Being associated with various research works in the area of water and wastewater treatment, such as treatment of tannery wastewater using membrane separation technology, as well as removal of pollutants using micellar-enhanced ultrafiltration, Dr. Das has gained expertise in membrane separation technology for removing various pollutants from contaminated water and wastewater. His research activity encompasses both understanding of fundamental principles during filtration as well as the development of technology based on membrane separation. In particular, his research areas are modeling of microfiltration, ultrafiltration, nanofiltration, reverse osmosis, treatment of oily wastewater, tannery effluent using membrane based processes. He has explored the detailed quantification of flux decline from fundamentals. As an offshoot of the major research, he has fabricated ceramic membranes using low cost precursors as sawdust. Catalyst is coated on the ceramic support for manufacturing catalytic membrane reactor.
He is also working on decontamination of chromium laden aqueous effluent using Spirulina platensis. He is actively involved in the productions of high value added products, namely, total phenolics, flavonoids, tocopherol, etc. from black rice as well as of 6-gingerol, vitamin C content, essential oil content from ginger of North East India.