Virus removal efficiency of ceramic water filters: effects of bentonite turbidity

Ceramic water filters (CWFs) are utilized in many developing countries as point-of-use (POU) water treatment devices, to reduce waterborne pathogens in potable water. Virus removal efficiencies of several CWFs are investigated under various influent conditions using MS2 (ATCC: 15597-B1) as a surrogate phage for human enteric viruses. The addition of bentonite turbidity (6-8 NTU) in the influent source water showed increased viral removal efficiency of CWFs by 0.1-0.2 log compared to tests involving clear (<1 NTU) influents. Trials employing an applied clay cake layer, formed using highly turbid influent source water (100 NTU) and no cleaning regime between trials, resulted in viral removal efficiency values of 1.5-2.5 log, compared to 0.2-0.5 log during non-obstructed trials.