Efficient inactivation of a broad spectrum of amoebae and endosymbionts by electrochemically generated peracetic acid

Waterborne emerging pathogens pose a significant threat to public health. Among these, amoebae have attracted considerable attention due to the health risks associated not only with the amoebae themselves but also with their endosymbionts. In this study, three distinct raw materials were employed to synthesize hydrothermal carbonation carbon (HTCC), including waste cartons, cellulose, and glucose. Subsequently, based on these HTCC materials, peracetic acid (PAA) was generated via in-situ catalysis under electrolytic conditions, and the inactivation efficacy against amoebae and their endosymbionts was evaluated. The results demonstrated that the combination of PAA with UV irradiation, catalyzed by cellulose-derived HTCC at 40 mA, achieved the highest inactivation of amoebae, with a reduction of 4.46-log. This method also approached nearly 100% efficiency in inactivating both free-living bacteria and amoeba endosymbionts. Microscopic observations indicated that the treatment did not cause severe damage to the cell membrane. Instead, inactivation was primarily attributed to the increase in intracellular pH. Importantly, the PAA/UV process exhibited broad-spectrum efficacy, achieving up to 4-log inactivation of amoebae and over 5-log reduction of their endosymbionts. This system exhibits favorable stability, yet its application in real water matrices still requires further optimization. In summary, our study presents a strategy with broad-spectrum efficacy for inactivating amoebae and their endosymbionts, which is characterized by low cost and high inactivation efficiency. With further optimization, this strategy could provide a highly promising technical solution for controlling the contamination of amoebae and their endosymbionts in water bodies. SYNOPSIS: A novel electrochemical peracetic acid strategy for broad-spectrum inactivation of amoebae and endosymbionts.