Manufacture of arsenic filters in domestic water

Using modified clay, laterite, limestone (limonite), Chemistry Department experts, Hanoi University of Natural Sciences, successfully fabricated equipment to treat arsenic in drinking water, very safe Full, convenient for households.

Basically, the filter is structured like normal filters but the filter column has oxidation and adsorption features to retain arsenic. Filter can be made of stainless steel or plastic with two compartments. The first compartment contains an adsorbent made of clay particles, laterite and sonstone that has been thermally modified and denatured. When water flows through this column, arsenic and manganese in the water will be retained, and clean water will flow into the second compartment for use.

According to calculations, equipment for treating arsenic of household size with a capacity of 20 liters has a cost of about 450,000 VND. Similar equipment but plastic cost about VND 300,000. When mass production, the price may be cheaper. Households of 5 people use drinking water, on average, one year must replace the adsorption column once at a cost of about 20,000 VND.

Arsenic is a poisonous substance (also known as arsenic), if using water with long-term arsenic contamination, there is a risk of poisoning.Recent studies show that in our country, the amount of arsenic in water exceeds 50 times the World Health Organization (WHO) standard.

Arsenic is completely recovered and can be used for other purposes or safely buried.

This arsenic filter was certified by UNICEF and the Vietnam Institute of Science and Technology for treatment after 3 ppm, below the World Health Organization's standard of 10 ppb.

Talking about the " origin " of this arsenic filter, Dr. Tran Hong Con, research leader, said that in 1996, during a heavy metal analysis in groundwater, he discovered Arsenic in many groundwater circuits in Hanoi. Since 2000, he and his colleagues began to study to find substances capable of adsorption of arsenic. And he decided to choose laterite after accidentally analyzing water in Tram Gian and Thay pagodas, seeing that the water flowing through laterite is very clean, the arsenic level is lower than the prescribed level despite the adjacent water area and right below. arsenic infection However, laterite has a clay inside, which will make the water cloudy. Therefore, new sintering and activating treatment is required to treat edible water.

Picture 1 of Manufacture of arsenic filters in domestic water Picture 2 of Manufacture of arsenic filters in domestic water Arsenic filter in domestic water. ( Photos provided by the author) Adsorbent - laterite after denaturation. ( Photos provided by the author)

After the research and testing, the filter kit containing arsenic adsorption equipment was tested in 2005. But for a long time, this scientific invention remained " still " in a good laboratory. Several times have been introduced at some scientific fairs in the country and abroad but still not to the people because the product has not been known to consumers and the demand is not high.

"Our biggest desire is to be able to transfer technology or link with a business to produce mass products, to meet the needs of many people ," said Dr. Con.

Yen Minh

Update 16 December 2018