Veena Sahajwalla

UNSW Sydney | UNSW · Centre for Sustainable Materials Research and Technology

The textile sector is a significant contributor to worldwide pollution, especially through the generation of microplastics. This study addresses the critical issue of microplastic pollution and focuses on identifying potential sources of microplastics from degraded domestic textiles. The samples were collected from shed or worn-out fibers of domest...

The ever-increasing market demand and the rapid uptake of the technologies of electronics create an unavoidable generation of high-volume electronic waste (e-waste). E-waste is embedded with valuable metals, alloys, precious metals and rare earth elements. A substantial portion of e-waste ends up in landfills and is incinerated due to its complex m...

This study investigates the synthesis and characterization of Al2O3 nanoparticles derived from multilayered packaging (MLP) waste, specifically postconsumer coffee capsules, and evaluates their efficacy in fluoride adsorption from aqueous solutions. The nanoparticles were synthesized using a facile thermal degradation technique followed by leaching...

The development of efficient recovery methods for waste printed circuit boards (WPCBs) not only tackles the environmental risks of disposal but also promotes the conservation of resources within the electronics industry. This study proposes a two-step leaching approach for recovering metals from WPCBs. Initially, transition metals are leached using...

Carbon anode‐based Li‐ion batteries (LIBs) have been widely used ranging from portable electronics to electric vehicles (EVs). Here a novel carbon material called microzonal carbon is introduced, synthesized from waste hard rubber (WHR), as an anode material for next‐generation LIBs. This material consists of a hybrid carbon structure embedded with...

Alkali activation followed by foaming techniques is an effective method for glass-ceramic foam development where early-age reactions in the alkali-activated precursors and the foaming reaction happen simultaneously. Therefore, this early reaction stage must be clearly understood to control the pore characteristic in the glass-ceramic foams. However...

Silicon (Si) is a versatile alloying element that can enhance the performance of high carbon steel by contributing to deoxidation, grain refinement, hardenability, strength, and toughness. The study investigates the influence of Si (0.8–3.6%) on the microstructural and magnetic properties of high carbon steel. The arrangement and density of magneti...

The microstructural phases in steel influence the magnetic moments due to different alignments and arrangements of the atoms in the crystal lattice. This study is based on the relationship of the microstructural phases with saturation magnetization (MS), a characteristic magnetic property of a phase in a material. Understanding the changes in micro...

The pore characteristics and stability of alkali-activated foams (AAFs) are crucial factors that determine their application and performance. These aspects are influenced by the material mix design and the foaming method employed. The interaction between the activator and precursor paste results in a change in the rheological properties which posse...

Post-consumer soft plastics often face inadequate management practices, posing threats to both human life and the environment while also leading to the loss of valuable recyclable materials when not recycled. Traditional mechanical recycling methods are unsuitable for waste soft plastics due to their thin and flimsy nature. This study presents an e...

The capacity of different polymers to effectively work as a reductant depends on the thermal and chemical energy contained in them. A knowledge of the reducing potential of different plastics is required to assess the qualitative and quantitative characteristics of the plastic wastes, whether individually or mixed. This study aims to investigate th...

The iron and steel industry is one of the prominent industrial sectors in the world since steel is a vital material with a wide range of applications in daily life. The ferrous industries are associated with various issues like extensive greenhouse gas emissions, energy‐intensive processes, and heavy reliance on fossil fuels and natural resources....

Packaging in India comprises around 59% of total plastic consumption, with most of the waste originating from single‐use and short shelf‐life products. The plastic recycling industry is primarily made up of informal processing units which have predominantly been recycling Polyethylene terephthalate (PET) waste due to ease of availability, sorting,...

Generally, fossil carbon materials (coal, coke/char, and petroleum coke), biological carbon materials (charcoal, woodchips), and quartz from the earth’s crust are sources of carbon and silica to synthesise silicon carbide (SiC) at temperatures between 2000 and 2200 °C. The study investigated the isothermal and non-isothermal kinetics of synthesisin...

The principles of Green Chemistry and Engineering were formalised more than 20 years ago to guide us toward a safe and sustainable future. This framework is as important as ever in the development of chemical technologies that support human well-being while addressing the complex challenges we face in sustainability. This perspective is a reflectio...

The lithium‐ion battery (LIB) market is growing, driven by consumer demand and the imperative to reduce greenhouse gas (GHG) emissions. The socio‐environmental impacts of LIBs production are vast; thus, it is of paramount importance to acquire knowledge about the consequences of lithium metal mining on human health, farming and the overall ecosyste...

The recycling of nickel-metal hydride batteries (NiMHBs) has garnered significant attention in recent years due to the growing demand for critical metals and the implementation of national and international legislation aimed at achieving zero carbon emissions and reducing environmental impact. Typically, NiMHBs contain 10 wt% of rare earth elements...

Developments in recycling technology have largely focused on short-life-cycle products, such as plastic waste from packaging, consumer electronics, and construction debris, while complex, resource-rich, long-life-cycle electronic products, energy-storage, and photovoltaic components have been somewhat overlooked due to their intrinsic property of c...

The complex waste glass (WG) coming from the automotive vehicle industry has very low recycling potential and goes mainly to landfills. This research aims to develop a sustainable and eco-friendly method to prepare lightweight glass foams using this waste. Glass foams are porous, lightweight materials and are extensively used in various industry se...

Carbon-based materials have become an indispensable component in a myriad of domestic and industrial applications. Most of the carbon-based end-of-life products discussed in this review end up in landfills. Where recycling is available, it usually involves the production of lower-value products. The allotropic nature of carbon has been analysed to...

Electrochemical analysis of energy storage materials in aqueous electrolytes requires an accurate determination of a working potential window. Applying potentials outside this window causes detrimental reactions, reducing the electrode's durability. Therefore, there is a need for rapid and accurate determination of the most desired potential window...

The work presents on the relationship between temperature, time and carbon content in the preparation of a carbon fibre cloth from end-of-life cotton textiles. The aim of this investigation was to identify the minimum energy requirements for this textile recycling opportunity. The composition of the carbon fibre was studied using elemental combusti...

In the arena of energy storage device, asymmetric supercapacitors (ASCs) are considered a key category due to its high‐power density and energy densities. In this study, a novel macroporous microrecycled ZnO nanoparticles (mi‐ZnO NPs) recovered from spent Zn–C battery‐decorated three‐dimensional graphene aerogel (GA) composite has been synthesized...

Plastic has transformed the world; however, it generates a huge amount of waste plastics. It is well evident that, if urgent action is not undertaken on plastic pollution, it will pose threats to not only the environment, but also human life. Just simply discarding waste plastics will result in wasting a lot of valuable materials that could be recy...

Abstract: Globally, about 7% of solid waste is waste glass (WG) which is destined to be landfilled, causing environmental problems. The complex WG coming from the automotive vehicle industry is one of the main parts of this landfilled waste. Thus, using these complex WG as a raw material in the construction industry reduces the need for landfilli...

Consumer behavior is a critical consideration for the development of sustainable waste management systems, including waste batteries, which pose a serious threat to human health and the environment if disposed of improperly. This study investigates the consumers’ perspective on the waste battery collection and recycling behaviors in Australia, and...

The disposal of electronic waste (e-waste) presents a number of environmental problems. However, there are great opportunities to use this problem waste as a source of value-added metals. These metals could be recovered and transformed for use in beneficial applications, such as the manufacture of nanomaterials for the generation of hydrogen throug...

Using problematic electronic waste to synthesise high-purity nanomaterials can enable sustainable production and create opportunities to divert waste from landfills. Reported here is a simple strategy for the controllable synthesis of in situ NiO doped CuO nanoflakes from waste flexible printed circuit boards (FPCBs) using a chemothermal microrecyc...

Plastic manufacturing accounts for 6% of global oil consumption and is one of the world's fastest-growing waste streams. As the global supply of fossil fuels becomes critical, it is important to quantify how virgin plastic made from fossil fuel sources is recovered, reused, and remanufactured. In this study, the authors undertook the first systemat...

Tanneries are well-known for generating a huge amount of solid wastes and it is crucial to develop novel environmentally sustainable technologies that would utilise these wastes. This study evaluated the possibility of using tannery solid wastes such as shavings, buffing dust and leather cuttings as a source of carbon in the ironmaking process. The...

Abstract To enhance the eco-friendliness of glass foam manufacturing, the gel casting method is designed with mechanical foaming process. This method requires gelation of glass powder by prolonged alkali-activation and precuring at raised temperature (40-75℃). Vigorous mechanical foaming provides limited pore stability; thus, lengthy energy-consumi...

Microrecycling based techniques are developed to synthesise phase pure porous Co3O4 using thermal isolation and controlled recycling pathways to achieve environmental outcomes that could manufacture and recycle hazardous spent Lithium-ion batteries (LIBs). The existing synthesising strategies for high surface area and small crystal grains of Co3O4...

Plastic waste (PW) is one of the most rapid-growing waste streams in municipal solid waste all over the world. India has become a global player in the plastic value chain. Despite low consumption, domestic generation and imports create a significant burden on the overall waste management system, which requires in-depth understanding of the scenario...

This review article aims to suggest recycling technological options in India and illustrates plastic recycling clusters and reprocessing infrastructure for plastic waste (PW) recycling in India. The study shows that a majority of states in India are engaged in recycling, road construction, and co-processing in cement kilns while reprocessing capabi...

Glass foams are porous high-performance insulation materials. The uniformly distributed and homogenously sized fine pores are crucial for the insulation properties of glass foam. To improve the homogeneity and stability of pores, stabilising chemicals are used in glass foam manufacturing. However, these chemicals release greenhouse gases during sin...

Growing utilisation of rare earth elements (REEs) has caused severe shortages in REE supply and shifted the state-of-the-art approaches toward sustainable recycling of REEs containing wastes. The present work reports a three-step strategy based on selective purification of rare earth oxides (REOs) isolated from end-of-life nickel-metal hydride (Ni-...

The application of insulation materials in buildings and energy storage facilities is gaining global attention to reduce energy consumption, heat loss, and CO2 emissions. Given the high insulation performance, glass foam is gaining popularity replacing combustible, high energy-consuming, and costly conventional insulation materials. The industrial...

The recycling of electronic wastes into value-added nanostructures for sustainable photo-induced hydrogen generation has been shown to contribute toward the circular economy goals for zero-net emissions. For the desired photocurrent performance, it is imperative to understand and control every step during the synthesis of photoelectrodes and the as...

The rapid transformation to renewable energy will require an equal uptake of energy storage technologies. Therefore, green hydrogen production via water electrolysis has been touted as a practical solution for...

The new class of oxide heterojunctions with mixed dimensionalities hold great promise for energy and environmental applications. However, the existing fabrication strategies typically involve low-yield and multistep processes leading to...

Recent research has revealed the promising potential of using waste glass (WG) as a binder or inert filler in cement and geopolymer concrete to deliver economic and environmental benefits to the construction sector. However, the outcomes obtained by different research groups are scat-tered and difficult to compare directly because of isolated proce...

Automotive waste represents both a global waste challenge and the loss of valuable embedded resources. This study provides a sustainable solution to utilise the mixed plastics of automotive waste residue (ASR) as a resource that will curtail the landfilling of hazardous waste and its adverse consequences to the environment. In this research, the se...

Having control over the architecture of functional materials to maximize their exposed surface area and the working potential window is critical yet challenging for surface‐sensitive applications, including energy storage and environmental remediation. Herein, a sustainable and green strategy is established to fabricate activated carbon (AC) materi...

Quenching and partitioning (Q andP) heat treatments of high- and low-silicon hyper-eutectoid steels, 0.21% and 1.7% silicon grades, have been investigated using dilatometry. In the present work, the amount and stability of retained austenite were quantified by a magnetic measurement technique. Optical microscopy (OM), high-resolution scanning elect...

In Australia, yearly, around 22,500 Tons of waste glasses (WG) are discarded from end-oflife vehicles being landfilled because of the costly and convoluted recycling process. This research is designed for recycling the automotive WG to produce sustainable glass foam by a modified method. Nonuniformity in size and distribution of pores within glass...

Growing concerns over non-renewable fossil fuel resources and anthropogenic emissions of greenhouse gases have attracted global interests towards development of sustainable and renewable energies using functional nanostructures. A sustainable approach that can confer multiple advantages is the engineering of nanostructures from the recycling of ele...

Controllable recycling of End-of-life rechargeable nickel-metal hydride (Ni-MH) batteries and by-products of steelmaking to added-value functional nanostructures is desired but challenging. The present work introduces an innovative and high-yield microrecycling strategy to simultaneous synthesis of TM alloy (i.e., Ni-based superalloy) and RE oxide...

In article number 2100880, Samane Maroufi and co‐workers report the synthesis of defect‐rich Mn1−x−y(CexLay)O2−δ ultrathin films with controllable thicknesses, transmittance, and outstanding areal capacitance. The performance originates from the intercalation/de‐intercalation of anionic O2− charges and intervalence charge transfer among cations wit...

To tackle the alarming increase in e-waste or end-of-life (EoL) electronic products, consumer behavior towards the end of their useful life needs to be thoroughly studied. End users or consumers are the starting point where e-waste starts its journey into several paths within the circular economy (CE), such as repair, reuse, remanufacturing, and re...

This study proposes the transformation of complex waste otherwise destined for landfill into valuable products and resources through molecular recycling. Specifically, it aims to leverage high-temperature reactions to thermally alter the atomic bonds of carbon and silicon within the molecules from the waste source in situ, to produce valuable silic...

Non-intrusive techniques for diagnosis and biomonitoring – for example, breath testing to detect biomarkers – have the potential to support the advancement of versatile and remote point-of-care (PoC) diagnostics. This paper investigates tuning the sensitivity and selectivity performance of chemo-resistive sensors to detect volatile organic compound...

This study reports the first experimental research of Ecklonia radiata macroalga as novel precursor material for the synthesis of one-dimensional Silicon carbide (1D-SiC) Nanoceramics. High-temperature carbothermic reduction of Biosilica (Bio-SiO2) at 1550 °C under controlled Argon purge is proposed as means of facile scalable bulk manufacturing me...

Control over the fabrication of state-of-the-art portable pseudocapacitors with the desired transparency, mechanical flexibility, capacitance, and durability is challenging, but if resolved will have fundamental implications. Here, defect-rich Mn1−x−y(CexLay)O2−δ ultrathin films with controllable thicknesses (5–627 nm) and transmittance (≈29–100%)...

Carbon coated cobalt oxide (CC-CO3O4) was prepared by colloidal processing using cobalt oxide and sucrose. Sucrose was used as a soluble carbon precursor in the preparation of CC-CO3O4. CC-CO3O4 was characterized by Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM), Transmission e...

Aluminium is a widely used metal in combination with polymers in flexible packaging materials applications. Cast-off polymer-metal multilayer food packaging materials (PMM-FPM) have been recycled in this study by two different techniques. First, a single-stage smelting at 900 °C as a traditional smelting recycling process was adopted for the waste...

Carbons utilised in the energy applications are often produced from non-renewable sources in harsh environments. By leveraging high temperature reactions, this study used thermal transformation to recover useful carbon materials from wood and plastic components of automotive shredder residue (ASR) and tune their properties in situ via selective the...

Biomass is an abundant and valuable carbon source that can be utilised in many applications such as gas separation and energy storage. Resolving methods to process biomass cheaply and efficiently into useful carbons for such applications remains a significant area of research. Herein carbons prepared via facile pyrolysis (or thermal transformation)...

The current work is based on the process study and synthesis of value-added ferrous material from EAF (electric arc furnace) slag through reduction and melting using a waste carbon resource of spent coffee grounds. Spent coffee grounds were carbonized at 400°C to obtain transformed-spent coffee grounds. Pitch coke has also been used in the current...

The present study contends with unveiling the damage mechanisms during compressive dwell-fatigue of β-annealed Ti-6242S alloy. The shearing/displacement of lamellar phases, stacking fault nodes formation, and formation of coarse grains (under the lower stress level) are identified as key factors influencing crack initiation and propagation which ma...

The significant usage of lithium-ion batteries (LIBs) in compact electronics – and more recently, electric automobiles – will lead to large quantities of scrap batteries and create serious environmental problems. Currently, spent LIBs are not very well recycled, and are predominantly disposed of in landfill. This is risky, due to the presence of ha...

Due to their exceptional properties, low-cost high-carbon steels have long been extensively utilized in many industrial applications. However, their corrosion resistance is poor for many applications and requires further enhancement. Various methods have been developed to achieve this, but they suffer from some limitations. In the work presented he...

This paper has reported a sustainable way of producing high strength glass foam using scrap LCD panel of TVs as the glass source and manganese dioxide from scrap alkaline battery and sodium carbonate as foaming agents, respectively. This work demonstrates the feasibility of producing foamed ceramic from the waste alumino-borosilicate glass with a c...