In January 2006, the U.S. Environmental Protection Agency started enforcing the new arsenic limit of 10 parts per billion (ppb) in drinking water. The previous limit was 50 ppb. Since that date, there has been a flurry of activity in bringing selective arsenic media to the market.
Effective arsenic removal applications for water treatment
The U.S. Environmental Protection Agency (EPA) has long regulated radium in drinking water, but in December 2000 the EPA lowered the maximum allowable levels for radionuclides. As a result, water utilities across the country retested for radium. Those that found radium contamination exceeding new EPA standards faced a three-year deadline to comply—by either removing the radium to improve the quality of the existing water supply or finding alternative water sources.
Water treatment system successfully removes radium from drinking water
Are PFCs the next public water concern?
Like other manmade chemicals that have been polluting our drinking water over the years, perfluorochemicals (PFC) are not naturally occurring chemicals; they were developed in a lab- oratory to meet an industry need. PFCs are carbon chains (typically four or eight carbon atoms) that are bonded to fluorine atoms.
PFCs can be used as an ingredient in a manufacturing process or as part of a finished product. Companies have used them for a number of years for products that resist heat, oil, grease and water.
All raw water supplies contain dissolved ions that are positively or negatively charged. The positively charged ions (called cations) include calcium and magnesium, which constitute hardness. Other cations present in water are sodium, potassium and iron. The negatively charged ions in water (called anions) include sulfates, chlorides, bicarbonates and silica.
Ion exchange for removal of groundwater contaminants