Chemical Engineering and Industrial Chemistry

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

Authors

Abstract

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.

Content

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