Gujarat varsity develops new tech to remove arsenic from drinking water

Dipping a calixarene pouch in your glass of water can make it arsenic free

Gandhinagar-based Gujarat Forensic Sciences University scientists have come up a novel solution to help those affected by arsenic poisining in India.

The product, which comes in a tea-like pouch, contains a special molecular compound, calixarene, to remove arsenic from drinking water. 

Y K Agarwal, director of the Institute of Research and Development (IRD) at the Gujarat Forensic Sciences University said that the idea to develop such a product came to him when he was attending a conference in Edinburgh, UK. 

"I developed a compound in the laboratory called calixarene," he said. "This compound costs about Rs 100 for 100 grams and can be easily made at any chemical laboratory."

Agarwal said he applied for a patent in 2009, which was eventually granted. 

The initial idea was to use calixarene for making an arsenic analyser machine that would be able to filter arsenic content which is even less than 10 parts per billion (ppb). Such a filter can be useful is factories that need to handle large volumes of water. IRD has developed an arsenic analyser filter as well that roughly costs about Rs 5 lakh and above depending on the size.

"Since calixarene is non-toxic, I then thought of the idea of using it in a tea-bag form to remove arsenic from drinking water," Agarwal said. 

One bag of the product containing calixarene can remove arsenic from about 500 ml of drinking water, or about a small jug of water.

IRD is already in talks with a handful of foreign companies for commercialising the technology. Agarwal said that the cost of a claixarene-pouch could be around Rs 2. 

"We are talking to companies that might be interested in commercialising the technology. We also want to involve the World Health Organisation (WHO) in this so that the technology reaches more people globally," he said. 

Existing technologies on arsenic removal primarily use a filtration process, and arsenic is left as a precipitate. 

Anil Gupta, faculty at the Indian Institute of Management-Ahmedabad (IIM-A) and the executive vice chairperson of the National Innovation Foundation said that it is good that this technology absorbs the arsenic without leaving a precipitate. 

"This basically makes it more user friendly compared to the available technologies. However, I think that efforts should be made to reduce the cost as much possible as arsenic poisoning basically affects people living in very poor districts of West Bengal, Bihar, UP etc," he added. 

According to a research report last year, around 31 districts of Uttar Pradesh were suffering from harmful concentration of arsenic in ground water, exceeding the Bureau of Indian Standards permissible limit (of 0.01 mg/litre). Districts like Ballia, Lakhimpur-Kheri,  Ghazipur, Gorakhpur, Bareilly, Unnao, Moradabad, Bijnor, Mirzapur, Meerut Rae Bareli featured in the list. Around six million people in West Bengal and Bihar are estimated to be exposed to water contaminated by arsenic. 

Exposure to arsenic can cause cancer of the lung, kidney, liver, skin and bladder. Those who are exposed to arsenic in-utero and early childhood may develop diseases such as acute myocardial infarction, childhood liver cancer and bronchiectasis, a chronic obstructive pulmonary disease.

Agarwal said, "Generally, even one or two parts per million (ppm) of arsenic in water is considered unfit for human consumption. This new technology can cleanse water which contains arsenic in the concentration of parts per billion (ppb), hence rendering it potable."