Files and links (2)
Published (Version of record)CC BY V4.0, Open Access
Published (Version of record)CC BY V4.0, Open
Journal article
Removal and Recovery of Ammonium Nitrogen from Dairy Processing Wastewater Using Air Stripping Technology: A Pilot-Scale Study
Water, Vol.18(2), pp.1-19
12/01/2026
Metrics
1 File views/ downloads
5 Record Views
Abstract
Ammonium nitrogen (NH4+-N) removal and recovery from wastewater have been critical issues worldwide and key to achieving a sustainable nitrogen cycle and circular economy. In this study, we designed and constructed a pilot-scale air stripping system integrated with a nutrient-capture unit and evaluated the effective pH, temperature, and airflow conditions for maximising NH4+-N removal and recovery from dairy processing wastewater (DPW). Our results demonstrated that increasing pH and temperature substantially enhances NH4+-N removal via air stripping, with higher airflow rates further improving performance. Under these conditions (pH 11, 32 °C, and 300 L min−1), NH4+-N removal from synthetic wastewater reached ≈40% after 6 h air stripping. In comparison, real DPW exhibited slightly lower removal efficiency under the same conditions, achieving ≈34%, likely due to its more complex matrix. Additionally, incorporating a chemical precipitation step followed by filtration prior to air stripping removed NH4+-N from DPW, achieving ≈43%. However, extending the stripping duration under identical conditions significantly improved removal performance, increasing NH4+-N removal in DPW to ≈70%. The downstream capturing system, consisting of acid bath and granulated activated carbon (GAC), consistently recovered 70–95% of the released ammonia (NH3) when even upstream NH4+-N removal via air stripping was moderate. The GAC effectively adsorbed the volatilised NH3, achieving adsorption capacities of up to ≈18 mg/kg. Overall, this integrated system demonstrates strong potential for simultaneous NH4+-N removal and recovery from industrial wastewater streams, offering notable environmental benefits.
Details
- Title
- Removal and Recovery of Ammonium Nitrogen from Dairy Processing Wastewater Using Air Stripping Technology: A Pilot-Scale Study
- Creators
- Md Sydur Rahman - Southern Cross UniversityToby Shapiro Ellis - Southern Cross UniversityIsaiah J. R. Freeburn - Richmond Valley CouncilAndrew Rose - Southern Cross UniversityAaron William Thornton - Southern Cross UniversityDirk Erler - Southern Cross University
- Publication Details
- Water, Vol.18(2), pp.1-19
- Publisher
- MDPI AG; BASEL
- Grant note
- This research was funded by Commonwealth Government’s Strategic University Reform Fund (SURF), a grant awarded to Southern Cross University.
- Identifiers
- 991013342290902368
- Copyright
- © 2026 by the authors.
- Academic Unit
- Faculty of Science and Engineering; Engineering; Science
- Language
- English
- Resource Type
- Journal article