Page 13 - U4SSC Case study: Reducing food waste, June 2020

Case Study 2 – Oslo, Norway: Circular Bioresources – Treatment of Food Waste,
Garden Waste and Sludge from Wastewater

Author:

Nikolaos Kontinakis

Introduction

Background

Oslo is the capital of Norway and the country’s largest city, with approximately 670 000 inhabitants. It
is a compact capital city surrounded by a nationally protected forest and the Oslo Fjord. The population
is young, highly educated and diverse – one third of the population are first or second-generation
immigrants. The standard of living, and thus consumption levels, is high. This also generates a lot of
waste from households, and roughly half of the waste is organic.

Oslo is one of the fastest growing cities in Europe, thus constituting a great opportunity, as well as
a great challenge. The city has to plan and build for growth in terms of infrastructure, schools, care
facilities and service production, while implementing an ambitious environmental and climate policy.

Challenge and response

The cycling of nutrients is critical for the growth of all plant and animal life on the planet. Humans
set the natural balance of nutrients and the soil carbon cycle under stress by intensive use of land,
harvesting plant material for food, feed and other applications. Mostly, the residues of these activities
end up as ‘bio-waste’.

Cities are major concentrators of bio-waste flows from food waste, garden and park waste, and the
urban wastewater sludge. The bio-waste represents a significant opportunity to recover nutrients and
return them to the soil. It is also possible to produce biogas and other bio-based products from the
bio-waste.

Moreover, the production of bio-waste-based products provides a positive climate impact in comparison
with landfilling and incineration, and by replacing fossil-based products such as mineral fertilizers, peat
and fossil fuels. No biodegradable waste is sent to landfills (this has been prohibited in Norway since
2009).

The city of Oslo wanted to establish a cycle-based waste management where the resources in the bio-
waste could be used for the benefits of the citizens and the society. Since the inner city is compact
and the spaces for waste bins are limited, Oslo decided to retain the system involving the collection
of waste from two bins at home. Therefore, it was decided to build optical sorting plants to be able to
put three waste fractions into one bin.

Case study: Reducing food waste, June 2020 7