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The metallurgical sector is one of the most emission- and energy-intensive industries. The possibility of using fossil carbon substitutes has been investigated to reduce the environmental impact of the steelmaking sector. Among others, biochar emerged as a promising fossil coal/coke substitute. We conducted a literature review on biochar use in the metallurgical sector and its potential environmental benefits. The possibility for biochar as a coal/coke substitute is influenced by the source of biochar production and the process within which it can be used. In general, it has been observed that substitution of biochar ranging from a minimum of 5% to a maximum of 50% (mostly around 20–25%) is possible without affecting, or in some cases improving, the process, in coke making, iron sintering, blast furnaces and electric furnaces application. In some studies, the potential CO2 reduction due to biochar use was estimated, ranging from 5% to about 50%. Despite there still being an area of further investigation, biochar appeared as a promising resource with a variety of uses in the metallurgical sector, contributing to the lowering of the environmental impact of the sector. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) constitute a group of organofluorine chemical synthetic compounds widely used in industries and manufacturing due to their hydrophobic properties. However, PFAS have been found to cause negative human health outcomes. Therefore, a strong interest in the possible removal of these compounds from wastewater (WW) has been shown. This work aims to present a systematic analysis of the scientific literature related to the innovative and alternative adsorbent materials that can be used for treating PFAS-contaminated WW. Moreover, the adsorption processes are considered, focusing the attention on virgin adsorbent materials and biochar as adsorbents. Virgin adsorbent materials comprise conventional adsorbent materials, functional clays, metal–organic frameworks, and functionalized organic polymers. Biochar includes materials obtained from agricultural or food residues and from sewage sludge. The review shows that conventional treatment units using virgin adsorbent materials are characterized by high adsorption capacity, but also high costs. In addition, the refunctionalization of adsorbent materials is difficult to obtain. On the contrary, biochar, which is a residual product of other production processes, appears to be a cost-effective solution. [ABSTRACT FROM AUTHOR]