Reverse osmosis (RO) systems are advanced water filtration systems that use a semi-permeable membrane to remove contaminants from water. By applying pressure, water is forced through the membrane, allowing only molecules small enough to pass through its microscopic pores—such as water molecules—while filtering out larger impurities. These impurities may include dissolved salts, heavy metals, pesticides, nitrates, fluoride, and some bacteria and viruses.
Reverse osmosis systems are widely used in residential, industrial, and commercial applications to produce clean, potable water. The system typically consists of multiple stages, including pre-filters to remove sediment and chlorine (which can damage the RO membrane), the RO membrane itself, and post-filters to improve taste and odor.
While reverse osmosis systems are highly effective at producing purified water, they have limitations. They do not remove volatile organic compounds (VOCs) or gases like carbon dioxide unless paired with additional filtration methods. Additionally, RO systems produce wastewater during the filtration process and may remove beneficial minerals, leading to “demineralized” water.
For health journalists, understanding reverse osmosis systems is critical when covering stories about water quality, public health risks, or environmental sustainability. Knowing their capabilities and trade-offs can help contextualize their role in addressing clean water challenges.