Heavy metals (HMs) are indestructible and non-biodegradable. Phytoremediation presents an opportunity to transfer HMs from environmental matrices into plants, making it easy to translocate from one place to another. The ornate features of HMs' phytoremediation are biophilia and carbon neutrality, compared to the physical and chemical remediation methods. Some recent studies related to LCA also support that phytoremediation is technically more sustainable than competing technologies. However, one major post-application challenge associated with HMs phytoremediation is properly managing HMs contaminated biomass generated. Such a yield presents the problem of reintroducing HMs into the environment due to natural decomposition and release of plant sap from the harvested biomass. The transportation of high yields can also make phytoremediation economically inviable. This review presents the design of a sustainable phytoremediation strategy using an ever-evolving life cycle assessment tool. This review also discusses possible post-phytoremediation biomass management strategies for the HMs contaminated biomass management. These strategies include composting, leachate compaction, gasification, pyrolysis, torrefaction, and metal recovery. Further, the commercial outlook for properly utilizing HMs contaminated biomass was presented.

The employment of used vegetable oils (UVOs) as raw materials in key sectors as energy production or bio-lubricant synthesis represents one of the most relevant priorities in the European Union (EU) normative context. In many countries, the development of new production processes based on the circular economy model, as well as the definition of future energy and production targets, involve the utilization of wastes as raw material. In this context, the main currently applied EU regulations are presented and discussed. As in the EU, the general legislative process consists of the definition in each State Member of specific legislation, which transposes the EU indications. Two relevant countries are herein considered: Italy and Spain. Through the analysis of the conditions required in both countries for UVOs’ collection, disposal, storage, and recycling, a wide panorama of the current situation is provided.

Environmental awareness and the necessary reduction in costs in industrial processes has facilitated the development of novel techniques such as Additive Manufacturing, decreasing the amount of raw materials and energy needed. The longing for improved materials with different and enhanced properties has resulted in research efforts in the Metal Matrix Composites field. These two novelties combined minimise environmental impacts and costs without compromising technical properties. Two technologies can feed Additive Manufacturing techniques with metallic powder: Gas Atomization and High Energy Ball Milling. This study provides a comparative Life Cycle Assessment of these technologies to produce one kilogram of metallic powder for the Directed Energy Deposition technique: a Ti6Al4V alloy, and a Ti6Al4V-TiC Metal–Matrix Composite, respectively. The LCA methodology is according to ISO 14040:2006, and large amounts of information on the use of raw materials, energy consumption, and environmental impacts is provided. Different impact categories following the Environmental Footprint methodology were analysed, showing a big difference between both technologies, with an 87.8% reduction of kg CO₂ eq. emitted by High Energy Ball Milling in comparison with Gas Atomization. In addition, an economic analysis was performed, addressing the viability perspective and decision making and showing a 17.2% cost reduction in the conventional process.

Lithium silicates have attracted great attention in recent years due to their potential use as high-temperature (450–700 °C) sorbents for CO₂ capture.

Carbon nanotubes (CNTs) have attracted the attention of academy and industry due to their potential applications, being currently produced and commercialized at a mass scale, but their possible impact on different biological systems remains unclear. In the present work, an assessment to understand the toxicity of commercial pristine multi-walled carbon nanotubes (MWCNTs) on the unicellular fungal model Saccharomyces cerevisiae is presented. Firstly, the nanomaterial was physico-chemically characterized, to obtain insights concerning its morphological features and elemental composition. Afterwards, a toxicology assessment was carried out, where it could be observed that cell proliferation was negatively affected only in the presence of 800 mg L⁻¹ for 24 h, while oxidative stress was induced at a lower concentration (160 mg L⁻¹) after a short exposure period (2 h). Finally, to identify possible toxicity pathways induced by the selected MWCNTs, the transcriptome of S. cerevisiae exposed to 160 and 800 mg L⁻¹, for two hours, was studied. In contrast to a previous study, reporting massive transcriptional changes when yeast cells were exposed to graphene nanoplatelets in the same exposure conditions, only a small number of genes (130) showed significant transcriptional changes in the presence of MWCNTs, in the higher concentration tested (800 mg L⁻¹), and most of them were found to be downregulated, indicating a limited biological response of the yeast cells exposed to the selected pristine commercial CNTs.