The Swedish city of Helsingborg is executing the city renewal project H+, linking existing districts to the city centre and enriching the living environment by converting former industrial sites into modern and green living spaces. The Oceanhamnen part of the H+ project, currently in the last phases of construction, is one of the Run4Life demonstration sites. It will accommodate an innovative waste and wastewater management system for around 320 apartments and several office buildings, amounting to around 1800 people equivalents. Toilet wastewater (black water), organic kitchen waste and other domestic wastewater (grey water) will be separately collected and treated, aiming for maximum resource recovery. The Oceanhamnen local treatment system is located at the existing Helsingborg sewage treatment plant and managed by project partner NSVA. The Reco Lab (recovery laboratory, test-bed facility) and an educational showroom will be implemented together with the treatment plant.
The Reco Lab will be a meeting-place and test-bed for research and development. Performing research in the area of resource recovery from separated wastewaters and other innovations within the whole wastewater treatment chain. It will not only focus on technological aspects, but also on communication with end-users and acceptance of the concept and its products. The Reco Lab, therefore, will offer superb opportunities for visualisation and education along with public communication that supports the implementation of this kind of sustainable sanitation systems.
‘Three pipes out’: optimal treatment and recovery for three flows
The new residences and office buildings in the Oceanhamnen district will be equipped with a vacuum collection system for toilet wastewater. Vacuum toilets only use around 1 litre of water per flush, resulting in a significant reduction in water use compared to standard flush systems, and a highly concentrated black water flow. Grinders for organic waste will be installed in the kitchens, connected to a separate low pressure sewer collection pipe. Grey water, originating from e.g. showers and washing machines, will be collected in a third pipe.
The organic kitchen waste and concentrated black water will be transported to the treatment plant where the flows will be treated in separate UASB reactors for anaerobic digestion. The produced biogas will be processed in the city’s central biogas network, for local use as fuel for public transport or street lighting. Sludge from both digesters will be dewatered and used as separate organic fertiliser fractions. The liquid effluents will be combined in one flow, which is used to recover struvite (a phosphate fertiliser) and ammonium sulphate (a nitrogen fertiliser). The leftover effluent is mixed with the grey water (not included in the Run4Life project). At first the effluent of this third treatment section will be sent to the Helsingborg sewage treatment plant, but options to use it as a water source are currently being explored.
Tailor made fertiliser products
The recovered struvite and ammonium sulphate can be used in a wide range of fertiliser products for agricultural applications. In the case of Helsingborg, they will be mixed in different ratios with hygienised sludge from either the kitchen waste digester or the black water digester to produce tailor made fertilisers according to farmer’s requirements. This tailor made production of pellets or granules from these sludges is possible due to the existing Swedish national sludge certifications and EU end-of-waste process.
As many people, companies and organisations are involved in the Run4Life project, it is interesting to see how these groups are connected to one another and how they are involved in the project. This can help with identifying possible new stakeholders and collaborations. For this purpose, stakeholder maps for each demo site were created. The stakeholder map is a tool that shows the connections between stakeholders and can therefore help visualise the social context. The initial mapping of stakeholders and expectations for all demo sites is described in project report Deliverable 6.1 and more information on the social context of Run4Life can also be found here.