NIT Women Researchers Develop Dairy Wastewater Treatment System

By: Women Entrepreneurs Review Team | Saturday, 23 May 2026

The researchers at National Institute of Technology (NIT), Rourkela, have invented and patented a low-cost, eco-friendly wastewater treatment system to treat the dairy waste and make it usable for agriculture, as Indian dairy industry produces billions of litres of wastewater daily and traditional treatment systems are expensive and labor intensive.

The innovative system has been developed by women scientists from the institute's Civil Engineering Department which involves four levels of biological treatment: earthworms, aquatic plants, microbial activity, and hydroponic filtration to help mitigate organic pollution and address the problem of clogging in traditional wastewater treatment technologies.

The wastewater produced during the making of paneer, cheese and yoghurt has high concentration of fats, proteins, and carbohydrates which leads to the high chemical oxygen demand (COD) in the wastewater. When untreated wastewater is discharged into rivers and ponds, it can cause high COD levels which, in turn, can lead to a decrease in dissolved oxygen (DO) in the water body, causing significant adverse impacts on aquatic ecosystems.

Current treatment technologies like membrane filtration are unable to cope with these issues well and suffer from regular clogging problems, the researchers said.

They have designed a multi-layered system that would serve different purification processes with each layer contributing in different ways to the stability of the process, said Kakoli Karar Paul, professor at Civil Engineering Department, NIT.

"The newly developed treatment model operates through a five-stage purification mechanism. In the first layer, wastewater enters a worm-active reactor containing earthworms and aquatic plants. The partially treated water passes through a sand filtration layer that removes suspended solids in the second phase. While the third layer uses fly ash pellets to adsorb pollutants and reduce phosphorus compounds, the fourth layer removes residual organic contaminants in a gravel bed through aerobic microbial action. The final treatment stage involves a hydroponic chamber where plant roots remain submerged in water and release oxygen," she said.

The combination of vermi-filtration, macrophyte-assisted treatment and hydroponic purification in a sustainable continuous system has enabled the NIT Rourkela research team to achieve improved pollutant removal efficiency and address the clogging issues faced during the wastewater treatment process.

Key Highlights:

• National Institute of Technology Rourkela developed a low-cost dairy wastewater treatment system
• The technology uses earthworms, plants, and microbes to remove pollutants
• Treated water can be reused for agriculture

The NIT Rourkela research team has succeeded in providing better efficiency of pollutant removal and solving the problem of clogging in the wastewater treatment process by combining the processes of vermi-filtration, macrophyte-assisted treatment, and hydroponic purification in a sustainable continuous system.

The laboratory scale unit is close to Rs 10,000 and can currently treat about 30 litres of dairy effluent per day but can be scaled-up based on the dairy industry's requirement, Paul added.

Actual dairy wastewater was used in the laboratory tests, and the quality of treated water was found suitable for irrigation purposes, while useful phosphate nutrients were left in the treated water beneficial for agriculture. The researchers also said that the water plants employed in the purification procedures might be utilized as fodder for livestock or biogas and biofuel manufacturing.

The technology has real-world applications, said Pragyan Das, research associate, as it provides an economically viable solution to treat wastewater in regions where access to large-scale treatment infrastructure is limited or non-existent. "The treated wastewater can be directly reused for agricultural purposes, promoting resource-efficient waste management while reducing environmental pollution," she added.

The research team is currently developing a more rapid treatment and optimizing the design of the reactors for large-scale implementation. They are also actively looking for industry partners for commercializing the technology and scaling it up from lab to field.