  Citation: Hill, C.L.; Harris, J.D.; Turner, S.S.; Wason, K.L.; Gaylord, A.P.; Hatley, M.G.; Hardcastle, L.T.; Roberts, I.T.; You, J.Y.; Renneker, K.O.; et al. Field and Laboratory Assessment of a New Electrolytic Point-of-Use Water Treatment Technology. Water 2022, 14, 1077. https://doi.org/10.3390/w14071077 Academic Editor: Christos S. Akratos Received: 1 February 2022 Accepted: 17 March 2022 Published: 29 March 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). water Article Field and Laboratory Assessment of a New Electrolytic Point-of-UseWater Treatment Technology Courtney L. Hill 1 , Jamie D. Harris 1 , Sydney S. Turner 1 , Kathryn L. Wason 1 , Amanda P. Gaylord 1 , Maya G. Hatley 1 , Lance T. Hardcastle 1 , Isaac T. Roberts 1 , Joshua Y. You 1 , Kathryn O. Renneker 1 , Joshua N. Edokpayi 2 and James A. Smith 1, * 1 Department of Engineering Systems and Environment, University of Virginia, Olsson Hall 111B, Charlottesville, VA 22904, USA; clh023@gmail.com (C.L.H.); jw3ek@virginia.edu (J.D.H.); sst2jb@virginia.edu (S.S.T.); klw8fg@virginia.edu (K.L.W.); apg4ge@virginia.edu (A.P.G.); mgh5dw@virginia.edu (M.G.H.); lth3dw@virginia.edu (L.T.H.); itr9fc@virginia.edu (I.T.R.); jyy3gx@virginia.edu (J.Y.Y.); kor3fm@virginia.edu (K.O.R.) 2 Department of Hydrology and Water Resources Mining and Environmental Geology, University of Venda, Thohoyandou 0950, South Africa; joshua.edokpayi@univen.ac.za * Correspondence: jas9e@virginia.edu Abstract: This research creates and implements a new electrolytic point-of-use water treatment (POUWT) device. Device development began by applying two voltages common to commercially available batteries to an apparatus with either two silver or copper wires submerged into synthetic groundwater. The effects of wire diameter, ionic strength of groundwater, and other POUWT parameters on metallic ion release were analyzed. We determined that the silver wire apparatus need only to be run for 2 min at 9 V to yield the target 50 μg/L concentration for water treatment. The 50 μg/L silver yielded up to a 5-log reduction in E. coli bacteria. The copper wire apparatus was excluded in prototype fabrication because it required 62 min to release the target 500 μg/L for disinfection when nine volts were applied to the system and was less effective in disinfection than silver wires. The electrolytic prototype was evaluated in 20 households in Limpopo, South Africa, over a four-week period. The device achieved a 2-log reduction in total coliform bacteria in household drinking water, which is comparable to the field performance of other POUWT devices in low-resource settings. The device also consistently released enough silver sufficient for disinfection while remaining below the WHO drinking water guideline. Keywords: point-of-use; water treatment; electrolysis; silver ions; copper ions 1. Introduction According to estimates by the World Health Organization, 2.2 billion people globally rely on drinking water sources that are not safely managed, and even those with improved sources sometimes travel substantial distances to reach the source [1]. Members of households without an improved water source suffer detrimental ef- fects from water-borne diseases such as cholera, typhoid, and schistosomiasis [2,3]. These diseases are especially dangerous to children, as they can cause severe diarrhea, killing 361,000 children under 5 every year [4]. Point-of-use water treatment (POUWT) technolo- gies provide an inexpensive, effective solution to reduce waterborne diseases by allowing for households to treat water in the home shortly before consumption, minimizing the risk of recontamination, which can happen during transport and storage [5]. It has long been known that ionic silver deactivates waterborne pathogenic bacte- ria [6,7]. Incorporating silver into POUWT technologies has been shown to disinfect bacterial pathogens in water just as well as chlorine, which is used widely in water pu- rification, providing up to a 4.2-log reduction in total coliform bacteria in drinking wa- ter [8,9]. Recently, silver has been shown to be capable of inactivating Adenovirus and Water 2022, 14, 1077. https://doi.org/10.3390/w14071077 https://www.mdpi.com/journal/water