Search

The global pollution crisis arising from the accumulation of plastic in landfills and the environment necessitates addressing plastic waste issues. Notably, polypropylene (PP) waste accounts for 20% of total plastic waste and holds promise for hydrophobic applications in the realm of recycling. Herein, the transparent and non-transparent superhydrophobic films made from waste PP are reported. A hierarchical structure with protrusions is induced through spin-casting and thermally induced phase separation. The films had a water contact angle of 159° and could vary in thickness, strength, roughness, and hydrophobicity depending on end-user requirements. The Bode plot indicated enhanced corrosion resistance in the superhydrophobic films. Antibacterial trials with Escherichia coli and Staphylococcus aureus microbial solutions showed that the superhydrophobic film had a significantly lower rate of colony-forming units compared to both the transparent surface and the control blank sample. Moreover, a life cycle assessment revealed that the film production resulted in a 62% lower embodied energy and 34% lower carbon footprint compared to virgin PP pellets sourced from petroleum. These films exhibit distinctiveness with their dual functionality as coatings and freestanding films. Unlike conventional coatings that require chemical application onto the substrate, these films can be mechanically applied using adhesive tapes on a variety of surfaces. Overall, the effective recycling of waste PP into versatile superhydrophobic films not only reduces environmental impact but also paves the way for a more sustainable and eco-friendly future. [Display omitted] • Waste PP is transformed into superhydrophobic films—transparent and non-transparent. • Films are suitable for weather resistance and self-cleaning applications. • Films demonstrate improved corrosion resistance compared to bare carbon steel. • Reduced microbial growth in films makes them suitable for antibacterial use. • Films show lower embodied energy and fewer carbon emissions than virgin PP pellets. [ABSTRACT FROM AUTHOR]

Environmental pollution caused by plastic waste and oil spills has emerged as a major concern in recent years. Consequently, there has been a growing interest in exploring innovative solutions to address these challenges. Herein, we report a method to upcycle polyolefins-based plastic waste by converting it into a bimodal super-oleophilic sorbent using dissolution, spin-coating, and annealing techniques. The resulting sorbent possesses an extensive network of pores and cavities with a size range from 0.5 to 5 µm and 150–200 µm, respectively, with an average of 600 cavities per cm2. Each cavity can swell up to twenty times the thickness of the sorbent, exhibiting sponge-like behavior. The sorbent had an oil uptake capacity of 70–140 g/g, depending on the type of sorbate and dripping time. Moreover, the sorbent can be mechanically or manually squeezed to recover the sorbed oil. Our integrated methodology provides a promising approach to upcycling plastic waste as an abundant source of value-added materials. [Display omitted] • Polyolefins, which make up 60% of plastic waste, were used to produce a super-sorbent for oil and organic removal from water. • The super-sorbent has pores and cavities, with an oil uptake capacity of 70–140 g/g. • Each cavity can swell up to twenty times the thickness of the sorbent, exhibiting sponge-like behavior. • The sorbent can be squeezed mechanically or manually to recover the sorbed oil, with at least 97% efficiency. • This technique can lead to greater utilization of plastic waste as a source of value-added materials. [ABSTRACT FROM AUTHOR]

Abstract: A number of chars from waste tyre rubber were prepared by carbonisation at 673–1173K. The effects of holding time, heating rate and particle size on the textural characteristics and elemental composition of the resultant chars were investigated. It was demonstrated that temperatures over 773K did not have a significant improvement on the total surface area but resulted in lower char yields following increased aromatisation. Modelling of dye adsorption isotherms showed that the Redlich–Peterson expression yields the best-fit between experimental and predicted data. Furthermore, for a larger sized dye like Acid Yellow 117 (MW=848g/mol), the amount adsorbed by the tyre char is not directly proportional to the total surface area when compared with a commercial carbon, revealing that factors other than total surface area are involved in the adsorption potential of the tyre chars. [Copyright &y& Elsevier]

This research demonstrates the capability of carbon nanotubes (CNT) modified with four generations of poly-amidoamine dendrimer (PAMAM, G4) to remove Cu 2+ and Pb 2+ heavy metals from aqueous solution in single and binary component systems. Uniquely high adsorption capacities for copper and lead, which are 3333 and 4870 mg/g respectively, were achieved. FTIR, H 1 NMR, Zeta potential, SEM and TEM techniques were employed for characterizing the synthetic nanocomposite and indicated that the dendrimer functionalized CNTs have been synthesized. The effects of several parameters including initial metal ion concentration, solution pH and the nanocomposite dosage were studied. The experimental data were analyzed by the Langmuir and Freundlich isotherms and the pseudo-first order and pseudo-second order kinetics models. The maximum adsorption occurred at pH = 7. The adsorption process for Cu 2+ and Pb 2+ in single and binary component systems fit the Langmuir and extended Langmuir models respectively. This study also tested the kinetic sorption of the metals on PAMAM/CNT in single and binary component metal systems at various metal ions concentrations. The results showed that PAMAM/CNT nanocomposite was a super-adsorbent, able to uptake uniquely large quantities of heavy metal from single and binary component liquid phase. [ABSTRACT FROM AUTHOR]

E-waste, in particular waste PCBs, represents a rapidly growing disposal problem worldwide. The vast diversity of highly toxic materials for landfill disposal and the potential of heavy metal vapors and brominated dioxin emissions in the case of incineration render these two waste management technologies inappropriate. Also, the shipment of these toxic wastes to certain areas of the world for eco-unfriendly “ recycling” has recently generated a major public outcry. Consequently, waste PCB recycling should be adopted by the environmental communities as an ultimate goal. This article reviews the recent trends and developments in PCB waste recycling techniques, including both physical and chemical recycling. It is concluded that the physical recycling techniques, which efficiently separate the metallic and nonmetallic fractions of waste PCBs, offer the most promising gateways for the environmentally-benign recycling of this waste. Moreover, although the reclaimed metallic fraction has gained more attention due to its high value, the application of the nonmetallic fraction has been neglected in most cases. Hence, several proposed applications of this fraction have been comprehensively examined. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel developed adsorbent material derived from waste printed circuit boards’ component. [•] The innovative adsorbent material can effectively remove cadmium ions from aqueous solutions. [•] The maximum capacity for cadmium ion removal is 2.1mmol/g. [•] Cadmium removal capacity is either equivalent or better than commercial resins. [Copyright &y& Elsevier]

Abstract: Printed circuit boards (PCBs) constitute one of the major sources of toxicity in landfill areas throughout the world. Hence, PCB recycling and separation of its metallic and nonmetallic components has been considered a major ecological breakthrough. Many studies focus on the metallic fraction of the PCBs due to its economic benefits whereas the nonmetallic powder (NMP) has been left isolated. In this work, the feasibility of using NMP as an adsorbent to remove charged toxic heavy metal ions have been studied and its efficiency has been compared with two widely-used commercial adsorbents. The results indicated that the virgin NMP material has no adsorption capacity, while the application of an activation stage to modify the NMP process has a significant effect on its porosity and thus adsorption capacity. The Cu and Pb removal capacity of the activated sample (A-NMP) at a pH level of 4 was 3mmol and 3.4mmol per gram of the adsorbent, respectively, which was considerably higher than the commercial ones. [Copyright &y& Elsevier]

Abstract: Experiments have been carried out to prepare char from waste bamboo scaffolding for wastewater treatment. Carbonisation parameters such as temperature, holding time, heating rate and particle size were investigated. When the material was heated to 1173K for 2h, surface area and total pore volume (V total) were 327m2/g and 0.185cm3/g, respectively. Particle size and heating rate appear less influential to the yield and textural characteristics of the resultant chars. Bamboo char obtained in this study did not show very high adsorption capacities for two acid dyes (Acid Blue 25 and Acid Yellow 117) but exhibited significant uptake of Methylene Blue. The equilibrium data were modelled by three different isotherms, namely, Langmuir, Freundlich and Redlich–Peterson model. Comparing the predicted data using optimised parameters from each model based on the SSE error function, the Redlich–Peterson isotherm appears the ‘best’ model to correlate experimental data. [Copyright &y& Elsevier]

Accidents involving oil transportation has increase due to directly connection with the elevation of global energy demand. The environmental losses are tremendous and brings huge economic issues to remediate the spilled oil. This report presents an up-to-date review on an overall aspects of oil spill remediation techniques, the fundamentals and advantages of sorption, the most applied materials through diverse types of oil spill sites and oils with variety features, highlight to natural materials and future prospective. As the environment preservation progressively becomes a major social concern issue, the achievement of a worldwide distribution process aligned with environmental legislation and economic viability is crucial to the oil industry. For this, a specific preparation considering several scenarios must be carried out regarding minimization of oil spillages. Since the sorbent materials are decisive for sorption, it was approached the main sorbents: natural, graphenic, nano, polymeric and waste materials, and future trends. ga1 • Oil spills became more reported in the last decades, usually spillage millions of tons of oil. • Natural, graphenic, nano, polymeric and waste materials are the main used sorbents worldwide. • New materials with specific applications are needed. [ABSTRACT FROM AUTHOR]