Water treatment systems with dual purpose ion exchange resin

A method comprising:

• providing a low pressure point-of-use water treatment system having a microbial inactivation capacity, the water treatment system comprising at least one inlet port in fluid communication with at least one outlet port to define a fluid pathway therethrough, an iodinated resin intermediate the at least one inlet port and the at least one outlet port, and an ion exchange resin intermediate the iodinated resin and the at least one outlet port;
• introducing water into the at least one inlet port;
• passing a first volume of water through the iodinated resin to transfer iodine from the iodinated resin into the fluid pathway, wherein the first volume of water corresponds to an effective life of the iodinated resin;
• passing a second volume of water through the ion exchange resin to remove at least a portion of the iodine transferred by the iodinated resin, wherein the second volume of water corresponds to a breakthrough point as measured by iodide leakage;
• and
• passing a third volume of water through the ion exchange resin to inactivate contaminants as the iodinated resin nears the end of its effective life, wherein the third volume of water corresponds to a microbial kill effective life of the ion exchange resin.