AquaClim – Triplicate (2023-2027)
AquaClim is a project financed by the Research council Formas and is led by Lund University, in cooperation with Luleå University of Technology, Uppsala University and Chalmers, as well as a number of water utilities and the Swedish water and wastewater association “Svenskt Vatten”. The project runs for five years and finances five PhD candidates and a research school (Water Research School). The Water Research School gathers the PhD candidates affiliated to the four Swedish water research clusters, partly financed by Svenskt Vatten. Today around 80 PhD candidates are part of the research school.
The overall aim of the research projects connected to AquaClim is to build transdisciplinary competences by today’s and the future experts to be able to transform the water sector and specifically work with questions related to climate change.
Triplicate is the subproject that is carried out at Luleå University of Technology, in cooperation with Lumire AB. This project investigates in what contexts source separating sewage systems with three pipes (triplicate system) can be resource efficient in relation to material use, CO2 emissions and other environmental impacts. Furthermore, it will be investigated from which economic perspectives it is profitable to produce fertilisers from the toilet fraction of the wastewater. Are there any other drivers for introducing triplicate systems, such as water scarcity, limitations in existing infrastructure or need for technical water? In new areas, it is easier to install triplicate systems with greywater and black water in separate pipes. But how would the transformation look like in existing areas. Is it legal and/or are economic measures needed to support this transformation? These questions will also be studied in the project. At Luleå University of Technology, researchers from the research subjects Urban Water Engineering, Building Construction Management and Building Technology as well as Economics are involved in the project.
Project news and events
When sewer networks lack capacity...
2024-10-20, Stormwater&Sewers newsletter #41
What to do when the existing sewer network lacks capacity? Separate sewer systems are a potential option for areas where it is not possible to build new houses because the existing sewer network is full.
Sewerage separation involves the separate collection and treatment of different wastewater fractions. Given that greywater represents the largest volume of wastewater generated by households, separate collection and local treatment of greywater is a potential option for areas where there are limited possibilities to use and/or replace the existing sewer network. This would reduce both investment costs and CO2 emissions due to construction works.
However, guidance is lacking on how source separated sewer systems can be implemented. Therefore, the aim of this study carried out within the framework of the Formas project AquaClim, is to develop a framework that can help understand how separated sewer systems would work by identifying considerations and implications for their implementation. But the study also describes options for source separated sewer systems in areas where the existing sewer network cannot handle more discharges.
Water infrastructure planning involves close collaboration between stakeholders, which is why three workshops were organized between Lumire and the Urban Water Engineering research group at Luleå University of Technology. In these workshops, the possible implementation of source separated sewer systems was discussed, and the main barriers were identified (see figure).
Our preliminary results indicate challenges mainly related to black water systems.Vacuum systems use less water than others and are the most feasible option.For both LPS and pumping systems, the risk of H2S formation is higher, and one of the main reasons is the lack of design standards to prevent this. Reuse of greywater is an advantage of source separated sewer systems, but in the context of the study, flushing toilets with treated greywater is not an option.The reasons are that vacuum systems do not need large amounts of water so having two pipes would not be economically practical, and contaminants in greywater can affect the quality of products from resource recovery.
Figure: barriers for implementation of source separated wastewater systems
Letty Mora
Contact
Annelie Hedström
Updated: