Residential / Commercial Water

Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form is important to industry.
The primary use of metallic arsenic is in alloys of lead (for example, in car batteries and ammunition). Arsenic is a common n-type dopant in semiconductor electronic devices, and the optoelectronic compound gallium arsenide is the second most commonly used semiconductor after doped silicon. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, and insecticides. These applications are declining, however
A few species of bacteria are able to use arsenic compounds as respiratory metabolites. Trace quantities of arsenic are an essential dietary element in rats, hamsters, goats, chickens, and presumably many other species, including humans.
Arsenic is notoriously poisonous to multicellular life. Arsenic trioxide compounds are widely used as pesticides, herbicides and insecticides. As a result, arsenic contamination of groundwater supplies is a problem that affects millions of people around the world.

Arsenate is a divalent anion with affinity for anion resins similar to but slightly lower than that of sulfate Arsenate can be exchanged by strong base anion exchange resins and then adsorbed into the iron hybrid adsorbent of ASM-10-HP.

Except for Gallium arsenide (used as a semiconductor), other arsenide compounds are generally only of academic interest. Gallium arsenide is an important semiconductor because it has much lower electrical resistance than silicon and therefore lower power use and less heat generation.

In most cases arsenite should be oxidized to arsenate so that it is converted to a form more easily removed. Oxidation can be accomplished with chlorine or with oxygen catalyzed by various redox medias.

Chlorine is a chemical element with symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity, behind only oxygen and fluorine.
The most common compound of chlorine, sodium chloride (common salt), has been known since ancient times. Around 1630, chlorine gas was first synthesised in a chemical reaction, but not recognised as a fundamentally important substance. Carl Wilhelm Scheele wrote a description of chlorine gas in 1774, supposing it to be an oxide of a new element. In 1809, chemists suggested that the gas might be a pure element, and this was confirmed by Sir Humphry Davy in 1810, who named it from Ancient Greek: χλωρός khlôros “pale green” based on its colour.

Chlorine is normally present in water as hypochlorous anion and is removed by strong base anion resins.

(Sodium) hypochlorite is widely used as a bleaching agent; in water treatment as a disinfectant. It is the strongest oxidant among the oxo-chloride series, chlorite, chlorate, or perchlorate.

Disinfection By-Product (DBP) are formed when chlorine reacts with organic compounds in water supplies. The removal of organic prior to chlorination can eliminate the DBP potential, otherwise the DBPs need to be removed by activated carbon.

Strong base anion resin have good affinity for nitrate. The higher amines (triethylamine, tributylamine, etc.) have increased affinity for nitrate and decreased affinity for divalent ions such as sulfate, making them preferred for many applications.

Naturally occurring organic matter (NOM) is readily removed by strong base anion resins. Acrylic strong base resins and styrenic resins with high porosity work better because they are easier to regenerate.

Scale occurs in some residential applications where water is heated, such as coffee and tea preparation, hot water heaters, and other washing operations. Comprised of calcium carbonate, the scale potential can be eliminated by softening the water.

Hardness ions, comprised of calcium and magnesium, can cause scaling of heated surfaces and shorten the life of appliances such as hot water heaters, dishwashers, and washing machines. The presence of1 hardness in water leads to greater soap consumption in laundry and cleaning operations.