Chemical Engineering and Industrial Chemistry

Nutrient recovery from wastewater in India: A perspective from mass and energy balance for a sustainable circular economy



Limited phosphorus availability and increased eutrophication (due to discharge of nitrogen) have pushed everyone to rethink, on how to recover these nutrients. Wastewater (WW) is a potential source to recover N, and P, whereas in India, it is scarcely explored. In this work, four different nutrient recovery methods were compared from a mass- and energy- balance perspective to understand the overall process flow. From 1000-m3 WW, chemical precipitation yielded 33.8 kg struvite, while micro-algae resulted in 299.1 kg (dry powder). Energy consumption was lowest for the fuel cells at 216.2 kWh/1000m3, while microalgae used the highest energy at 943.3 kWh/1000m3. Nonetheless, cost-saving analysis showed that microalgae (78.6$/1000 m3) as a nutrient recovery choice, had higher savings than any other methods compared. For a country like India, where the two-thirds of urban wastewater is untreated, wastewater-biorefinery options such as nutrient recovery hold the key for a sustainable circular economy.

Version notes

We have modified the diagrams and tables with standard deviations for better understanding. In addition, we have included two authors.


Thumbnail image of Revised manuscript - Clean copy (without changes marked).pdf

Supplementary material

Thumbnail image of Supplementary file S1.docx
Design, sizing, and volume; energy balance calculations for nutrient recovery systems with conventional sewage treatment plant
The supplementary material consists of four boxes. Box 1- Design and calculations of a conventional sewage treatment plant; Box 2- Sizing and volume calculations of various nutrient recovery systems; Box 3- Energy consumption calculations of various unit operations in a conventional sewage treatment plant; Box 4- Energy consumption and power rating calculations of various nutrient recovery systems