Mercury in the Southwestern Atlantic reef-building coral Montastraea cavernosa (Cnidaria, Scleractinia).

Coastal ecosystems, such as coral reefs, are particularly vulnerable to mercury contamination due to direct contact with terrestrial sources. Here, we evaluated, for the first time, the concentration of mercury in coral reefs in the Southwestern Atlantic using the amphi-atlantic scleractinian coral Montastraea cavernosa. Sampling was realized over an extension of 200 km along different coral reefs. Our data show mercury values ranging from 0.01 to 0.27 mg kg-1 in the tissue and 0.001-0.06 mg kg-1 in the skeleton and higher values when compared to coral worldwide. The concentration of mercury in the tissue from Todos os Santos Bay was higher than in open sea regions but also higher compared to other coral reefs of the world, while the skeleton concentration did not indicate any differences when compared to the open sea regions. The data presented is of concern as we consider the importance of coral reefs and should be used in future environmental management planning.

Experimental study, simulation and technical-economic feasibility of an interesterification plant for hydrocarbons synthesis by using plastics and frying oil waste.

This work presents the experimental assessment of a 20 mL batch reactor's efficacy in converting plastic and oil residues into biofuels. The reactor, designed for ease of use, is heated using a metallic system. The experiments explore plastic solubilization at various temperatures and residence times, employing a mixture of distilled water and ethylene glycol as the solvent. Initial findings reveal that plastic solubilization requires a temperature of 350 °C with an ethylene glycol mole fraction of 0.35, whereas 250 °C suffices with a mole fraction of 0.58. Additionally, the study includes a process simulation of a plant utilizing a double fluidized bed gasifier and an economic evaluation of the interesterification/pyrolysis plant. Simulation results support project feasibility, estimating a total investment cost of approximately $12.99 million and annual operating expenses of around $17.98 million, with a projected payback period of about 5 years.