ABSTRACT
The COVID-19 pandemic has caused huge health and economic damages. Various protective face masks, such as single-use, cotton, and the most widespread FFP2 or KN95 masks, are used to prevent the spread of this virus. However, these face masks are usually packaged in plastic packaging, which increases the amount of plastic waste. Plastic gloves are also often used in the connection of the pandemic. All this leads to a large production of protective equipment, but their use contributes to the increase of this type of waste, which presents a new challenge in waste management. This article investigates a complete element analysis of these mentioned materials and observes potential harmful substances. Further, pellets, as a potential fuel for combustion or pyrolysis purposes, were produced with the content of 5% and 10% of face masks. FFP2 were firstly separated from ear straps and wires, then disintegrated, added to spruce sawdust, and compressed into pellets. A series of experiments were realized and aimed at elemental, thermogravimetric, and calorific value analyses of produced pellets. Based on the results, it can be concluded that the presence of face masks FFP2 in pellets increases the content of carbon, hydrogen, and nitrogen, volatile matter, and calorific values, but decreases the content of fixed carbon. According to elemental analysis of produced pellets, no significant amounts of harmful elements were found. © 2023 The Author(s)
ABSTRACT
Biodrying is an essential part of the mechanical–biological treatment process that minimizes moisture content and simultaneously maximizes heating value for refuse-derived fuel (RDF) production. Although the mechanical separation process operates effectively in Thailand's RDF production, high organic content levels and their degradation cause moisture contamination in RDF, producing wet RDF. Aeration is essential for an effective biodrying process, and can reduce RDF's moisture content as well as increase its heating value. To maximize the biodrying effect, aeration should be optimized based on the waste conditions. This study proposes a modified aeration-supplied configuration for wet RDF biodrying. The aeration rate was modified based on the period within the biodrying operation;the first period is from the beginning until day 2.5, and the second period is from day 2.5 to day 5. The optimal aeration supply configuration was 0.5 m3/kg/day in the first period and then 0.3 m3/kg/day until the end of the process;this configuration yielded the greatest moisture content decrease of 35% and increased the low heating value of the biodried product by 11%. The final moisture content and low heating value were 24.07% and 4787 kcal/kg, respectively. Therefore, this optimal aeration-supplied configuration could be applied to meet the moisture content and low heating value requirements of the RDF production standard for Thailand's local cement industry.
ABSTRACT
The problem of food waste is a global phenomenon. Food waste occurs at all stages of the food chain. Households, especially in developed countries, produce the most food waste. In order to effectively prevent consumers from throwing food away, it is important to understand the factors that determine these behaviors in the household. The aim of this study was to define the goal of using dietary catering in Polish society as a form of consumption of wholesome meals with a specific calorific value and distribution of macronutrients in the aspect of reducing losses related to food waste. The research was carried out online in the years 2020–2022 among the clients of a catering company. The survey respondents were residents of the Małopolskie Voivodeship in Poland. The research tool was an original anonymous questionnaire in the form of a shortened nutritional interview. On the basis of the obtained results, it can be concluded that factors such as age and gender influence consumer behavior. The reasons for the decision to choose dietary catering were mainly indicated as wasting and throwing away food, as well as inadequate management of food supplies and preparing too large portions of meals.
ABSTRACT
The article presents an analysis of the impact of bio-based materials on the environment, with a special focus on polylactic acid (PLA), as it is considered one of the most popular bioplastics in the market. The results show that there are several factors that must be taken into account when choosing the best end-of-life option for this type of material, in agreement with the newly introduced concept of the circular economy, according to the physical–chemical analysis obtained at the end of this study. The ecotoxicity tests showed that all tested materials (PLA spoon, PLA filament, b2w technology bag and cocoa paper tray) could be suitable for incineration with energy recovery without producing dioxines during combustion (chlorine content in all tested materials was below 1.00% w/w). It was also determined that PLA was the material with the highest potential for energy recovery since it presented the highest calorific value and highest carbon content (18.73 MJ/kg and 52.23%, respectively). The biodegradation rate of the different bio-based materials was also tested under different environments during three months, with Baltic Sea water and medium-grain sand being the environments in which the majority of the bio-based materials showed the lowest degradation rates. An additional test in a small-scale electric composter with microbe technology was carried out in order to evaluate the degradation of the studied materials in an environment with controlled conditions, and results showed high values of weight loss for the majority of the bio-based materials (all above 80% weight loss) due to the high temperature that the device could reach during the composting process. Finally, a strategy for providing guidance in selecting routes for the waste management of bioplastics, depending mainly on the available infrastructure and material properties, was proposed as a result of this work. For the case of low- and medium-income countries, an Extended Producer Responsibility (EPR) policy is proposed as a provisional solution to control plastic waste pollution, which should be complemented by regulations and systems aimed at the successful introduction of bioplastics.