Recovery and applications of ammoniacal nitrogen from nitrogen-loaded residual streams

Recovery and applications of ammoniacal nitrogen from nitrogen-loaded residual streams: A review

Deng, Z. (TU Delft Sanitary Engineering)
van Linden, N. (TU Delft Sanitary Engineering)
Guillen, Elena (AEE - Institute for Sustainable Technologies)
Spanjers, H. (TU Delft Sanitary Engineering)
van Lier, J.B. (TU Delft Sanitary Engineering)

2021

Total ammoniacal nitrogen (TAN) is considered to be a pollutant, but is also a versatile resource. This review presents an overview of the TAN recovery potentials from nitrogen (N)-loaded residual streams by discussing the sources, recovery technologies and potential applications. The first section of the review addresses the fate of TAN after its production. The second section describes the identification and categorisation of N-loaded (≥0.5 g L⁻¹ of reduced N) residual streams based on total suspended solids (TSS), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), TAN, and TAN/TKN ratio. Category 1 represents streams with a low TAN/TKN ratio (<0.5) that need conversion of organic-N to TAN prior to TAN recovery, for example by anaerobic digestion (AD). Category 2 represents streams with a high TAN/TKN ratio (≥0.5) and high TSS (>1 g L⁻¹) that require a decrease of the TSS prior to TAN recovery, whereas category 3 represents streams with a high TAN/TKN ratio (≥0.5) and low TSS (≤1 g L⁻¹) that are suitable for direct TAN recovery. The third section focuses on the key processes and limitations of AD, which is identified as a suitable technology to increase the TAN/TKN ratio by converting organic-N to TAN. In the fourth section, TAN recovery technologies are evaluated in terms of the feed composition tolerance, the required inputs (energy, chemicals, etc.) and obtained outputs of TAN (chemical form, concentration, etc.). Finally, in the fifth section, the use of recovered TAN for three major potential applications (fertilizer, fuel, and resource for chemical and biochemical processes) is discussed. This review presents an overview of possible TAN recovery strategies based on the available technologies, but the choice of the recovery strategy shall ultimately depend on the product characteristics required by the application. The major challenges identified in this review are the lack of information on enhancing the conversion of organic-N into TAN by AD, the difficulties in comparing the performance and required input of the recovery technologies, and the deficiency of information on the required concentration and quality of the final TAN products for reuse.

ammoniacal nitrogen
Anaerobic digestion
Nitrogen-loaded
Residual streams
Resource recovery

http://resolver.tudelft.nl/uuid:8c57bcee-3709-4767-add4-480bc0fe122d

https://doi.org/10.1016/j.jenvman.2021.113096

0301-4797

Journal of Environmental Management, 295, 1-20

Institutional Repository

review

© 2021 Z. Deng, N. van Linden, Elena Guillen, H. Spanjers, J.B. van Lier