Materials Recovery Biological Treatment (MRBT) is a better way of dealing with residual waste than incineration, according to a life cycle analysis study.
A report on the study, What is the best disposal option for the ‘Leftovers’ on the way to Zero Waste?, concluded that MRBT, which extracts remaining recyclable material from residual waste and reduces landfill gas produced by material that is buried, has the lowest environmental impact of all current disposal methods.
The study, carried out for US zero waste social enterprise Eco-Cycle, compared the environmental and health impacts of three disposal methods: Energy from Waste, energy from landfill gas and MRBT. The comparisons were across categories including climate change, water pollution, air pollution and health impact.
The research concluded that MRBT recovered the most extra recyclables, stabilized the organic fraction of residuals and reduced the amount of material to be disposed of to landfill.
The study estimated that the city of Seattle, Washington, could divert 87% of waste from landfill by employing MRBT.
Eco-Cycle executive director Eric Lombardi said: “MRBT is not a replacement or substitution for source separation, but it is a tool for helping communities reduce the environmental impacts of managing their leftovers as they progress on their way to Zero Waste.”
Other key findings include:
- All options resulted in increased pollution in at least one of the seven public health and environmental impact categories included in this study.
- The climate impacts of landfills depended highly upon the effectiveness of the landfill gas capture system.
- The combustion of Energy from Waste had higher relative human health impacts than the non-combustion MRBT-to-landfill scenarios.
- Communities should continue to focus on decreasing the amount of leftovers they produce through recycling, composting and waste reduction programs.
The study was undertaken by Dr Jeffrey Morris, an economist and life-cycle assessment expert with Sound Resource Management Group based in Olympia, Washington; Dr Enzo Favoino, senior researcher at Scuola Agraria del Parco di Monza in Milan, Italy; and two of the Eco-Cycle staff.