Studies concerning the implementation of food waste disposers (FWDs) shows that 20-30 % of the domestic waste may be removed from the domestic waste upon installation FWD in private households. Danish studies do not indicate increased problems of sedimentation or blockage. However, regarding the operation of drainage systems, it is concluded that drainage systems with long retention time may be exposed to increased risk of hydrogen sulphide formation upon installation of FWDs which is however technologically manageable.
From an energetic point of view the incineration the most efficient waste to energy conversion technology (65 % more than wastewater treatment plants), followed by biogas plant (14 % more than wastewater treatment plants).
Although energy production from waste incineration at national scale replaces coal and therefore saves fossil fuel needed for electricity and heating, anaerobic digestions offers the greatest savings of greenhouse gases emissions, as biogas has a higher electricity generation efficiency compared to waste incineration (DANVA, 2011; Thomsen et al., 2016).
It should be noted that the energy and environmental benefits of the organic waste management and conversion technology systems depends on the energy sources used to produce electricity and heat, and the fuel type used in the transport sector. Therefore the assessment of the synergies between management of waste as a resource and the existing energy system in the city needs to be evaluated at the city scale.
The site conditions in both waste and energy sectors are essential for what is environmentally advantageous and in general, results cannot be directly transferred from one region to another. For example in Aarhus they have no separate collection of organic waste which makes FWDs a seemingly plausible solution.
A previous analysis performed by COWI shows that the feasibility of implementing FWDs needs to be evaluated for each particular case as there are no clear advantage of using FWDs as vehicle for source separation of food waste from the solid domestic household stream prior to energy conversion. Therefore, it is important to assess the environmental performances of the waste management scenarios in Aarhus, evaluating their potential contribution in achieving the fossil free and carbon neutral goals targeted by Aarhus Municipality council.
Want to know more?
Delivery no. D.2.4.3 Feasibility study of food waste disposers from households
Please contact: Mr. Steffen Petersen, Aarhus University, firstname.lastname@example.org