Practical odour management solutions for preparing for predicted climate changes in the UK: PRESENTATION ONLY
David Sivil, WRc
(free)
Key themes:
- Changes in the UK’s climate predicted by the Met Office.
- Effects of the predicted climate changes on the operation and odour emissions of sewer networks and sewage and sludge treatment processes.
- Practical solutions currently available to mitigate increases in odour emissions.
- Additional solutions that will be required.
An overview of the full presentation
Climate modelling carried out by the Met Office in 2018 has predicted that UK summers will become hotter and drier, winters will be warmer but wetter, and rainfall will be more intense. In March 2020, WRc held an Odour Management User Group workshop with water industry representatives to predict the effects of climate change on the operation and odour emissions from sewer networks and sewage and sludge treatment processes. . It included a step-by-step odour risk assessment of sewer network and treatment assets. Current solutions available to mitigate odour emissions were identified. These included improving operational practices to minimise odour emissions, such as cleaning storm tanks quickly, and installing or upgrading odour control technologies, such as chemical dosing or covering processes and treating odorous air. However, the needs for additional solutions were also noted such as developing septicity prediction models for sewer networks or preventing sea water intrusion in coastal sewer networks. This presentation will summarise the findings of the workshop.
Technical details
Drier summers in the future, as predicted by the Met Office, will produce stronger sewage and increase the residence time in sewer networks and treatment processes. The combination of this with hotter temperature will increase the risk of higher odour emissions. In addition, more frequent periods of more intense rainfall will result in storm tanks being used more often. Settled solids at the bottom of storm tanks will need to be removed more often or risk the increase of odour emissions.
There are currently a range of odour management solutions available that fall into the following categories:
- Manage the operation of sewer network and sewage treatment processes to minimise odour development and emissions.
- Reduce odour emission by design.
- Cover odour source, extract and treat the odorous air in an OCU and direct through stack to increase dispersal.
- Dose additives to wastewater or sludge to control/reduce its odour potential.
More advanced odour management solutions may be required in the future, such as developing models to predict the risk of septicity in sewer networks or preventing sea water intrusion in coastal sewer networks.
