Campus Ås is a property of the Norwegian University of Life Science, NMBU. It is located in the peri-urban area of Ås Municipality, situated 30 km south of Oslo.

Within the SiEUGreen project, Campus Ås demonstrated how different technologies are combined to turn waste into resources in a circular system. A bubble greenhouse lies at the core of the circular system and showcases how sub-products of wastewater and solid waste are transformed into fertilisers to grow food. The closed system is fed by various sources and uses a combination of technologies. For example, student housing and administrative buildings were equipped with vacuum toilets. The toilet wastewater is treated in a reactor that transforms it into a concentrated liquid fertiliser used to grow food in the bubble greenhouse. While vacuum toilets enable a reduction of 90% of water consumption, on-site treatment and recycling of blackwater into nutrients allow for an ecological and economically efficient system that saves resources. In addition, greywater from an administrative building is pre-treated in wetland/filter beds, processed in tanks, and used for irrigation and generation of bubbles in the greenhouse. These bubbles improve the greenhouse’s insulation in the winter and cooling in the summer, thus extending the growing period within a cold climate.

Household waste is also transformed into vermicompost, which is used as a soil additive to grow food in the bubble greenhouse. Campus Ås also showcases a borehole thermal energy storage system (BTES). In this system, the heat from solar energy captured through PV panels is stored in rock sediment underground. This system allows the harvested heat in the summer to be used in the cold season to warm up the surrounding buildings.

Campus Ås also demonstrated the efficiency of green roofs for rainwater management and the potential of nature-based solutions such as a network of rain gardens, ponds, and open streams to drain stormwater while creating a diverse and attractive landscape. The interlinkages between these different systems aim to demonstrate how low and high technologies can be employed in urban environments contributing to urban sustainability and resilience.

In Aarhus Municipality (Denmark), the programme “Taste Aarhus” adopts an inclusive approach to facilitate different social groups (e.g., residents, businesses, and local institutions) to engage in urban agriculture. This case provides valuable lessons on how to engage diverse sectors of society (such as urban planning, social, health, and educational sectors) while capitalising on available resources (e.g., underutilised spaces in the city, human resources). The case also empowers residents to address the challenges of segregated communities, obesity, lack of access to green areas, and absence of physical activity. In the context of SiEUGreen, two gardens acted as testbeds for different technologies: Brabrand Fællesgartneriet and World Gardens.

 

The Turunçlu greenhouse in Antakya, Turkey, was built with the support of SiEUGreen and Hatay Municipality and has been in operation since May 2021. The purpose of the greenhouse is two-fold: to introduce new technologies to produce food in the region and to promote social integration of vulnerable groups. In the context of Antakya, agriculture plays a vital role in the region’s economy; however, reliance on traditional soil-based modes of food cultivation and soil depletion due to unsustainable agricultural practices has led to a growing need for new technologies that can improve the region’s resilience. In the greenhouse, aquaponics technology is adopted to grow food. Aquaponics combines aquaculture (fish farming) with hydroponics (cultivation of food in water) into a sustainable system that does not require soil, can save water usage by around 90%, and uses fish manure as a nutrient for the production of herbs and leafy greens to feed people. 

Turunçlu greenhouse has approximately 1,500 m², about half of which is occupied by growing channels where lettuce and basil are cultivated. The aquaponics system includes six fish tanks, each with a capacity of five tons of water. These tanks are connected to a biofiltration pool that collects fish waste to produce a liquid fertiliser used in the hydroponic system.

Regarding social integration, the greenhouse became an educational centre offering training on aquaponics, hydroponics, and paper-based microgreen cultivation techniques to disadvantaged groups (specifically, Syrian refugees, low-income residents, and women). The collaboration with local universities is also an added value as it helps to anchor aquaponics technology as a feasible and efficient means of producing food that local entrepreneurs can embrace. Furthermore, the greenhouse functions as a centre for disseminating the value of urban agriculture to younger students from primary and secondary schools. In 2021, 148 people participated in six workshops held in the greenhouse providing information about the potential of aquaponics for food production in the region.

Unfortunately, in February 2023, Antakya was severely affected by earthquakes that left the region devasted, including the collapsing of the Turunçlu greenhouse.

Sanyuan Farm is a state-owned farm in Beijing, China, which has been in operation since 1949. It is located in the peri-urban area of Beijing and has an area of 667,000 m² divided into two equal halves. In the West District, several greenhouses produce fresh vegetables. This production significantly impacts Beijing’s food resilience as it supplies the city with vegetables that previously came from South of China.

The East District consists of a cherry forest and flower fields managed by the government. In 2008, approximately 165,000 m², about half of the district, was divided into small plots (between 50 and 80 m²) and rented out to people who wanted to grow their own food. This area attracts around 1,300 middle-class, well-educated Beijing households. A large greenhouse was built in the East District and, since 2012, demonstrates hydroponics and aquaponics technologies. This greenhouse is a centre that combines urban agriculture with tourism, technology, and education and attracts a diverse group of stakeholders. The greenhouse advises companies on the potentialities of soilless and aquaponic technologies, hosts school kids that learn how to grow food, and gives tourists the opportunity to harvest the food produced in the greenhouse and open fields.

Sanyuan Farm’s vision is to demonstrate resource-efficient UA and a healthy, happy lifestyle. Within SiEUGreen, the farm demonstrates the implementation of aquaponics technology to grow vegetables and focuses on recovering nutrients from organic waste. The farm tested organic fertiliser generated by biological processors that recycle household waste.

 

The Futiancangjun residential area in Changsha, China, demonstrates a resource-efficient, intelligent, and sustainable urban development with reduction, reuse, and recycling of waste, local supply of safe food, and effective utilisation of solar energy (Michailidis, 2021). Futiancangjun development covers an area of 320,000 m² with a total construction area of 700,000 m², which includes 35 high-rise buildings (18 floors) with around 100 apartments per building. The entire development accommodates 3,500 families. The buildings are similar to one another and offer apartments of 70, 100, 120, and 180 m² to attract families with different needs. In addition to the residential buildings, the development includes a kindergarten, primary school, junior school, and a park, and there are also plans to add a shopping mall (Borges et al., 2019).

Within the SiEUGreen project, 18 apartments were equipped with low-flush toilets. This technology reduces water usage and enables struvite precipitation from blackwater. In addition, 100 hydroponic devices that support growing vegetables, fruits and herbs on apartment balconies were donated to some of the residents to promote urban agriculture.

Overall, the knowledge and technology sharing between the European and Chinese partners was successful, especially in the green and blue technologies. For example, the paper-based microgreen production (which involves growing edible sprouts in paper as an alternative to sowing them in the soil) used by the Chinese partner, Beijing Green Valley Sprout Ltd (BGVS) was also tested in Norwegian research institute NIBIO. Another example comes from the implementation of wastewater treatment technology which took place both in Changsha (by Hengkai and in collaboration with Scan Water) and at NMBU in Norway.

The main challenges encountered in the project originate from cultural differences and linguistic barriers. Strategies like the promotion of several scientific visits between China and Norway, specialists’ exchanges, and regular online meetings and communications were employed to ease these shortcomings.

REDUCE: Input minimisation and efficient use of regenerative resources

This strategy focuses on the prevention and reduction of raw materials and energy consumption

REUSE: Life cycle extension and systems reconceptualization

This strategy is related to expanding/optimising lifespans; reconceptualising products to greater lifecycles from the outset; facilitating maintenance, repair, reconditioning, and re-manufacturing options; and creating new business models

RECYCLE/RECOVER: Waste reduction, valorisation and minimisation

This strategy relates to waste management and recycling of waste that cannot be reused or re-manufactured. It also involves using waste/by-products from one process as raw materials for another, thereby ascribing a higher value to waste materials as potential resources that can feed production.