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The production of activated carbon (AC) from biomass holds substantial environmental potential, but its impact varies widely depending on the synthesis methods employed. However, unreliable experimental data results in inconsistent life cycle assessments (LCA), often dependent on generic or highly localized information. Most available data focuses solely on production metrics, neglecting crucial performance-based indicators. This study conducts LCA for a conceptual AC production facility designed to produce 1 kg of AC per batch of coconut shell (CS), particularly examining potassium hydroxide (KOH) and sodium hydroxide (NaOH) activation routes. Environmental impacts (EIs) are evaluated using two functional units—mass-based and adsorption-based—and span eighteen metrics, including six key ones: net energy, climate change (CC), ozone depletion, fine particulate matter formation, marine eutrophication, and metal depletion. CC (kg CO₂ eq.) for 1 kg of AC production is 1.255 for KOH and 1.209 for NaOH, while energy requirements (in MJ) are 28.314 for KOH and 27.063 for NaOH. Notably, the pyrolysis step emerges as the most energy-intensive and significant contributor to carbon emissions. Per the adsorption-based unit, the KOH-led pathway shows a higher adsorption capacity of 729 g/kg versus 662 g/kg for NaOH, requiring less AC per kg of dye adsorbed. Consequently, the KOH pathway achieves 5% greater energy efficiency and 6% lower carbon emissions than the NaOH pathway. Synthesized ACs outperform commercial AC in all metrics, especially in energy use and carbon emissions. The study proposes improvements, such as alternative drying methods, to mitigate EIs and emphasizes the need to consider both production efficiency and functional performance to guide sustainable AC production and application.

Plastic waste is an underutilized resource that has the potential to be transformed into value-added materials. However, its chemical diversity leads to cost-intensive sorting techniques, limiting recycling and upcycling opportunities. Herein, we report an open-loop recycling method to produce graded feedstock from mixed polyolefins waste, which makes up 60% of total plastic waste. The method uses heat flow scanning to quantify the composition of plastic waste and resolves its compatibility through controlled dissolution. The resulting feedstock is then used to synthesize blended pellets, porous sorbents, and superhydrophobic coatings via thermally induced phase separation and spin-casting. The hybrid approach broadens the opportunities for reusing plastic waste, which is a step towards creating a more circular economy and better waste management practices. [Display omitted] •Plastic waste valorization to high quality materials.•Mixed polyolefins waste as feedstock.•Superhydrophobic coatings and porous sorbents prepared via thermally induced phase separation and spin-casting.

Sorbent pads and films have been commonly used for environmental remediation purposes, but designing their internal structure to optimize access to the entire volume while ensuring cost-effectiveness, ease of fabrication, sufficient strength, and reusability remains challenging. Herein, we report a trimodal sorbent film from recycled polypropylene (PP) with micropores, macro-voids, and sponge-like 3D cavities, developed through selective dissolution, thermally induced phase separation, and annealing. The sorbent has hundreds of cavities per cm 2 that are capable of swelling up to twenty-five times its thickness, allowing for super-fast saturation kinetics (within 30 s) and maximum oil sorption (97 g/g). The sorption mechanism follows a pseudo-second-order kinetic model. Moreover, the sorbent is easily compressible, and its structure is retained during oil sorption, desorption, and resorption, resulting in 96.5% reuse efficiency. The oil recovery process involves manually squeezing the film, making the cleanup process efficient with no chemical treatment required. The sorbent film possesses high porosity for effective sorption with sufficient tensile strength for practical applications. Our integrated technique results in a strengthened porous polymeric structure that can be tailored according to end-use applications. This study provides a sustainable solution for waste management that offers versatility in its functionality.

The use of Polypropylene PP in disposable items such as face masks, gloves, and personal protective equipment has increased exponentially during and after the COVID-19 pandemic, contributing significantly to microplastics and nanoplastics in the environment. Upcycling of waste PP provides a useful alternative to traditional thermal and mechanical recycling techniques. It transforms waste PP into useful products, minimizing its impact on the environment. Herein, we synthesized an oil-sorbent pouch using waste PP, which comprises superposed microporous and fibrous thin films of PP using spin coating. The pouch exhibited super-fast uptake kinetics and reached its saturation in fewer than five minutes with a high oil uptake value of 85 g/g. Moreover, it displayed high reusability and was found to be effective in absorbing oil up to seven times when mechanically squeezed between each cycle, demonstrating robust oil-sorption capabilities. This approach offers a potential solution for managing plastic waste while promoting a circular economy.

Recycling low-end, one-time-use plastics—such as low-density polyethylene (LDPE)—is of paramount importance to combat plastic pollution and promote sustainability in the modern green economy. This study valorizes LDPE waste by transforming it into 3D oleophilic swellable thin films through a process involving dissolution, phase separation, and extraction. These films are subsequently layered using a customized polypropylene (PP) based nonwoven fabric separator and securely sealed in a zigzag pattern. The zigzag-shaped seal enhances the adhesion of pollutants to the sorbent by providing wire curvatures that increase retention time and uptake capacity. As a result, the sorbent exhibits impressive oil uptake capacities, with immediate and equilibrium values of 120 g/g and 85 g/g, respectively. Notably, the as-prepared sorbent demonstrates low water retention and high selectivity for oil, outperforming commercially available oil sorbents. The unique design involving a 3D-film structure, superposed films, and a zigzag-shaped seal offers a sustainable and value-added solution to the issues of LDPE waste and oil spills on water surfaces.

Polyolefin waste is an abundant yet underutilized resource for developing value-added materials, while palm fronds (PF), a lignocellulosic biomass, offer a promising feedstock for activated carbon (AC) production. However, conventional AC from biomass is typically obtained in powdered form, making it difficult to handle and recover in aqueous systems without external support. Incorporating polyolefins during synthesis enables the formation of chemically activated polymer–carbon composite (PCC), which offers improved usability and recovery. This study aims to evaluate the environmental sustainability of producing PCC from PF and polyolefins, using Life Cycle Assessment (LCA) to quantify energy consumption and climate change impact. The LCA results show a net energy demand of 88.59 MJ and a climate change impact of 3.57 kg CO2 eq. per kg of PCC. Substituting conventional petroleum-based AC with PCC led to a 28% reduction in climate change impact and a 30% decrease in energy demand. By integrating biomass and plastic waste, this research supports sustainable material development and promotes circular economy practices in water treatment applications.

Traditional bulk adsorbents, employed for the removal of dyes and metal ions, often face the drawback of requiring an additional filtration system to separate the filtrate from the adsorbent. In this study, we address this limitation by embedding the adsorbent into the polymer matrix through a process involving dissolution–dispersion, spin-casting, and heat-stretching. Selective dissolution and dispersion facilitate the integration of the adsorbent into the polymer matrix. Meanwhile, spin-casting ensures the formation of a uniform and thin film structure, whereas heat-induced stretching produces a porous matrix with a reduced water contact angle. The adsorbent selectively captures dye molecules, while the porous structure contributes to water permeability. We utilized inexpensive and readily available materials, such as waste polyethylene and calcium carbonate, to fabricate membranes for the removal of methylene blue dye. The effects of various parameters, such as polymer-adsorbent ratio, initial dye concentration, and annealing temperature, were investigated. Equilibrium data were fitted to Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms. The equilibrium data were best represented by the Langmuir isotherm, with maximum adsorption capacity of 35 mg/g and 43 mg/g at 25 °C and 45 °C, respectively. The membranes can be regenerated and recycled with a 97% dye removal efficiency. The study aims to present a template for adsorbent-embedded polymeric membranes for dye removal, in which adsorbent can be tailored to enhance adsorption capacity and efficiency.

Microfiltration membranes derived from semi-crystalline polymers face various challenges when synthesized through the extrusion–casting technique, including the use of large quantities of polymer, long casting times, and the generation of substantial waste. This study focuses on synthesizing these membranes using spin-casting, followed by stretch-induced pore formation. Recycled high-density polyethylene (HDPE) and virgin polyethylene powder, combined with a calcium carbonate filler, were used as the source materials for the membranes. The influence of the polymer–filler ratio with and without stretching on the morphology, tensile strength, and water flow rate was investigated. Optimal conditions were determined, emphasizing a balance between pore structure and mechanical integrity. The permeable membrane exhibited a water flow rate of 19 mL/min, a tensile strength of 32 MPa, and a water contact angle of 126°. These membranes effectively eliminated suspended particles from water, with their performance evaluated against that of commercially available membranes. This research, carried out utilizing the spin-casting technique, outlines a synthesis route for microfiltration membranes tailored to semi-crystalline polymers and their plastic forms.

Polyethylene (PE) accounts for approximately 40% of total global plastic production, yet PE waste remains an underutilized feedstock. Meanwhile, activated carbon (AC) derived primarily from coconut shells (CS), the most popular source, is usually produced as powder, posing challenges in handling and recovery. This study explores the synergistic valorization of these two waste streams to produce value‐added AC polymer flakes (ACPF) through (a) chemical activation and pyrolysis of the CS, (b) dissolution of PE and dispersion of activated CS in a common solvent, and (c) heat treatment to form flakes. Life cycle assessment (LCA) results indicate an energy net (EN) consumption of 55 MJ for the NaOH route and 56 MJ for the KOH route, with corresponding climate change (CC) impacts of 2.11 kg CO 2 eq. and 2.17 kg CO 2 eq., respectively. Performance testing of ACPF using rhodamine B and methylene blue dyes demonstrated maximum adsorption capacities of 892 and 389 g/kg, respectively. Besides, replacing the commercial AC with ACPF led to approximately a 56% reduction in both CC impact and EN consumption. The integration of CS and PE waste leads to more sustainable AC production and promotes the utilization of waste for environmental purposes.

Mixed polyolefin-based waste needs urgent attention to mitigate its negative impact on the environment. The separation of these plastics requires energy-intensive processes due to their similar densities. Additionally, these materials cannot be blended without compatibilizers, as they are inherently incompatible and immiscible. Herein, non-wettable microporous sheets from recycled polyethylene (PE) and polypropylene (PP) are presented. The methodology involves the application of phase separation and spin-casting techniques to obtain a bimodal porous structure, facilitating efficient oil–water separation. The resulting sheets have an immediate and equilibrium sorption uptake of 100 and 55 g/g, respectively, due to the presence of micro- and macro-pores, as revealed by SEM. Moreover, sheets possess enhanced crystallinity, as evidenced by XRD; hence, they retain their structure during sorption and desorption and are reusable with 98% efficiency. The anti-wetting properties of the sheets are enhanced by applying a silane coating, ensuring waterless sorption and a contact angle of 140°. These results highlight the importance of implementing sustainable solutions to recycle plastics and mitigate the oil spill problem.