Filtration of arsenic-contaminated water

With the orientation of searching for materials from natural minerals to treat arsenic (arsenic) to pollute the water, Prof. Dr. Tran Hong Con and colleagues at the Department of Chemistry at the University of Natural Sciences (Hanoi National University) ) find raw materials of clay, laterite and limestone (limonite) that have been modified to successfully manufacture equipment for treating arsenic in drinking water.

Dr. Tran Hong Con with water filtration device for small arsenic contamination - (Photo: T.Hà)

The filter is structured as a normal filter but the filter column has oxidation and absorption features to retain arsenic. This filter has a very simple structure, including a bin with two stainless steel compartments. The first compartment (inlet) contains a filter column of size 75m3 or 300m3 of water. When water flows through the filter column, arsenic in the water is oxidized, clay particles, laterite and denatured rocks which retain arsenic and manganese. Clean water flows into the second tank, which can be used.

With the device mentioned above, arsenic is completely recovered and can be used for other purposes or safely buried. This device has also been tested to filter water from drilled wells in the collective area of ​​51 Cam Hoi, Dong Mar ward, Hai Ba Trung district, Hanoi for ten consecutive days. The results showed that before filtering arsenic concentrations in the water in the area ranged from 0.186-0.198mg / l in the dry season, after treatment was less than 0.01mg / l, below the permitted limit of the Organization. World Health (WHO) and VN standards for arsenic.

According to calculations, equipment for treating arsenic of household scale with a capacity of 20 liters, serving the demand of drinking water, the price is not high, from VND 300,000-400,000 / bottle. On average, one column must be replaced once a year at a cost of about VND 20,000.

You can contact Dr. Tran Hong Con, Department of Chemistry, Hanoi University of Natural Sciences, 19 Le Thanh Tong, Hanoi, Tel: 04.8245527 - 0989092396.

THANH HA