Managing food waste is key to tackling climate change

Energy from food waste

Hospitals produce and waste large amounts of food. When disposed in landfill it creates greenhouse gases (GHGs) from the decomposition process. While various food waste management strategies exist that divert hospital food waste to an alternative end of life pathway to landfill, it is not clear which can decrease GHG emissions the most. This study aimed to (a) compare the differences in GHG emissions associated with hospital foodservice food waste before and after adopting a food waste management strategy, and (b) identify which waste management strategy can prevent the most GHGs in 1 year. A secondary analysis of data from a systematic review reporting on food and food-related waste diversion strategies in hospital foodservice was conducted. The online "ReFED Impact Calculator" was used to calculate GHG emissions from food waste in the original scenario (e.g., landfill), and the alternative scenario after a food waste management strategy that reused, recycled or recovered resources was implemented. The net change of GHGs was calculated, and the GHGs emissions avoided in paired samples and between food waste management scenarios was analyzed statistically. Fifty-five food waste management strategies (surplus food donation, feeding animals, anaerobic digestion or industrial uses, and composting) were eligible for analysis and were grouped into eight scenarios. The median GHGs generated decreased after adopting the alternative strategy in all scenarios. There was a statistically significant median reduction in GHGs when changing from landfill to donations (-11.54, p < 0.001), landfill to industrial uses (-25.92, p < 0.001), and landfill to composting (-15.24, p < 0.001). Percentage change in GHGs generated in these 3 scenarios demonstrated a significant difference (p < 0.001), with landfill to donations displaying the greatest reduction in GHGs (-92.02%), followed by composting (-8.69%) and industrial uses (-7.75%). Various food waste diversion strategies can handle types and volumes of hospital food waste, yet each strategy displays a reduction in GHG emissions compared to a lower prioritized strategy. Donating waste shows the greatest reduction in GHG emissions and if food waste cannot be avoided, it may be the preferred end of life pathway for food waste.

Reducing our waste size

Methane mitigation strategy for food waste management: Balancing socio-economic acceptance and environmental impacts

<abstract> <bold>Abstract.</bold> Food waste is one of the largest component of municipal solid waste (MSW) in Canada and USA. About 30%-50% of global produced food becomes waste and this value is around 40% in North America. On average a Canadian produces almost 300 kg food waste annually and half of it is collected separately from individual households which needs immediate treatment. In majority of the cities and municipalities in North America (especially in USA) the food waste is collected and disposed in a MSW landfill. There has been recent trends in many cities and municipalities in North America including Ontario is to collect the food waste as part of source separated organics (SSO) and treat and manage the SSO using either compost plants (aerobic process) or as part of an anaerobic digestion (AD) plants with composting treatment being a dominant one. Both these approaches have their benefits and drawbacks. In very recent, there has been discussions in the waste related symposiums and conferences has been to use a hybrid approach, which is to separately collect the readily degradable food waste and treat them in an AD system to capture the methane gas and use it as an energy source and use the AD solid digestate along with other organic wastes to produce a good quality compost to recover nutrient value and use it as the soil amendment. For evaluation of this hybrid approach, a laboratory scale wet mesophilc type AD treatment of food waste was considered to determine optimum operational conditions for maximum energy recovery from food waste streams. In addition, the AD solid digestate composting was evaluated mixing with other organic waste to produce good quality compost. A batch scale continuous stirred-tank reactor (CSTR) type food waste AD for biogas production in the laboratory at mesophilic temperature can determine the optimum production parameters. An existing southwest Ontario food waste AD facility was evaluated for this AD reactor. Food waste characterization and pre-treatment can be carried out at AD plant and the laboratory set up condition can be same as the existing food waste AD plant. A windrow composting process activities can be monitored and evaluated from the same city composting facility. AD solid digestate co-compost in this compost plant was evaluated. Temperature, P^H, C/N ratio, moisture content and produced gases from AD and other parameters along with aerobic composting parameters were considered same as the existing facility. Finally this hybrid approach was compared with the existing systems in an Ontario city e.g., Greater Toronto (GTA) AD and composting facility.

Assessing the environmental performance for more local and more circular biowaste management options at city-region level

Food waste has a high potential for greenhouse gas (GHG) emission, particularly methane, which has been causing climate change issues worldwide. This quantitative research is aimed to investigate the situations of food waste and assess its greenhouse gas emission potential in Thailand. Food waste management in eight municipalities was analysed across four regions countrywide. The findings showed that the COVID-19 pandemic led to a dramatic reduction in municipal food waste (MFW). This led to a total of around 26,657 tonnes/day in 2021, which was nearly 39% of the total MSW and the average MFW generation per capita was 0.4 kg/capita/day. Household food waste (HFW) represented a major component of MFW. In large urban municipalities and cities (notably tourist cities), significant food waste per capita exceeded the peri-urban municipalities (P &lt; 0.05). Moreover, the treatment of MFW could result in significantly higher GHG emissions than from fossil fuel emissions created by the collection and transportation of MFW. This comparison between the four food waste management technologies that emits the most greenhouse gases showed that landfill had the most GHG emission potential, followed by incineration, composting, and anaerobic digestion, respectively. The research findings clearly illustrated that the municipalities at all levels needed to take the following actions: 1) conduct a survey and study the situations of food waste problems in local area, 2) formulate the policy for food waste management and treatment using the appropriate selection of technologies available with a minimum of impact on the environment and the Earth’s atmosphere, and 3) utilise the GHG emission potential for food waste disposal, such as energy recovery as well as possible trading-in for carbon credit.

The food waste hierarchy as a framework for the management of food surplus and food waste

Waste prevention, energy recovery or recycling - Directions for household food waste management in light of circular economy policy

5 - Practices of food waste management and its impact on environment

The management and prevention of food losses and waste in low- and middle-income countries: A mini-review in the Africa region.

The (FWE)2 nexus: Bridging food, food waste, water, energy, and ecosystems for circular systems and sustainable development

Food manufacturing is comprised of a number of complex processes which generate vast amounts of food waste. Frequently, strategies for dealing with these materials are rudimentary and provide a low economic and environmental value, for instance animal feeding, anaerobic digestion, composting, incineration, landspreading and landfilling. However, food wastes contain numerous chemicals with a wide range of potential commercial applications, which makes these materials suitable feedstocks for valorisation. This paper applies a Waste Flow Modelling methodology to achieve two aims: to provide valuable food manufacturing and waste data in order to better understand current food manufacturing activities, and to analyse existing food waste management practices to lay the foundation for the implementation of alternative food waste valorisation solutions. Four UK industrial companies have been selected and assessed to represent four different food sectors where food waste valorisation could provide an economic and/or environmental advantage: a fruits supplier, a brewery, a potato supplier and a producer of peas. The production line of each of these four businesses is defined and characterised, which allows the identification of food wastes generated. Next, food wastes are categorised and quantified, and their patterns of generation and current waste management practices are described. Sankey diagrams and performance indicators are used to assess the efficiency of processes, combination of processes and the complete production line in terms of food waste generation. Finally, the results are analysed and used to obtain the main conclusions and provide recommendations for an improved food waste management system, with a focus on valorisation opportunities.

Korea recycles approximately four million tons of food waste (FW) annually. Around 80% of this waste is treated as animal feed and compost. As the demand for animal feed and compost from FW decreases, there is an increasing need to find innovative solutions for this waste. Anaerobic digestion (AD) is currently the most realistic solution, and Korea has plans to construct more AD facilities by 2030. Before these facilities can be built, it is essential to study the indicators and frequencies representative of the characteristic changes in FW. The current literature is lacking in this area, as many studies only focus on a few critical indicators over short periods of time. This study aims to overcome this lack of information by analyzing two processes. The first process analyzes the monthly and seasonal variations in FW characteristics of Pohang city for one year. Biochemical methane potential (BMP) tests were performed, and their data was analyzed to provide basic information for AD design. The second process evaluates different methods of estimating methane production to determine which is the most suitable. The FW characterization study was conducted twice a month and the BMP analysis was conducted once a month. An analysis of the physicochemical parameters for one year indicated an average pH of 4.82, an average moisture content of 80.68%, an average volatile solid (VS) value of 174.48 g/L, an average chemical oxygen demand (COD) of 275.48 g/L, the average carbohydrate, protein, and lipid contents in VS basis were 41.87%, 33.59 %, and 14.34% respectively, and the average BMP was 259.97 ± 12.96 mL/g COD. Principal component analysis of FW characteristics resulted in two significantly different clusters - one for winter and spring and the other for summer and fall. The ANOSIM R-value for these characteristics was 0.821 (p < 0.01). Methane production levels were estimated from FW characteristics using COD, organic composition, and heat value basis. The data indicated that estimating methane production from FW using an organic composition basis rendered more accurate results than the other two methods. These results are beneficial for designing and managing food waste using AD processes as understanding the substrate characteristic change is important to maintaining stability.

Food waste, among the organic wastes, is one of the most promising substrates to be used as a renewable resource. Wide availability of food waste and the high greenhouse gas impacts derived from its inappropriate disposal, boost research through food waste valorization. Several innovative technologies are applied nowadays, mainly focused on bioenergy and bioresource recovery, within a circular economy approach. Nevertheless, food waste treatment should be evaluated in terms of sustainability and considering the availability of an optimized separate collection and a suitable treatment facility. Anaerobic codigestion of waste-activated sludge with food waste is a way to fully utilize available anaerobic digestion plants, increasing biogas production, energy, and nutrient recovery and reducing greenhouse gas (GHG) emissions. Codigestion implementation in Europe is explored and discussed in this paper, taking into account different food waste collection approaches in relation to anaerobic digestion treatment and confirming the sustainability of the anaerobic process based on case studies. Household food waste disposal implementation is also analyzed, and the results show that such a waste management system is able to reduce GHG emissions due to transport reduction and increase wastewater treatment performance.