Environmental and geometric optimisation of cylindrical drinking water storage tank
The construction of infrastructures related to the urban water cycle is key to ensuring the sustainability of this basic system. Several studies have assessed the sustainability of the urban water cycle but so far none had focused on municipal drinking water tank from an environmental perspective.
The study is evaluating 147 water (theoretical) tanks from a technical (amounts of materials) and environmental (quantification of environmental impacts) perspective. The study was conducted as part of a collaboration between the Universitat Autònoma de Barcelona and the Universitat Politècnica de Catalunya, combining a vision of civil engineering with a more environmental approach.
The tanks under assessment include water storage capacities between 100 and 10,000 m3. For each tank volume, different combinations of dimensions (radius and height) and positions (surface, buried, semi-buried) have been considered. Using a life cycle approach, the materials and processes for the construction of tanks have been accounted. Subsequently, a study was conducted considering the amounts of materials needed and applying the methodology of life cycle assessment to quantify the environmental impacts.
The results show that the consumption of materials is the main contributor to the environmental impact over transport, installation or demolition. Also, deposits with a storage capacity of between 1,000 and 2,500 m3 are less impacting. Regarding the dimensions, higher tanks are less impacting (for a 10,000 m3 tank, the highest option is 60-70% less impacting than the shortest). Finally, the superficially placed option impacts 15-35% less than the buried one, as earthmoving and transport is avoided.
In addition, environmental standards (selecting the best environmental option when building a new water tank) obtained from the study have been applied to three realistic case studies. For example, the application of these standards to an 8,000 m3 tank can save 170.5 tons of CO2 equivalent emissions (16 % of the total).
Considering these results in the construction sector may allow a significant reductions in the environmental impacts and contribute to the environmental sustainability of cities.
Reference:
Sanjuan-Delmás D., Hernando-Canovas E., Pujadas P. et al. (2015) "Environmental and geometric optimisation of cylindrical drinking water storage tanks". The International Journal of Life Cycle Assessment.
Read the article: http://link.springer.com/article/10.1007/s11367-015-0963-y