Collected Food Waste Research Articles

Hot Water Washing Pre-Treatment Effects on Hot Air-Drying Process of Food Waste

The study aims to determine the effects of pre-treatment and temperature on the drying behavior of food waste. The collected food waste was pre-treated by soaking in warm distilled water at 50°C for 10 minutes before the hot air-drying process at 70°C and 85°C. A hot air dryer at different drying times and temperatures were used to measure the food waste until no noticeable weight loss. In the beginning, the moisture content fell quickly, and then progressively decreased with increasing drying time. Food waste at 85°C recorded the shortest drying time of 121 minutes to reach equilibrium compared to another drying parameter 70 °C. The equilibrium moisture content of pre-treated food waste with hot distilled water at a temperature of 70 ˚C was 0.609g H2O g-1 dry solid since the non-pre-treated food waste was 0.767 g H2O g-1 dry solid. The equilibrium moisture content of pre-treated food waste at 85˚C was 0.489 g H2O g-1 dry solid. In conclusion, washing pretreatment has a significant impact on the drying process because pretreated samples reach equilibrium faster than non-washed ones. Overall, Drying technologies are essential for reducing the moisture content of food waste, which is required for environmental sustainability and safety.

Food waste collection versus food waste disposers: A case study of a Portuguese city

The European Union (EU) prioritises sustainable development and aims to achieve climate neutrality by 2050 through investments in green technologies and a legislative climate framework. Waste collection and treatment systems, including biowaste like food waste, protect natural capital and citizens' well-being. Directive 2008/98/EC defines biowaste and sets the stage for exploring alternative solutions. This study focuses on the city of Guarda (Portugal) and analyses the use of disposers for food waste treatment. By comparing storage/collection systems with disposers regarding environmental and economic costs and benefits, the study aims to determine the most effective solution for collecting food waste. The analysis utilises a simulator provided by the Portuguese Fundo Ambiental®. The results show that while operating costs are higher for food waste collection systems, disposers require a more significant initial investment. Nevertheless, the cost-benefit ratio favours disposers, while the net present value analysis suggests that the food waste collection system is more favourable. Additionally, food waste collection systems contribute to higher greenhouse gas (GHG) emissions per tonne of food waste compared to using disposers.

Environmental and economic impacts of improper materials in the recycling of separated collected food waste through anaerobic digestion and composting

Separately collected food waste (SC-FW) is effectively recycled through industrial anaerobic digestion (AD) and composting. However, the presence of improper materials in SC-FW not only generates technical problems to AD and composting, but also lowers the quality of the outputs of the processes. As a consequence, improper materials found in SC-FW cause not negligible environmental and economic burdens.In this study, the environmental and economic impacts due to the presence of unsuitable materials in the SC-FW, determined through compositional analysis, were estimated through life cycle assessment and environmental life cycle costing approaches. Three different scenarios were analysed for both AD and composting processes: (i) the current situation (CS); (ii) the improved scenario (AS) with an amount of improper materials in SC-FW reduced to 3 % (w/w); (iii) the ideal scenario (IS) with the total absence of foreign materials.Environmental benefits were determined for the AS and IS scenarios in 17 of the 19 analysed impact categories. Considering the GHG emissions, higher savings were measured for AD in AS and IS scenarios (47 % and 79 %, respectively) than in CS scenario. Similarly, savings of −10.4 kg fossil oil eq/tonSC-FW (AS) and − 17.1 kg fossil oil eq/tonSC-FW (IS) for AD could be obtained with respect to the CS scenario. Greater economic benefits were calculated for AD (−76.4 €/tonSC-FW) and composting (−52.2 €/tonSC-FW) in the IS scenario. Savings up to € 2,249,780 and € 3,888,760 could have been obtained in 2022 by reducing to 3 % (w/w) and eliminating, respectively, the amount of improper materials in the SC-FW.The results of the compositional analyses of SC-FW allowed to identify the incorrect behaviours in FW source-sorting activity and to plan interventions to improve the current FW management system. The quantified environmental and economic benefits could further motivate citizens to correctly differentiate FW.

Conversion of food waste to renewable energy: A techno-economic and environmental assessment

Increasing quantities of food waste have become a concern due to high disposal costs in landfills and high greenhouse gas emissions. With this increase in food waste generation, there is also an increasing demand for renewable natural gas to supplement traditional fossil fuel combustion and offset the impacts of climate change. Collecting food waste from landfills and turning it into renewable natural gas using anaerobic digestion could be a win-win option for both food waste disposal and renewable energy production. While some literature exists on the energy potential, economic feasibility, and environmental benefit of food waste disposal via anaerobic digestion, no existing study simultaneously evaluates the energy, economic and environmental effect of food waste to renewable energy via anaerobic digestion, especially on a plant and city scale. This study is focused on the techno-economic and environmental assessment of food waste to energy via anaerobic digestion in order to fill this gap. Four anaerobic digestion pathways are considered in this study: flare, pipeline natural gas, combined heat and power, and combined cycle for efficient power generation. Using a city of 1 M people the results show that renewable natural gas from food waste could supply the natural gas usage for 1.9% of residential use, 2.7% of commercial use, 1.1% of industrial use, 167.5% of the compressed natural gas vehicle fleet, 0.7% of electric power generation, or 2.5% of industrial high-temperature heating processes. All pathways except pipeline natural gas will have a positive net present value in the baseline scenario, and the pipeline natural gas pathway will become economically viable with a net present value of 31 USD/t of food waste with renewable energy credits. Lastly, all of the pathways achieve negative greenhouse gas emissions, which indicates that anaerobic digestion is a more environmentally friendly method for the handling of food waste than landfills.

A Model for Finding a Suitable Location for a Micro Biogas Plant Using Gis Tools

The article presents a model for finding the most suitable locations for setting up micro-biogas plants (<50 kW), which represent an efficient way of processing organic waste in small local communities. The input parameters of the model, which was made with GIS tools, were the number of farms and heads of large livestock with their locations, the number of food establishments and their collected food waste and waste fat. We tested the case study model in the Gorenjska region in Slovenia. The result of processing the input data in the model are four locations in three municipalities Naklo 1, Naklo 2, Kranj and Cerklje. We evaluated the locations with economic indicators net present value (NPV), internal rate of return (IRR) and discounted payback period (DPP). With sensitivity analysis, we investigated the impact of increasing investment costs, decreasing energy prices and different scenarios with adding corn silage to the anaerobic process. Location Naklo 1 has NPV 31,410.26 €, IRR 10.53% and DPP 22 years, Naklo 2 has NPV −58,808.91 € and DPP of more than 25 years, location Kranj has NPV 140,313.00 €, IRR 13.07% and DPP 16 years, location Cerklje has NPV −43,026.82 € and DPP of more than 25 years.

Estimating emissions from household organic waste collection and transportation: The case of Sydney and surrounding areas, Australia

Australian waste related emissions are poorly characterised in National Greenhouse Accounts, with only landfill emissions directly attributed. Direct and indirect emissions however occur at all points along the waste management chain resulting from the consumption of energy and fuel during collection, transportation, and waste recovery activities. Without knowledge of waste-related emissions, it is difficult to evaluate the potential of different management pathways for achieving resource recovery and emission reduction objectives. Previous studies tend to utilise life cycle assessment (LCA) in examining waste transport emissions. Some studies have developed country-specific emissions factors for waste transportation based on LCA, however such factors have high variability owing to these models being dependent on widely varying local conditions. The aim of this study is to estimate emissions associated with kerbside organic waste collection from households and transportation in the Greater Sydney area in 2018–19. High-resolution road network and property-lot waste generation data was utilised in a GIS integrated route optimisation model. Our model considered transport of collection vehicles ‘to’ and ‘from’ transfer stations and kerbside collection areas across the 43 council areas, as well as transport of waste collected to reprocessing and landfill facilities. Greenhouse gas emissions for organic waste transport and collection were estimated at approximately 43,700 t CO 2 -e, equal to approximately 2% of all road transport emissions in the study area. Kerbside collection was the largest contributor to overall transport emissions, accounting for approximately 89%. Average emissions intensity on a tonnes diverted from landfill basis was lowest for councils separating food waste out of the mixed waste stream at 45 kg CO 2 -e/tonne, owing to the greater quantities of waste diverted via food collection and mixed waste recovery pathways. Average emissions intensity across all councils was 96 kg CO 2 -e/tonne. Findings indicate that improved efficiency of bin-lift mechanisms, including increasing the intensity of bin-lifts per stop, as well as collection vehicle fuel efficiency and electrification, would have the greatest impact on reducing tra and collection emissions. • Route optimisation model was applied to estimate emissions from the collection of household organic wastes in Sydney, Aus. • Emissions from waste collection vehicle activities and transfer to recovery and disposal facilities were estimated. • Analysis shows kerbside collection is the most significant contributor to waste transport emissions. • Councils collecting food waste separately had the lowest emissions per-tonne of organic waste diverted from landfill. • Approach has a number of applications in supporting the transition towards low-carbon and cleaner waste systems.

Managing food waste is key to tackling climate change

Managing food waste is key to tackling climate change

Optimal Control Analysis of Food Waste Treatment Methods Based on Improved Pressure Sensors

With the rapid development of the economy and society, people's overall living standard continues to rise, and food waste generated by various industries is becoming a major part of domestic waste, how to dispose of waste in a real-time and resourceful manner is a major test for urban environmental maintenance. This paper focus on the weight perception of solid food waste after pre-treatment and proposes an optimisation strategy for the first time. The core structure of the traditional sensor is improved from three perspectives: temperature, capacitance value and external stress, thus building an improved capacitive pressure sensor to accurately detect the weight of waste and trim the measured data more accurate. Secondly, based on the remote monitoring system, the multi-level control enables the collected food waste to be eliminated in a timely manner, which helps the resource utilization of food waste.

Life cycle assessment of the food waste management with a focus on the collection bag.

The organic fraction (mainly food waste) is typically the most abundant of the separately collected waste streams. The research aims at investigating the influence of different types of collection bag on the environmental performances of the food waste management chain in Italy. A comparative life cycle assessment (LCA) between two alternative systems based on paper or bioplastic collection bags was carried out. It included the collection bags manufacturing and distribution, their use at the household, the transportation of collected food waste and its subsequent anaerobic digestion, including the valorisation of useful outputs and the management of residues. The two systems were modelled mainly with primary data related to the current management system and to tests performed on bags. The LCA was performed with two different modelling approaches applied in the environmental product declaration (EPD) system and in the product environmental footprint (PEF) studies, respectively. In the scenario representing the average conditions, higher environmental impacts are shown by the use of bioplastic bags compared to paper ones with the EPD approach (+257%/+576%). With the PEF approach, the differences between the two systems are lower (-55%/+133%). Moreover, paper bags could allow for further impact reductions assuming a decrease of the food waste collection frequency, allowed by higher weight losses and a lower generation of leachate and odour during the household storage.

Viability of Food Waste to Biogas Energy Through Anaerobic Digestion

This study was conducted on the feasibility of food waste for biogas production in Wolaita Sodo University, Ethiopia. The study aimed to investigate the potential of different food waste categories for biogas production through anaerobic digestion. A total of 40 representative food waste samples with 100 grams each were collected from four source-separated food waste categories based on the various food menus of the University. The collected food waste samples were tested for %TS, %TN, %TVS and %TC. Besides, laboratory-scale anaerobic digestions were carried out exhaustively for each food sample for 25 days at 35 o C. Thus, the proportion of CH 4 and CO 2 of the biogas produced from each food waste categories was also evaluated. The analysis was done using IBM SPSS Statistics 21. Results showed that %TN, %TS, %TVS and %TC were 1.62%, 30.75%, 29.29 % and 16.27%, respectively. Small C: N ratio (10:1) was scored. The ratio of VS: TS was very high (95%). The mean CH 4 proportion produced from ISV, RB, IML and MA were 61, 65, 63 and 63 respectively. However, the mean CO 2 proportion produced from ISV, RB, IML and MA were 22, 20.5, 15.5 and 16 respectively. Thus, the proportion of CH 4 produced 61-65% and high ratio of VS: TS showed the viability of all food waste categories to biogas energy production. However, the small C: N ratio which is an indicator for the resistance of anaerobic digestion implied in need of other organic wastes rich in carbon content to the reactor. In general, the food wastes generated from WSU students’ cafeteria are a promising feedstock for anaerobic digesters concerning biogas production. Keywords: Food waste , Anaerobic digestion, C: N ratio, %CH 4 , % CO 2 and Biogas DOI: 10.7176/JETP/10-4-01 Publication date: August 31 st 2020

Economic development and human ties in informal food waste recycling: A follow-up study in Da Nang, Vietnam

This study examined the effects of economic development on the commercialised and non-commercialised segments of informal food waste recycling in Da Nang City, Vietnam. Food waste was collected from the urban centre and used as pig feed in swine farms in suburban areas. The commercialised and non-commercialised segments of this system have evolved differently over time. During our observation period of 2011-2016, swine farmers became concerned about economic efficiency, which affected the manner in which they used food waste. By 2016, more farmers had begun to use food waste brokers instead of collecting food waste themselves so that they could concentrate on rearing pigs. The price of food waste remained low, reflecting the farmers' need for low-cost feeding. This resulted in the closure of commercialised transactions between households and waste collectors amid increased household income. Instead, non-commercialised transactions supported by human ties became the main mode of household participation in food waste recycling . Our findings can guide the use of different elements in this informal recycling system within the framework of a formalised recycling system implemented by the government.

Turning Food Waste into Value-Added Resources: Current Status and Regulatory Promotion in Taiwan

Food waste is daily generated in significant amounts around the world, implying the depletion of natural resources and the emergence of environmental pollution issues if discarded without valorization or utilization. In this regard, food waste management poses an important challenge in the circular society. Based on the official statistics and the national laws and regulations database in Taiwan, this study analyzed the on-line reporting amounts of collected food waste since it has been officially designated as one of the mandatory recyclable wastes. Furthermore, the regulatory measures for promoting food waste utilization in Taiwan were addressed to valorize it for the production of value-added resources and also prevent the spread of African swine flu. It showed that the collected amounts of food waste from residential and commercial sectors in Taiwan significantly increased from about 168,600 metric tons in 2003 to the maximal amount (i.e., 834,500 metric tons) in 2012, reflecting the regulatory promulgation and promotional measures. Based on the joint efforts by the central governing authorities (including the Environmental Protection Administration, the Council of Agriculture, and the Ministry of Economic Affairs), this study also examined the regulatory promotions for utilizing food waste as an available resource for the production of value-added resources (i.e., organic fertilizer, pig feed, and bioenergy). Through the central governing authority, local governments, and private recyclers, about 2000 metric tons of food waste in Taiwan was recycled every day, which can not only mitigate the pressure on waste incineration and disposal systems, but also conform to the trends of environmental sustainability and circular bioeconomy. Therefore, the Taiwan government is currently supporting the establishment of anaerobic digestion and aerobic composting plants for turning food waste into organic fertilizers and biogas-to-electricity because they have been evaluated as the best options of food waste valorization.

Institutional aspects of solid waste treatment in Russia

Institutional aspects of solid waste treatment in Russia

Coloured Plastic Bags for Kerbside Collection of Waste from Households—To Improve Waste Recycling

Today, considerable amounts of resources are landfilled or incinerated, and recyclable materials such as metal, glass, plastic, and paper are disposed of as residual waste instead of being sorted into recyclable fractions. Recycling is one way of transitioning towards a circular economy and a more resource-efficient society. However, in many older cities there is insufficient space for waste bins, which makes waste sorting difficult. The aim of the study was to test how the introduction of a new kerbside collection system, using different-coloured plastic bags, would influence the amounts of residual waste and separately collected food waste. Coloured plastic bags were introduced in an old city centre in Kalmar, in the southeast of Sweden. This type of kerbside collection was applied to 38 apartments with a total of 87 residents for four weeks. Results show that residual waste decreased directly by 15 percent and the collected amount of food waste increased directly by 35 percent. The residents perceived that the sorting system facilitated sorting and that the sorting of recyclable materials increased. Kerbside collection, close to properties, seemed to be an important factor in reducing the amount of residual waste, leading to increased sorting, and hence improved recycling.

Turning organic waste into hydrogen

A narrow tower two stories high sits behind chemical engineer S. Venkata Mohan’s lab at the Council of Scientific and Industrial Research’s Indian Institute of Chemical Technology. Every other day for 6 months in 2017, he and his team fed this “beast.” They collected food waste from the institute’s cafeteria, ground it up, filtered out large particles, drained the oils, and added it to the tower, which contains an anaerobic digester filled with a soup of waste and bacteria. Munching on the leftover lunch, those microorganisms didn’t produce a conventional biogas, the typical output of digesters. With some scientific innovation from Mohan and his team, the microbes instead produced a gas rich in hydrogen. Building on the beast’s ability to pump out 5 kg of hydrogen per day, Mohan is now in talks with Indian officials to build similar plants 10 times as large to treat municipal waste in Delhi

A multi-criteria sustainability assessment framework: development and application in comparing two food waste management options using a UK region as a case study.

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.

Direct and indirect effects of waste management policies on household waste behaviour: The case of Sweden

Swedish legislation makes municipalities responsible for recycling or disposing of household waste. Municipalities therefore play an important role in achieving Sweden’s increased levels of ambition in the waste management area and in achieving the goal of a more circular economy. This paper studies how two municipal policy instruments – weight-based waste tariffs and special systems for the collection of food waste – affect the collected volumes of different types of waste. We find that a system of collecting food waste separately is more effective overall than imposing weight-based waste tariffs in respect not only of reducing the amounts of waste destined for incineration, but also of increasing materials recycling and biological recovery, despite the fact that the direct incentive effects of these two systems should be similar. Separate food waste collection was associated with increased recycling not only of food waste but also of other waste. Introducing separate food waste collection indirectly signals to households that recycling is important and desirable, and our results suggest that this signalling effect may be as important as direct incentive effects.

Food waste management through composting process in Malaysia: case study in selected area in Kuantan, Pahang

The best method to treat food waste is composting but it is still unnoticeable because it is hard to monitor and a longer time is needed to complete it. The focus in this research is to enhance process and reduce time during composting. The final product which is compost can be used as a fertiliser or as a soil amendment. The collected food waste will undergo pre-treatment steps before starting the process. Throughout the process, the food waste will be stirred for three days. Data for moisture content, pH and temperature will be recorded. Temperature below 20°C, pH between 6-8 and moisture content between 30%-70% indicates that the compost is matured, meaning it is stable for use. Research about systematic method to treat food waste is crucial because it will lessen the food waste quantity dispose in landfill. And thus, protect the environment.

Potential reuse of kitchen food waste

Kitchen food waste provides serious environmental pollution including its handling and disposal problem. In this study, an initiative has been taken to chemically characterize food waste and identify possible reuse and disposal techniques. Food waste samples were collected from kitchen of girls hostel of National Institute of Technology, Rourkela, India. Collected food waste samples were dried by various methods. It is observed that oven drying method at 105°C is the optimum temperature for maximum dewatering of collected food waste. The dried samples were further used for lipid extraction. Lipid profile analysis of the food waste samples was performed by using combination of different time of contact (20, 40 and 60min) with varying solvent to food waste volumes (1:4, 1:2, 1:1 and 2:1). Gas chromatography–mass spectrometry and gas chromatography- flame ionization detector analyses have been performed to identify and quantify the presence of organic compounds in lipid from food waste. Caproic acid (6:1), lauric acid (12:0), mystric acid (14:0), palmitic acid (16:0), stearic acid (17:0) and oleic acid (18:0) are the fatty acids that have been identified in GC–MS. Palmitic acid (60.89mg/l), stearic acid (74.11mg/l) and oleic acid (3.81mg/l) dominate the lipid profile. The results obtained from lipid profile analysis suggest that the kitchen food waste can be an innovative raw material for biodiesel production. Physico-chemical characterization identify considerable amount of calcium (20.36mg/l), iron (30.84mg/l), magnesium (3.00mg/l) and chromium (1.28mg/l), suggest its reuse in pharmaceutical and agricultural industries after extracting these metals.

A problem unstuck? Evaluating the effectiveness of sticker prompts for encouraging household food waste recycling behaviour

This Randomised Control Trial (RCT) investigated the effectiveness of using stickers as a visual prompt to encourage the separate collection of household food waste for recycling in two local authorities in South East England. During a baseline period of up to 15weeks, separately collected food waste was weighed (in tonnes) and averaged across households in both treatment (N=33,716 households within 29 defined areas) and control groups (N=30,568 households within 26 areas). A sticker prompt was then affixed to the lids of refuse bins in the treatment group area only. Weights for both groups were subsequently measured across a 16-week experimental period. Results showed that, in the control group, there was no change in the average weight of food waste captured for recycling between the baseline and experimental period. However, there was a significant increase (20.74%) in the treatment group, and this change in behaviour persisted in the longer term. Sticker prompts therefore appear to have a significant and sustained impact on food waste recycling rates, while being simple, practically feasible and inexpensive (£0.35 per household) for local authorities to implement at scale.