The Institute of Nano Science and Technology (INST) Mohali, an autonomous institute of the Department of Science and Technology, has developed a sustainable multifunctional machine learning-enabled filter for wastewater treatment. This technology integrates green-synthesized zinc oxide (ZnO) nanoparticles with biodegradable polylactic acid (PLA) nanofibers to provide an environmentally friendly solution for treating dye-contaminated wastewater, particularly addressing challenges from textile industry discharges where persistent organic dyes represent significant environmental concerns due to their stability, toxicity, and resistance to natural degradation.
The research team led by Dr. Aviru Kumar Basu synthesized ZnO nanoparticles using turmeric extract, where naturally occurring bioactive compounds like curcumin, flavonoids, and phenolic compounds acted as reducing and stabilizing agents, avoiding conventional synthesis routes involving harmful reagents. The fabrication of PLA-ZnO nanofibers through electrospinning produced a porous, high-surface-area catalytic membrane with mechanical stability. The integration of photocatalysis and piezocatalysis enables pollutant degradation using both light and mechanical vibrations, where mechanical vibrations generate piezoelectric polarization that suppresses photogenerated electron-hole recombination and enhances reactive-species formation.
The technology demonstrated exceptional performance with 98.6% methylene blue (MB) and 96.7% Congo red (CR) decolorization achieved within 120 minutes under combined light and ultrasonic excitation. Additionally, the material showed significant antibacterial activity, achieving approximately 75% inactivation of E. coli and 71% of S. aureus after 6 hours of treatment. Machine learning was integrated with experimental studies to predict dye-decolorization behavior from parameters including wavelength, time, catalyst amount, ultrasonic frequency, light intensity, and dye concentration.
This development addresses several challenges of conventional photocatalytic systems including recovery of nanoparticle catalysts, separation of catalysts from treated water, electron-hole recombination, dependence on light availability, and the requirement for efficient catalyst-pollutant contact. The technology has applications for treating wastewater containing persistent organic dyes and microbial contaminants, particularly from textile and industrial effluents, and can be used for photocatalytic and piezocatalytic environmental remediation as well as antibacterial water-treatment membranes. The research was published in the journal Advanced Functional Materials (Wiley) with the DOI: https://doi.org/10.1002/adfm.77852.