A1 Journal article (refereed)
Enhanced nitrogen removal of low carbon wastewater in denitrification bioreactors by utilizing industrial waste toward circular economy (2020)

Kiani, S., Kujala, K., Pulkkinen, J., Aalto, S. L., Suurnäkki, S., Kiuru, T., Tiirola, M., Kløve, B., & Ronkanen, A.-K. (2020). Enhanced nitrogen removal of low carbon wastewater in denitrification bioreactors by utilizing industrial waste toward circular economy. Journal of Cleaner Production, 254, Article 119973. https://doi.org/10.1016/j.jclepro.2020.119973

JYU authors or editors

Publication details

All authors or editors: Kiani, Sepideh; Kujala, Katharina; Pulkkinen, Jani; Aalto, Sanni L.; Suurnäkki, Suvi; Kiuru, Tapio; Tiirola, Marja; Kløve, Bjørn; Ronkanen, Anna-Kaisa

Journal or series: Journal of Cleaner Production

ISSN: 0959-6526

eISSN: 1879-1786

Publication year: 2020

Volume: 254

Article number: 119973

Publisher: Elsevier

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1016/j.jclepro.2020.119973

Publication open access: Not open

Publication channel open access: 

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/73644

Abstract

Aquaculture needs practical solutions for nutrient removal to achieve sustainable fish production. Passive denitrifying bioreactors may provide an ecological, low-cost and low-maintenance approach for wastewater nitrogen removal. However, innovative organic materials are needed to enhance nitrate removal from the low carbon effluents in intensive recirculating aquaculture systems (RAS). In this study, we tested three additional carbon sources, including biochar, dried Sphagnum sp. moss and industrial potato residues, to enhance the performance of woodchip bioreactors treating the low carbon RAS wastewater. We assessed nitrate (NO3−) removal and microbial community composition during a one-year in situ column test with real aquaculture wastewater. We found no significant differences in the NO3− removal rates between the woodchip-only bioreactor and bioreactors with a zone of biochar or Sphagnum sp. moss (maximum removal rate 31–33 g NO3−-N m−3 d−1), but potato residues increased NO3− removal rate to 38 g NO3−-N m−3 d−1, with stable annual reduction efficiency of 93%. The readily available carbon released from potato residues increased NO3−-N removal capacity of the bioreactor even at higher inflow concentrations (>52 mg L−1). The microbial community and its predicted functional potential in the potato residue bioreactor differed markedly from those of the other bioreactors. Adding potato residues to woodchip material enabled smaller bioreactor size to be used for NO3− removal. This study introduced industrial potato by-product as an alternative carbon source for the woodchip denitrification process, and the encouraging results may pave the way toward growth of blue bioeconomy using the RAS.

Keywords: aquaculture; waste water treatment; denitrification; bioreactors; biochar; potato; circular economy

Free keywords: recirculating aquaculture system; woodchip bioreactor; carbon source; potato residues; nitrate; microbial community

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Ministry reporting: Yes

VIRTA submission year: 2020

JUFO rating: 2