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Featured Application: The results of this research show the scale of the environmental problem related to the discharge of shredded solid waste from catering facilities to the sewage network and wastewater treatment plants. The study results indicate the viability of implementing a system for managing food waste from catering facilities in tourist towns. The basic and initial element of this system would be the collection of food waste from catering facilities and its processing in closed digesters on the premises of the treatment plant in order to produce methane, which can be used for heating and energy purposes. At the same time, electricity consumption at wastewater treatment plants will decrease due to lower pollutant loads in sewage flowing to the treatment plant, thereby reducing the carbon and nitrogen footprint of purification. The use of food waste disposers in gastronomical facilities influences municipal wastewater composition. Ground food waste poses problems in the operation of the sewerage network and generates high electric energy consumption in wastewater treatment plants (WWTPs). This study aimed to determine, for five towns with a PE (Population Equivalent) ranging from 4000 to 220,000, the volumes of catering waste discharged to the WWTPs. The towns differed in the number of inhabitants, beds in hotels, and catering places. The calculations were undertaken based on data received from the operators of the WWTPs. The pollutant concentrations in 2019 were compared with data from the "pandemic" year—2020. The loads of catering waste entering the sewerage system in 2019 ranged from 32.7 to 1062 tons. In the town with the largest tourist base, the BOD (Biochemical Oxygen Demand) value in 2020 accounted for 62.3% of the 2019 value. In the largest town, the annual energy consumption for food waste treatment could be up to 2,539,770 kWh. If the waste was fermented, up to 1,376,650 m3 of methane could be obtained. There is a strong need to implement a collection system for food waste from catering facilities, and the fermentation of this waste to produce methane, which can be used for energy purposes. [ABSTRACT FROM AUTHOR]

The article discusses the issue of food waste in the United States, highlighting the shift in cultural attitudes towards wasting food over the years. It addresses the magnitude of food waste in the country and examines the regulations and initiatives implemented by the U.S. government to combat this problem. The article also compares the approaches taken by France and Canada, the top-ranking countries in terms of food waste reduction.

Septic systems are typically designed to treat domestic wastewater from households without access to centralized facilities. The installation of a food waste disposer (FWD) may increase the discharge of food waste (FW) into the wastewater; therefore, the installation of a FWD is discouraged in households that have a septic system. This study was conducted to determine how a typical dose of FW from a FWD can affect the performance of a septic system in terms of sewage treatment and solids accumulation. A 20-L control tank was compared with an experiment tank to which FW was added, increasing the amount of total suspended solids (TSS) by 31.3% and total chemical oxygen demands by 46.3% for a period of 110 days. Although the influent water quality changed dramatically, the effluent from the experiment tank had a substantially lower percentage increase in water quality parameters compared with the effluent from the control. It was found that in the experiment tank, 75.8% of FW TSS was degraded, whereas only 36.7% of sewage TSS was degraded, and that 18.8% of FW TSS and 44.9% of sewage TSS accumulated in the experiment tank. The addition of FW increased the scum accumulation, even though the dry matter of the scum layer was much less in quantity than the sludge layer. It also increased the lipid content in the sludge. The increase in the scum layer was mainly due to the increase in protein from the addition of the FW. Overall, compared with sewage TSS, FW TSS tends to be more biodegradable, which indicates that the impact on pumping frequency from adding FW will be insignificant. [ABSTRACT FROM AUTHOR]

Preventing food wastage is a key element of sustainable resource management. But as food waste is still generated at high volumes, priority is placed on its proper management as a resource, maximising sustainability benefits. This study, by integrating a multi-criteria decision analysis with a sustainability assessment approach, develops a screening and decision support framework for comparing the sustainability performance of food waste management options. A structured process for selecting criteria based on the consideration of environmental, economic and social aspects related to region-specific food waste system planning, policy and management has been developed. Two food waste management options, namely the use of food waste disposal units, which grind food waste at the household's kitchen sink and discharge it to the sewer, and the anaerobic co-digestion of separately collected food waste with sewage sludge, were selected for comparison due to their potential to create synergies between local authorities, waste and water companies, with local circumstances determining which of the two options to adopt. A simplified process used for assessing and comparing the two food waste management options in the Anglian region in the UK, indicated that there are benefits in using the framework as a screening tool for identifying which option may be the most sustainable. To support decision-making, a detailed analysis that incorporates stakeholders' perspectives is required. An additional use of the framework can be in providing recommendations for optimising food waste management options in a specific region, maximising their sustainability performance. [ABSTRACT FROM AUTHOR]

Abstract The increasing challenge in waste disposal and high dependency on imported fossil fuel has compelled Singapore to make continuous efforts in advancing waste to energy (WTE) technology, which could ensure sustainable development on one hand and energy resilience on the other hand. This paper summarizes the current WTE practices and research trends in Singapore, covering anaerobic digestion (AD), gasification, combustion-based biomass combined heat and power (CHP) production, and incineration, with the aim to define future perspectives of Singapore WTE application. Among the different aspects assessed, source-separated food waste (FW) and brown water present the biggest energy potential if AD is adopted instead of incineration. Given that the purity of source separated waste determines the extent of recovered energy, suggestions are made to increase the participating rate in source separation among Singapore residents, such as environmental education through social media and phone apps and proper facilities installation at household and community. Moreover, additional benefits can be credited to WTE system if the waste to material practice is also conducted on top of energy production. Highlights • A comprehensive review on Singapore Waste-to-Energy technologies. • AD, biomass CHP, gasification and incineration are included. • Current status, future trend and development obstacles are discussed. • Possible improvement solutions are proposed. [ABSTRACT FROM AUTHOR]

The disposal of large amounts of food waste has caused significant environmental pollution and financial costs globally. Compared with traditional disposal methods (i.e., landfilling, incineration, and composting), anaerobic digestion (AD) is a promising technology for food waste management, but has not yet been fully applied due to a few technical and social challenges. This paper summarizes the quantity, composition, and methane potential of various types of food waste. Recent research on different strategies to enhance AD of food waste, including co-digestion, addition of micronutrients, control of foaming, and process design, is discussed. It is envisaged that AD of food waste could be combined with an existing AD facility or be integrated with the production of value-added products to reduce costs and increase revenue. Further understanding of the fundamental biological and physicochemical processes in AD is required to improve the technology. [ABSTRACT FROM AUTHOR]

When assessing the environmental and human health impact of a municipal food waste (FW) management system waste managers typically rely on the principles of the waste hierarchy; using metrics such as the mass or rate of waste that is ‘prepared for recycling,’ ‘recovered for energy,’ or ‘sent to landfill.’ These metrics measure the collection and sorting efficiency of a waste system but are incapable of determining the efficiency of a system to turn waste into a valuable resource. In this study a life cycle approach was employed using a system boundary that includes the entire waste service provision from collection to safe end-use or disposal. A life cycle inventory of seven waste management systems was calculated, including the first service wide inventory of FW management through kitchen in-sink disposal (food waste disposer). Results describe the mass, energy and water balance of each system along with key emissions profile. It was demonstrated that the energy balance can differ significantly from its’ energy generation, exemplified by mechanical biological treatment, which was the best system for generating energy from waste but only 5 th best for net-energy generation. Furthermore, the energy balance of kitchen in-sink disposal was shown to be reduced because 31% of volatile solids were lost in pre-treatment. The study also confirmed that higher FW landfill diversion rates were critical for reducing many harmful emissions to air and water. Although, mass-balance analysis showed that the alternative end-use of the FW material may still contain high impact pollutants. [ABSTRACT FROM AUTHOR]

Reducing food waste is one of the key challenges of the food system and addressing it in the institutional catering industry can be a quick win. In particular, school canteens are a significant source of food waste and therefore embody a great opportunity to address food waste. The goal of our research is the development of guidelines for audit and self-assessment in measuring and managing food waste produced at school canteens. The purpose of the tool is to standardise food waste audits to be executed either by scholars, school staff or by catering companies with the objective of measuring and reducing food waste at schools. We performed a research among public and private schools and catering companies from which we obtained the key performance indicators to be measured and then pilot-tested the resulting tool in four schools with over 2900 pupil participants, measuring plate waste from over 10,000 trays. This tool will help managers in their efforts towards more sustainable organisations at the same time as the standardisation of food waste audits will provide researchers with comparable data. The study suggests that although there is low awareness on the amount of food wasted at school canteens, managers and staff are highly interested in the topic and would be willing to implement audits and reduction measures. The case study also showed that our tool is easy to implement and not disruptive. [ABSTRACT FROM AUTHOR]

Data on the extent of food loss and waste and on the destinations of lost and wasted food during the upstream stages of supply chains – primary production and processing – are currently scarce in France and in other industrialized countries. The reasons include a lack of available measurements, wide differences in the definition of what food loss and waste are at these stages, and, especially in the primary sector, its diversity. Research plays an essential role in filling this knowledge gap in order to support decision-makers in adopting strategies for more sustainable food use, to innovate in technology and practices aimed at food loss and waste reduction, and to raise awareness about the role of food in human societies. This study aimed to answer key questions on: i) the extent of food loss and waste at the upstream stages of food supply chains in industrialized countries; ii) how it can be measured at these stages; and iii) the role that reuse and recycling play in the reduction of food loss and waste. The paper provides answers to these questions and discusses methodological issues of food loss quantification relevant to the upstream stages of food supply chains. In this study, food loss is defined as discarded or lost food products, initially intended for human consumption, unless they were used for animal feed (excluding pet food). INRA internal multidisciplinary working groups organized per food sector collected data from a large array of available reports, published studies, and interviews with technical experts and businesses. Four plant sectors (cereals, pulses, oil crops, and fruit/vegetables/potatoes) and six animal sectors (milk, beef, lamb, pork, poultry, eggs, and farmed fish) were analyzed. The results indicate that food loss does indeed occur at the upstream stages of supply chains. The role of the different supply chain stages varies between the food sectors. Based on our study results for the year 2013, between 3 and 11% of food was lost, and up to 12% for fruit, vegetables and potatoes, from production to processing (up to retailing in the case of fruit and vegetables). Recycling, including reuse of discarded food directly as food or indirectly as animal feed, plays a moderate role in food waste reduction during primary production and processing. Our paper shows the limits of implementation, in terms of method and access to data, of the current quantification framework at these stages. Because of data scarcity, a wide range of data sources was used to gather information which, with the help of experts, was interpreted, converted and recalculated into food loss estimates. We therefore argue for a food sector-specific approach to data collection and to the identification of food loss determinants and solutions for reduction. Insights from our study point out the need for improvements towards a more handy and robust quantification framework. [ABSTRACT FROM AUTHOR]

The disposal of food waste is a large environmental problem. In the United Kingdom (UK), approximately 15 million tonnes of food are wasted each year, mostly disposed of in landfill, via composting, or anaerobic digestion (AD). European Union (EU) guidelines state that food waste should preferentially be used as animal feed though for most food waste this practice is currently illegal, because of disease control concerns. Interest in the potential diversion of food waste for animal feed is however growing, with a number of East Asian states offering working examples of safe food waste recycling – based on tight regulation and rendering food waste safe through heat treatment. This study investigates the potential benefits of diverting food waste for pig feed in the UK. A hybrid, consequential life cycle assessment (LCA) was conducted to compare the environmental and health impacts of four technologies for food waste processing: two technologies of South Korean style-animal feed production (as a wet pig feed and a dry pig feed) were compared with two widespread UK disposal technologies: AD and composting. Results of 14 mid-point impact categories show that the processing of food waste as a wet pig feed and a dry pig feed have the best and second-best scores, respectively, for 13/14 and 12/14 environmental and health impacts. The low impact of food waste feed stems in large part from its substitution of conventional feed, the production of which has substantial environmental and health impacts. While the re-legalisation of the use of food waste as pig feed could offer environmental and public health benefits, this will require support from policy makers, the public, and the pig industry, as well as investment in separated food waste collection which currently occurs in only a minority of regions. [ABSTRACT FROM AUTHOR]

Household food waste (FW) management has become an emerging environmental issue affecting sustainable urban development. The application of in-sink domestic food waste disposers (FWDs) have brought significant public attentions due to its simplified waste handling process and reduced household expenses. However, the potentail negative impacts of mixing FW in the sewer system, i.e., the reduction of aeration efficiency in wastewater treatment processes (WWTPs) and corresponding increase of greenhouse gas (GHG) emission, has not been quantified. In this study, real-time oxygen transfer efficiency in processing water was measured in WWTPs receiving negligible amount of FW and compared with those receiving sewage combined with FWD effluent. WWTP receiving sewage with FW had 6–10% lower oxygen transfer rate than those without FW, resulting in extra energy consumptions of 0.25–0.30 kWh/m3 and GHG emissions of 0.35–0.41 kg CO 2 /m3. For estimating the substantial impacts of FWD to the carbon cycle, sludge treatment scenarios were designed among anaerobic digestion (AD), incineration, and direct landfill disposal. Compared with AD (−0.07 kWh/kg) and incineration (0.112 kWh/kg), FWD/WWTP consumed more energy (0.69–0.9 kWh/kg) and most of which (∼64%) was required by aeration. The operating costs of WWTPs also increased by 1.6–2.1 times in comparison with those did not receive FW. The application of FWD, however, could reduce the overall GHG emissions by 35.2% in comparison with direct landfilling. Decision-makers should guide householders and waste management practitioners through new policies such as carbon credits and/or waste charging scheme to support more environmental-friendly disposal methods of FW, especally when the maturity of socio-economic conditions are of concerns. Compared with AD and incineration, FWD may be a compromising alternative to control GHG emissions with existing wastewater treatment facilities especially to those regions where complete FW classification and treatment are not well-established. [Display omitted] • Carbon emission in wastewater treatment plants with food waste disposer was studied. • Dynamic changes of oxygen transfer efficiency were monitored. • Additional energy consumption from aeration was quantified by off-gas tests. • Diffusor fouling cost in non-food sewage was calculated for the first-time. • Energy/carbon balance for region-based food waste diversions was reported. [ABSTRACT FROM AUTHOR]

The effect of temperature on bio-hydrogen production by co-digestion of sewerage sludge with food waste and its two derivatives, i.e. noodle waste and rice waste, was investigated by statistical modelling. Experimental results showed that increasing temperature from mesophilic (37 °C) to thermophilic (55 °C) was an effective mean for increasing bio-hydrogen production from food waste and noodle waste, but it caused a negative impact on bio-hydrogen production from rice waste. The maximum cumulative biohydrogen production of 650mL was obtained from noodle waste under thermophilic temperature condition. Most of the production was observed during the first 48 h of incubation, which continued until 72 h of incubation. The decline in pH during this interval was 4.3 and 4.4 from a starting value of 7 under mesophilic and thermophilic conditions, respectively. Most of the glucose consumption was also observed during 72 h of incubation and the maximum consumption was observed during the first 24 h, which was the same duration where the maximum pH drop occurred. The maximum hydrogen yields of 82.47 mL VS-1, 131.38 mL COD-1, and 44.90 mL glucose-1 were obtained from thermophilic food waste, thermophilic noodle waste and mesophilic rice waste, respectively. The production of volatile fatty acids increased with an increase in time and temperature in food waste and noodle waste reactors whereas they decreased with temperature in rice waste reactors. The statistical modelling returned good results with high values of coefficient of determination (R²) for each waste type and 3-D response surface plots developed by using models developed. These plots developed a better understanding regarding the impact of temperature and incubation time on bio-hydrogen production trend, glucose consumption during incubation and volatile fatty acids production. [ABSTRACT FROM AUTHOR]

In developing countries like Turkey, food waste has the highest share compared to other municipal solid waste components. A detailed life cycle assessment has been performed to evaluate different food waste management options (i.e., landfilling, anaerobic digestion, thermal treatment, co-treatment with municipal wastewater) for Istanbul which is the largest city of Turkey and Europe. The current waste management has the worst environmental performance compared to proposed waste management scenarios as follows: Anaerobic digestion, thermal treatment and co-treatment with municipal wastewater. The thermal treatment scenario has been found to have the best environmental performance in most of the impact categories including climate change. The anaerobic digestion scenario ranks in the first place only in freshwater eutrophication, which is attributed to avoided fertilizer use in this scenario. A drastic improvement with 866% has been found in this category if the anaerobic digestion scenario was followed. Co-treatment with municipal wastewater refers to use of food waste disposers at households and provides improvements especially in marine eutrophication and ecotoxicity. Lower effluent emissions by means of biological wastewater treatment in the co-treatment scenario compared to other proposed scenarios lead to better performance in these categories. Various sub-scenarios have also been investigated such as using biogas as vehicle fuel, replacing a combined heat and power with a condensing plant and increasing food waste addition to sewer lines. Important improvements are not achievable in the first two sub-scenarios; however, increasing food waste addition to sewer lines reduces various environmental impact categories by −41% and −60%. • The baseline scenario (mainly landfilling) has the worst environmental performance. • Higher energy recovery from food waste improves the life cycle assessment results. • Thermal treatment with heat and power generation provides the highest energy recovery. • Turkish electricity and heating mixes have significant impacts on the results. • Food waste management has higher environmental impacts than wastewater treatment. [ABSTRACT FROM AUTHOR]

In our reply to Grainger and Stewart (2017) we concur with their observation on the need for evidence-based synthesis in examining the efficacy of behaviour change interventions. We argue that our paper (Young et al., 2017) makes a contribution to the body of knowledge on behaviour change and in so doing it provides an important piece of the jigsaw in understanding the influence of social media on food waste behaviour. [ABSTRACT FROM AUTHOR]