A first: Mohali tech institute invents water filter to purify toxic dyes

In a first-of-its-type invention in the country, scientists at the Institute of Nanoscience and Technology (INST), Mohali, have developed a smart and biodegradable water filter that not only removes toxic dyes from industrial wastewater but also breaks them down using a combination of sunlight and vibrations.

The innovation, seen as a major breakthrough in eco-friendly water purification, has featured recently as the cover art of the journal Nano Energy (Elsevier IF=17.1), the INST scientist Dr Aviru Kumar Basu, who led the research performed by his research student, Manshu Dhillon, and team, told The Tribune, here on Friday.

He said it depicts a futuristic setup where dye-laden water is purified using a 3D-printed biodegradable polylactic acid scaffold activated by solar energy and subtle mechanical vibrations.

“This smart filter, coated with a catalytic layer of Bismuth Ferrite (BiFeO₃), degrades dyes like Congo Red and Methylene Blue using a green process called piezo-photocatalysis,” Dr Basu disclosed, while sharing that this dual-triggered process harnesses both light and mechanical energy to initiate powerful chemical reactions that dismantle toxic dye molecules.

He said even under cloudy conditions where solar output is limited, the system continues to function using ambient vibrations.

“This makes it ideal for year-round deployment, especially in resource-limited areas,” the scientist said.

The researchers tested the setup in real-time degradation of dyes, achieving remarkable efficiency, removing 98.9 per cent of Congo Red and 74.3 per cent of Methylene Blue from contaminated water samples.

To evaluate the practical applicability of this filter, tests were conducted using real textile wastewater samples obtained from the Common Effluent Treatment Plant (CETP) at Sanganer in Jaipur. “This facility, which currently treats effluents from 192 out of 860 connected textile industries, provided a representative sample for real-world conditions,” Dr Basu divulged.

The filter demonstrated effective dye degradation within 60 minutes under visible light and mechanical stimulation.

The results revealed that degradation efficiency varied depending on the nature and composition of the wastewater, which can fluctuate daily due to differences in industrial discharge.

Adding a layer of machine learning (ML), a subfield of artificial intelligence (AI) that focuses on developing algorithms and allows computers to learn from and make predictions or decisions based on data without explicit programming, to the system, the researchers used artificial neural networks (ANNs) to train predictive models that simulate how the filter performs under varying light, dye concentration, and vibration levels.

“These models achieved up to 99 per cent accuracy in predicting catalytic performance, helping optimisation of the filter for diverse field conditions,” the researchers said.

The device is reusable, low-cost, and avoids the need for harmful chemicals, positioning it as a sustainable alternative to conventional techniques like ozonation and electrochemical oxidation, which are often expensive and energy-intensive.

The innovation is being hailed as a scalable solution for industries like textiles, leather, and pharmaceuticals, all major contributors to dye pollution, and may also benefit rural and off-grid communities where clean water access is still a challenge.