Application of COVID-19 single-use shredded nitrile gloves in structural concrete: Case study from Australia

[Sustainability in occupational dermatology : Starting points, challenges, and potentials for sustainable care of work-related skin diseases]

Sustainability is becoming increasingly important in healthcare and has moved into focus at various levels. This article aims to provide an overview of guiding principles, concepts, and target systems of sustainability and to transfer these to occupational dermatology. Current and future starting points are outlined for various levels, e.g., politics, research, industry, and patient care, in order to link sustainability and occupational dermatology in a structured and systematic way and to transform the structures of patient care in occupational dermatology care towards sustainability. Using the specific example of protective gloves, which is a pivotal personal protective measure to prevent work-related hand eczema, starting points, potentials, and challenges are analyzed and specific possibilities and perspectives for more ecologically sustainable action are presented.

Biodegradation of Nitrile Gloves as Sole Carbon Source of Pseudomonas aeruginosa in Liquid Culture

Nitrile gloves have become a significant environmental pollutant after the COVID-19 pandemic due to their single-use design. This study examines the capability of P. aeruginosa to use nitrile gloves as its sole carbon energy source. Biodegradation was determined by P. aeruginosa adapting to increasing nitrile glove concentrations at 1%, 3%, and 5% (w/v). The growth kinetics of P. aeruginosa were evaluated, as well as the polymer weight loss. Topographic changes on the glove surfaces were examined using SEM, and FT-IR was used to evaluate the biodegradation products of the nitrile gloves. Following the establishment of a biofilm on the glove surface, the nitrile toxicity was minimized via biodegradation. The result of the average weight loss of nitrile gloves was 2.25%. FT-IR analysis revealed the presence of aldehydes and aliphatic amines associated with biodegradation. SEM showed P. aeruginosa immersed in the EPS matrix, causing the formation of cracks, scales, protrusions, and the presence of semi-spherical particles. We conclude that P. aeruginosa has the capability to use nitrile gloves as its sole carbon source, even up to 5%, through biofilm formation, demonstrating the potential of P. aeruginosa for the degradation of nitrile gloves.

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.

Recycling of discarded face masks for modification and use in SBS-modified bitumen

Since the outbreak of the COVID-19 pandemic, the discarded face masks have attracted widespread attention in society. In line with sustainable development, a physicochemical treatment method was used to recycle discarded face masks into styrene-butadiene-styrene (SBS) modified bitumen. Utilizing the highly adhesive polydopamine-polyethyleneimine (PDA-PEI) coating, it has improved the surface damage of the discarded face mask fibers (DFMF) caused by natural aging and mechanical fragmentation, simultaneously strengthening the connection between the fibers and bitumen. At 46 °C, the 2% embellish-face mask fiber (E-FMF)/SBS modified bitumen, compared to the 2%DFMF/SBS modified bitumen, exhibited improvements in complex modulus (G*), elastic modulus (G'), and loss modulus (G″) by 12.27%, 16.39%, and 13.35%, respectively. Furthermore, at 0.1 kPa and 3.2 kPa, the creep recovery rate (R) increased by 23.3% and 32%, and the average creep compliance (Jnr) decreased by 54.7% and 64%. It was demonstrated that DFMF adhered with the coating, were more effective in improving the mechanical properties, deformation resistance, and shear resistance of the bitumen. This approach enriches the application scenarios of discarded single-use face masks and supports environmental protection and road construction.

On the possibility of using waste disposable gloves as recycled fibers in sustainable 3D concrete printing using different additives

Due to the Covid-19 pandemic, using large amounts of personal protective equipment (PPE) throughout the world has extensively increased in recent years. The lack of a practical method to dispose of these recycled materials is one of the main concerns of researchers. Hence, comprehensive experimental tests were conducted in the present study to investigate the feasibility of using disposable gloves in mortars to achieve a sustainable mixture. Accordingly, latex and vinyl gloves as recycled fibers were considered in the experimental program to improve the sustainability of 3D printing concrete. As using these recycled materials causes some deficiencies for printing layers, different mineral and chemical admixtures were used in the present study, including graphene oxide nanomaterials, polyvinyl alcohol, Cloisite 15A nanoclay, and micro silica fume. Also, the hybrid use of latex, vinyl, and polypropylene (PP) fiber was considered to improve the printability of concrete mixtures containing waste fibers. Moreover, the effect of internal reinforcement was also considered by using plain steel wire mesh to increase the composite behavior of printed layers in this simplified experimental program. Results indicate that the synergic influence of recycled fibers and admixtures meaningfully enhanced the 3D printing properties of mortar so that about 20%, 80%, 50%, and more than 100% improvements were obtained for workability, direct tensile strength, flexural strength, and buildability index respectively. However, an average percentage - 28.3% reduction was recorded for the concrete compressive strength. Sustainability analysis also showed that using waste disposable gloves considerably reduced CO₂ emissions.

Recycling COVID-19 health care wastes in bitumen modification: a case of disposable medical gloves

Disposable medical gloves (DMGs) have long been used to mitigate the risk of direct exposure to diverse microorganisms and body fluids; hence, they are a critical weapon to protect patients and healthcare staff from infectious diseases. Measures to control the spread of COVID-19 have sparked the production of an excessive number of DMGs, most of which are eventually being disposed of in landfills. Untreated DMGs in landfills do not only pose a direct risk of transmitting coronavirus and other pathological germs but also pollute air, water, and soil dramatically. As a healthier alternative, recycling discarded polymer-rich DMGs into bitumen modification is considered to be a prospective waste management strategy applicable to the asphalt pavement industry. In this study, this conjecture is tested by examining two common DMGs - latex gloves and vinyl gloves - at four different percentages (1%, 2%, 3%, and 4% by weight). The morphological characteristics of DMG-modified specimens were inspected by using a high-definition scanning electron microscope (SEM) equipped with an energy dispersive X-ray analyzer (EDX). A wide range of laboratory tests including penetration, softening point temperature, ductility, and elastic recovery were undertaken to evaluate the impact of waste gloves on the conventional engineering properties of bitumen. Moreover, viscoelastic behavior and modification processing were studied by conducting the dynamic shear rheometer (DSR) test and the Fourier transform infrared spectroscopy (FTIR) analysis. Test results have revealed the outstanding potential of recycled DMG waste for modifying neat asphalt binder. More specifically, bitumens modified with 4% latex glove and 3% vinyl glove were seen as capable of superiorly withstanding permanent deformations caused by heavy axle loads at high service temperatures. Furthermore, it has been shown that 1.2 tons of modified binder would embed approximately 4000 pairs of recycled DMGs. This study shows that DMG waste can be used as a viable modifier, which would help open a new avenue for mitigating the environmental pollution arising from the COVID-19 pandemic.

Property assessment of an eco-friendly mortar reinforced with recycled mask fiber derived from COVID-19 single-use face masks

Wearing a face mask is strongly advised to prevent the spread of the virus causing the COVID-19 pandemic, though masks have produced a tremendous amount of waste. As masks contain polypropylene and other plastics products, total degradation is not achievable, and masks may remain in the form of microplastics for several years in the environment. Therefore, this urgent issue ought to be addressed by properly handling waste face masks to limit their environmental impact. In relation to this goal, a novel application of recycled mask fiber (MF) derived from COVID-19 single-use surgical face masks (i.e., shredded mask fiber-SMF and cut mask fiber-CMF) has been undertaken. Eighteen mortar mixes (9 for water and 9 for 10% CO₂ concentration curing) were fabricated at 0%, 0.5%, 1.0%, 1.5%, and 2.0% of both SMF and CMF by volume of ordinary Portland cement-based mortar. The compressive strength, flexural strength, ultrasonic pulse velocity, shrinkage, carbonation degree, permeable voids, and water absorption capabilities were assessed. The outcomes reveal that the compressive strength decreased with an increased percentage of MFs due to increased voids of the mixes with MFs as compared to a control mix. In contrast, significantly higher flexural strength was noted for the mortar with MFs, which is augmented with an increased percentage of MFs. Furthermore, the inclusion of MFs decreased the shrinkage of the mortar compared to the control mix. It was also found that MFs dramatically diminished the water absorption rate compared to the control mix, which reveals that MFs can enhance the durability of the mortar.

Performance of Reinforced Foam and Geopolymer Concretes against Prolonged Exposures to Chloride in a Normal Environment

The utilization of sustainable cement replacement materials in concrete can control the emission of carbon dioxide and greenhouse gases in the construction industry, thus contributing significantly to the environment, society, and the global economy. Various types of sustainable concrete including geopolymer concrete are tested for their efficacy for construction in laboratories. However, the performance and longevity of sustainable concrete for civil engineering applications in corrosive environments are still debatable. This paper aims to investigate the performance of the reinforced geopolymer (GPC) and foam concretes (FC) against corrosive chloride exposure. Two long term key parameters, i.e., corrosion rate and mechanical performance of reinforcing steel in geopolymer and foam concrete were assessed to evaluate their performance against chloride attack. For experiments, reinforced GPC and FC specimens, each admixed with 3 and 5% chlorides, were kept at varying temperatures and humidity levels in the environmental chambers. The corrosion rates of the reinforced geopolymer and foam concrete specimens were also compared with control specimens after 803 days and the tensile strength of the corroded reinforcing steel was also determined. Moreover, the long term efficacy of repaired patches (810 days), in a chloride-rich surrounding environment utilizing FC and GPC, was investigated. The results suggested greater performance of FC compared to GPC under standard environmental conditions. However, the simulated patch repair with GPC showed better resistance against chloride attack compared to FC. The research also undertook the fractographical examination of the surfaces of the reinforcement exposed to 5% admixed chloride and develops models for the corrosion rates of foam concrete as a function of the corrosion rates of geopolymer concrete and chloride content. A correlation model for the corrosion rates of FC and GPC was also developed. The findings of the current research and the model developed are novel and contribute to the knowledge of long term degradation science of geopolymers and form concrete materials. Furthermore, the findings and methodology of the current research have practical significance in the construction and repair industry for determining the remaining service life for any reinforced and steel infrastructure.

Reusing COVID-19 disposable nitrile gloves to improve the mechanical properties of expansive clay subgrade: An innovative medical waste solution

The COVID-19 pandemic not only poses an unprecedented threat to global health but also severely disrupts the natural environment and ecosystems. Mitigating the adverse impacts of plastic-based personal protective equipment (PPE) waste requires the cooperation of professionals from various fields. This paper discusses a novel, cleaner approach to soil stabilisation by repurposing the nitrile gloves into a sustainable road material to improve the mechanical properties of expansive clay soil as pavement subgrade. For the first time, extensive geotechnical testings, including standard compaction, unconfined compressive strength (UCS), unsoaked California bearing ratio (CBR), repeated load triaxial (RLT), and swelling-shrinkage tests, were carried out to investigate the engineering performance of different proportions of the shredded nitrile gloves (SNG) (e.g., 1%, 1.5%, 2%) were blended with expansive clay (EC). In addition, surface roughness, scanning electron microscopy (SEM), and X-ray micro-CT analyses were conducted, and images were obtained to study the microstructural modification of the EC-SNG mixtures. The experimental results indicated that the blend of expansive clay with SNG helped in increasing the compressive strength, resilient modulus, and CBR and assisted in reducing the swelling and shrinkage of the soil. SEM and surface roughness analyses indicated the interaction between the soil matrix interface and the rough surface of the SNG. The main reasons for increasing the strength and stability of clay soil could be attributed to the high tensile strength of the SNG and the formation of the three-dimensional grid, and friction between the soil particles and SNG. According to the X-ray micro-CT test results, the incorporation of SNG led to an increase in closed porosity.

Sustainable Recycling of Waste from Nitrile Gloves: Prolonging the Life Span by Designing Proper Curing Systems

A massive demand for rubber-based goods, particularly gloves, was sparked by the emergence of the COVID-19 epidemic worldwide. This resulted in thousands of tons of gloves being scrapped due to the constant demand for the items, endangering our environment in a grave way. In this work, we aimed to focus on the utilization of waste nitrile gloves (r-NBR) as a component blended with natural rubber (NR). The life span and other related properties of the blend can be improved by proper control of the chemical recipe. This study assessed three types of crosslinking systems, namely sulfur (S), peroxide (DCP), and mixed sulfur/peroxide (S/DCP) systems. The results indicate that choosing S/DCP strongly affected the tensile strength of the blend, especially at relatively high contents of r-NBR, improving the strength by 40-60% for cases with 25-35 phr of r-NBR. The improvement depended on the crosslink types induced in the blends. It is interesting to highlight that the thermal resistance of the blends was significantly improved by using the S/DCP system. This indicates that the life span of this blend can be prolonged by using a proper curing system. Overall, the S/DCP showed the best results, superior to those with S and DCP crosslinking systems.

Fire releases micro- and nanoplastics: Raman imaging on burned disposable gloves

Raman imaging can effectively characterise microplastics and nanoplastics, which is validated here to capture the items released from the plastic gloves when subjected to a mimicked fire. During the COVID-19 pandemic, large quantities of personal protective equipment (PPE) units have been used, such as the disposable gloves. If discarded and poorly managed, plastics gloves might break down to release secondary contaminants. The breakdown process can be accelerated by burning in a bushfire or at the incineration plants. During the burning process, the functional groups on the surface can be burned differently due to their different thermal stabilities. The different degrees of burning can be distinguished and visualised via Raman imaging. In the meantime, at the bottom of the burned plastics, microplastics and nanoplastics can be generated at a significant amount. The possible false Raman imaging on microplastics and nanoplastics is also discussed, by effectively extracting and distinguishing the weak signal from the background or noise. Overall, these findings confirm the importance of effectively working waste incineration plants and litter prevention, and suggest that Raman imaging is a suitable approach to characterise microplastics and nanoplastics.

Use of COVID-19 single-use face masks to improve the rutting resistance of asphalt pavement

Today, the world faces an enormous increase in plastic waste pollution caused by the emergence of the COVID-19 pandemic. Plastic pollution has been already one of the greatest threats to our planet before the Coronavirus outbreak. The disposal of millions of personal protective equipment (PPE) in the form of face masks has significantly contributed to the generation of plastic waste and has exacerbated plastic pollution. In an attempt to mitigate pollution caused by the excess PPE waste, an innovative way was developed in this research to reduce pandemic-generated wastes by using the shredded face mask (SFM) fibers as an additive to hot mix asphalt (HMA) to enhance rutting resistance. Rutting or permanent deformation is one of the major distresses of asphalt pavement. Since the SFM behaves as a semi-liquid between 115.5 and 160 °C, which is in the range of HMA mixing and paving temperature, it can function as a binding agent to glue the aggregates. When the pavement is cooled down to ambient temperature, the hardened SFM can provide stability and stiffness to HMA. Based on the results of this study, the modified mixes exhibited excellent resistance to permanent deformation under the Asphalt Pavement Analyzer (APA), as rutting depth values were reduced from 3.0 mm to 0.93 mm by increasing the SFM content from 0% to 1.5%. From the rutting test results and premature distress mechanism study, the appropriate addition of SFM modifiers could improve the high-temperature properties of HMA that can be used to strengthen high-compression and shearing zones in the pavement structure.