Publications by authors named "Ehsan Vahidi"

Rare earth elements (REEs) are pivotal for advanced technologies, driving a surge in global demand. Import dependency on clean energy minerals raises concerns about supply chain vulnerabilities and geopolitical risks. Conventional REEs productionis resource-intensive and environmentally harmful, necessitating a sustainable supply approach.

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Heedless disposal of oil-based fly ash contributes to the contamination of the air, water, and soil. Acid leaching of industrial solid wastes is recognized as a versatile, cost-effective, and environmentally friendly solid waste treatment approach. The present study investigated the viability of conventional leaching (CL) and microwave-assisted leaching (MAL) of predominant heavy metals from Mazut-burnt fly ash.

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This study focuses on connecting graphite demand to battery materials demand, providing a solution to the identified shortage of battery materials and promoting sustainable development. This research used modified Hummer's method to synthesize graphene from the recycled graphite and compared it with graphene synthesized from purified recycled graphite. The purification of recycled graphite was implemented by acid curing-leaching and calcination.

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A novel third-generation biorefinery approach, including two paths of Ethanol/methane production pathway (EMP) and the direct methane production pathway (DMP), for astaxanthin and ethanol and biogas production from the freshwater microalgae Haematococcus pluvialis was developed previously. To ensure its environmental sustainability, a comprehensive life cycle assessment (LCA) study was conducted based on 1-GJ energy generation from biomethane as the functional unit. Results indicate that the EMP pathway had higher environmental impacts on all categories due to more stages and chemicals/energy consumption (at least five times greater effect).

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Despite the strict environmental management regulations, there is still a considerable adverse impact on the ecosystem and human health when it comes to large-scale gold mining operations. Gold mining is an energy-intensive process that can discharge substantial quantities of chemicals combined with gaseous emissions into the environment. Considering gold mining's significant role in Nevada's economy and the growing concern about climate change, it's necessary to investigate the environmental burdens of this sector.

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The fly ash (FA) from the combustion of heavy oil in power stations is characterized by fine particles containing toxic metals. The sample utilized in this study was gathered from the dust precipitators of seven heavy-oil-consuming Iranian power plants. Substantial quantities of heavy metals, particularly vanadium, iron, and nickel, have been detected in the sample, indicating both its potential utility and hazard to the soil and groundwater.

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The development of new generations of electric vehicles is expected to drive the growth of lithium-ion batteries in the global market. Life Cycle Assessment (LCA) method was utilized in this study to evaluate the environmental impacts of various hydrometallurgical processes in critical materials recovery from lithium-ion battery (LIB) cathode powder. The main objective of this work was to fill the knowledge gap regarding the environmental sustainability of various processes in LIB recycling and to generate a comprehensive comparison of the environmental burdens caused by numerous hydrometallurgical methods.

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In recent years, the pavement industry has been seeking sustainable development through recycling reclaimed asphalt pavement and reusing other waste materials as replacements for asphalt mixture constituents. Incorporating waste material into asphalt mixture and the presence of pollutants such as exhaust fumes and gasoline due to vehicle traffic may lead to contaminants leaching from asphalt pavements to underlying soil layers and groundwater aquifers, posing serious risks to ecosystems and the environment. To cast light on contaminant leaching from asphalt pavements, this article presents a comprehensive review of the literature that is divided into four research areas: evaluation of leaching measurement methods, leaching from recycled asphalt materials, leaching characteristics of porous asphalt pavements, and waste-modified asphalt mixtures.

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Concrete is a critical component of deep decarbonization efforts because of both the scale of the industry and because of how its use impacts the building, transportation, and industrial sectors. We use a bottom-up model of current and future building and pavement stocks and construction in the United States to contextualize the role of concrete in greenhouse gas (GHG) reductions strategies under projected and ambitious scenarios, including embodied and use phases of the structures' life cycle. We show that projected improvements in the building sector result in a reduction of 49% of GHG emissions in 2050 relative to 2016 levels, whereas ambitious improvements result in a 57% reduction in 2050, which is 22.

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Over the past decade, Rare Earth Elements (REEs) have gained special interests due to their significance in many industrial applications, especially those related to clean energy. While REEs production is known to cause damage to the ecosystem, only a handful of Life Cycle Assessment (LCA) investigations have been conducted in recent years, mainly due to lack of data and information. This is especially true for the solvent extraction separation of REEs from aqueous solution which is a challenging step in the REEs production route.

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An environmentally-friendly route based on hydrometallurgy was investigated for the recovery of cobalt and lithium from spent lithium ion batteries (LIBs) using different organic acids (citric acid, Dl-malic acid, oxalic acid and acetic acid). In this investigation, response surface methodology (RSM) was utilized to optimize leaching parameters including solid to liquid ratio (S/L), temperature, acid concentration, type of organic acid and hydrogen peroxide concentration. Based on the results obtained from optimizing procedure, temperature was recognized as the most influential parameter.

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Leaching was performed to recover zinc from a zinc leach residue which contained 9.87% Zn and 4.93% Fe.

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