"Maybe it's still good?" A qualitative study of factors influencing food waste and application of the E.P.A. Food recovery hierarchy in U.S. supermarkets

Environmental sustainability assessment of a new food waste anaerobic digestion and pyrolysis hybridization system

This research conducted an environmental life cycle assessment (LCA) to evaluate an anaerobic digestion-co-pyrolysis (ADCo-Py) system in which pyrolysis was added to traditional food waste (FW) anaerobic digestion (AD) systems to treat the solid fraction and impurities separated from FW. The solid fraction, including impurities such as wooden chopsticks, plastics, eggshells, and bones, is usually incinerated, while pyrolysis can be a viable alternative to optimize FW treatment. The environmental impact of ADCo-Py was compared with stand-alone AD, pyrolysis, and ADCo-INC (AD with incineration of separated solids). The results indicated that both ADCo-Py (-1.726 kg CO2-Eq/kgFW) and ADCo-INC (-1.535 kg CO2-Eq/kgFW) outperform stand-alone AD (-0.855 kg CO2-Eq/kgFW) and pyrolysis (-0.181 kg CO2-Eq/kgFW) in mitigating global warming potential (GWP). Additionally, pretreatments were found to have the most significant influence on GWP, ecotoxicity potential (ETP), and acidification potential (AP). The two-step pretreatment in ADCo-Py, including the separation of solids and drying, significantly improved the environmental sustainability of the system when compared with standalone pyrolysis.

Investigation on Bacterial Growth and pH in Milk after the Expiration Date

Food waste is a serious national and global problem. Milk is one of the most frequently wasted food items. This study aims to determine how long postexpiration-pasteurized milk may still be safe to consume and what is the relationship between bacterial growth from the milk and time after expiration. The experiments were carried out by incubating milk with agarose gel. The results showed that the bacterial growth was relatively low for at least the first few days after expiration. The more the days passed after the expiration date, the more the bacteria grew from the milk. There was no significant difference in the bacteria colony numbers in the whole milk samples opened either on day 0 or day 5 of expiration. None of the fat-free milk samples collected on the later (1-10) days showed any statistically significant difference in bacterial growth compared to the samples collected on the day after expiration (day 0). The bacterial growth increased with the increasing fat content of the milk. In addition, the rate of bacterial growth from the milk correlated with the acidity of the milk that is measured by pH. No significant sensory changes could be detected in any of the milk samples immediately after opening on the day of expiration or for up to 10 days after expiration when the unopened cartons were kept refrigerated. However, within 24 hours of opening the carton, whole milk that has expired for 6 or more days and 2% milk that has expired for 8 or more days developed a sour taste and mildly pungent smell. This sensory change was accompanied by the formation of lumps and fat-water separation. Fat-free milk samples remained unchanged under the same conditions. The experimental results suggest that whole and 2% skim milk may be safe for consumption up to 5-6 days after expiration. Fat-free milk may be safe for consumption up to 10 days after expiration, possibly longer. This study devised a way to show that milk is still safe for consumption after expiration; it will help reduce food waste.

On the implementation of the circular economy route for E-waste management: A critical review and an analysis for the case of the state of Kuwait

Electronic waste (e-waste) has become one of the major causes of environmental concerns due to its large volume, high generation rate and toxic environmental burdens. Recent estimates put e-waste generation at about 54 million tonnes per annum with figures reaching approximately 75 million tonnes per annum by 2030. In this manuscript, the state-of-the-art technologies and techniques for segregation, recovery and recycling of e-waste with a special focus on the valorisation aspects of e-plastics and e-metals which are critically reviewed. A history and insight into environmental aspects and regulation/legislations are presented including those that could be adopted in the near future for e-waste management. The prospects of implementing such technologies in the State of Kuwait for the recovery of materials and energy from e-waste where infrastructure is lacking still for waste management are presented through Material Flow Analysis. The information showed that Kuwait has a major problem in waste accumulation. It is estimated that e-waste in Kuwait (with no accumulation or backlog) is generated at a rate of 67,000 tpa, and the imports of broadcasting electronics generate some 19,428 tonnes. After reviewing economic factors of potential recovered plastics, iron and glass from broadcasting devices in Kuwait as e-waste, a total revenue of $399,729 per annum is estimated from their valorisation. This revenue will open the prospect of ventures for other e-waste and fuel recovery options as well as environmental benefits and the move to a circular economy.

An overview of the waste hierarchy framework for analyzing the circularity in construction and demolition waste management in Europe

The construction sector is the biggest driver of resource consumption and waste generation in Europe. The European Union (EU) is making efforts to move from its traditional linear resource and waste management system in the construction sector to a level of high circularity. Based on the theory of circular economy, a new paradigm called waste hierarchy was introduced in the EU Waste Framework Directive. This work uses the framework of the waste hierarchy to analyze the practice of construction and demolition waste (CDW) management in Europe. We explore the evolution of the waste hierarchy in Europe and how it compares with the circular economy. Then, based on the framework, we analyze the performance of CDW management in each EU member state. Innovative treatment methods of CDW, focusing on waste concrete, is investigated. This brings insight into optimizing and upgrading the CDW management in light of advanced technologies and steering the pathway for transitioning the EU towards a circular society.

Mapping the landscape of Consumer Food Waste

Since 2015 there has been a surge of academic publications and citations focused on consumer food waste. To introduce a special issue of Appetite focused on the drivers of consumer food waste we perform a transdisciplinary and historical review of the literature through a co-citation network analysis and topic modelling approach. We show that the rapid increase in publications is largely attributable to an urgency caused by the Sustainable Development Goals and climate change. Topic modelling reveals that the dramatic quantitative increase of publications has also produced a variety of evolving themes, and that a metaphorical Cambrian Explosion is occurring after decades of academic inactivity. Network analysis results show that consumer food waste features in thousands of articles and hundreds of journals, but that the citation practices of academics are becoming highly concentrated, as 20% of journals attract over 80% of citations. Finally, by examining the burstiness and transdisciplinary structure of citation networks we show that though the field has historically been dominated by empirical articles, it is now starting to show signs of maturity as a flurry of review papers help to consolidate knowledge.