After learning about sustainability education in Germany from Astrid Wasmann-Frahn, we hopped on a bus and headed to the sewage treatment plant outside of Quickborn. For many of us, this was our first visit to such a facility and we found it fascinating (and actually not as smelly as one might think), though there were a few nose-plug worthy moments.
The sewage treatment plant that we visited serves 735,000 people and has more than 40 inflow stations that feed into the plant. The process is quite advanced and includes such processes as:
- Pumping sewage up 10M before entering the plant
- Running through steel screens to remove large debris
- Removal of heavier organic compounds such as grit and grease
- Aeration tanks that consume and dissolve remaining impurities
- Incineration of dry sludge (not usable on fields because of high presence of heavy metals)
This sewage treatment plant produces biofuels that provide 60% of the facility's energy needs. Something we have found impressive with many places we have visited thus far is the extent to which many places produce their own energy or tap other renewable energy sources.
Something else to note is that the sewage treatment plant discussed a slightly different definition of sustainability than we are accustomed to.
Luther's Definition of Sustainability:
Sewage Plant Definition of Sustainability:
It will be interesting to see whether we come across other definitions in the next few weeks.