Iranian researchers at Payamavaran Nanofanavari Fardanegar Company in Tehran have indigenized knowhow to develop a nanotechnology to remove arsenic from drinking water.
This system, in which granular adsorbents of iron oxide hydroxide are used, has been implemented in 10 cities by water and wastewater companies in East and West Azarbaijan, Ardabil and Qazvin provinces among others, ISNA reported.
Arsenic, a natural chemical element, is a heavy metal that is naturally present in high volumes in the groundwater in many countries. It is highly toxic in its inorganic form.
The presence of arsenic in concentrations higher than 10 micrograms per liter can be harmful for health. Long-term exposure to arsenic from drinking-water and food can cause cancer and skin lesions. It has also been associated with cardiovascular disease and diabetes.
Since groundwater is the main source of drinking water in many regions in Iran, arsenic contamination of the waters is a serious cause of concern in both urban and rural areas.
Given the unending water shortages it is crucial to preserve existing water resources and treat its pollutants, including arsenic.
There are several methods for purification of heavy metals from drinking water on an industrial scale, including reverse osmosis and using ion exchanging resins. Some methods such as reverse osmosis are costly despite their high efficiency. Others like using ion exchanging resins are inappropriate in many areas in Iran due to the presence of ions in other elements such as sulfate.
In sum, creating suitable facilities for the development of cost-effective systems in the water treatment industry has become a priority for water managers.
Nanotechnology removes heavy metals in drinking water at a cost of two or three times lower than the cost of the reverse osmosis.
Only a limited number of developed countries have the knowledge to create such a system, and now Payamavaran Nanofanavari Fardanegar has done it for the first time in Iran.
Arsenic species in groundwater occur in two oxidation states, known as As III and As V. PNF, with a natural phenomenon of cavitation, produces nanocavitation device for oxidation of heavy metals.
The use of nanocavitation technology oxidizes AS III into AS V. This material is highly adsorbed by alumina sorbents. The life of sorbents increases 2 or 3 times because no chemical oxidant is used in the product, and as a result, the operational cost decreases.
Established in 2007, PNF Company is focused on creating and developing advanced nanotechnology process.
Production of nano-emulsion and homogenization with nanocavitation technology was achieved by PNF for the first time in Iran. The technology has been used in various industries including water and wastewater treatment, food and non-thermal pasteurization, pharmaceutical and nano-drug production, dye and polymer, as well as oil and petrochemicals.
