Rourkela: A research team of National Institute of Technology-Rourkela (NIT-R) has developed a process for efficiently treating industrial wastewater contaminated with persistent dyes such as Bismarck Brown R.
The research team has been granted a patent for this technology.
The team led by Prof Sujit Sen of the department of Chemical Engineering and comprising research graduate of NIT-R Madhumita Manna and former professor of IIT-Kharagpur Prof Binay Kanti Dutta, come up with this cutting-edge wastewater treatment system by combining nanocomposite-based ceramic membranes with microbubble technology that can help enhance dye removal efficiency.
The research work, supported by Anusandhan National Research Foundation, has been published in the prestigious Journal of Environmental Chemical Engineering.
“Dyes such as Bismarck Brown R are small enough to pass through microfiltration membranes of the existing methods, making them particularly challenging to treat. These dyes can cause significant environmental and health issues due to their intense colour and potential carcinogenic properties,” said Sen.
He explained that conventional treatment methods, such as those relying on ultraviolet light, often struggle with large-scale applications, especially when separating dye particles from water. “To address these challenges, we developed this cutting-edge treatment system that combines two advanced technologies,” he said.
The ceramic membrane coated with an industrial-waste derived zeolite and zinc oxide nanocomposite, which is a photocatalyst, helps break down dye molecules when exposed to light, while microbubbles generated via a simple air diffuser enhances mass transfer and improves the breakdown process.
A continuous tangential flow membrane photoreactor was designed and tested using both simulated and real wastewater from a local dyeing factory. “Our hybrid system successfully achieved 95.4 per cent decolorisation of Bismarck Brown R and 94 per cent removal of chemical oxygen demand (COD) in just 90 minutes. The nanocomposite performed well under visible light, making this approach suitable for practical wastewater treatment applications,” the prof added.
Sen further stated that the system offers a more efficient and cost-effective alternative to conventional oxidation methods, which often rely on expensive chemicals and complex equipment. “The use of industrial waste-derived nanocomposites further enhances the sustainability of the system. It can be transported easily. Cost-effective and easily assembled technology. We will soon transfer technology to any interested industrial house or company that manufactures components for wastewater treatment plants. It is not for domestic purposes,” he said.
Additionally, the hybrid membrane is less prone to fouling, a common issue in long-term wastewater treatment processes, and can be easily regenerated through backflushing, minimising the need for chemical cleaning, he added.
The team is working on scaling up this technology for broader application across industries such as textile manufacturing, chemical, steel, petrochemical and pharmaceutical where robust wastewater treatment is required.
