Article courtesy of Bharath Joshi | August 18, 2014 | The New Indian Express | Shared as educational material
BANGALORE: Millions of children can be saved from the ill-effects of fluoride and arsenic contamination in water with the use of a nanoparticle technology patented by a Bangalore University professor.
G T Chandrappa (58) from the Department of Chemistry has bagged an Indian patent for his method of using magnesium oxide (MgO) and zinc oxide (ZnO) nanoparticles to remove fluoride and arsenic content from water.
“We use a simple combustion process in which a chemical acts as a burning agent to produce powdered nanoparticles of MgO and ZnO. I found that these particles adsorb the fluoride and arsenic content and settle at the bottom. The result was that we could remove over 90 per cent of the contamination,” Prof Chandrappa told Express.
After initial tests at his Central College laboratory, Prof Chandrappa collected water samples from Kolar, Pavagada and parts of north Karnataka, where the fluoride content is as high as 300 parts per million (ppm) against the acceptable limit of 10-15 ppm. “To our surprise, we achieved similar results.”
Since arsenic is not found in and around Bangalore, Prof Chandrappa prepared to test water containing 1,500 parts per billion (ppb) of arsenic III and arsenic V species.
“Arsenate is more dangerous. Even 1.5 ppb is enough to cause damage. The results in our tests were again positively similar.”
The presence of fluoride is rampant in underground water in south India, whereas arsenic content is dangerously high in the north-east. Consumption of fluoride water leads to dental fluorosis (tooth discolouration and decay) and skeletal damage. Arsenicosis leads to skin pigmentation changes, skin thickening and cancer of the skin, lungs, bladder and kidney.
The World Health Organisation, which has declared that “endemic fluorosis remains a challenging health problem in India”, estimates that the country could have 20 million sufferers of dental fluorosis.
Prof Chandrappa’s tests show that 0.15 mg of commercial MgO in 100 ml of water containing 10 ppm of fluoride could remove only 15 per cent of fluoride.