Pretreatment Essential to RO Membrane Success

The United States Environmental Protection Agency classifies chlorine as a disinfectant and allows a maximum contaminant level goal (MCLG) of four milligrams per liter (mg/L) in drinking water supplies. The agency does recognize that chlorine’s presence in water can cause digestive discomfort and eye or nose irritation in some consumers. For most residential and medicinal purposes, four mg/L or ppm is unacceptable. Furthermore, the chlorine in public drinking water supplies is damaging to the membranes in a reverse osmosis (RO) system.

Since the membranes are typically the most costly part of a water filtration system, it is best to remove as much chlorine as possible from the water before it even touches an RO membrane.

Carbon: Simple and Inexpensive

This is where carbon pretreatment earns its keep. Although technically not part of the reverse osmosis process, one or more carbon pretreatments to remove harmful chlorine is essential to the life of RO membranes. It is not an exaggeration to state that chlorine will damage an RO membrane.

Pretreatment: No Compromises

To save money and/or space, some users may be tempted to skip the carbon or the sediment removal pretreatment steps when considering a reverse osmosis system for home use. Both steps are not only critical to the process of producing clean water but are also imperative to preserving the life and investment made in the RO membranes.