Project 8: Aquafin – Environmental impact study

Planning Realisation Monitoring Evaluation
Aquafin – Environmental impact study

Sewage contains a large amount of heat that could potentially be used for renewable heating. A lot of heat produced in the urban water cycle for washing, taking a shower, etc. is lost through the sewage. While heat recovery from sewage has local benefits, it reduces the temperature of the sewage and in case of a significant temperature drop at the treatment plants influent, the waste water treatment process may be affected.

The project is aiming to give a scientifically proven answer to the questions:

  • Is heating with sewage heat an option for me? Does it reduce our ecological footprint?
  • Will heat extraction from sewage using a heat pump affect my waste water treatment plant?

Therefore, with the measured data in this cooperative INNERS project, Bradford university will develop a heat transport model based on a measurement in the sewer catchment of Antwerp-South. This model should allow asset managers to predict heat transport in their catchments when they have a calibrated model of the sewer catchment.

Deciding whether a heat pump in the sewerage system is feasible or not and whether it affects water treatment downstream, may be hard. Therefore, the impact of many heat pump locations will be evaluated virtually through heat transport modeling of the sewerage system and dynamic activated sludge modeling of the waste water treatment plant. The methods used do not only take energy consumption into account for scenario evaluation, but also environmental impact, nutrient loads in the effluent and greenhouse gas emissions, will be considered. From the modeling results, a decision support system will be created that allows  to verify where a heat consumer could use a heat pump for environmentally friendly heat extraction from sewage.

Currently, initial modeling started and measurements for the temperature monitoring campaign are installed and data collection is going on:

  • 20 temperature sensors for sewage and  sewer air temperature
  • 2 temperature sensors for storm water temperature
  • 4 rainfall measurements
  • 7 flow measurements
  • Soil temperature profile at  2 locations and  1.5, 2.25, 3.0 and 3.75 m depth
  • Greenhouse gas monitoring campaign on  WWTP each season: impact of  temperature variation on greenhouse gas emissions