Solutions for Wastewater Treatment Plants

Freshwater is increasingly a scarce resource and wastewater produced by urban and agricultural areas is a significant source of pollution. Wastewater treatment plants therefore provide a valuable service and need to be looked after. Sika’s long term know-how and expertise is there to support Owners, Specifiers and Contractors in choosing the right sustainable solution.

As the industry leader in concrete repair and protection, Sika can provide long lasting construction and refurbishment solutions to prolong the longevity of wastewater treatment plants. Sika’s wide range of repair and concrete protective solutions aims for long term sustainable refurbishment strategies, in terms of cost, time, materials and impacts.

Environmental Impact Criteria

CED accounts for the consumption of energy resources, namely the primary energy from renewable and non-renewable resources.

GWP measures the potential contribution to climate change, focusing on emissions of greenhouse gases, such as carbon dioxide (CO₂).

POCP is the potential contribution to summer smog, related to ozone induced by sunlight on volatile organic compounds (VOC) and nitrous oxides (NOx).

Protecting Water and the Environment

A refurbishment project with a surface of 1,000 m² for a typical time period of 60 years was analysed for two refurbishment strategies: a typical traditional system (scenario 1) and a Sika State-of-the-Art system (scenario 2):

Scenario Description Characteristics      
    Material efficient Time efficient Overall cost efficient VOC content
1 Traditional Mineral and solvent based products
Resurfacing mortar and protective coating
- - ++ ++
2 Sika state-of- the-art Polymer based products (low VOC content)
Hydrophobic impregnation and protective coating
+++ ++ ++ +

Qualitative characterization of the scenarios

Legend: - very low; + low, ++ average; +++ high; ++++ very high


Results and Conclusions

To depict the environmental impacts from both scenarios, they were compared using a Life Cycle Assessment (LCA). The LCA is from cradle to grave, which means it investigates the potential environmental impacts from raw material acquisition, production, use, to end-of-life treatment, and final disposal.

To illustrate the environmental impacts from both scenarios, the Cumulative Energy Demand (CED), the Global Warming Potential (GWP) and the Photochemical Ozone Creation Potential (POCP) were determined.

70% Material Savings
1. 70% Material Savings

Scenario 1 uses products of lower quality and therefore needs to repeat the different refurbishment steps several times (total 4 times). On the other hand, scenario 2 uses products of higher quality, so the different refurbishment steps can take place only once, followed by a refreshing coat every 20 years (total 1 time). Scenario 2 allows more than 70% material savings and lower refurbishment frequency and intensity, and represents a material efficient and time saving solution.

Refurbishment strategies for 60 years
2. Higher Resource Efficiency

Since traditionally used products are mainly cementitious with lower cradle to gate environmental impacts than polymer modified and polymer based technologies, the environmental savings are not as significant as the material savings. Even so, the new technologies of higher quality have comparable environmental impacts over the complete refurbishment regime.

In terms of POCP, scenario 2 has higher impacts. However, these relate to a 60 years period, so one can regard this as a slight disadvantage of a scenario which brings huge benefits from a resource efficiency point of view.

Comparison for the main sustainability drivers in refurbishment
3. More Sustainable Value

To show the overall environmental and economic performance of Sika state of the art systems vs. traditional systems, a relative comparison for the main sustainability drivers in refurbishment (materials, time, costs, GWP, CED, POCP) is shown below. The Sika state-of-the-art system has the best overall performance.