This document summarizes a study investigating nitrogen removal at an aerobic landfill leachate treatment plant in southern Sweden. The study aimed to examine (1) nitrogen removal capabilities of on-site treatment plants, (2) the treatment capacity of the Hedeskoga plant in particular, and (3) potential nitrification inhibition from different leachate qualities. Methods included analyzing biological activity and inhibition in the aerobic treatment plant. Results found the Hedeskoga plant has sufficient capacity and retention time to aerobically treat leachate in the aerated lagoon, removing ammonia satisfactorily during warmer seasons primarily via nitrification and denitrification. Some leachate showed slightly higher inhibition potential but mixing with

1. Investigation of an aerobic-based
landfill leachate treatment plant in
southern Sweden
Alessandro Sarno, Lund University
e-mail address:
bio12as3@student.lu.se

2. Why this project?
"On-site" vs "off-site" treatment
- Water quality standards EU
- Landfill emissions: leachate
- REVAQ certificate (Sweden)
Management of biological treatment methods:
any issues?
- Precipitation
- Ammonia (NH3)
- Leachate toxicity

3. Aims
Primarily,
Secondarily,
1. Nitrogen removal, what can be expected from an
on-site treatment plant?
2. Examine treatment capacity in Hedeskoga
and put into context
3. Potential nitrification inhibition caused by
different leachate qualities.

4. Hedeskoga
Ystad, 3 Km

5. - Data collection and investigation on nitrogen
removal processes
- Hydrological and nitrogen mass balance in
Hedeskoga
- Comparison with other existing case studies
Methods

6. Methods
- Biological activity (nitrification) in the aerobic-
based treatment plant
- Inhibition due to leachate
Biotest
Screening method

7. Results
Craggs, 2005
Nitrogen removal processes in waste stabilization ponds

8. Results

9. Results

10. Results

11. Results

12. Conclusion
• In Hedeskoga, capacity and hydraulic retention times are enough to store and pre-
treat (colder months), and to aerobically treat leachate in the aerated lagoon with
a satisfactory NH3 removal (warmer season)
• Nitrification and denitrification main nitrogen removal processes during summer in
the ponds´ environment; HRT > 30 days and T < 5 °C enhance possibility for NH3 to
be removed by sedimentation during winter rather than by active nitrification
• Leachate in P5B shows higher potential of nitrification inhibition in comparison
with P0; situation non alarming when these two qualities of leachate are mixed
together in the equalization basins: NH4
+ load received by aerated lagoon is
reduced after pre-treatment

13. Future work
• microbiological assays for identification of bacterial communities
inhabiting the basins
• Chla as inexpensive indicator for algal biomass growth; how much
nitrogen leaves the ponds through biomass settlement (since the
last pond is a sedimentation basin)? Winter vs summer
• Monthly measurements of NH3 air stripping grounded on T, pH and
%NH4
+ transformed into NH3 could clarify actual ammonia
emissions from the ponds

14. Questioning...