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• Food waste ground by food waste disposers is easier to block pipes. • Liquid bridge force is the internal cause of deposits to aggregate. • Diameter of aggregations is positively correlated with adhesion on pipes. • Reducing particle size or choosing CI or HDPE pipes may reduce blockage. Food waste disposers (FWDs) streamline kitchen waste management and facilitate waste classification, whether they would increase the potential of blockage in kitchen drainage system is still unknown. This study conducted a theoretical analysis of the interactive forces between fat, oil, and grease (FOG) deposits and their aggregation on pipe walls. The study involved grading food waste particles processed by FWDs using sieving and weighing techniques to determine the mean weight diameter (MWD) of various aggregations. A full-scale experimental system, implemented in a 60-m high test tower, simulated blockages in horizontal pipes of high-rise buildings. The effect of pipeline materials and particle sizes on blockage were examined by measuring the adhesion of deposits on horizontal pipes. Energy dispersive spectrometer (EDS) analysis suggested that liquid bridge force is a primary factor in aggregate formation. Hand-cut particles formed aggregates with the highest MWD value. Particle size analysis revealed that sizes ranging from 2.36 to 4.75 mm, 1.18–2.36 mm, and 0.60–1.18 mm constituted over 80 % of particles ground by FWDs, with an average size of 2.16 mm. Results of full-scale experiment indicate particle diameters, friction coefficients and lipophilic coefficient significantly affected the propensity of these aggregates to adhere to pipes. Notably, particles processed by FWDs tended to cause blockages more frequently than hand-cut particles. These findings elucidate the deposition mechanism of FOG deposits and offer strategies to reduce blockages in kitchen drainage systems, such as reducing current grinding particle size by 18 % to 1.77 mm or selecting pipes like cast iron and high-density polyethylene. [ABSTRACT FROM AUTHOR]

Global warming has become a main challenge that threatens life on Earth. It is mainly blamed on the unprecedented levels of atmospheric greenhouse gases emanating from natural and anthropogenic sources including food systems that encompass different processes including agricultural practices, food packaging, refrigeration, transportation, and disposal of food waste. Therefore, signatory nations to the Paris Agreement are called upon to assess the contributions of their food systems to national budgets of greenhouse gases and to take necessary actions to reduce these emissions. In this paper, we present the findings of an attempt to quantify the national emissions of greenhouse gases emanating from food systems in Jordan based on validly published emission rates and locally relevant agricultural data reported by the Jordanian Department of Statistics including cultivated areas, harvested goods, and imported food items. Our calculations revealed that more than 12.5 million tons of carbon dioxide equivalent in 2019 were generated by food systems in Jordan constituting about 47% of the total national emissions in that year. The transportation sector is found to be a main emitter of carbon dioxide, making imported meat and rice the main generators of carbon dioxide in the food systems in Jordan. Landfilling of food remains or losses generate massive quantities of greenhouse gases with no social gain. [ABSTRACT FROM AUTHOR]

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.

The introduction of food waste disposers (FWDs) has been discussed in various countries, and in Korea, a method for utilizing FWDs has been considered. The results of the study show that the use of FWDs is more eco-friendly and economical than other forms of food waste (FW) disposal. However, there are also studies showing that FWDs are worse, for example, they aggravate water pollution and deteriorate the function of municipal wastewater treatment plants (WWTPs). Therefore, this study analyzed the concentration of pollutants of wastewater from FWD and the effect on the operation rate and GHG emission of WWTP when FW was introduced into the sewer by FWD using operation data for each WWTP. As a result of the analysis, when FWD was used, facilities exceeding the appropriate operation rate accounted for 86% of the total WWTP, and net-GHG emissions increased by 58%. Through this, FWD wastewater showed much higher contaminant concentrations than regular wastewater; thus, the introduction of FWD in the current situation will have a negative effect on maintaining the function of WWTP and reducing GHG. To introduce FWDs, improvement in WWTPs regarding pollutant load and discharge characteristics of FW and input of digestion systems through a separate FWD pipe, the introduction of high-efficiency energy facilities, and the recycling of wastewater sludge are necessary to reduce GHG emissions. [ABSTRACT FROM AUTHOR]

The valorisation of food waste via anaerobic digestion has shown to be a promising option for tackling waste accumulation and achieve energy security. In this study, a lab scale and a pilot scale anaerobic digester, with food waste as the feedstock and palm oil mill effluent (POME) as the microbial inoculant, were evaluated for their biogas production. For the lab scale study, the effect of different food waste to POME ratio, ranging from 1:1, 1:2 and 2:1, on the biogas production were investigated for a period of 7 d. From the experimental work, the ratio of food waste to POME at 2:1 gave the highest biogas yield of 0.14 L. For the pilot scale study, a digester was designed based on a daily electricity demand of 9.5 kW of an eco-park. With the use of the Pro Engineer Software, it is estimated that a digester with a volume of 4.27 m3, handling capacity of 200 L of food waste daily, and a hydraulic retention time of 15 d, can generate sufficient biogas to meet the electricity demand for the eco-park. [ABSTRACT FROM AUTHOR]

Towards sustainable urbanization, food waste and wastewater from buildings need the appropriate infrastructure systems for management. The zero-waste concept is gaining interest as a promising option for the sustainable development of society. The study aims to assess the cumulative energy demand and GHG emissions of a prototype zero-waste system for building wastewater recycling and food waste management. The system is the combination of the Moving Bed Biofilm Reaction-Membrane Bioreactor (MBBR-MBR) for wastewater treatment and the anaerobic digester with energy recovery for food waste management. The functional unit is set as the management of 60 kg of food waste along with 2 m3 of building wastewater. The results revealed that the prototype zero-waste system could bring the negative fossil energy use (-96 MJ-eq) and the negative life-cycle GHG emissions (-4.4 kg CO2-eq/functional unit). The main credit came from the avoided fossil energy use and GHG emissions due to the substitution of LPG with biogas. The biogas generation was 0.00013 Nm3/mg COD removal (based on the hydraulic retention time (HRT) about 30 d). For anaerobic digestion system, pig slurry transport from the pig farm to the university as seed sludge and electricity consumption for the stirrer in the digester and the food waste shredder are the major sources of energy use and GHG emission. For the MBBR-MBR system, the primary source for both energy use and GHG emission is the electricity consumption for the air pump. The study shows the initial stage of the implementation of the prototype zero-waste, which there still has the potential to improve operational efficiency. [ABSTRACT FROM AUTHOR]

Over the past years, the high generation of municipal solid waste has been identified as a considerable global environmental issue, due to population growth, economic development, and the industrial revolution. The present research study was conducted to evaluate the quantity, ingredients, and generation of municipal solid waste (MSW) in Pshdar district during winter and summer in 2019. The results revealed that the average of solid waste production in the district reached 94 tons/day and 0.761kg-capita/day. The most abundant MSW constituents are organic matter forming 75.71% of MSW of the district, followed by 13.18% of plastic content and the least ingredient is metal 0.93%. While the average ratio of paper and cardboard, textile and leather, and glass waste ingredients are 3.74%, 4.85%, and 1.66% respectively. The seasonal effect on solid waste content has been observed obviously in this research, more specifically in organic matter and textile & leather, as well as in waste generation rate. Organic matter increased from 70.73% to 80.68% from winter to summer, while, percentage of textile and leather significantly declined from 6.93% to 2.76% from winter to summer. Similarly, waste generation rate was reduced from wet to dry season from 0.846kg-cap/day to 0.676kgcap/day. [ABSTRACT FROM AUTHOR]

In this study, an integrated system of siphon-driven self-agitated anaerobic reactor (SDSAR) and anaerobic fixed bed reactor (AFBR) was conducted for the treatment of wastewater from food waste disposer (FWD), and the effect of influent total solids (TS) concentration on the process performance was evaluated. When the influent TS concentration increased from 7.04 to 15.5 g/L, the methane gas production rate increased from 0.45 to 0.92 L-CH4/L/day. However, with the influent TS concentration of food waste (FW) further increased to 23.5 g/L, a large amount of scum formed and accumulated in the SDSAR. According to the result of chemical oxygen demand (COD) recovery, the proportion of COD remained in the effluent at different TS concentrations was only around 2%. On the other hand, with an increase in TS concentration, the proportion of COD remained in the reactors increased significantly. Our results demonstrated that effluent from the integrated system can meet the water quality requirements recommended by Japan Sewage Works Association (JSWA) for wastewater from FWD. In addition, to enhance the process stability, the influent TS concentration should be maintained below 15.5 g/L. [ABSTRACT FROM AUTHOR]

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]

Summary: Vermicomposting using black soldier fly (BSF) larvae (Hermetia illucens) has gradually become a promising biotechnology for waste management, but knowledge about the larvae gut microbiome is sparse. In this study, 16S rRNA sequencing, SourceTracker, and network analysis were leveraged to decipher the influence of larvae gut microbiome on food waste (FW) biodegradation. The microbial community structure of BSF vermicompost (BC) changed greatly after larvae inoculation, with a peak colonization traceable to gut bacteria of 66.0%. The relative abundance of 11 out of 21 metabolic function groups in BC were significantly higher than that in natural composting (NC), such as carbohydrate‐active enzymes. In addition, 36.5% of the functional genes in BC were significantly higher than those in NC. The changes of metabolic functions and functional genes were significantly correlated with the microbial succession. Moreover, the bacteria that proliferated in vermicompost, including Corynebacterium, Vagococcus, and Providencia, had strong metabolic abilities. Systematic and complex interactions between the BSF gut and BC bacteria occurred over time through invasion, altered the microbial community structure, and thus evolved into a new intermediate niche favourable for FW biodegradation. The study highlights BSF gut microbiome as an engine for FW bioconversion, which is conducive to bioproducts regeneration from wastes. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Deficiency of trace elements in FW was critical factor causing process imbalance. • Investigation was from viewpoints of methanogens community structure and diversity. • Correlation between system performance and methanogens community function was good. • A possible mechanism of process imbalance of FW anaerobic digestion was proposed. • Role of trace metals in governing process stability was elucidated. Abstract This study investigated mechanism of process imbalance of long-term anaerobic digestion (AD) of food waste (FW) and role of trace elements (TEs) in maintaining process stability. AD of FW was strongly inhibited by volatile fatty acids (VFA, mainly propionate). The deficiency of essential TEs in FW was the fundamental reason. TEs contents in digester gradually decreased with regular substrate feeding and digestate discharge, which greatly limited growth and metabolism of hydrogenotrophic methanogens and Methanosarcina. Finally, Methanosaeta replaced Methanosarcina and became dominant methanogen and hydrogenotrophic methanogens almost disappeared accompanied by declining methanogenic community diversity, which greatly suppressed ecological functions of methanogens and led to propionate inhibition. TEs supplementation eliminated all factors causing process imbalance and significantly enhanced process stability by maintaining strong ecological functions of methanogens via stimulating dominant growth of Methanosarcina (relative abundance between 67.2% and 87.5%), sustaining stable relative abundances of hydrogenotrophic methanogens (about 10%) and enhancing methanogenic community diversity. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Biochar has constructive features to assist composting of OFMSW. • Compost stability as a result of biochar addition was achieved. • Biochar has a potential impact on N retention during composting. • Biochar addition clearly decreased pathogenic microorganisms during composting. • Small dose of biochar (1.5%) reduce compost toxicity. Abstract The article evaluates the effect of small selected doses of biochar addition (0%, 1.5%, 3% and 5%, wet weight) on the composting process of the organic fraction of municipal solid waste (OFMSW) with a low initial C/N ratio under real conditions. The low C/N composting mixtures with addition of biochar at low rates can have a positive effect on the compost quality and on the reduction of N losses in compost. The novelty of this work consists in studying the impact of small biochar doses on the composting process at full-scale. The research was conducted under real conditions in the Brno Central Composting Plant (Czech Republic) receiving food waste, grass, straw, sawdust, mineral waste, paper, wood and sewage sludge for processing. The experimental processing time was 12 weeks. We evaluated changes in carbon (C), nitrogen (N), moisture content (MC), organic matter (OM), respiration activity (AT4), as well as changes in the microbiocenotic composition of microorganisms colonizing the processed waste. OFMSW with the addition of biochar and compost were assessed for the content of heavy metals (HM). It was found out that biochar reduced the compost toxicity. The resulting compost with the addition of biochar exhibited higher moisture content and lower waste density. Biochar had an impact on N retention during composting but it did not change the course or accelerate the composting process. The highest OM loss (62.6%) was observed in the OFMSW with no biochar addition. The abundance of potentially pathogenic microorganisms clearly decreased during the OFMSW composting process with the addition of biochar. [ABSTRACT FROM AUTHOR]

Highlights • Managerial approaches to food waste mitigation in UK coffee shops are explored. • Food waste represents an important issue but its management lags behind. • Major barriers are the lack of governmental support and imperfect legislation. • Limited internal resources and poor consumer awareness also play a role. Abstract The hospitality industry generates substantial amounts of food waste. Although the issue has been politically recognised, it remains under-researched. Studies are limited in number and restricted in sectoral and geographical coverage. They have attempted to quantify and characterise food waste in hospitality ventures while the managerial approaches to its reduction have not been scrutinised. The coffee shop sub-sector of the hospitality industry has been entirely excluded from analysis. This study examined food waste in UK coffee shops through the managerial lens. While food waste represents a significant challenge, the managerial approaches to its minimisation are conservative and focus on disposal, rather than prevention. Lack of governmental support, imperfect legislation, irresponsible consumer behaviour and restricted internal resources inhibit application of more advanced managerial approaches. To enhance the effectiveness of food waste management within the sub-sector, targeted policy interventions designed to strengthen corporate commitments and facilitate pro-environmental changes in consumer behaviour are necessary. [ABSTRACT FROM AUTHOR]

Garbage accumulation around terrestrial nature reserves poses a risk to many species. We monitored animal visitation patterns and foraging behaviour at garbage dumps near a forested area in Uttarakhand Himalaya, India, to examine plastic consumption by animals. We recorded 32 species of birds and mammals visiting garbage dumps and classified them as 'peckers', 'handlers' and 'gulpers' based on their foraging behaviour. Gulpers (carnivores and ruminants) were observed feeding more frequently and spent longer durations (3.8 ± 0.2 min) at garbage dumps. Our results highlight the importance of at-source segregation of waste to prevent wild and domestic animals from ingesting hazardous wastes, including plastics at garbage dumps. [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]

Objective: Hermetia illucens is a voracious insect scavenger that efficiently decomposes food waste. To exploit novel hydrolytic enzymes from this insect, we constructed a fosmid metagenome library using unculturable H. illucens intestinal microorganisms.Results: Functional screening of the library on carboxymethyl cellulose plates identified a fosmid clone with a product displaying hydrolytic activity. Fosmid sequence analysis revealed a novel mannan-degrading gene (ManEM17) composed of 1371 base pairs, encoding 456 amino acids with a deduced 54 amino acid N-terminal signal peptide sequence. Conceptual translation and domain analysis revealed that sequence homology was highest (46%) with endo-1,4-β-mannosidase of Anaerophaga thermohalophila. Phylogenetic and domain analysis indicated that ManEM17 belongs to a novel β-mannanase containing a glycoside hydrolase family 26 domain. The recombinant protein (rManEM17) was expressed in Escherichia coli, exhibiting the highest activity at 55 °C and pH 6.5. The protein hydrolyzed substrates with β-1,4-glycosidic mannoses; maximum specific activity (5467 U mg−1) occurred toward locust bean gum galactomannan. However, rManEM17 did not hydrolyze p-Nitrophenyl-β-pyranosides, demonstrating endo-form mannanase activity. Furthermore, rManEM17 was highly stable under stringent conditions, including polar organic solvents as well as chemical reducing and denaturing reagents.Conclusions: ManEM17 is an attractive candidate for mannan degradation under the high-organic-solvent and protein-denaturing processes in food and feed industries. [ABSTRACT FROM AUTHOR]

Food waste (FW) in Australia costs an estimated $8 to 10 billion per year, and is associated with detrimental environmental and socio-economic implications such as greenhouse gas emissions and loss of human and natural capital. Preventing domestic food waste (DFW) generation and/or redirecting these resources to recyclable outputs is an important policy issue, however effective policy must first begin with an understanding of behavioural drivers for DFW generation. To examine this issue, a case study was conducted in two local government areas in Australia. Using focus group discussions, consumers’ understanding of and opinions about DFW generation, diversion and prevention options were assessed. Four hypothetical DFW policy options were explored: these included diversion options of home/backyard composting, community composting, and a residential FW collection program; and a prevention option, which was education programs to avoid over purchasing and over consumption. Home/backyard composting and education were the first and second preferred options, respectively. The sub-sample of residents were already practicing helpful food waste reduction habits, such as home composting and frugality in food spending and consumption habits. The findings demonstrate that understanding residents’ views requires an exploration of the complex psychological, socio-economic, environmental, and regulatory factors that shape opinions and behaviours towards food utilisations. The research demonstrates the potential value in embedding community perspectives in policy instruments, with the aim of encouraging sustainable food consumption and utilisation behaviours in regional communities. [ABSTRACT FROM AUTHOR]

There is low utilisation of plastic waste in the Nordic region and only a fraction of plastic materials go back into production processes through reuse and recycling practices. This paper aims to increase knowledge concerning factors that inhibit demand for recycled plastics, and to identify critical barriers for plastic recycling across the regional plastics value chain. A literature review and targeted interviews with key actors across the plastics value chain enabled the mapping of interactions between the major actors and identified hotspots that act as barriers to the flow of plastic materials. Barriers identified include the lack of both supply and demand of recycled plastic and are mainly attributed to the fragmented market of secondary materials. The main hotspots identified are the low demand due to price considerations, insufficient traceability and transparency in value chain transactions, and general design deficiencies in the recyclability of products. Value chain coordination is considered as the most important intervention by the interviewees, followed by the need for increased investment in innovation and technology development. Complementary measures that could counteract the identified barriers include public procurement for resource efficiency, ban on the incineration of recyclable materials, and specifications on the design of plastic products for reducing the number of different polymers, and the number and usage of additives. [ABSTRACT FROM AUTHOR]

Hunger is a global crisis and impacting the world for a very long time. Significant efforts have been made in the past by various organizations employing various means to address this persisting problem. Despite this, it still remains far from being resolved. Recently, the United Nations has published a report on global hunger, which claims that the global food production is fairly enough to feed the entire world with a population of about 7.3 billion. However, a major quantity of the food grown is not channeled appropriately and effectively to reach the needy and thus gets wasted unfortunately. Using the advanced computer technologies, we devise and develop a web-based computational framework ( eFeed-Hungers.com ) that serves as a bridge between the food waste and the hunger to mitigate the hunger issue; the food waste is the excess, unused, edible food, which otherwise is destined to the dumpster unfortunately. The eFeed-Hungers.com encourages and assists the food waste donation announcements with the least minimal efforts with the best possible outreach. Through the eFeed-Hungers.com , the food donations are globally searchable by the needy, with enough additional information imparted for quick decisions making to fetch the appropriate donated food. The eFeed-Hungers.com is envisioned to be a fully functional organization eventually with global outreach. [ABSTRACT FROM AUTHOR]

Reducing food waste has many positive environmental and socio-economic ramifications. Even though many programs exist to reduce the amount of food waste, the attitudes and the behaviors driving food waste as well as the strategies to reduce it remain poorly understood. In this paper, we investigate how restaurateurs in Berkeley, California, USA perceive food waste given current financial incentives and policies. We found that 65% of the restaurants are measuring amounts of food waste and more than three-quarters of them (84%) use compost bins to dispose inedible food waste. Our survey results also show that the most common method employed to dispose of food waste (72%) was giving edible leftovers to restaurant's employees. However, three-quarters of restaurants avoided food donation because of unfounded fear of the legal liability. Finally, 14% of surveyed restaurants dumped their food waste into landfill bins. We suggest that further studies explore ways to target specific attitudes and behavioral changes, but also to quantify the impact of these changes. [ABSTRACT FROM AUTHOR]

From a waste management perspective, high-barrier, multi-layer, biodegradable food packaging could be a useful replacement for current multi-layered packaging that is non-recyclable and non-degradable. Whilst there is still technical research required, it is envisioned that a biodegradable thermoplastic starch (TPS) and polyhydroxyalkanoate (PHA) layered material could be a promising target. However, there is currently limited research identifying what environmental trade-offs are associated with using such a material – meaning there is no guidance regarding what design characteristics are important to consider during development of such packaging. The aim of this study was to quantify the greenhouse gas (GHG) trade-offs associated with using the proposed biodegradable packaging and identify the important design considerations. To our knowledge this is the first study to discuss the implications of including food wastage when assessing biodegradable food packaging materials. It also considers the impacts of landfill methane capture efficiency, which is an important aspect as biodegradable packaging may release methane when disposed of in a landfill whereas non-biodegradable packaging is inert. However, a key result is that when food waste is included in the system boundaries, it contributes over 50% of the GHG emissions associated with the system, regardless of whether the package is biodegradable or not. This shows that even for biodegradable packaging, reducing food waste is a key design consideration. In fact, the negative environmental impacts associated with disposal of a PHA-TPS packaging in landfill with low gas capture rates can actually be offset if the package reduces food wastage (beef) by approximately 6%. The overarching result is that a PHA-TPS food packaging only delivers positive GHG outcomes if it reduces food wastage or increases the viability of biological food waste processing. [ABSTRACT FROM AUTHOR]

Anaerobic codigestion has been practiced at water resource recovery facilities to increase methane production, but the impact of many variables is still not well understood. In this study, the feasibility of codigesting fats, oils, and grease (FOG), and other high strength wastes (HSWs) with municipal sewage sludge was investigated. Four laboratory-scale digesters were operated at a working volume of 9.75 L, 15 days solids retention time (SRT), and at a temperature of 37 °C. Wastes including whey (cheese), juice, grease trap waste (GTW), and dissolved air flotation waste (DAF), along with municipal sewage sludge, were fed to the digesters in varying amounts. The addition of HSWs led to higher methane production at lower organic loadings. However, at higher organic loadings, the GTW appeared to be toxic to methanogens, leading to a decrease in digester pH and biogas production, and an accumulation of volatile fatty acids within the digester. [ABSTRACT FROM AUTHOR]

Organics degradation is vital for food waste anaerobic digestion performance, however, the influence of organics degradation on biomethane production process has not been fully understood. This study aims to thoroughly investigate the organics degradation performance and identify the interaction between the reduction of organic components and methane yield based on the evaluation on 12 types of food waste. Five models (i.e. exponential, Fitzhugh, transference function, Cone and modified Gompertz models) were compared regarding the prediction of organic degradation and the results showed that the exponential model fit the experiments best, whereas kinetic parameters could not be commonly used for all situations. The exponential model was then used to study the impacts of organics reduction on the methane production and results revealed that the cumulative methane production (385–627 mL/g volatile solid) increased exponentially with the removal efficiency of volatile solids, lipids, and proteins for all feedstocks, whereas volatile solid reduction increased exponentially and linearly, respectively, with the removal efficiency of lipids and proteins. Additionally, protein degradation increased exponentially with the reduction efficiency of lipids. The experimental data and model simulation results suggested that higher methane production (530–548 mL/g volatile solid) and removal efficiency of volatile solids (65.0–67.8%), lipids (77.8–78.2%), and proteins (54.7–58.2%) could be achieved in a shorter digestion retention when carbohydrate content was higher than 47.6%, protein content lower than 24.1%, and lipid content lower than 28.3%. [ABSTRACT FROM AUTHOR]

This study explores the environmentally innovative and low-impact technology, a zero food waste system (ZFWS) that utilizes food waste and converts it into composts or biofuels and curtails carbon emissions. The ZFWS not just achieves food waste reductions but recycles food waste into fertilizer. Based on a fermentation-extinction technique using bio wood chips, the ZFWS was employed in a field experiment of the system installed in a large-scale apartment complex, and the performance of the system was examined. The on-site ZFWS consisted of three primary parts: 1) a food waste slot into which food waste was injected; 2) a fermentation-extinction reactor where food waste was mixed with bio wood chips made up of complex enzyme and aseptic wood chips; and 3) deodorization equipment in which an ultraviolet and ozone photolysis method was employed. The field experiment showed that food waste injected into the ZFWS was reduced by 94%. Overall microbial activity of the food waste in the fermentation-extinction reactor was measured using adenosine tri-phosphate (ATP), and the degradation rate of organic compounds, referred to as volatile solids, increased with ATP concentration. The by-products generated from ZFWS comply with the national standard for organic fertilizer. [ABSTRACT FROM AUTHOR]

Anaerobic digestion has been practically applied in agricultural and industrial waste treatment and recognized as an economical-effective way for food waste disposal. This paper presented an overview on the researches about anaerobic digestion of food waste. Technologies (e.g., pretreatment, co-digestion, inhibition and mitigation, anaerobic digestion systems, etc.) were introduced and evaluated on the basis of bibliometric analysis. Results indicated that ethanol and aerobic prefermentation were novel approaches to enhance substrates hydrolysis and methane yield. With the promotion of resource recovery, more attention should be paid to biorefinery technologies which can produce more useful products toward zero emissions. Furthermore, a technological route for food waste conversion based on anaerobic digestion was 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]

Separate household food waste collection for anaerobic digestion is one method used in the sustainable management of biodegradable municipal solid waste (MSW). Recycling of food waste contributes to the UK’s reuse, recycling and composting targets and can help local authorities boost plateauing rates whilst encouraging landfill diversion. This study explored the reasons for differences in the provision of food waste collections, using two comparable local authorities, one with a collection in Wales (Cardiff), and the other absent of such service in England (Southampton). A PESTLE analysis investigated the political, economic, social, technological, legal and environmental impacts of separate food waste collections. The greenhouse gas impacts of the collection and treatment systems of MSW in both cities were estimated for 2012/13. Results showed significant policy and legislative differences between devolved governments, that separate food waste collections can save local authorities significant sums of money and substantially reduce greenhouse gas impacts. A survey of one hundred respondents in each city aimed to understand attitudes and behaviours towards recycling, food waste segregation, cooking and purchasing habits. The number of frequent recyclers and levels of satisfaction were higher in the authority which provided a separate food waste collection. In the area which lacked a separate collection service, over three-quarters of respondents would participate in such a scheme if it were available. [ABSTRACT FROM AUTHOR]

Steam autoclaving is an efficient method for the separation and near complete recovery of organics from MSW. The material produced by the autoclave contains a high concentration of solubilized food waste absorbed onto a lignocellulosic matrix. Reported here is the operation of a 1500 gal (5677 L) high solids anaerobic digester to digest this feedstock. Total solids (TS) reductions were high, 56%, and volatile solids (VS) and biodegradable volatile solids (BVS) reductions were 63 and 79%, respectively. Gas yields were also high, producing 248 L CH 4 /kg VS fed or 393 L CH 4 /kg VS destroyed at a methane content of 60%. Unique design elements such as hydraulic conveyance of material, in situ classification, and in-place buffering to maintain pH stability were tested and confirmed. The digestate passed all criteria for land application of biosolids in the US, but exceeded the EU limits for Cu, Ni, and Zn. [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]

An attributional life cycle assessment (LCA) of the management of 1 ton of household waste was conducted in accordance with ISO 14044:2006 and the ILCD Handbook for seven European countries, namely Germany, Denmark, France, UK, Italy, Poland and Greece, representing different household waste compositions, waste management practices, technologies, and energy systems. National data were collected from a range of sources regarding household waste composition, household sorting efficiency, collection, waste treatments, recycling, electricity and heat composition, and technological efficiencies. The objective was to quantify the environmental performance in the different countries, in order to analyze the sources of the main environmental impacts and national differences which affect the results. In most of the seven countries, household waste management provides environmental benefits when considering the benefits of recycling of materials and recovering and utilization of energy. Environmental benefits come from paper recycling and, to a lesser extent, the recycling of metals and glass. Waste-to-energy plants can lead to an environmental load (as in France) or a saving (Germany and Denmark), depending mainly on the composition of the energy being substituted. Sensitivity analysis and a data quality assessment identified a range of critical parameters, suggesting from where better data should be obtained. The study concluded that household waste management is environmentally the best in European countries with a minimum reliance on landfilling, also induced by the implementation of the Waste Hierarchy, though environmental performance does not correlate clearly with the rate of material recycling. From an environmental point of view, this calls for a change in the waste management paradigm, with less focus on where the waste is routed and more of a focus on the quality and utilization of recovered materials and energy. [ABSTRACT FROM AUTHOR]

In this study, the carbon footprint of introducing a food waste disposer (FWD) policy was examined in the context of its implications on solid waste and wastewater management with economic assessment of environmental externalities emphasizing potential carbon credit and increased sludge generation. For this purpose, a model adopting a life cycle inventory approach was developed to integrate solid waste and wastewater management processes under a single framework and test scenarios for a waste with high organic food content typical of developing economies. For such a waste composition, the results show that a FWD policy can reduce emissions by nearly ∼42% depending on market penetration, fraction of food waste ground, as well as solid waste and wastewater management schemes, including potential energy recovery. In comparison to baseline, equivalent economic gains can reach ∼28% when environmental externalities including sludge management and emissions variations are considered. The sensitivity analyses on processes with a wide range in costs showed an equivalent economic impact thus emphasizing the viability of a FWD policy although the variation in the cost of sludge management exhibited a significant impact on savings. [ABSTRACT FROM AUTHOR]