ABSTRACT
High amount of polymeric food packaging wastes had been increasing during the Covid-19 epidemic, especially polystyrene (PS) and polypropylene (PP) packaging. This paper investigates the utilization of polymeric wastes as a liquid steel recarburizer in ladle refining process. PP was blended with PS into the ratios of up to 60 wt%, namely Blend#1 - Blend#6. The blends were pyrolyzed at 1550 °C for 15 min under argon atmosphere. The chars had high carbon content ranges between 86 and 91.47 wt%, and the crystallite size ranges between 0.27 and 2.45 nm. The chars were brought into contact with an electrolytic pure iron at 1550 °C under argon atmosphere for carbon dissolution experiment. It was found that overall carbon dissolution rates (K) for the chars were 1.46 × 10-3 - 8.4 × 10-3 s-1, which occurred within the first 4-10 min and then keep pace with the maximum carbon content of 4.08-4.97 wt%. Sulphur transfer into liquid steel was slow for all cases with the content was in between 0.01 and 0.025 wt%. The rate controlling mechanism for carbon dissolution from polymeric chars was the dissociation of carbon atom from its host lattice. CaH2O2 is a filler in the PS, was found to retard the carbon dissolution, however it can be decomposed at steelmaking temperature. The chars produced from PS and PP can be replaced a commercial recarburizer without negative effect on steel quality.
ABSTRACT
Plastic in the linear consumption model is frequently manufactured and disposed of, leading to the creation of excessive plastic waste, which has significant consequences for the environment. Single-use food packaging waste is a large constituent of plastic waste that needs to be addressed urgently. The implementation of reusable packaging systems (RPSs) to close the loop of consumption appears to be promising, but the insights into consumers’ willingness to accept them are limited. This research investigates the aspect of consumers’ adoption of RPSs by identifying the particular user acceptance issues and eventually providing a set of design recommendations to address them. The data collection methods are remote interviews, engaging with 42 participants in three iterations, to evaluate three user experiences of RPSs in order to identify the user acceptance issues. After the user acceptance issues are identified in each iteration, the Theory of Attitude-Behaviour-Context is employed to advance the understanding of the acceptance issues. In order to continuously refine the user experiences, insights from design for sustainable behaviour are applied to address the user acceptance issues. The research results include three refined user experiences, four user acceptance issues—namely hygiene, usability, finance and motivation—and design recommendations to address those user acceptance issues. This research may be of interest to packaging professionals, and could be used to design and refine the RPSs to induce consumers’ adoption.
ABSTRACT
Public schools in the U.S. generate about 14,500 tons of municipal solid waste daily, and approximately 42% of that is food packaging generated by school foodservice, contributing significantly to the global packaging waste crisis. This literature review summarizes methods used to evaluate food packaging waste in school foodservice. This review has two objectives: first, to understand which methodologies currently exist to evaluate food packaging waste generation and disposal in school foodservice;and second, to describe the creation of and share a practical standardized instrument to evaluate food packaging waste generation and disposal in school foodservice. A systematic review was conducted using the following search terms: solid waste, school, cafeteria and food packaging, waste, and school. The final review included 24 studies conducted in school environments (kindergarten through twelfth grade or college/university), 16 of which took place in the U.S. Food packaging waste evaluations included objective methods of waste audits, models, and secondary data as well as subjective methods of qualitative observations, questionnaires, interviews, and focus groups. Large variation exists in the settings, participants, designs, and methodologies for evaluating school foodservice packaging waste. Lack of standardization was observed even within each methodology (e.g., waste audit). A new instrument is proposed to support comprehensive and replicable data collection, to further the understanding of school foodservice food packaging waste in the U.S., and to reduce environmental harms.