IIT Guwahati develops plant-based system for piggery wastewater

Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a low-energy, nature-based system designed to treat highly polluted swine wastewater. The technology utilizes taro plants (Colocasia esculenta) combined with an engineered “zig-zag flow” design to improve treatment efficiency.

Unlike traditional constructed wetlands, this system uses internal baffles to force water along a longer path. This design increases contact time between the wastewater, microorganisms, plant roots, and gravel media, facilitating more effective biological and chemical processes. The research, conducted in collaboration with the ICAR-National Research Centre on Pig in Assam, aims to provide a decentralized solution for rural livestock farms where conventional infrastructure is often impractical.

Experimental results showed a significant reduction in organic pollutants and pathogens. Total coliform levels dropped from approximately 60,000 to 1,200 MPN per 100 mL, while E. coli levels decreased from around 2,200 to 350 MPN per 100 mL. Additionally, toxicity tests indicated that the treated water showed significantly reduced cytotoxic and phytotoxic effects.