Due to the lack of reliable municipal water supply services and the increase in consumer awareness of water-borne diseases, the domestic purification industry was expected to grow at 25% compounded annually between 2012 and 2015. Domestic point-of-use home purification industry was anticipated to be worth 1.5 billion USD industry in India at the end of 2015, with reverse osmosis (RO) systems accounting for 43% of the total share. However, with the per-capita consumption forecasted to increase nearly two-fold to 167 L/day from 2000 to 2025, the condition of water supply in India will be in a critical state. In this environment, the use of RO systems - which waste between 50 to 75% of the input water - will be undesirable. Instead, the GEAR Lab is developing an alternative solution that relies on electrodialysis (ED) to achieve a higher recovery of 90% while maintaining cost-competiveness with existing RO products in India.
Functional requirements for a home-scale ED system were identified by interviewing stakeholders across India, including users, distributors, and manufacturers. A model for brackish water ED desalination, including hydraulic losses, was developed by the GEAR Lab to facilitate design and analysis of different stack configurations and system architectures. Applying these models, the optimal geometry, flow-rates, and applied voltage for total cost minimization were explored using a genetic algorithm, for satisfying the production rate (9-15 L/hr) and product concentration (100-300 mg/L) requirements for the device. Finally, two bench-scale prototype systems were developed in conjuction with our partner, Eureka-Forbes Limited, and used to experimentally demonstrate >80% recovery from feed concentrations as high as 3000 mg/L.
In the next phase, we aim to build and integrate a third prototype into an existing RO purifier body for pilot testing.
Feasibility Study of an Electrodialysis System for In-Home Water Desalination and Purification in Urban India
Nayar, K. G., Sundararaman, P., Schacherl, J. D., O’Connor, C. L., Heath, M. L., Gabriel, M. O., Shah, S., Wright, N. & Winter, A., Development Engineering (2017)
Optimal Design of a Batch Electrodialysis System for Domestic Desalination
Shah, S.R., Wright, N.C., Nepsky, P., & Winter, A., Proceedings of the International Desalination Association World Congress on Water Reuse and Desalination (2017), IDA17WC-58064, Sau Paulo, Brazil
Feasibility Study of an Electrodialysis for In-Home Water Desalination and Purification in Urban India
Nayar, K.G., Sundararaman, P., Scharcherl, J.D., O'Connor, C.L., Heath, M.L., Gabriel, M.O., Wright, N.C., & Winter, A., 41st Design Automation Conference, ASME IDETC/CIE (2015)
Cost-optimal design of a household batch electrodialysis desalination device
Shah, S.R., Master's Thesis (MIT, 2017)
Decentralized Water Treatment in Urban India, and the Potential Impacts of Reverse Osmosis Water Purifiers
Connor, C., Master's Thesis (MIT, 2016)
Best Paper Award, State of the Art Category. IDA World Congress 2017, São Paulo (Shah, Wright, Nepsky, Winter) : “Optimal Design of a Batch Electrodialysis System for Domestic Desalination.” [🔗 ]