Publications by authors named "Rajeev Roychand"

Nanoplastics (NPs) are generated from the fragmentation of microplastics (MPs) through mechanical forces such as mixing, sonication and homogenization in wastewater treatment plants (WWTPs). Despite their environmental significance, the formation mechanisms and size distribution of NPs in WWTPs are not well understood. This study presents an in-depth investigation into the fragmentation mechanisms of polyethylene (PE) and polystyrene (PS) MPs, sized 250 μm and 106 μm, under simulated WWTP conditions.

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The deterioration of concrete sewer structures due to bio-corrosion presents critical and escalating challenges from structural, economic and environmental perspectives. Despite decades of research, this issue remains inadequately addressed, resulting in billions of dollars in maintenance costs and a shortened service life for sewer infrastructure worldwide. This challenge is exacerbated by the absence of standardized test methods and universally accepted mitigation strategies, leaving industries and stakeholders confronting an increasingly pressing problem.

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Wastewater treatment plants (WWTPs) are major recipients of microplastics (MPs) that break down into nanoplastics (NPs) during wastewater treatment through physical, chemical, and biological processes. In particular, mechanical stress induced by the mixing process commonly used in WWTPs is thought to play a crucial role in the production of secondary MPs/NPs, which are then discharged into the open water environment through the WWTP effluent. This study investigated the fragmentation of 250 and 106 μm-sized pristine and weathered polystyrene (PS) particles using a four-blade mechanical impeller.

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Nano/microplastic (NP/MP) pollution is a growing concern for the water environment. Wastewater treatment plants (WWTPs) are considered the major recipients of MP before discharging into local waterbodies. MPs enter WWTPs mainly from synthetic fibers through washing activities and personal care products.

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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.

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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.

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Microplastics (MP) have become a major emerging class of pollutants representing significant eco-toxicological risks for ecosystems and marine environments. The aim of this study was to identify, classify and quantify MP present in both road dust and stormwater samples. A significantly higher level of MPs within road dust samples was detected from industrial area (1130 particles/kg of dust) than from residential area (520 particles/kg of dust), while stormwater samples from industrial and residential sites yielded 26 particles/L and 17 particles/L, respectively.

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The use of single-use nitrile gloves has been on a sharp incline since the Coronavirus pandemic first started in late 2019. This led to a significant increase in the generation of this clinical waste that requires various recycling solutions to reduce its environmental impact from disposal or incineration. This paper explores its application in structural concrete by adding shredded nitrile gloves at 0.

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With the ongoing global pandemic due to Coronavirus (COVID-19), the use of personal protective equipment (PPE), specifically single-use surgical masks, have been on a sharp incline. Currently, many countries are experiencing second and third waves of COVID-19 and as such have resorted to making face masks a mandatory requirement. The repercussions of this have resulted in millions of single-use face masks being discharged into the environment, washing up on beaches, floating beneath oceans and ending up in vulnerable places.

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The global demand of lithium is rising steadily, and many industrially advanced countries may find it hard to secure an uninterrupted supply of lithium for meeting their manufacturing demands. Thus, innovative processes for lithium recovery from a wide range of natural reserves should be explored for meeting the future demands. In this study, a novel integrated approach was investigated by combining nanofiltration (NF), membrane distillation (MD) and precipitation processes for lithium recovery from salt-lake brines.

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Microplastics (MPs) contamination in water environment has recently been documented as an emerging environmental threat due to their negative impact on the ecosystem. Their sources are many, but all of them are from synthetic materials. The sources of MPs are cosmetics and personal care products, breakdown or abrasion processes of other plastic products, textile and tyre, bitumen and road marking paints.

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