Effective recycling of disposable medical face masks for sustainable green concrete via a new fiber hybridization technique

Unveiling the duality of cement and concrete addressing microplastic pollution: a review

Microplastic pollution has emerged as a global environmental concern, with diverse consequences for ecosystems and human health. While the focus has primarily been on the sources and impacts of microplastics, this review paper explores the roles of cement and concrete in potentially mitigating microplastic pollution and addressing their negative impacts with the focus of 165 relevant publications. Cementitious materials, widely used in construction, have unique properties that greatly increase the formation and transport of microplastics in the environment, and affect circular economy practice. This paper gathers all the information we already know about how cement, concrete, and microplastics interact with each other. It also presents the potential opportunities and challenges of using these materials to deal with microplastic pollution, entailing the advancement of porous concrete as a filtering system, exploration of concrete wetting phenomena based on concrete's surface chemistry and characteristics, proper urban water management systems for concrete green spaces, assessment of innovative technologies with concrete for microplastic mitigation, and the formation of standards and guidelines such as precise Life Cycle Assessment (LCA) tools, environmental product declaration (EPD), policy for urban planning, and green finance paradigms.

Mechanical Behavior of Masonry Mortars Reinforced with Disposable Face Mask Strips

This research presents an experimental analysis of the mechanical behavior of masonry mortars incorporating disposable face masks (FMs) cut into two different sizes. The objective is to provide experimental data contributing to the consolidation of recycling FMs in mortar mixtures. To achieve this, two types of mixtures were prepared: one with strips of 3 × 3 mm and another with strips of 3 × 10 mm. These FM strips were added in different proportions by the volume of mortar (0%, 0.2%, 0.5%, 0.8%, 1.0%, and 1.5%). In all mortars, the dry bulk density, volume of permeable voids, and water absorption, as well as compressive, flexural, and tensile strengths, were evaluated after a 28-day water immersion curing period. Additionally, two essential properties in masonry mortars were analyzed: air content and shear bond strength. The results indicated that, for both strip sizes, adding FMs up to 0.2% positively affected the flexural and tensile strengths; concerning control mortar, increases of 6% and 1.4%, were recorded, respectively, for the longer strips. At this percentage, the density, air content, and compressive and shear bond strengths are not significantly affected. The results demonstrated that incorporating FMs into mortar mixtures is a promising avenue for sustainable recycling and helps reduce microplastic environmental contamination.

A New Paradigm on Waste-to-Energy Applying Hydrovoltaic Energy Harvesting Technology to Face Masks

The widespread use of single-use face masks during the recent epidemic has led to significant environmental challenges due to waste pollution. This study explores an innovative approach to address this issue by repurposing discarded face masks for hydrovoltaic energy harvesting. By coating the face masks with carbon black (CB) to enhance their hydrophilic properties, we developed mask-based hydrovoltaic power generators (MHPGs). These MHPGs were evaluated for their hydrovoltaic performance, revealing that different mask configurations and sizes affect their efficiency. The study found that MHPGs with smaller, more structured areas exhibited better energy output, with maximum open-circuit voltages (VOC) reaching up to 0.39 V and short-circuit currents (ISC) up to 65.6 μA. The integration of CB improved water absorption and transport, enhancing the hydrovoltaic performance. More specifically, MHPG-1 to MHPG-4, which represented different sizes and features, presented mean VOC values of 0.32, 0.17, 0.19 and 0.05 V, as well as mean ISC values of 16.57, 15.59, 47.43 and 3.02 μA, respectively. The findings highlight the feasibility of utilizing discarded masks in energy harvesting systems, offering both environmental benefits and a novel method for renewable energy generation. Therefore, this work provides a new paradigm for waste-to-energy (WTE) technologies and inspires further research into the use of unconventional waste materials for energy production.

Design optimization and validation of UV-C illumination chamber for filtering facepiece respirators

In this study, we constructed an UV-C illumination chamber using commercially available germicidal lamps and other locally available low-cost components for general-purpose biological decontamination purposes. The illumination chamber provides uniform illumination of around 1 J/cm2 in under 5 min across the chamber. The control mechanism was developed to automate the on/off process and make it more secure minimizing health and other electrical safety. To validate the decontamination efficacy of the UV-C Illumination Chamber we performed the Geobacillus spore strip culture assay. Additionally, we performed the viral load measurement by identifying the COVID-19-specific N-gene and ORF1 gene on surgical masks. The gold standard RT-qPCR measurement was performed to detect and quantify the COVID-19-specific gene on the mask sample. The biochemical assay was conducted on the control and test group to identify the presence of different types of bacteria, and fungi before and after exposure under the illumination chamber. The findings of our study revealed satisfactory decontamination efficacy test results. Therefore, it could be an excellent device in healthcare settings as a disinfection tool for biological decontamination such as SAR-CoV-2 virus, personal protection equipment (PPE), (including n95, k95 respirators, and surgical masks), and other common pathogens.

Recycling facemasks into civil construction material to manage waste generated during COVID-19

Growing plastic pollution in the context of COVID-19 has caused significant challenges, exacerbating this already out-of-control issue. The pandemic has considerably boosted the demand for personal protective equipment (PPE), such as facemasks and gloves, all over the globe, and mismanaging this growing plastic pollution has harmed the environment and wildlife significantly. To mitigate negative environmental impacts, it is necessary to develop and implement effective waste management strategies. This present study estimated the daily facemask generation throughout the pandemic in Iran based on the distribution of urban and rural populations and, likewise, the daily generation of hand gloves in the COVID-19 era and the amount of medical waste generated by COVID-19 patients were calculated. In the next step, the quantities of discarded facemasks dumped into the Caspian Sea, the Persian Gulf, and the Gulf of Oman from the coastal cities were determined. Finally, the innovative alternatives for repurposing discarded facemasks in civil construction materials such as concrete, pavement, and partition wall panel were discussed.

Global face mask pollution: threats to the environment and wildlife, and potential solutions

Face masks are an indispensable low-cost public healthcare necessity for containing viral transmission. After the coronavirus disease (COVID-19) became a pandemic, there was an unprecedented demand for, and subsequent increase in face mask production and use, leading to global ecological challenges, including excessive resource consumption and significant environmental pollution. Here, we review the global demand volume for face masks and the associated energy consumption and pollution potential throughout their life cycle. First, the production and distribution processes consume petroleum-based raw materials and other energy sources and release greenhouse gases. Second, most methods of mask waste disposal result in secondary microplastic pollution and the release of toxic gases and organic substances. Third, face masks discarded in outdoor environments represent a new plastic pollutant and pose significant challenges to the environment and wildlife in various ecosystems. Therefore, the long-term impacts on environmental and wildlife health aspects related to the production, use, and disposal of face masks should be considered and urgently investigated. Here, we propose five reasonable countermeasures to alleviate these global-scale ecological crises induced by mask use during and following the COVID-19 pandemic era: increasing public awareness; improving mask waste management; innovating waste disposal methods; developing biodegradable masks; and formulating relevant policies and regulations. Implementation of these measures will help address the pollution caused by face masks.