Case Study 4A - Contaminants from secondary fertilisers

Emission and fate of compounds of emerging concern (CECs) released to agricultural fields from secondary fertilisers

Sewage treatment facility

Institutions: AU-ENV

CS Coordinator: Kai Bester

Objectives / Hypothesis

Assess fate, uptake, and effects of chemicals of emerging concern (CECs), especially antimicrobials introduced to ecosystems via sewage sludge application as secondary fertiliser.

Description of the case study

Case Study 4A concentrates on the emission and fate of Contaminants of Emerging Concern (CECs) in soil ecosystems.

Case Study Goal

  • Exposure assessment

    • In the field:

      • CEC concentrations in soil, pore water and crops of the fields treated with sewage sludge

      • Suction cups to study CEC movement with pore water towards groundwater

      • Time series on soil to track in-situ degradation and soil profiles to determine transfer into deeper layers over time

      • Analysis of field crops (barley) to understand potential for plant uptake

  • Preliminary persistence assessment/properties/fate at lab scale

    • Degradation kinetics in soil under controlled conditions indicate unexpectedly high persistence of antimicrobials in soil

    • Microbial metabolisation of key CECs in soil

  • Effect assessment

    • Effect studies on microbial communities: Bacterial communities show adverse effects of bactericidal loadings of soil

Species

  • Bacterial communities

Photos from field work in SYBERAC Case Study 4A

Involved stakeholders

  1. Danish EPA

  2. National food industry (Dairy Arla having some demands on not using sludge)

  3. SEGES (farmers’ knowledge centre)

  4. Environmental protection groups

  5. Dalgas (Sludge distributor)

Locations

Description:

  • Research farm (Høje Taastrup, Denmark) belonging to the University of Copenhagen

  • 0.6 ha plots, one receiving and one not receiving sludge for 20 years, both amended with fresh inputs in 2025

 

Learn more about the case study

Featured
Kai Bester about sludge processing & threats to biodiversity
Case Study 4A
Kai Bester about sludge processing & threats to biodiversity
Case Study 4A

Kai Bester reveals the risks of using sewage sludge as fertilizer, threats to biodiversity in this interview. He also talks about the research carried out within the case studies and how they significantly contribute to SYBERAC´s objectives.

Case Study 4A