Systematic Review of the Microbiological Performance of Household Water Treatment Technologies

Abstract

Household water treatment (HWT) is a prevalent method for improving the safety of drinking-water. We conducted a systematic review of peer-reviewed literature from 1997 to 2021 on microbiological performance of common HWT technologies including porous ceramic filters, carbon block or membrane filtration, granular media filtration, thermal treatment, solar disinfection, UV irradiation, chemical disinfection, and combined coagulation-disinfectant products. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) best practices and searched SCOPUS, Web of Science, PubMed, and Agricola and further consulted an expert working group to add relevant publications reporting microbial performance of HWT (n = 396 peer-reviewed studies). Reported log10 reduction values (LRVs) varied widely across and within technology categories. We summarize microbial performance by technology type; pathogen class (bacteria, virus, protozoa); and study setting (field or laboratory). Combined coagulation-disinfectant products had the highest LRV performance for bacterial (6.3) and viral (5.3) classes, and porous ceramic had the highest LRV for protozoa (3) when n > 3. Findings can inform the selection of candidate HWT options, but factors such as product design, time burden of use, cost, and long-term maintenance requirements are important considerations in technological performance. Microbiological performance is meaningless if the technology is not used consistently, correctly, and sustainably.