Comprehensive Review on Metallurgical Upgradation Processes of Nickel Sulfide Ores

Revolutionizing soil heavy metal remediation: Cutting-edge innovations in plant disposal technology

Soil contamination with heavy metals has emerged as a global environmental threat, compromising agricultural productivity, ecosystem integrity, and human health. Conventional remediation techniques often fall short due to high costs, operational complexities, and environmental drawbacks. Plant-based disposal technologies, including biochar, phytometallurgy, and phrolysis, have emerged as promising solutions in this regard. Grounded in a novel experimental framework, biochar is studied for its dual role as soil amendment and metal adsorbent, while phytometallurgy is explored for its potential in resource recovery and economic benefits derived from harvested metal-rich plant biomass. Pyrolysis, in turn, is assessed for transforming contaminated biomass into value-added products, thereby minimizing waste. These plant disposal technologies create a circular model of remediation and resource utilization that holds the potential for application in large-scale soil recovery projects, development of environmentally friendly agro-industries, and advancement in sustainable waste management practices. This review mainly discussed cutting-edge plant disposal technologies-biochar application, phytometallurgy, and pyrolysis-as revolutionary approaches to soil heavy metal remediation. The efficacy, cost-effectiveness, and environmental impact of these innovative technologies are especially evaluated in comparison with traditional methods. The success of these applications could signal a paradigm shift in how we approach both environmental remediation and resource recovery, with profound implications for sustainable development and circular economy strategies.

Driving sustainable circular economy in electronics: A comprehensive review on environmental life cycle assessment of e-waste recycling

E-waste, encompassing discarded materials from outdated electronic equipment, often ends up intermixed with municipal solid waste, leading to improper disposal through burial and incineration. This improper handling releases hazardous substances into water, soil, and air, posing significant risks to ecosystems and human health, ultimately entering the food chain and water supply. Formal e-waste recycling, guided by circular economy models and zero-discharge principles, offers potential solutions to this critical challenge. However, implementing a circular economy for e-waste management due to chemical and energy consumption may cause environmental impacts. Consequently, advanced sustainability assessment tools, such as Life Cycle Assessment (LCA), have been applied to investigate e-waste management strategies. While LCA is a standardized methodology, researchers have employed various routes for environmental assessment of different e-waste management methods. However, to the authors' knowledge, there lacks a comprehensive study focusing on LCA studies to discern the opportunities and limitations of this method in formal e-waste management strategies. Hence, this review aims to survey the existing literature on the LCA of e-waste management under a circular economy, shedding light on the current state of research, identifying research gaps, and proposing future research directions. It first explains various methods of managing e-waste in the circular economy. This review then evaluates and scrutinizes the LCA approach in implementing the circular bioeconomy for e-waste management. Finally, it proposes frameworks and procedures to enhance the applicability of the LCA method to future e-waste management research. The literature on the LCA of e-waste management reveals a wide variation in implementing LCA in formal e-waste management, resulting in diverse results and findings in this field. This paper underscores that LCA can pinpoint the environmental hotspots for various pathways of formal e-waste recycling, particularly focusing on metals. It can help address these concerns and achieve greater sustainability in e-waste recycling, especially in pyrometallurgical and hydrometallurgical pathways. The recovery of high-value metals is more environmentally justified compared to other metals. However, biometallurgical pathways remain limited in terms of environmental studies. Despite the potential for recycling e-waste into plastic or glass, there is a dearth of robust background in LCA studies within this sector. This review concludes that LCA can offer valuable insights for decision-making and policy processes on e-waste management, promoting environmentally sound e-waste recycling practices. However, the accuracy of LCA results in e-waste recycling, owing to data requirements, subjectivity, impact category weighting, and other factors, remains debatable, emphasizing the need for more uncertainty analysis in this field.