Food Waste Diversion Research Articles

Optimization of phytase production from potato waste using Aspergillus ficuum.

Solid-state fermentation (SSF) can divert food waste from landfills and produce high-value products. This study was aimed to investigate the feasibility of using SSF and optimize the conditions of production of phytase by Aspergillus ficuum from potato waste. Different parameters including pH of the potato waste, inoculum level, moisture content, incubation period, temperature, and supplementary nitrogen and carbon sources were evaluated. The results indicated that pH, inoculum level, and moisture content did not significantly vary phytase production. However, different incubation periods, incubation temperatures, nitrogen sources, and carbon sources changed the phytase production significantly. The ideal and economic conditions for phytase production consisted of a normal moisture content (79%) of potato waste, 1.0 ml inoculum size, and normal pH 6.1 at room temperature for 144 h incubation time. The highest phytase activity (5.17 ± 0.82 U/g ds) was obtained under the aforementioned optimized conditions. When (NH4)2SO4 was used as a nitrogen source in the substrate, the phytase activity increased to 12.93 ± 0.47 U/g ds, which was a 2.5-fold increase compared to the control treatment. This study proposed a novel and economical way to convert food processing waste to highly valuable products and investigated the optimal conditions of the production of phytase during SSF in potato waste.

A great or heinous idea?: Why food waste diversion renders policy discussants apoplectic

Comprehensive agri-food policy includes food waste reduction as an important policy goal. Food bank donor indemnification is codified in law in several countries to support the charitable food sector. Other policy instruments to address waste reduction have emerged recently, among them tax measures to incentivize private sector action. These have been increasingly linked to the discourse on hunger in many jurisdictions. We asked 17 Canadian food insecurity policy entrepreneurs to comment on a vignette scenario featuring a hypothetical proposal for food waste diversion as a policy response to household food insecurity; the polarization in responses – ‘Not human garburators,’ vs. ‘everyone wins’ – was remarkable. This case of an unexpected divergence in the response to a policy idea in the food insecurity realm provides an opportunity to understand fundamental differences in societal perspectives that might be relevant to public health more generally. In particular we address the parallel humanist and ecological imperatives at work in contemporary public health practice. It appears that objections to food waste diversion for human consumption could be crystallized in terms of Mary Douglas’s theory of morality within particular worldviews. From a humanist viewpoint, the proposal was an indignity; for those with an ecological worldview, it was sensible and pragmatic. Public health has embraced ecosystem thinking and takes for granted that its ecological approach is sensitive to humanist perspectives but the two worldviews may differ and humanist ideals of dignity may raise moral rancor when considered in the context of ecological good.

Co-management of domestic wastewater and food waste: A life cycle comparison of alternative food waste diversion strategies

Food waste is increasingly viewed as a resource that should be diverted from landfills. This study used life cycle assessment to compare co-management of food waste and domestic wastewater using anaerobic membrane bioreactor (AnMBR) against conventional activated sludge (CAS) and high rate activated sludge (HRAS) with three disposal options for food waste: landfilling (LF), anaerobic digestion (AD), and composting (CP). Based on the net energy balance (NEB), AnMBR and HRAS/AD were the most attractive scenarios due to cogeneration of produced biogas. However, cogeneration negatively impacted carcinogenics, non-carcinogenics, and ozone depletion, illustrating unavoidable tradeoffs between energy recovery from biogas and environmental impacts. Fugitive emissions of methane severely increased global warming impacts of all scenarios except HRAS/AD with AnMBR particularly affected by effluent dissolved methane emissions. AnMBR was also most sensitive to food waste diversion participation, with 40% diversion necessary to achieve a positive NEB at the current state of development.

Development of a Novel Food Waste Collection Kiosk and Waste-to-Energy Business Model

The U.S. generates more than 37 million metric tons of food waste each year, and over 95% of it is disposed of at U.S. landfills. This paper describes the development of a novel food waste collection kiosk and business model called “Greenbox” that will collect and store food waste from households and restaurants with incentives for user participation to spur food waste-to-energy production in a local community. Greenbox offers a low-cost collection point to divert food waste from landfills, reduce greenhouse gases from decomposition, and aid in generating cleaner energy. A functional prototype was successfully developed by a team of engineering students and a business model was created as part of a senior design capstone course. Each Greenbox unit has the potential to reduce 275 metric tons of food waste per year, remove 1320 kg of greenhouse gases, and create 470,000 liters of methane gas while providing a payback period of 4.2 years and a rate of return of 14.9%.

Systematic Evaluation of Industrial, Commercial, and Institutional Food Waste Management Strategies in the United States.

New regulations and targets limiting the disposal of food waste have been recently enacted in numerous jurisdictions. This analysis evaluated selected environmental implications of food waste management policies using life-cycle assessment. Scenarios were developed to evaluate management alternatives applicable to the waste discarded at facilities where food waste is a large component of the waste (e.g., restaurants, grocery stores, and food processors). Options considered include anaerobic digestion (AD), aerobic composting, waste-to-energy combustion (WTE), and landfilling, and multiple performance levels were considered for each option. The global warming impact ranged from approximately -350 to -45 kg CO2e Mg(-1) of waste for scenarios using AD, -190 to 62 kg CO2e Mg(-1) for those using composting, -350 to -28 kg CO2e Mg(-1) when all waste was managed by WTE, and -260 to 260 kg CO2e Mg(-1) when all waste was landfilled. Landfill diversion was found to reduce emissions, and diverting food waste from WTE generally increased emissions. The analysis further found that when a 20 year GWP was used instead of a 100 year GWP, every scenario including WTE was preferable to every scenario including landfill. Jurisdictions seeking to enact food waste disposal regulations should consider regional factors and material properties before duplicating existing statutes.

Towards low carbon society in Iskandar Malaysia: Implementation and feasibility of community organic waste composting

Rapid population growth and urbanisation have generated large amount of municipal solid waste (MSW) in many cities. Up to 40-60% of Malaysia's MSW is reported to be food waste where such waste is highly putrescible and can cause bad odour and public health issue if its disposal is delayed. In this study, the implementation of community composting in a village within Iskandar Malaysia is presented as a case study to showcase effective MSW management and mitigation of GHG emission. The selected village, Felda Taib Andak (FTA), is located within a palm oil plantation and a crude palm oil processing mill. This project showcases a community-composting prototype to compost food and oil palm wastes into high quality compost. The objective of this article is to highlight the economic and environment impacts of a community-based composting project to the key stakeholders in the community, including residents, oil palm plantation owners and palm oil mill operators by comparing three different scenarios, through a life cycle approach, in terms of the greenhouse gas emission and cost benefit analysis. First scenario is the baseline case, where all the domestic waste is sent to landfill site. In the second scenario, a small-scale centralised composting project was implemented. In the third scenario, the data obtained from Scenario 2 was used to do a projection on the GHG emission and costing analysis for a pilot-scale centralised composting plant. The study showed a reduction potential of 71.64% on GHG emission through the diversion of food waste from landfill, compost utilisation and significant revenue from the compost sale in Scenario 3. This thus provided better insight into the feasibility and desirability in implementing a pilot-scale centralised composting plant for a sub-urban community in Malaysia to achieve a low carbon and self-sustainable society, in terms of environment and economic aspects.

Environmental and health impacts of using food waste as animal feed: a comparative analysis of food waste management options

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.

Combined material flow analysis and life cycle assessment as a support tool for solid waste management decision making

Material flow analysis (MFA) and life cycle assessment (LCA) have both widely been applied to support solid waste management (SWM) decision making. However, they are often applied independently rather than conjointly. This paper presents an approach that combines the MFA and LCA methodologies to evaluate large and complex SWM systems from an environmental perspective. The approach was applied to evaluate the environmental performance, focusing on greenhouse gas (GHG) emissions, of a local authority SWM system and to compare it with alternative systems to assess the potential effectiveness of different waste policy measures. The MFA results suggest that national recycling targets are unlikely to be met even if the assessed policies are implemented optimally. It is likely that for the targets to be met, investigated policies would need to be combined with additional policies that target reductions in waste arisings. The LCA results found landfilling of residual waste to be the dominant source of GHG burdens for the existing system, whilst material reprocessing was found to result in GHG benefits. Overall, each of the alternative systems investigated were found to result in lower GHG impacts compared to the existing system, with the diversion of food waste from the residual waste stream found to be potentially the most effective strategy to reduce GHG emissions. The results of this study demonstrate that the complementary methodologies of MFA and LCA can be used in combination to provide policy and decision makers with valuable information about the environmental performance of SWM systems.

What’s in a Dog’s Breakfast? Considering the Social, Veterinary and Environmental Implications of Feeding Food Scraps to Pets Using Three Australian Surveys

Diverting food waste away from landfills is one way to minimise its serious environmental impact. Given that over a third of Australian households have at least one pet, the feeding of food waste to dogs constitutes one potentially significant waste diversion path. However, the proportion of dog owners that feed food waste to their pets is unknown. Moreover, there has been no investigation into any relationship between practices of feeding scraps to pets and the animals’ body condition, living arrangements (inside or outside) and exercise regime. To provide some insight, this paper presents findings from three surveys across two Australian studies. The first reports both pet and dog-specific findings from two surveys within a wider food waste research project (n = 1017), establishing that 28% of respondents fed leftovers to pets as a main food waste minimization strategy, yet in only 5% of households did this constitute more than half of the household’s food scraps. This modest diversion of food scraps from landfill to feeding pets was reflected in the finding that there was no significant difference seen in the claimed level of food discards to the waste stream for households feeding food scraps to dogs and those that did not. The second—a dog owner specific study (n = 355)—found that almost half (44%) of respondents reported feeding table scraps to dogs. They were more likely to be females, owners of medium sized dogs, and in larger households. There was no significant difference in self-rated dogs’ body condition scores between respondents who fed table scraps to their dog and those who did not. Further multidisciplinary research is recommended to reconcile the social, veterinary and environmental risks and benefits of feeding food waste to animals.

Food Waste Auditing at Three Florida Schools

School cafeterias are a significant source of food waste and represent an ideal opportunity for diverting food waste from landfills. In this study, cafeteria waste audits were conducted at three Florida schools. Food waste comprised the largest fraction of school cafeteria waste streams, ranging from 47% to 58%, followed by milk, paper products (tissue, milk cartons, pasteboard, paper plates, and cardboard), and plastics (plastic wrap, packaging, and utensils). Metal and glass comprised the smallest fraction of the waste stream. Average total waste generation ranged from 50.5 to 137.6 g·student−1·day−1. The mean generation rates for food waste ranged from 24.7 to 64.9 g·student−1·day−1. The overall average for cafeteria waste generation among all three schools was 102.3 g·student−1·day−1, with food waste alone contributing 52.2 g·student−1·day−1. There are two primary approaches to diverting school food waste from landfills: reduction and recycling. Food waste can be reduced through educating students and staff in order to change behaviors that cause food waste. Food waste can be collected and recycled through composting or anaerobic digestion in order to generate beneficial end products, including soil amendments and bioenergy. Over 75% of the cafeteria waste measured in this study could be recycled in this manner.

Life cycle greenhouse gas (GHG) impacts of a novel process for converting food waste to ethanol and co-products

Waste-to-ethanol conversion is a promising technology to provide renewable transportation fuel while mitigating feedstock risks and land use conflicts. It also has the potential to reduce environmental impacts from waste management such as greenhouse gas (GHG) emissions that contribute to climate change. This paper analyzes the life cycle GHG emissions associated with a novel process for the conversion of food processing waste into ethanol (EtOH) and the co-products of compost and animal feed. Data are based on a pilot plant co-fermenting retail food waste with a sugary industrial wastewater, using a simultaneous saccharification and fermentation (SSF) process at room temperature with a grinding pretreatment. The process produced 295L EtOH/dry t feedstock. Lifecycle GHG emissions associated with the ethanol production process were 1458gCO2e/L EtOH. When the impact of avoided landfill emissions from diverting food waste to use as feedstock are considered, the process results in net negative GHG emissions and approximately 500% improvement relative to corn ethanol or gasoline production. This finding illustrates how feedstock and alternative waste disposal options have important implications in life cycle GHG results for waste-to-energy pathways.

Integrating Food Waste Diversion into Food Systems Planning: A Case Study of the Mississippi Gulf Coast

Food waste presents a great challenge for the efficiency of food systems and for solid waste management. Many solid waste management strategies can be used for managing food waste in the food system, but their implementation depends on local factors. Strategies must also be modified or designed to accommodate local needs and unique circumstances. This paper reports the planning process undertaken in the Mississippi Gulf Coast to develop a food system plan that integrated strategies to manage food waste more sustainably. The planning process was a three-step process that engaged stakeholders in the food supply chain from production, distribution, retail, and consumption through to post-consumption. The article describes the specific steps taken to assess the generation of food waste in the foodshed, engage stakeholders, and develop strategies for food waste diversion and management. It concludes by offering recommendations on how communities can integrate food waste diversion into their food system planning efforts.

Integrating Food Waste Diversion into Food Systems Planning: A Case Study of the Mississippi Gulf Coast

First paragraph: can be a common and unifying force socially, culturally, and spiritually,” write the authors of Whole Measures for Community Food Systems (WM CFS), a truth with which I heartily agree. In the past decade, I have been a teacher, student, organ­izer, dreamer, schemer, more recently a gar­dener, and always an eater. Much of my personal and professional energy is directed toward food-related initiatives. Particularly in multicultural and multilingual environments, food has proven a com­mon language, providing fertile soil in which these efforts are cultivated....

An economic analysis of energy generation and food waste diversion for enhanced biogas production at a colorado wastewater treatment facility

Food waste diversion to enhance biogas production for energy generation in municipal wastewater treatment plants (WWTPs) is an emerging trend in the United States. Using an interested WWTP in Fort Collins, Colorado a study was completed to determine the efficacy and viability of implementing a food waste diversion program utilizing food waste as a feedstock in their existing anaerobic digesters to enhance biogas production. The results of the study concluded that a food waste diversion program would result in a loss of approximately $2.5 million over a 20 year period making the program unfeasible currently. However, the use of excess biogas produced in the plant's anaerobic digesters from the processing of the municipal solid waste stream (MSW) to fuel a reciprocating engine energy generation technology would result in an estimated return on investment of $1.63 million, and an estimated return on investment of $1.25 million for a microturbine energy generation technology over the same 20 year time period. Changes to multiple variables in the economic analysis such as higher energy costs and higher landfill tipping fees could result in a more positive outlook for a future food waste diversion program in Northern Colorado. This study can be used by other WWTPs in the US and other countries as a model to determine the initial economic feasibility of a food waste diversion program in their area. WWTPs in locations with greater costs associated with energy and tipping fees than those reported in this study may find a food waste diversion program economically viable and beneficial.

Pathways and Management of Phosphorus in Urban Areas

SummaryDue to the finite nature of mineral phosphorus reserves, effective management of anthropogenic phosphorus flows is currently under investigation by the international research community. This article emphasizes the importance of urban phosphorus flows, which are often marginalized due to the greater magnitude of agricultural phosphorus flows. A study on phosphorus flows in Gothenburg, Sweden, points out the potential role of solid waste in nutrient management, as the amounts of phosphorus in solid waste and in wastewater were found to be equal. Importation of food commodities accounts for 50% of the total inflow of phosphorus, and food waste is a major contributor of phosphorus to solid waste. The results suggest that solid waste incineration residues represent a large underestimated sink of phosphorus. Focusing on wastewater as the sole source of recovered phosphorus is not sufficient. The Swedish national goal on phosphorus recycling, which is limited to sewage sludge, targets only a part of the total phosphorus flow that can potentially be recovered. In contrast to previous studies, agricultural flows in Gothenburg were marginal compared to flows related to the urban waste management infrastructure. We emphasize the need for debate on preferable routes for disposal of waste with a high phosphorus content. Both recovery potential and usefulness of the recovered product for agricultural purposes have to be considered. Impacts of five waste management strategies on phosphorus flows were evaluated: incineration of all the waste, comprehensive food waste separation, installation of kitchen grinders, urine diversion, and separation of blackwater and food waste.

Assessment of anaerobic degradation of Ingeo™ polylactides under accelerated landfill conditions

Ingeo™ polylactide (PLA)11Trademark or registered trademark of NatureWorks LLC in the USA and other countries. biopolymers are used world-wide in a diverse range of applications and, after the useful life of the particular application, they can be recycled (either mechanically or chemically) or disposed of via various end-of-life options, such as composting, incineration and landfilling. The use of compostable materials for food packaging could be an enabling technology to allow the diversion of food waste from landfills into composting facilities. However, despite many new initiatives and existing programs it is still true that a significant part of industrial and household waste still ends up in landfills. Because polylactide polymers are known to be compostable the question is often raised about the behaviour of these materials in landfills.In order to study the behaviour of Ingeo polylactides (PLA) in landfills two studies were performed aimed at generating reliable information on the anaerobic biodegradation of PLA under conditions of extended time and modest temperatures. The first test (under accelerated landfill conditions) was done at 21 °C, and three moisture levels, extending to 390 days and the second test (a high solids anaerobic digestion test under optimal and significantly accelerated conditions) was conducted at 35 °C for 170 days. Each test is meant to represent an accelerated test of what could happen under anaerobic landfill conditions. These two tests each had accelerated the biological degradation sufficiently that they were in some sense equivalent to approximately a century of a “typical” biologically active landfill.The semicrystalline polylactide samples did not produce a statistically significant quantity of biogas during either test. The amorphous PLA did generate a small amount of biogas in the test at 35 °C, but none in the test at ambient temperature. Here it should be noted that the tests were conducted under accelerated, optimal landfill conditions, the biodegradation was observed in a 100 year timeframe and the market volume of amorphous PLA is low. We conclude that semicrystalline PLA (typical of >96 wt% of resin used to manufacture products), under anaerobic biological conditions typical of a landfill at moderate temperatures (where PLA hydrolysis is slow), will not lead to significant generation of methane, and that no significant population of organisms is available under anaerobic conditions to directly degrade high molecular weight PLA. Because there was no direct biological degradation of PLA under the anaerobic conditions, it is likely that any degradation of PLA in a landfill would require a chemical hydrolysis step prior to any biodegradation, which is analogous to the situation in aerobic composting. At 20 °C this process is estimated to take 100+ years, and under those conditions the degradation of the PLA would be extremely low. Additional data on the time/temperature history experienced in landfills will be needed to understand the net effect for disposal of PLA globally.

Food waste disposal units in UK households: The need for policy intervention

The EU Landfill Directive requires Member States to reduce the amount of biodegradable waste disposed of to landfill. This has been a key driver for the establishment of new waste management options, particularly in the UK, which in the past relied heavily on landfill for the disposal of municipal solid waste (MSW). MSW in the UK is managed by Local Authorities, some of which in a less conventional way have been encouraging the installation and use of household food waste disposal units (FWDs) as an option to divert food waste from landfill. This study aimed to evaluate the additional burden to water industry operations in the UK associated with this option, compared with the benefits and related savings from the subsequent reductions in MSW collection and disposal. A simple economic analysis was undertaken for different FWD uptake scenarios, using the Anglian Region as a case study. Results demonstrated that the significant savings from waste collection arising from a large-scale uptake of FWDs would outweigh the costs associated with the impacts to the water industry. However, in the case of a low uptake, such savings would not be enough to cover the increased costs associated with the wastewater provision. As a result, this study highlights the need for policy intervention in terms of regulating the use of FWDs, either promoting them as an alternative to landfill to increase savings from waste management, or banning them as a threat to wastewater operations to reduce potential costs to the water industry.

Regional prediction of long-term landfill gas to energy potential

Quantifying landfill gas to energy (LFGTE) potential as a source of renewable energy is difficult due to the challenges involved in modeling landfill gas (LFG) generation. In this paper a methodology is presented to estimate LFGTE potential on a regional scale over a 25-year timeframe with consideration of modeling uncertainties. The methodology was demonstrated for the US state of Florida, as a case study, and showed that Florida could increase the annual LFGTE production by more than threefold by 2035 through installation of LFGTE facilities at all landfills. The estimated electricity production potential from Florida LFG is equivalent to removing some 70 million vehicles from highways or replacing over 800 million barrels of oil consumption during the 2010–2035 timeframe. Diverting food waste could significantly reduce fugitive LFG emissions, while having minimal effect on the LFGTE potential; whereas, achieving high diversion goals through increased recycling will result in reduced uncollected LFG and significant loss of energy production potential which may be offset by energy savings from material recovery and reuse. Estimates showed that the power density for Florida LFGTE production could reach as high as 10 W m −2 with optimized landfill operation and energy production practices. The environmental benefits from increased lifetime LFG collection efficiencies magnify the value of LFGTE projects.

Estimation of Waste Component-Specific Landfill Decay Rates Using Laboratory-Scale Decomposition Data

The current methane generation model used by the U.S. EPA (Landfill Gas Emissions Model) treats municipal solid waste (MSW) as a homogeneous waste with one decay rate. However, component-specific decay rates are required to evaluate the effects of changes in waste composition on methane generation. Laboratory-scale rate constants, k(lab), for the major biodegradable MSW components were used to derive field-scale decay rates (k(field)) for each waste component using the assumption that the average of the field-scale decay rates for each waste component, weighted by its composition, is equal to the bulk MSW decay rate. For an assumed bulk MSW decay rate of 0.04 yr(-1), k(field) was estimated to be 0.298, 0.171, 0.015, 0.144, 0.033, 0.02, 0.122, and 0.029 yr(-1), for grass, leaves, branches, food waste, newsprint, corrugated containers, coated paper, and office paper, respectively. The effect of landfill waste diversion programs on methane production was explored to illustrate the use of component-specific decay rates. One hundred percent diversion of yard waste and food waste reduced the year 20 methane production rate by 45%. When a landfill gas collection schedule was introduced, collectable methane was most influenced by food waste diversion at years 10 and 20 and paper diversion at year 40.

Recycle Florida Today and Florida Organics Recyclers Association: Then, Now, and Beyond

In 1988, the Florida Legislature passed the Solid Waste Management Act that affected the solid waste disposal practices of every county in the state. With legislation directly affecting the industry, organic recyclers and Florida Department of Environmental Protection (FDEP) regulators recognized a need to establish a professional organization that could serve as a unified industry voice, and foster high standards and ethics in the business of recycling and reuse of organic materials. In December 1994, a meeting was held to discuss the formulation of a Florida organic recycling association which became known as the Florida Organics Recyclers Association (FORA). FORA's first major contribution to the industry was the development of a recycling best management practice manual for yard trash in 1996. The second major project undertaken by FORA was a food waste diversion project which sought to promote an increase in food waste recovery and reuse. In Spring 1999, FORA became the organic division of Recycling Florida Today (RFT) further unifying recycling efforts within the State of Florida. In an attempt to address mounting concerns regarding industry marketing and promotional needs, RFT/FORA developed an organic recycling facility directory for the State of Florida in Spring 2000. Most recently RFT/FORA developed an organic recycling facility operator training course outline to assist the FDEP in identifying industry training needs. From its modest beginnings in 1994, to future joint programming efforts with the University of Florida's Florida Organic Recycling Center for Excellence (FORCE), RFT/FORA continues to emerge as a viable conduit of educational information for public and private agencies relative to organic recycling in Florida.