Creating Zero Waste Cities
Circular economy in waste and wastewater treatment — innovative solutions for resource efficiency in Smart Cities
Do we want to live in an intact environment in the future and slow down climate change?
If we want to achieve this, a drastic reduction in the volume of waste and wastewater is an essential piece of the puzzle. There are innovative solutions in cities and regions that focus on sustainable waste and wastewater treatment and on high-quality recycling, such as separating wastewater streams and fermenting residual materials to produce biogas or automated waste management. This article offers an innovative solution and highlights steps for implementing the circular economy in urban planning processes.
According to forecasts from the United Nations, annual global resource consumption will double by 2060. Associated with this, greenhouse gas emissions will continue to rise dramatically. At the same time, the World Bank estimates that global municipal waste will increase by 70% by 2050.
If we want to live in an intact environment in the future and mitigate climate change, the volume of waste produced must be drastically reduced. The Green Deal, a central element of the new EU Commission’s agenda for the next five years, aims to transform Europe’s economic system in such a way that greenhouse gases can be saved quickly and on a large scale. The concept of the circular economy plays a key role here and is also seen as a solution to the global waste problem.
With its orientation towards closed cycles, the circular economy preserves the value of products, materials and resources for as long as possible and contributes to the strong reduction or avoidance of waste.
Transitioning toward circular economy in waste and wastewater treatment
The concept of the circular economy offers an alternative model to the globally dominant linear economic model.
Major barriers in the way to achieving a circular economy in waste and wastewater treatment include other cheaper disposal options (compared to sustainable recycling), such as waste incineration; low prices for primary raw materials; and insufficient demand for recycled products. The closure of landfills for waste that is not pre-treated, as well as thermal waste treatment plants, to avoid corresponding landfill gas emissions has undoubtedly already contributed to the reduction of greenhouse gas emissions.
However, it is more sustainable to manage waste in such a way that less is generated, and resources are reused again and again. Improved waste collection can be the first step towards a comprehensive circular economy. Waste collection — as well as waste and wastewater treatment — are tasks of municipal institutions. There are innovative solutions in cities and regions that, on the one hand, aim for more responsibility on the part of producers and, on the other hand, focus on high-quality recycling and sustainable waste and wastewater treatment — such as separation, fermentation and biogas production.
Helsingborg installs three separate pipes for wastewater and waste collection
As an example of a city on the way to achieving a circular economy, Helsingborg has been the number one Swedish municipality in sustainability for four years in a row. Helsingborg’s vision is a circular economy for all and the goal is to become a zero-waste city until 2030. Together with citizens, businesses and academia, the city has tested and implemented many different small and large initiatives.
For instance, in 2020, the City of Helsingborg and the municipal wastewater company in the city’s Oceanhamnen district were awarded for their transformative initiative to build a globally unique wastewater system. This project was the overall winner of the Smart City Implementation Award (SMAVARD) 2020, organised together with BABLE. The project comprises of around 350 flats and 30,000 m² of office space. The first residents moved into the development in March 2020 and the system is now gaining valuable experience in operation.
In this system, the traditional sewage pipe is split into three separated sewage pipes: food waste, toilet water or black water and grey water from bathing and washing are collected separately in three pipes at the point of use in each household. The separation of municipal wastewater aims to increase water and energy conservation, eliminate food waste and recycle black water in an environmentally friendly manner. The recovery centre collects nutrients and materials to produce biogas and organic fertiliser that meet the EU end-of-waste criteria. It also collects residual heat from the greywater stream to heat more houses before the remaining wastewater from the three streams is transferred to the treatment plant.
The challenge in Helsingborg has mainly been to implement a new integrated management system for waste, water and energy, which was previously managed by separate entities. The new wastewater system, separated into three pipes, overlaps the waste, water and energy sectors and therefore requires increased cooperation between the city and its utilities.
“Another challenge is to meet the application of EU End of Waste criteria and to convince a traditionally conservative water sector that wastewater systems with a circular economy approach could be an economical way to address current and future environmental challenges. Being up and running since spring 2020, I can now say that it is going smoother than expected!” — Hamse Kjerstadius, Development Engineer in Helsingborg
Citizens have played an important role in the success of the project in various roles. The project was designed from the outset with broad-based participation by developers, citizens and water and waste management experts, resulting in a high rate of approval for the solution.
The system with three separate pipes for wastewater and waste is an excellent example of a circular economy in action. It is possible for Helsingborg residents to keep the environment clean and save water, and to keep energy and nutrients from ending up in the rubbish. The maximum recyclable share of the food and water consumed is used. Greenhouse gas emissions are reduced by more than 50% compared to the conventional system, reducing energy and water consumption and landfill waste to an absolute minimum.
Many other projects that show how innovative technologies are saving resources in European cities can also be found as Use Cases on the BABLE platform.
Aspects to focus on for successful urban implementation of resource-saving measures
The transformation from a linear economy to a circular economy requires new consumer behaviour and new solutions for recycling waste into resources. However, challenges like the ones Helsingborg faced to implement its solutions can be effectively addressed.
A transition to a different form of economy affects many areas and thus numerous actors in different sectors and administrative levels. Individual institutions or companies cannot implement the circular economy model in isolation. Rather, a circular economy requires the willingness of all stakeholders to cooperate and communicate and to work together across disciplines. Oftentimes, it also requires new business models.
The key areas “information transfer”, “citizen participation” and “funding and financing” have to be considered during the process for successful urban implementation of resource-saving measures. These are described in the following figure.
Cities and regions should define their commitment to a circular economy in a strategy paper. Local priorities, planned actions and possible support have to be integrated into this strategic document. Such documents can include EU regional operational programmes, long-term development plans, environmental strategies, and thematic or sectoral strategies; for example, on waste management. This enables local and regional actors to plan their activities in the long term.
The importance of the sharing of such solutions is the ability for replication and scalability throughout other cities. Use Cases like in Helsingborg and innovative waste management systems give other cities the blueprint and opportunity to reach new goals and to provide a better future for all their residents.
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