate (TPP) as a crosslinking agent. The obtained results revealed that the synthesised nanocomposite exhibited high antibacterial activity against and . At a relatively low nanocomposite dosage of 2 μg mL, it effectively eliminated all at a concentration of ∼10 CFU mL within one min. For , a higher dosage of 5 μg mL and a longer time of 5 min were required for complete elimination. In real HWW treatment tests, 99.4% of and 95.8% of total coliforms were eliminated at a nanocomposite dosage of 10 μg mL. At 30 μg mL, the nanocomposite completely removed all .