Gaps between Attitudes and Behavior in the Use of Disposable Plastic Tableware (DPT) and Factors Influencing Sustainable DPT Consumption: A Study of Hong Kong Undergraduates

Total waste from human activities, including waste plastics, is huge in Hong Kong. In particular, as a result of the prevention and control measures implemented during the COVID-19 pandemic, take-away meals increased tremendously in Hong Kong, generating disposable plastic tableware (DPT). Although Hong Kong has a charging scheme for plastic bags, it does not have a scheme for plastic tableware. Therefore, this study aimed to understand the attitudes and behavior of people in Hong Kong toward DPT. Our study focused on undergraduate students in Hong Kong, given that they will play a significant role in the future of environmental sustainability. The attitudes and behavior of Hong Kong undergraduate students toward DPT were examined through an online survey with 385 respondents. A multiple stepwise regression was conducted to investigate whether cognitive attitude formation factors could explain the sustainable attitudes formed by undergraduate students in Hong Kong. The survey results revealed that most undergraduates considered DPT to be one of the major causes of environmental damage in Hong Kong;however, many of them, particularly those who strongly agreed with this statement, said that the problem of DPT did not affect their quality of life. The regression analysis showed that imposing a DPT charge would be the most significant driver to reduce its use. The research findings identified gaps between attitudes and behavior regarding the use of DPT and the factors influencing sustainable DPT consumption.

Investigation in PO blending and compression ratio on engine performance and gas emissions including environmental health risk assessment and economic analysis.

Waste management and mitigation is the primary necessity across the globe. The daily use of plastic materials in different forms emergence the plastic pollutions, and it has been significantly increased during the COVID-19 pandemic. Thus, mitigation of waste plastics generation is one of the major challenges in the present situation. The present study addressed the conversion of waste plastics into value-added products such as liquid hydrocarbon fuels and their application in reducing greenhouse gas emissions. A comprehensive investigation has been performed on engine performance and combustion characteristics at various compression ratios and PO blending. The effect of liquid fuel blending with commercial diesel was investigated at three different compression ratios (15.1, 16.2, and 16.7) under various BMEP conditions. The results revealed that blending of liquid fuel produced from waste plastic can improve the BTE significantly, and the highest 35.77% of BTE was observed for 10% blending at 15.1 CR. While the lowest BSFC of 5.77 × 10-5 kg/kW-s was estimated for 20% PO blending at 16.7 CR under optimum BMEP (4.0 bar) conditions. The investigation of combustion parameters such as cylinder pressure, net heat release rate, rate of pressure rise, and cumulative heat release showed that it increases with the compression ratio from 15.1 to 16.7. At the same time, the emissions of CO, CO2, and unburnt hydrocarbon was decreased significantly. The economic analysis for the present lab-scale study estimated that approximately ₹12.17 ($0.15) profit per liter is possible in the 1st year, while the significant profit starts from the 2nd year onward, which is in the range of ₹59.78-₹84.48 ($0.75-$1.07) when the PO is blended with CD within the permissible limits as per the norms.

Characterization of the Products of the Catalytic Pyrolysis of Discarded COVID-19 Masks over Sepiolite

This research aims to develop a new strategy to valorize wasted COVID-19 masks based on chemical recycling by pyrolysis to convert them into useful products. First, surgical and filtering face piece masks, as defined in Europe by the EN 149 standard (FFP2), were thermally pyrolyzed at temperatures of 450, 500, and 550 °C, and the yields of valuable solid (biochar), liquid (biooil), and syngas products and their characteristics were determined. At low temperatures, biochar formation was favored over biooil and syngas production, while at high temperatures the syngas product yield was enhanced. The highest yield of biooil was found at a pyrolysis temperature of 500 °C, with both surgical and FFP2 masks achieving biooil yields of 59.08% and 58.86%, respectively. Then, the pyrolysis experiments were performed at 500 °C in a two-stage pyrolysis catalytic reactor using sepiolite as a catalyst. Sepiolite was characterized using nitrogen adsorption–desorption isotherms and Fourier-transform infrared spectroscopy. Results showed that the two-stage process increased the final yield of syngas product (43.89% against 39.52% for surgical masks and 50.53% against 39.41% for FFP2 masks). Furthermore, the composition of the biooils significantly changed, increasing the amount of 2,4-Dimethyl-1-heptene and other olefins, such as 3-Eicosene, (E)-, and 5-Eicosene, (E)-. Additionally, the methane and carbon dioxide content of the syngas product also increased in the two-stage experiments. Ultimately, the effect of sepiolite regeneration for its use in consecutive pyrolysis tests was examined. Characterization data showed that, the higher the use-regeneration of sepiolite, the higher the modification of textural properties, with mainly higher changes in its pore volume. The results indicated that the pyrolysis of face masks can be a good source of valuable products (especially from biooil and syngas products). © 2023 by the authors.

Effects of Alcohol-Blended Waste Plastic Oil on Engine Performance Characteristics and Emissions of a Diesel Engine

The current study aims to investigate and compare the effects of waste plastic oil blended with n-butanol on the characteristics of diesel engines and exhaust gas emissions. Waste plastic oil produced by the pyrolysis process was blended with n-butanol at 5%, 10%, and 15% by volume. Experiments were conducted on a four-stroke, four-cylinder, water-cooled, direct injection diesel engine with a variation of five engine loads, while the engine's speed was fixed at 2500 rpm. The experimental results showed that the main hydrocarbons present in WPO were within the range of diesel fuel (C13–C18, approximately 74.39%), while its specific gravity and flash point were out of the limit prescribed by the diesel fuel specification. The addition of n-butanol to WPO was found to reduce the engine's thermal efficiency and increase HC and CO emissions, especially when the engine operated at low-load conditions. In order to find the suitable ratio of n-butanol blends when the engine operated at the tested engine load, the optimization process was carried out by considering the engine's load and ratio of the n-butanol blend as input factors and the engine's performance and emissions as output factors. It was found that the multi-objective function produced by the general regression neural network (GRNN) can be modeled as the multi-objective function with high predictive performances. The coefficient of determination (R2), mean absolute percentage error (MAPE), and root mean square error (RSME) of the optimization model proposed in the study were 0.999, 2.606%, and 0.663, respectively, when brake thermal efficiency was considered, while nitrogen oxide values were 0.998, 6.915%, and 0.600, respectively. As for the results of the optimization using NSGA-II, a single optimum value may not be attained as with the other methods, but the optimization's boundary was obtained, which was established by making a trade-off between brake thermal efficiency and nitrogen oxide emissions. According to the Pareto frontier, the engine load and ratio of the n-butanol blend that caused the trade-off between maximum brake thermal efficiency and minimum nitrogen oxides are within the approximate range of 37 N.m to 104 N.m and 9% to 14%, respectively.

Research progress in high value-added utilization technology of waste plastics

The low degradability of waste plastics will continue to pollute the environment, and the spread of the COVID-19 has exacerbated the use and accumulation of plastics, and thus the efficient treatment of waste plastic resources has become an urgent technical problem to be solved. By analyzing several mainstream waste plastics treatment technologies, it was clear that resourceful and high value-added utilization technology was the most competitive and environmentally friendly waste plastics treatment route in the market. The research progress of high value-added utilization technology of waste plastics at home and abroad in recent years were reviewed. The development and variation of conventional thermal cracking technology were discussed. Through this route, the highest yield of waste plastics into fuel products can reach 97%—98%. It was pointed out that the conversion of waste plastics into jet fuel, high value-added chemicals and functional materials for special applications through chemical, catalytic and biological technologies was the mainstream research direction and development trend in this field. Among them, the yield of conversion to high value-added monomer could reach more than 97%, so as to realize the upgrading of plastic waste from the primary treatment stage of "waste clearance” to "turning waste into use” and "turning waste into treasure”, and help China achieve the goal of "double carbon”。. © 2023 Chemical Industry Press. All rights reserved.

Packaging plastic waste management in the cosmetic industry

PurposeThis paper aims to explore the relationship between the various variables present in the packaging plastic waste management system in the cosmetics industry.Design/methodology/approachIn this paper, the authors deal with plastic packaging waste in the cosmetic industry with the help of system dynamics. The model broadly divides the system into six sections – Cosmetic Packaging, Waste Generation, Waste Collected, Waste Sorted, Waste Treated and Waste Dumped. Businesses have been investing in each section depending on their progress and targets. The authors are looking at case studies of two leading cosmetic brands, L'Oréal and L'Occitane en Provence, to validate the industry practices against our model.FindingsFrom a business perspective, using the case study methodology for L'Oréal and L'Occitane, the authors inferred that out of the various investment vehicles available, companies are targeting technological advancement and third-party collaborations as they have the potential to offer the greatest visible change. However, most of these investments are going toward the treatment subsection. Still, there is a scope for improvement in the collection and sorting subsystems, increasing the efficiency of the whole chain.Originality/valueThere has been a lot of research on packaging plastic waste management in the past, but only a few of them focused on the cosmetic industry. This study aims to connect all the possible variables involved in the cosmetic industry's packaging plastic waste management system and provide a clear output variable for various businesses looking to manage their packaging waste because of their products efficiently.

Medical waste generation during COVID-19 pandemic in selected member countries of Arabian Gulf region, Google trend analysis

The variant SARS-CoV-2 (COVID-19) has affected the entire globe;it has caused acute respiratory illnesses and has led to massive environmental problems associated with extra medical waste and single-use plastics. Herein the total quantity of waste generated in the selected GCC countries from different sources has been calculated. The popularity of the medical waste issue through using relative search volume was investigated to associate it with the quantities of Waste. Data was collected from the first COVID-19 case in the respective country until March 26, 2022, from the public domains, "Worldmeter”, "Our World in Data” and "Google Trends”. Autoregressive Integrated Moving Average (ARIMA) was used to predict the amount of CMW. The calculated values are 1107.980 kg/day from the facemask used by the public, 2,554,812 kg from vaccination, 2,595,772 kg from PCR tests, also the predicted daily total amount of COVID-19 related Medical Waste (CMW) by the end of 2022 (December 31, 2022) to be 3667.25 kg/day. The trend in the generation of CMW has been identified in selected countries. Generally, the waste is expected to get minimized, but it is a lesson for future planning. Especially With extensive vaccination, the cases are drastically decreased, and life is resuming in the regions. © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the University of Bahrain.

The utilization of palm kernel shells and waste plastics in asphaltic mix for sustainable pavement construction. (Special Issue: Technology and innovation for a post COVID recovery and growth: the contribution of industry and academia.)

Natural aggregates are being depleted due to the high demand for road and building construction and need to be replaced with alternative materials. This study investigated the potential of using Palm kernel shells (PaKS) as a partial replacement for natural aggregates (NA) and waste plastics (WP) as a binder. The physical and volumetric properties of the different asphaltic mixes (AM) were assessed using the Marshall Method. The bitumen content of the mix design samples was varied from 4.0% to 7.5% of the total weight of aggregates utilized. According to the Marshall parameters, at 5.5% bitumen content, the maximum Marshall Stability value of the different mix designs increased from 9.8 kN to 12.1 kN and the flow value increased from 3.0 mm to 3.7 mm. The experimental results based on the optimum bitumen content determined by the Marshall method demonstrate that PaKS and WP can be utilized to modify AM. However, additional tests will be needed to evaluate the use of this composition in road construction.

Biodegradación de espumas plásticas por larvas de insectos: ¿una estrategia sustentable?

Many modern human activities rely greatly on plastic foams, whose consumption and production have considerably increased in the past decades. The use of plastic products has had positive impacts on human general welfare;however, the negative effects derived from their inappropriate disposition have become a major concern, especially during the current COVID-19 sanitary emergency, in which the utilization of single-use plastics has rapidly increased. Although some plastic polymers such as polyethylene (PE) and polystyrene (PS) can be recycled, the high demand for energy and technology, the use of potentially toxic substances and the low profitability of the process, make this option non-optimal. In this situation, biological treatment of plastic waste is emerging as a promising alternative and the use of PE and PS-eating organisms, such as mealworms and waxworms, has attracted the attention of researchers around the world. The aim of this review is to synthesize the most recent advances in the field of plastics polymers degradation by insects larvae and an analysis of the current and future trends of this developing research area.