Most often in the form of a gray solid, arsenic is a member of the pnictogen family as it has properties that vary between those of metals and metalloids. Although once popular as a poison, arsenic is now widely used in the production of semiconductors, insecticide production, metal alloys and wood preservation.
Risks associated with arsenic in water
Arsenic in water has been shown to cause skin, lung, bladder and kidney cancers when exposed to it for a long time. In addition, skin problems can also result. In short, concentrations of 0.05mg/litre are considered dangerous and drastically increase the risk of cancer.
Sources of arsenic
Most often arsenic in water comes from the erosion of rocks and minerals with traces of arsenic in their composition. When water flows over these rocks and minerals, the arsenic in them erodes and remains in the water. This is why, in general, more arsenic is found in groundwater than in surface water.
In addition to erosion, arsenic can also come from industrial activities. These include improperly treated wastewater discharges, the use of certain pesticides, and atmospheric deposition.
How to remove arsenic from water
As stated above, arsenic in water is a serious problem and should not be taken lightly. In short, there are several ways to remove arsenic. These include ion exchange, nanofiltration, reverse osmosis, certain physical-chemical processes and special absorbent media.
The treatment technology should be selected according to the user's needs. In general, all of these technologies have the ability to remove arsenic from water. However, if the feed water to a RO system is too high in suspended solids, the effluent quality will be affected and the arsenic may not be removed. In other words, these technologies must be properly evaluated for your situation before you can confirm that arsenic will be removed.