BACKGROUNDTo address the objective of disinfecting water, copper nanoparticles (Cu-NPs) have been synthesized and impregnated on activated carbon (AC). This material when packed in a continuous column can potentially satisfy the need of a household-scale water disinfection unit. RESULTSAccordingly, Cu-NPs of 6.11 nm mean diameter were deposited in the form of discrete NPs, on plasma treated AC, with a Cu loading of 2.1 wt%, in Cu-AC. Selective impregnation of Cu-NPs was achieved on the external surface of plasma treated AC, as plasma treatment generates surface function groups on the AC surface. The superior qualities of the hybrid achieved complete killing of 10(4) CFU mL(-1) of E. coli cells in only 10 min contact, on using 8 mg mL(-1) of Cu-AC in batch mode. A flow-column (8 cm diameter and 25 cm height) designed on the basis of this batch contact time achieved disinfected water at a high flow rate of 4.13 L h(-1), even when operated non-stop, over 7 days. Simultaneously, it maintained a very low steady state Cu concentration (83.7 g L-1) in the disinfected water, much below the permissible limit of 1000 g L-1 for drinking water. CONCLUSIONThis study achieved: (i) selective impregnation of Cu-NPs on AC with controlled degree of oxidation; (ii) maximum flow rate of E. coli-free drinking water in a continuously operating column, packed with Cu-AC granules; and (iii) complete E. coli cell-killing and Cu concentration within the permissible limit for drinking water over a very long duration. (c) 2017 Society of Chemical Industry