Although anaerobic digestion is the mainstream technology for treating food waste (FW), the high pollutant concentration in the resultant food waste anaerobic digestate (FWAD) often poses challenges for the subsequent biochemical treatment such as activated sludge process. In this study, taking a typical FW treatment plant as an example, we analyzed the reasons behind the difficulties in treating FWAD and tested a novel process called as bio-conditioning dewatering followed by activated sludge process (BDAS) to purify FWAD. Results showed that high concentrations of suspended solids (SS) (16439 ± 475 mg/L), chemical oxygen demand (COD) (24642 ± 1301 mg/L), and ammonium nitrogen (NH4+-N) (2641 ± 52 mg/L) were main factors affecting the purification efficiency of FWAD by the conventional activated sludge process. By implementing bio-conditioning dewatering for solid-liquid separation, near 100% of SS and total phosphorus (TP), 90% of COD, 38% of total nitrogen (TN), and 37% of NH4+-N in the digestate could be effectively removed or recovered, consequently generating the transparent filtrate with relatively low pollution load and dry sludge cake (<60% of moisture content). Furthermore, after ammonia stripping and biochemical treatment, the effluent met the relevant discharge standards regulated by China, with the concentrations of COD, TN, NH4+-N, and TP ranging from 151 to 405, 10-56, 0.9-31, and 0.4-0.8 mg/L, respectively. This proposed BDAS approach exhibited stable performance and low operating costs, offering a promising solution to purify FWAD in practical engineering and simultaneously realize resource recovery.

Upcycled foods are created from surplus food, edible food waste and by-products. Food and beverage brands are launching upcycled foods and promoting their product to consumers. Little is known about how consumers respond to upcycled foods, nor how these products can be most effectively promoted. To better understand marketing strategies for upcycled foods, two studies were conducted, one online (n = 300) and one in retail stores (n = 65), in New Zealand to examine differences in consumer sentiment toward upcycled beer. In both studies, environmental benefits were identified as the most important benefits of upcycled foods and information provision on pack and online were important promotional strategies. Consumers reported greater awareness and acceptance of upcycled food in-store, yet raised concerns relating to taste and price. Only 31% of participants surveyed in-store associated \'no negatives\' with upcycled foods compared with 47% of consumers surveyed online. These findings help differentiate a potential promotion strategy for upcycled foods.

In this study, the efficacy of two of the best performing green solvents for the fractionation of lignocellulosic biomass, cholinium arginate (ChArg) as biobased ionic liquid (Bio-IL) and ChCl:lactic acid (ChCl:LA, 1:10) as natural deep eutectic solvent (NADES), was investigated and compared in the pretreatment of an agri-food industry waste, apple fibers (90°C for 1 h). For the sake of comparison, 1-butyl-3-methylimidazolium acetate (BMIM OAc) as one of the best IL able to dissolve cellulose was also used. After the pretreatment, two fractions were obtained in each case. The results gathered through FTIR and TG analyses of the two materials and the subsequent DNS assay performed after enzymatic treatment led to identify ChArg as the best medium to delignify and remove waxes, present on the starting apple fibers, thus producing a material substantially enriched in cellulose (CRM). Conversely, ChCl:LA did not provide satisfactorily results using these mild conditions, while BMIM OAc showed intermediate performance probably on account of the reduced crystallinity of cellulose after the dissolution-regeneration process. To corroborate the obtained data, FTIR and TG analyses were also performed on the residues collected after the enzymatic hydrolysis. At the end of the pretreatment, ChArg was also quantitatively recovered without significant alterations.

Food waste (FW) has become a worldwide issue, while anaerobic digestion (AD) has appeared as a widely adopted technology to recover energy and resources from FW. Compared to many existing case studies of centralized AD system, the comprehensive study of decentralized micro-AD system from both system energy efficiency and carbon emission perspective is still scanty, particularly system operated under ambient temperature conditions. In this study, an actual decentralized micro-AD system with treating capacity of 300 kg FW/d for a local hawker center in Singapore was reported and evaluated. The results showed that 1894.5 kg of FW was treated and 173 m3 biogas with methane content of 53 % was produced during the experimental period of 75 days. The methane yield results showed a high FW degradation efficiency (87.87 %). However, net energy consumption and net carbon emission were observed during the experimental period. Nevertheless, energy self-efficiency and carbon neutrality, even net energy output and carbon reduction, can be achieved by increasing daily FW loading and biogas engine efficiency. Specifically, the FW loading for system energy self-efficiency was identified as 159 kg/d for engine efficiency of 35 % at a high kitchen waste/table waste ratio (63 %/37 %, with covid-19 dine-in restrictions); while they were 112 and 58 kg/d for engine efficiency of 25 % and 35 %, respective, at a low kitchen waste/table waste ratio (31 %/69 %, without covid-19 dine-in restrictions). The carbon emission ranged from 156.08 kg CO2-eq/t FW to -77.35 kg CO2-eq/t FW depending on the FW loading quantity and engine efficiency. Moreover, the sensitivity analysis also showed that the used electricity source for substitution influenced the carbon emission performance significantly. The obtained results imply that the decentralized micro-AD system could be a feasible FW management solution for energy generation and carbon reduction when the FW loading and engine electrical efficiency are carefully addressed.

The increasing rate of food waste is becoming a threat to realizing Sustainable Development goal 2 by 2030. A significant portion of food is wasted along the entire food supply chain, resulting in adverse economic, ecological and social consequences. Inferring from the norm activation model (NAM), the study investigates the influence of benefits awareness, lack of concern and personal norm on households\' food waste reduction intention. Gathering research data via an online survey in Jiangsu province in China, a total sample of 408 responses were analyzed using structural equation model. It was found that the extended NAM model developed is more appropriate for assessing food waste reduction intention with a significant improved explanatory potential from 32.0 to 52.0%. Households\' awareness of consequences was established to have a positive effect on ascription of responsibility, and they both impact personal norm positively. Personal norm influences food waste reduction intention positively. Again, the awareness of the benefits for reducing food waste affects households\' intention to reduce food waste positively. Lack of concern for food waste negatively affects their personal norm and food waste reduction intentions. These findings furnish valuable insights for future campaigns to educate people and influence their moral norms toward the importance and involvement in achieving Sustainable Development Goals related to food waste.

Despite the ability to perform both processes in the same reactor, hydrothermal carbonization (HTC) and hydrothermal liquefaction (HTL) are considered two distinct processes differentiated by their reaction temperatures. As temperatures increase from the less severe HTC range into the HTL regime, the product distribution progressively favors an organic bio-oil phase relative to solid hydrochar. Solvents are commonly used to extract bio-oil from the solid residues produced during HTL, and to separate the amorphous secondary char from the coal-like primary char of HTC hydrochars. This suggests secondary char is a HTL biocrude precursor. Lipid-rich food waste was hydrothermally processed between 190 and 340 °C, spanning HTC to HTL conditions. Higher temperatures produce more gas, less liquid, and similar amounts of a progressively less oxygenated hydrochars, suggesting a gradual transition from HTC to HTL. However, analyses of ethanol-separated primary chars and secondary chars tell a different story. While the primary char is progressively more carbonized with temperature, the secondary char composition sharply changes at 250 °C. That is, lipid hydrolysis begins around 220 °C, but proceeds rather completely at 250 °C and above. A lower HTL temperature reduces the energy cost of the hydrothermal process, yet enables full lipid hydrolysis into long chain fatty acids while minimizing recondensation and repolymerization of fatty acids onto the primary char and their subsequent amidation. This maximizes the conversion of lipid-rich feedstocks into liquid fuel precursors with up to 70 % energy recovery.

The municipal solid waste (MSW) sector is an important source of greenhouse gas (GHG) emissions. MSW classification can achieve waste reduction and improve resource utilization. However, few studies have investigated the effects of MSW classification on GHG emission reduction. Therefore, the GHG emissions under different MSW disposal modes before and after classification were studied based on the life cycle assessment method in the four districts of Qingdao City. The results showed that MSW classification could significantly reduce the GHG emissions during the whole MSW treatment process. The net carbon emissions(in CO2/MSW)during the whole process of waste treatment for mode 1 (mixed collection+landfill), mode 2 (mixed collection+incineration), mode 3 (waste classification+anaerobic digestion of food waste and other incineration), and mode 4 (waste classification+anaerobic digestion of food waste, recycling of recyclable waste, and other incineration) were 686.39, -130.12, -61.88, and -230.17 kg·t-1, respectively. Improving the classification efficiency of food waste had no significant impact on carbon emissions. The reduction in carbon emissions increased linearly with the improvement of waste recycling efficiency. For every 10% increase in the recovery efficiency of recyclable waste, the net carbon emission decreased by 26.6%(16.5 kg·t-1). Appropriate separation of food waste, improving the recycling efficiency of recyclable waste, and reducing the leakage rate of biogas from anaerobic digestion are feasible strategies to reduce carbon emissions from MSW disposal units through the classification of MSW.

Food rescue has been identified as a sustainable approach in preventing wastage of surplus food and achieving food security. Although food insecurity is widely prevalent in developing countries, there is a paucity of research investigating food donations and rescue operations in these countries. This study focuses on surplus food redistribution activities from a developing country perspective. Specifically, the study analyses the structure, motivations, and limitations of the existing food rescue system in Colombo, Sri Lanka, by conducting a series of structured interviews with twenty food donors and redistributors. The food rescue system in Sri Lanka characterises a sporadic redistribution, and food donors and rescuers are mainly driven by humanitarian motives. The findings also reveal missing institutions - facilitator organisations and back-line organisations - in the surplus food rescue system. Food redistributors identified that inadequate food logistics and establishing formal partnerships as major challenges in food rescue operations. Establishing intermediary organisations such as food banks to provide the required food logistics, imposing food safety parameters and minimum quality standards required for surplus food redistribution, and community awareness programmes on food redistribution can increase the efficiency and effectiveness of food rescue operations. There is an urgent need to embed food rescue as a strategy to reduce food wastage and to enhance food security in existing policies.

Worldwide, more than 1.3 billion tonnes of food are wasted each year, which is equivalent to releasing 4.4 Gt of CO2 equivalents (CO2e). In this context, the Food Bank of Navarra (FBN) annually avoids the waste of approximately 3000 tons of perfectly consumable food. The aim of this study was twofold: on the one hand, to analyse the carbon footprint of the FBN and, on the other hand, to perform a comparative analysis of the greenhouse gas (GHG) emissions in two scenarios, \"with\" and \"without\" the actions of the FBN, in order to identify and quantify the environmental benefits, in terms of GHG emissions reduction, associated with the reduction in food waste. The analyses were conducted in two different years. The carbon footprint associated with the FBN\'s activities was 147 t of CO2e in the year 2018. The quantification of GHGs in the scenario \"without the FBN\" showed that if the FBN did not exist 4715 t of CO2e would have been emitted. The results obtained in consecutive years were similar, highlighting the importance of the FBN-not only in social terms but also environmental terms-as it prevented a large amount of GHGs from being emitted into the atmosphere. A detailed account of the carbon emission reduction associated with the food bank\'s operations and the knowledge of the benefits involved could boost their positive effects in facilitating the integration of their activities into policies aimed at climate neutrality.

There remains little understanding of fruit and vegetable wastage and the influencing factors within retail. This study aimed to examine the processes contributing to vegetable and fruit wastage in traditional farmers\' markets widely existing in China, Thailand, and South Korea, with the farmers\' market in Hangzhou, China used as a case study. Questionnaires and follow-up surveys were conducted with the market stakeholders (market managers, retailers, and market cleaners) from April 2021 to January 2022. The results showed that the categories of discarded fruits and vegetables were related to their sales varieties, with leaf vegetables and bananas constituting the categories of vegetables and fruit with the most daily wastage. Wastage of fruits and vegetables mostly occurred in the morning. However, there was seasonal variation in fruit and vegetable wastage, with wastage in summer exceeding that in winter. The quantity of fruit and vegetable wastage was related to the size of the farmers\' market. The volume of sales was also shown to be positively correlated to wastage. The analysis showed that the rank of factors influencing fruit and vegetable sales was: market service community size > appearance of fruits and vegetables > weather > market environment > fruit and vegetable price > fruit and vegetable origin. Finally, most stakeholders were motivated to reduce wastage, with their motivations including ethics, legal requirements, and economic reasons. The results of this study can act as an important reference for improving the management fruit and vegetable waste.