New method to remove arsenic in water

With a loss of 1,000-2,000 VND / kg, people have an additional method to filter arsenic at home using manganese-containing pyrolusite ore.

October 23, TS. Bui Quang Cu - Ho Chi Minh City Institute of Chemical Technology, said that using pyrolusite ore to remove arsenic (arsenic - As) in water is a study to diversify methods of treatment. Arsenic in groundwater. Thereby, the research team wants to find cheap materials, easy to use at family scale and safe for users.

Dr. Bui Quang Cu is trying to use pyrolusite ore to remove arsenic in water.(Photo: V. Giang)

Pyrolusite ore used in the above study is ore of Cao Bang origin. The main component of ore is mangan dioxide (MnO ₂ ), accounting for 40-60%. In addition, there are many other metal compounds from iron, silicon, aluminum . Ore samples are used by grinding into fine powder and processing at 400 ^o C. The ore powder is then put into the beakers. glass contains arsenic solution in many different concentrations. The results showed that, when heated to 400 ^o C, pyrolysite ore has the highest ability to absorb arsenic in water.

The application of pyrolusite to remove arsenic in groundwater actually shows that after treatment, the arsenic content in water decreases from 170ppb to less than 10ppb (0.01mg / liter) according to Vietnam standards and meets the standards for drinking water. .

Every 1 gram of pyrolusite can filter up to 0.175mg of arsenic in a liter of water.

However, according to TS. Residential, this is just an initial study. Ore contains many different impurities, so scientists need to study more carefully to avoid contaminating the water after purifying arsenic. If it is clean ore, people only need to wash the ore with water, then crush it and put it directly into the water. Arsenic in the water will be purified.

In addition, the treatment of ore powder containing arsenic is still under study. Arsenic is an inorganic substance, so it does not transform into other substances. Careful handling will return arsenic back to the water source.

To treat arsenic removal in groundwater, people use various methods such as flocculation using metal salts, iron salts, aluminum salts .

Currently, the market also has a method to filter alum and arsenic in water is the manganese dioxide sand outside (manganese sand) for 11USD / kg. However, this type is mainly used for large-scale water treatment technology.

Incomplete statistics show that the country now has more than 1 million drilled wells, of which many wells have a higher concentration of arsenic from 20-50 times the permitted concentration (0.01mg / l).

In the Red River Delta, the most severely affected areas are south of Hanoi, Ha Nam, Ha Tay, Hung Yen, Nam Dinh, Ninh Binh, Thai Binh and Hai Duong.In the Mekong Delta, many wells with high arsenic concentrations were also found in Dong Thap and An Giang.In drinking water, arsenic is not visible, does not taste, so it cannot be detected.The discovery of arsenic-infected people is difficult because the symptoms of the disease must appear 5 to 15 years later.Arsenic poisoning is a chronic disease caused by the use of drinking water containing arsenic in high concentrations over a long period of time.Effects include changes in skin color, formation of skin stains, skin cancer, lung cancer, kidney and bladder cancer as well as possible necrosis.

(Source: Wikipedia, VietNamNet)

Sand incense