The continued threat of viral contamination in municipal water supplies requires the systematic evaluation of existing unit processes and develop new technologies to better attenuate pathogenic viruses in the water as an effort to protect public health. Four coagulation approaches (i.e., conventional alum and FeCl₃ coagulation and aluminum and iron electrocoagulation) were compared in terms of their ability to remove/inactivate a coronavirus surrogate (Phi6) and a non-enveloped virus surrogate (MS2) under identical experimental conditions. The ability of existing conventional treatment plants to well-attenuate enveloped viruses was demonstrated by facile reduction of Phi6 by alum and FeCl₃. However, MS2 was attenuated to a lower extent indicating relatively weaker protection against non-enveloped viruses by conventional treatment. Performance of aluminum electrocoagulation was akin to alum suggesting the equivalence of both coagulant dosing chemistries. In contrast, iron electrocoagulation outperformed the other three approaches and was the sole technique capable of simultaneously inactivating and removing both bacteriophages owing to its oxidative stress. Hence, this technology presents a harsh physicochemical environment capable of inactivating viruses via oxidative modifications, likely through electro-Fenton reactions. Only iron electrocoagulation of MS2 and Phi6 resulted in appearance of new presumptive carbonyl derivatives and intense peaks associated with the trans geometric isomer of lipid hydrocarbon chains respectively in FTIR spectra. However, all four coagulation approaches ruptured the Phi6 phospholipid envelope and damaged its nucleocapsid’s structural integrity. Finally, monitoring RNA loss using the reverse transcription quantitative polymerase chain reaction was likely to underestimate infective virus control potentially overstating viral risks.

$<b>Figure 1. </b>Infective virus fraction after conventional coagulation and electrocoagulation of MS2 (A and C) and Phi6 (B and D) with aluminum and iron.$

Figure 1. Infective virus fraction after conventional coagulation and electrocoagulation of MS2 (A and C) and Phi6 (B and D) with aluminum and iron.

Kyungho Kim

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