Removal of Human Coronavirus OC43 (HCoV-OC43) in Simulated Drinking Water Treatment Processes

In this work, we evaluate the inactivation of human coronavirus (HCoV-OC43) during different stages of water treatment, including enhanced coagulation-flocculation, membrane ultrafiltration processes, and water disinfections (free-chlorine (free-Cl-2), ozone (O-3), low-pressure ultraviolet light (LP-UV), and monochloramine). While iron- and aluminum-based coagulation-flocculation processes can achieve similar to 0.5-2.0 log(10) virus removal (LVR), the use of a polymeric coagulant aid (polyDADMAC) can significantly enhance the process, increasing removal by up to 4.7-fold when compared to the use of FeCl3 alone. Ceramic membranes also provide an equivalent removal to that of polymeric cellulose ultrafiltration membranes (100 kDa) (0.9 to 2.0 vs 1.3 to 3.3 LVR, respectively), while maintaining much greater water flux (200 L m(-2) h(-1)). Primary disinfection processes (free-Cl-2, O-3, and LP-UV) achieve rapid viral inactivation; however, HCoV-OC43 has a different sensitivity to these processes from what has been previously reported for enveloped viruses' surrogates, such as the phi 6 bacteriophage. The use of coagulant aids and ceramic membranes might provide an alternative to the efficient removal of coronaviruses during water treatment.