"There are four broad systems for treating drinking water to remove such contaminants in the home"
Recent news about PFAS "forever chemicals" in Australian drinking water supplies has been very confronting. Many people are asking how they can remove these contaminants from their home drinking water. In short, it is difficult and expensive to do this effectively in your home. The United States Environmental Protection Agency provides useful and clear advice about per- and polyfluoroalkyl substances (PFAS) and how they can be removed from drinking water. One of the major challenges in removing PFAS chemicals from drinking water is the enormous number (more than 10,000) of individual chemicals in this group. US authorities warn these can cause cancer over a long period of time. No single filtration or treatment technology is 100% effective at removing them. So, what are the options? And can you filter too much out of your drinking water? Four treatment systems US authorities have reviewed dozens of controlled studies on how to remove PFAS and other contaminants from drinking water. The costs involved in many of the treatment options that remove PFAS can be expensive. Many of the cheapest filters will not be effective. There are four broad systems for treating drinking water to remove such contaminants in the home. 1. Activated carbon The first two treatment systems use an adsorption process (rather than absorption) to attract and trap PFAS and other contaminants from water. Absorption is when one substance is absorbed into another, but adsorption is when particles stick onto the surface of another substance. Adsorption using "activated carbon" is a widely used industrial process for drinking water treatment to remove a range of substances. Adsorption binds PFAS or other contaminants through ionic bonds using either negatively charged or positively charged particles. It can be used to filter water as "granular activated carbon" or as "carbon block filters". These are two broad types of water filters that use activated carbon. 2. Ion exchange resins This…