RAJESH MOHANTY, OP
Rourkela: Researchers at the National Institute of Technology (NIT), Rourkela have developed an innovative process for efficiently treating industrial wastewater contaminated with persistent dyes such as Bismarck Brown R. The research, supported by Science and Engineering Research Board of the Department of Science and Technology, has been published in the prestigious Journal of Environmental Chemical Engineering and the team has been granted a patent for the developed technology.
Led by Sujit Sen, Professor, Department of Chemical Engineering at NIT Rourkela, the research team includes Madhumita Manna, research graduate, NIT Rourkela and Binay Kanti Dutta, former professor, IIT Kharagpur. According to Sen, waste water from industries like textiles and dye manufacturing often contains harmful dyes that are difficult to remove with traditional filtration methods. “Dyes such as Bismarck Brown R are small enough to pass through microfiltration membranes, making them particularly challenging to treat. These dyes can cause significant environmental and health issues due to their intense colour and potential carcinogenic properties.” “Conventional treatment methods, such as those relying on ultraviolet light, often struggle with large-scale applications, especially when separating dye particles from water,” he said. Sen explained that to address these challenges, the research team developed a cutting-edge treatment system that combines two advanced technologies. “The first is a ceramic membrane coated with an industrial-waste derived Zeolite and Zinc Oxide nanocomposite. This photocatalyst can break down dye molecules when exposed to light.” “The second technology incorporates micro bubbles, generated via a simple air diffuser, to enhance mass transfer and improve the breakdown process. A continuous tangential flow membrane photoreactor was designed and tested using both simulated and real waste water from a local dyeing factory,” he said. Sen said, “Our hybrid system successfully achieved 95.4 per cent decolourisation 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.” There are a host of potential applications of this hybrid system, which is more efficient and cost effective in comparison to conventional oxidation methods. This technology could be applied across industries such as textile manufacturing, chemical industries, steel, petrochemicals, and pharmaceuticals, where robust wastewater treatment is required. It can also be scaled up and integrated into existing wastewater treatment plants to improve the efficiency of treating dye-laden wastewater. Furthermore, the system may prove effective for treating contaminants that are typically difficult to remove using conventional methods, such as those found in hospital and pharmaceutical waste water.
