01.06.2015 | Ausgabe 8/2015

Assessing the Energetic and Environmental Impacts of the Operation and Maintenance of Spanish Sewer Networks from a Life-Cycle Perspective
- Zeitschrift:
- Water Resources Management > Ausgabe 8/2015
Wichtige Hinweise
Electronic supplementary material
The online version of this article (doi:10.1007/s11269-015-0958-2) contains supplementary material, which is available to authorized users.
Highlights
The electricity consumption in sewers varies depending on the city.
On average, Spanish sewers consume 6.4 kWh per capita.
Atlantic cities require more energy to pump wastewater than Mediterranean regions.
The electricity needs depend on the length of the sewer and the wastewater production
Abstract
The environmental impacts resulting from sewer networks are best analysed from a life-cycle perspective to integrate the energy requirements into the infrastructure design. The energy requirements for pumping wastewater depend on the configuration of the city (e.g., climate, population, length of the sewer, topography, etc.). This study analyses and models the effect of such site-specific features on energy consumption and related effects in a sample of Spanish cities. The results show that the average annual energy used by sewers (6.4 kWh/capita and 0.014 kWh/m3 of water flow) must not be underestimated because they may require up to 50 % of the electricity needs of a typical treatment plant in terms of consumption per capita. In terms of Global Warming Potential, pumping results in an average of 2.3 kg CO2eq./capita. A significant positive relationship was demonstrated between the kWh consumed and the length of the sewer and between other factors such as the population and wastewater production. In addition, Atlantic cities can consume 5 times as much energy as Mediterranean or Subtropical regions. A similar trend was shown in coastal cities. Finally, a simple predictive model of the electricity consumption was presented that considers the analysed parameters.