Food waste minimization from a life-cycle perspective.

This article investigates potentials and environmental impacts related to household food waste minimization, based on a case study in Southern Sweden. In the study, the amount of avoidable and unavoidable food waste currently being disposed of by households was assessed through waste composition analyses and the different types of avoidable food waste were classified. Currently, both avoidable and unavoidable food waste is either incinerated or treated through anaerobic digestion. A hypothetical scenario with no generation of avoidable food waste and either anaerobic digestion or incineration of unavoidable food waste was compared to the current situation using the life-cycle assessment method, limited to analysis of global warming potential (GWP). The results from the waste composition analyses indicate that an average of 35% of household food waste is avoidable. Minimization of this waste could result in reduction of greenhouse gas emissions of 800-1400 kg/tonne of avoidable food waste. Thus, a minimization strategy would result in increased avoidance of GWP compared to the current situation. The study clearly shows that although modern alternatives for food waste treatment can result in avoidance of GWP through nutrient and energy recovery, food waste prevention yields far greater benefits for GWP compared to both incineration and anaerobic digestion.

Bernstad Saraiva Schott A ，Andersson T 《-》

Potentials for food waste minimization and effects on potential biogas production through anaerobic digestion.

Schott AB ，Vukicevic S ，Bohn I ，Andersson T ... -  《-》

Mitigation of global greenhouse gas emissions from waste: conclusions and strategies from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. Working Group III (Mitigation).

Bogner J ，Pipatti R ，Hashimoto S ，Diaz C ，Mareckova K ，Diaz L ，Kjeldsen P ，Monni S ，Faaij A ，Gao Q ，Zhang T ，Ahmed MA ，Sutamihardja RT ，Gregory R ，Intergovernmental Panel on Climate Change (IPCC) Working Group III (Mitigation) ... -  《WASTE MANAGEMENT & RESEARCH》

A life cycle approach to the management of household food waste - A Swedish full-scale case study.

Environmental impacts from incineration, decentralised composting and centralised anaerobic digestion of solid organic household waste are compared using the EASEWASTE LCA-tool. The comparison is based on a full scale case study in southern Sweden and used input-data related to aspects such as source-separation behaviour, transport distances, etc. are site-specific. Results show that biological treatment methods - both anaerobic and aerobic, result in net avoidance of GHG-emissions, but give a larger contribution both to nutrient enrichment and acidification when compared to incineration. Results are to a high degree dependent on energy substitution and emissions during biological processes. It was seen that if it is assumed that produced biogas substitute electricity based on Danish coal power, this is preferable before use of biogas as car fuel. Use of biogas for Danish electricity substitution was also determined to be more beneficial compared to incineration of organic household waste. This is a result mainly of the use of plastic bags in the incineration alternative (compared to paper bags in the anaerobic) and the use of biofertiliser (digestate) from anaerobic treatment as substitution of chemical fertilisers used in an incineration alternative. Net impact related to GWP from the management chain varies from a contribution of 2.6kg CO(2)-eq/household and year if incineration is utilised, to an avoidance of 5.6kg CO(2)-eq/household and year if choosing anaerobic digestion and using produced biogas as car fuel. Impacts are often dependent on processes allocated far from the control of local decision-makers, indicating the importance of a holistic approach and extended collaboration between agents in the waste management chain.

Bernstad A ，la Cour Jansen J 《-》

Impact of waste processing byproducts on the carbon footprint of integrated waste-to-energy strategies.

Resource recovery is a promising solution for multiple waste and economic challenges worldwide. Although the life cycle environmental performance of resource recovery systems has been widely studied, the impacts of their resultant waste processing byproducts remain unassessed. Depending on their management techniques and destinations, such large waste streams, such as non-recovered recyclables and anaerobic digestate, may significantly alter the overall environmental footprint of the integrated solid waste management (ISWM) strategy. This research aimed to assess the life cycle impacts of various ISWM strategies incorporating material recovery and waste-to-energy (WTE) systems. The examined strategies were based on combinations of incineration (INC) and anaerobic digestion (AD) plants, in addition to material recovery facilities (MRFs) and landfills. The study used eighteen scenarios to explore the effect of the potential pathways of waste processing byproducts on the overall carbon footprint of the strategies. The proposed lifecycle assessment framework was applied to an emerging metropolis. The highest energy recovery was achieved in the dual AD and INC scenarios, particularly when the digestate was incinerated, followed by the mono INC scenario. The highest material recovery, specifically recycled materials and digestate, was accomplished in the MRF+AD and MRF +AD+INC scenarios, in which digestate was marketed and non-recovered recyclables were incinerated. It was found that alternative pathways of waste-processing byproducts can reduce the overall global warming potential (GWP) of the base scenarios. Combining MRF and INC as well as MRF, AD, and INC while incinerating non-recovered recyclables, disposing ash, and marketing digestate (if any) were the optimum environmental options in terms of GWP. Incineration of non-recovered recyclables reduced carbon emissions by 29% compared to disposal, whereas marketing and incinerating the digestate positively impacted GWP compared to landfilling (83 and 77%, respectively). A breakdown of the sub-processes revealed that the energy recovery, recycling, and landfilling processes had the highest contributions to the total GWP (up to 88, 92, and 98%, respectively); the collection and transportation processes had the least impacts (2 and 13%, respectively). The more waste-processing byproducts were incinerated, the greater GWP contribution of energy recovery.

Abdallah M ，Elfeky A 《-》