If testing indicates that you have unsafe levels of arsenic in your water supply (considered by the U.S. EPA to be 10 parts per billion [ppb]), remember that arsenic is a contaminant with numerous negative health effects on people and should not be taken lightly. There are several treatment methods available to remove arsenic from drinking water and decrease its levels below the limit. Here is a refresher:
Oxidation technologies, using natural air or a chemical compound to expose oxygen to a substance, convert arsenic into another chemical form so that it can be filtered out of the water. This filters out the toxins, including dangerous levels of arsenic, through natural methods of chemical conversion. Water treatment utilizing oxidation is readily available and effective; however, it can potentially be very slow. Luckily, the addition of another non-toxic substance can speed up oxidation, and you can have quicker access to clean, arsenic-free water.
Coagulation and Filtration
Coagulation and filtration involve the use of metal salts, lime and/or iron, and have been effective methods of treatment for decades. This involves dissolving additional compounds into the water, allowing arsenic and other toxic substances that may be present to attach their ions—electricity on an atomic level—to the additives. When this happens, arsenic that would otherwise not be filtered through an ordinary filtration process will have coagulated enough to be caught in the filters. Iron is especially effective in allowing arsenic to coagulate, so many filtration systems rely on the use of iron.
Granular Ferric Oxide
Water treatment systems that use granular ferric oxide (GFO) are considered more advanced and effective technologies for treating and/or removing arsenic from drinking water. GFO reactors are toxin absorbers that function much like any other filter. When used, water directed downward through filters with GFO will be treated and cleansed of dangerous contaminants including arsenic. A simple and safe method, GFO systems are proven to be effective for eliminating arsenic from contaminated water.
There are additional methods for filtering arsenic out of water, including ion exchange, the use of synthetic membranes, sludge treatments and biological processes that rely on bacteria as a filtration assistance. While some of these methods may be only able to catch a certain percentage of arsenic in water, a customizable treatment system utilizing the right technologies from any of the above can work for your situation.