Reusable Water Filter with Light and Vibration

Why in News?

Recently, Scientists from the Institute of Nano Science and Technology (INST) in Mohali, IIT-Dharwad, and IIT-Kharagpur have designed a cheap reusable water filter.

• Need - Dyes such as Congo Red and Methylene Blue are industrial pollutants released into rivers and groundwater causes stomach, skin, and breathing illnesses.
• Exiting filtering methods - These are costly and having higher foot print as they burn through chemicals and electricity.
  • For example - Ozone, Fenton chemistry and other methods work to clean the water.
• Filter specification - First 3D printed thin, sponge-like sheets of polylactic acid (PLA), a biodegradable plastic often used in compostable cups.
• PLA is naturally water-repelling, So that it was soaked in a mild sodium-hydroxide solution to make it water-loving.
• Made up of - Nanoparticles of bismuth ferrite (BFO) and dipped the prepared PLA sheets into a BFO ink.
• The treated sheets stayed strong through five reuse cycles, losing only about 3% of their cleaning power.
• Mode of operation - Combining both light and vibration yielded piezo-photocatalysis, a process that worked day or night.
• Components –
  • Visible light - Under it, BFO acted like a solar-powered catalyst that split water molecules and created highly reactive radicals that shred organic dye molecules.
  • Ultrasound shaking - BFO’s piezoelectric nature generated an internal electric field that drove the same radical-making reactions even in the dark.
• Working - When light and vibration were used together, the filter removed about 99% of Congo Red and 74% of Methylene Blue in 90 minutes.
  • It also partially cleaned real wastewater collected from a textile plant.
• Capability –Tto understand performance the computer fed by thousands of experimental data points, including dye concentration, catalyst amount, light intensity, and ultrasound frequency.
• Modern algorithms such as random forests, XGBoost, and an artificial neural network are used and got results far beyond the experimental ones.
• Deployment – At near treatment plants.
• Developments underway - For its use in Jal Nigam and Namami Gange projects as well.
• Efforts are underway to make this product more sustainable using plant-derived products.

Reference

The Hindu| Reusable Water Filter with Light and Vibration