Possible destination for sewage sludge sustainable disposal is its transformation in biochar, achieved by post-processing of the sludge itself through pyrolysis. Biochar from sludge is considered one of the most interesting final products in wastewater-based circular economy, as proven by the multitude of its possible uses tested so far in different areas. Recently, combined activated sludge (AS)-microalgae systems have been proposed to simultaneously remove both carbon and nutrients from wastewaters, as alternative to conventional technologies such as those based on AS. Such innovation could be efficient from the point of view of removal of regulated components from effluents, but it adds potential issues to solid residue disposal practices, as algae normally respond poorly to traditional, mechanical drying processes. In this study, a disposal solution was investigated, consisting of pyrolysation of a mixed sludge/bioalgae matrix under different conditions: in such way, not only landfilled residuals are practically eliminated, but a material with multiple possible beneficial end uses is generated. Initial materials (algae, sludge and 2 combinations thereof) and end-products (biochar and bio-oil) were physically and chemically characterized after pyrolysis under different conditions. Algae alone were also subject to preliminary solvent oil extraction to assess whether increased biochar production would result from this process modification (which did, increasing biochar production by 25-33%). A comprehensive discussion on properties of end products as function of process design, possible applications in a circular economy cycle, and advantages of co-pyrolysis follows.

Two hundred and sixty seven workers employed in the manufacture of silicon carbide (SiC) were examined to determine the effects of exposure to contaminants (SiC, quartz, and SO2) in the workplace on pulmonary function. No exposure concentrations exceeded the current permissible limits. Ten

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