CO2-mediated thermal treatment of disposable plastic food containers

In accordance with global economic prosperity, the frequencies of food delivery and takeout orders have been increasing. The pandemic life, specifically arising from COVID-19, rapidly expanded the food delivery service. Thus, the massive generation of disposable plastic food containers has become significant environmental problems. Establishing a sustainable disposal platform for plastic packaging waste (PPW) of food delivery containers has intrigued particular interest. To comprise this grand challenge, a reliable thermal disposable platform has been suggested in this study. From the pyrolysis process, a heterogeneous plastic mixture of PPW was converted into syngas and value-added hydrocarbons (HCs). PPW collected from five different restaurants consisted of polypropylene (36.9 wt%), polyethylene (10.5 wt%), polyethylene terephthalate (18.1 wt%), polystyrene (13.5 wt%), polyvinyl chloride (4.2 wt%), and other composites (16.8 wt%). Due to these compositional complexities, pyrolysis of PPW led to formations of a variety of benzene derivatives and aliphatic HCs. Adapting multi-stage pyrolysis, the different chemicals were converted into industrial chemicals (benzene, toluene, styrene, etc.). To selectively convert HCs into syngas (H2 and CO), catalytic pyrolysis was adapted using supported Ni catalyst (5 wt% Ni/SiO2). Over Ni catalyst, H2 was produced as a main product due to C[sbnd]H bond scission of HCs. When CO2 was used as a co-reactant, HCs were further transformed to H2 and CO through the chemical reactions of CO2 with gas phase HCs. CO2-assisted catalytic pyrolysis also retarded catalyst deactivation inhibiting coke deposition on Ni catalyst. © 2022 Elsevier B.V.

Depressive Symptoms Among Migrant Workers in South Korea Amid COVID-19 Pandemic

Background: The purpose of this study was to investigate the depressive symptoms among migrant workers in South Korea amid the coronavirus disease 2019 pandemic. Methods: This web-based cross-sectional survey involved migrant workers in South Korea to examine their depression levels using the Patient Health Questionnaire-9 scale. Logistic regression was used to find out the factors associated with depression. Results: Migrant workers exhibited mild to severe depressive symptoms (98.4%) of which 41.7% had severe depression (n = 161). Migrant workers aged above 25 years were shown to have a significantly higher level of depression (odds ratio = 2.13, 95% CI: 1.084-4.193). Male workers (71.1%) had a higher depression level than females (28.9%). Losing a job during the coronavirus disease 2019 pandemic (odds ratio = 3.89, 95% CI = 1.705-8.906) and not having any social relief support (odds ratio = 1.92, 95% CI: 1.109-3.351) were significantly associated with depression. Conclusion: Migrants workers were found to be experiencing a severe level of depression. Mental healthcare should be prioritized and made accessible to vulnerable and risk groups.