Indian Scientists Develop Green Nano-Fibre Filter To Clean Dye-Polluted Water

Researchers at the Institute of Nano Science and Technology (INST), Mohali, have developed a sustainable filter that can clean water polluted with dyes. The filter also uses machine learning to predict how well it works.

The technology joins green-made zinc oxide (ZnO) nanoparticles with biodegradable polylactic acid (PLA) nanofibers. It uses both light and mechanical vibration to break down pollutants. The study was published in the journal Advanced Functional Materials.

 

Industries, especially textile makers, release long-lasting organic dyes into water bodies. These dyes are stable and toxic, and they do not break down easily in nature. This makes them a serious threat to the environment.

Why do current methods fall short?

Common treatment methods include adsorption, sedimentation, and flocculation. They can separate dyes from water, but they do not always destroy them. Biological treatment can also be slow when dyes are very stable.

 

The new filter offers a possible green alternative to these methods. It uses light and vibration to break down pollutants rather than just moving them elsewhere.

It also solves several problems seen in usual photocatalytic systems. These include recovering the nanoparticle catalyst, separating it from treated water, and stopping electrons and holes from recombining. They also include reliance on light and the light and the need for good contact between the catalyst and the pollutant.

 

Scientists made the ZnO nanoparticles using turmeric extract. Natural compounds such as curcumin, flavonoids, and phenolics acted as reducing and stabilising agents, so no harmful chemicals were required. The ZnO nanoparticles were placed inside porous PLA nanofibers using a method called electrospinning. This created a strong membrane with a large surface area, instead of loose catalyst powder. The system combines photocatalysts, which use light, with piezocatalysis, which uses mechanical vibration.These vibrations create piezoelectric polarisation. This stops electrons and holes from recombining and produces more reactive particles that break down pollutants.

 

The PLA ZnO nanofibers removed 98.6 per cent of methylene blue (MB) dye and 96.7 per cent of Congo red (CR) dye within 120 minutes, using light and ultrasound together.

The material also showed antibacterial action. After six hours, it inactivated about 75 per cent of E.coli and 71 per cent of S.aureus bacteria.

Machine learning was added to the study to predict how well dyes would be removed. It used factors such as wavelength, time, catalyst amount, ultrasonic frequency, light intensity, and dye concentration.

 

The nanofibers can be used to treat wastewater containing long-lasting organic dyes and germs, especially from textile and industrial sources, for cleaner and safer water. They can also be used for environmental clean-up through photocatalytic and piezocatalysis, and as antibacterial membranes for water treatment.