Interested in Filtration?
Get Filtration articles, news and videos right in your inbox! Sign up now.
Filtration + Get AlertsIn this Q&A, AdEdge Water Technologies discusses arsenic treatment options. Find out how a customized treatment solution can solve contaminant problems in your water system.
Q: What is the acceptable arsenic limit? Do any states have a lower limit?
A: The U.S. Environmental Protection Agency has set the standard of 10 mg/L or 10 ppb for arsenic in drinking water. Some states, such as New Jersey, have adopted the more stringent standard of .005 mg/L or 5 ppb. The World Health Organization has set a standard limit at .010 mg/L.
Q: How is arsenic typically treated?
A: There are many ways to treat arsenic including adsorption, oxidation/filtration, coagulation/filtration, ion exchange and membranes. It is important to know water quality and hydraulics before designing an arsenic removal system to ensure the best treatment technology is chosen.
Q: How can you treat arsenic with oxidation/filtration?
A: Oxidation/filtration is a precipitative process that removes naturally occurring arsenic — if it coexists with high levels of iron — iron, manganese and hydrogen sulfides from water. The process oxidizes the insoluble forms of these contaminants into their soluble forms and then removes them via filtration. Oxidation/filtration media has a high catalytic and oxidation capacity, superior handling properties, NSF 61-certification, does not require permanganate or coagulant addition, and has low operating and capital costs.
Q: How can you treat arsenic with coagulation/filtration?
A: Coagulation/filtration is a process that introduces a coagulant, typically an iron or aluminum salt, to pretreat water contaminated with arsenic, iron, manganese and/or sulfides. The process allows for significantly higher flow rates per square foot of media, creates less backwash water than other conventional treatment approaches, and has a smaller footprint that allows for lower operating and capital costs. This process involves a chemical addition, automated processes, which decreases operator involvement and expense, and does not generate hazardous waste.
AdEdge’s integrated system approach can create a custom treatment solution for arsenic removal. By using our AdEdge Packaged Unit (APU), modular and/or membrane systems, we integrate pre- and post-treatment processes to provide a turnkey approach. For more, visit www.adedgetech.com