India's NIT Warangal develops wastewater treatment tech for textiles

They developed a pilot-scale textile effluent treatment plant harnessing biosurfactants (BS), cavitation (C), and membrane (M) technology, ministry of science and technology said in a press release.

Textile effluents are typically heavily polluted with contaminants such as dyes, dissolved solids, suspended solids, and toxic metals. It has been a significant challenge to find robust, efficient technologies to treat these effluents before their discharge into the environment.

Led by Shirish H. Sonawane, Murali Mohan Seepana, Ajey Kumar Patel from NIT Warangal, and Mousumi Debnath from Manipal University Jaipur (MUJ), the team initially worked on individual systems at their respective laboratories and optimised the process parameters. The biosurfactant for use in the Moving Bed Biofilm Reactor (MBBR) was derived from microorganisms isolated from textile effluent and textile effluent contaminated soil by MUJ.

The use of biosurfactants in the MBBR facilitated dye removal and proved to be effective in decreasing operational time and cost compared to other biological treatment methods. The cavitation process, an advanced oxidation process (AOP), helped lower both the installation cost and carbon footprint.

The new technology's ability to generate oxidising radicals in-situ significantly reduced reliance on external oxidising agents. Meanwhile, modifying the membrane's surface with a boehmite sol synthesised using a sol-gel process decreased pore size from micro to nano-scale, significantly enhancing performance.

The pilot-scale setup, situated at Prime Textiles' premises, includes a sequence of processes crucial to the effluent treatment. The coagulation process removes turbidity caused by suspended solids, while the biofilm grown on MBBR reduces heavy metal content and degrades biodegradable pollutants. The cavitation phenomenon destroys all types of pollutants, resulting in the in-situ generation of radicals and energy responsible for pollutant degradation. Lastly, the surface-modified membrane separates all remaining pollutants. This sequence in the 200-liter per day capacity pilot plant effectively removes pollutants, repurposing the treated water for agricultural and cleaning purposes, the release added.

This successful collaboration has led to the transfer of technology and two patents. It provides a sustainable solution for KMTP's textile effluent, turning toxic wastewater into an irrigation source for nearby agricultural areas. It also has immense potential to replace existing secondary treatment plants due to its lower installation cost and lesser carbon footprint.

Fibre2Fashion News Desk (DP)