Abstract

In household wastewater, a large proportion of organic micropollutants (OMPs) load is attributed to human urine. OMPs could pose a risk to human and environmental health when urine collected in source-separating sanitation systems is recycled as crop fertiliser. This study evaluated degradation of 75 OMPs in human urine treated by a UV-based advanced oxidation process. Fresh urine and water samples were spiked with a broad range of OMPs and fed into a photoreactor equipped with a UV lamp (185 and 254 nm) that generated free radicals in situ. Degradation rate constant and the energy required to degrade 90% of all the OMPs in both matrices were determined. At a UV dose of 2060 J m-2, average & sigma;OMP degradation of 99% (& PLUSMN;4%) in water and 55% (& PLUSMN;36%) in fresh urine was achieved. The energy demand for removal of OMPs in water was <1500 J m-2, but for removal of OMPs in urine at least 10-fold more energy was needed. A combination of photolysis and photo-oxidation can explain the degradation of OMPs during UV treatment. Organic substances (e.g. urea, creatinine) likely inhibited degradation of OMPs in urine by competitively absorbing UV-light and scavenging free radicals. There was no reduction in the nitrogen content of urine during treatment. In summary, UV treatment can reduce the load of OMPs to urine recycling sanitation systems.

Keywords

Circular sanitation; Fertiliser; Nutrient recycling; Pharmaceuticals; Urine diversion; Wastewater treatment

Published in

Water Research
2023, Volume: 242, article number: 120221
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

SLU Authors

• Demissie, Natnael

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    
  • Addis Ababa University

• Simha, Prithvi

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

• Lai, Foon Yin

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Ahrens, Lutz

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Vinnerås, Björn

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Water Treatment


Publication identifier

DOI: https://doi.org/10.1016/j.watres.2023.120221

Permanent link to this page (URI)

https://res.slu.se/id/publ/123590