IIT Mandi’s New Innovation: Self-Cleaning Glass That Can Purify Water Using Sunlight

Researchers at IIT Mandi have developed a self-cleaning glass that can remove microbes and organic pollutants (like detergent, dyes etc) & drugs from wastewater using only sunlight.

Wastewater from textile industries & pharmaceutical is a significant source of river pollution in India and abroad.

While existing refinement techniques can eliminate solid pollutants as well as dissolved inorganic compounds, removing suspended organic compounds remain a challenge, said Rahul Vaish, associate professor at Indian Institute of Technology (IIT) Mandi in Himachal Pradesh.

"Industries do not clean their wastewater but simply dump it in the river. It is only after the river is contaminated completely that we think about taking action to clean the river," Vaish told Press Trust of India (PTI).

Alternatively, Vaish recommends the use of the process recognised as photocatalysis to treat the wastewater before the harmful contaminants make their way into our river streams.

The team, which includes Sandeep Kumar and Gurpreet Singh, have developed a transparent calcium borate glasses and TiO₂ crystallised glass nanocomposites which can kill microbes and break down organic chemicals in the presence of sunlight.

"These glasses have self-cleaning and photocatalytic properties which support in destroying the bacteria and other microbes from wastewater in the presence of sunlight," said Vaish, the corresponding author of the study published in the Journal of the American Ceramic Society.

"There is no extra cost or machinery involves. If the water is kept in this glass container it will treat the organic compounds in a few hours. You only need sunlight," he said.

The technology has a variety of applications, the researcher said.

These easy to fabricate glasses can be made in the form of large panels which can have a wide range of applications from self-cleaning water bottles to large cleaning tanks for industrial discharge.

"The glass can also remove detergents from water. It could be used in washing machines to clean the water at the discharge point itself, rather than letting the contaminated water flow into our river systems," Vaish said.

Removal of such toxic chemicals from water is successfully demonstrated by many researchers at a laboratory scale.

However, cost & efficiency associated with existing technologies is major hurdles in their commercial usage.

Vaish said that his fabrication process is cost-efficient.

"This technology can also be used to clean air. It can remove NOx (oxides of nitrogen) from the air. If we place these glasses in our windows, we can fight air pollution too," he said.

"We are trying to improve transparency off the glasses so that they can be used to replace regular windows," Vaish added.

With input from PTI