UNCONVENTIONAL POLYAROMATICS COMPOUNDS AND MERCURY IN THE TODOS OS SANTOS BAY, BRAZIL: RECENT ADVANCES AND CONTRIBUTIONS TO BETTER UNDERSTAND OF THEIR ROLE IN THE MARINE ENVIRONMENT. Baía de Todos os Santos (BTS) is the second-largest Brazilian bay; it was the first oil producing region in Brazil, with three large industrial parks in its north-northeast portion. In addition, the BTS has two large ports and a population of around 3 million inhabitants distributed among 14 cities. In the present study, recent studies on contamination by polycyclic aromatic compounds (PACs) and Hg in sediments, water, and biota from the BTS region are presented and critically discussed. Among the PACs, studies evaluating the presence of polycyclic aromatic hydrocarbons (PAHs) and their nitrated (nitro-PAHs), oxygenated derivatives (oxy-PAHs), and those containing atoms of S as a heteroatom (PASHs) are considered, as well as the element Hg distributed in seawater, sediments, and biota. Regarding biomonitoring organisms, recent results on polychaetes, ascidians, and corals are presented. Trends for future studies are presented at the end of the text.

Bark of acuri and endocarp of baru are residues generated during the processing of these fruits. One alternative to consider is the pyrolysis of these materials to generate bio-oils, opening the perspective for the production of environment-friendly, added value products. Samples of acuri and baru were subjected to laboratorial scale pyrolysis. At the optimized pyrolysis conditions, the bio-oils yields (m/m) were 30% for bark of acuri and 29% for endocarp of baru. Next, the obtained bio-oil was submitted to proximate analysis and GC×GC-TOF/MS (two-dimensional gas chromatography with time-of-flight mass spectrometric detection). The bio-oil generated from the bark of acuri proved to be of the highest complexity with 113 identified compounds, while the bio-oil generated from the endocarp of baru sample led to 71 identified compounds. A total of 29 compounds were confirmed using standards in the acuri bark bio-oil, while 23 compounds were confirmed for endocarp of baru bio-oil. There was a predominance of phenols and ketones for the bio-oil generated from acuri bark, and hydrocarbons and phenols for the bio-oil from baru endocarp.

The aim of this study was to evaluate the antimicrobial activity of bio-oil (obtained by pyrolysis of biomass: soybean oil, eucalyptus sawdust and coffee grounds) added to the blend B10 (diesel and biodiesel). The bio-oil is compatible to diesel oil and it contains promising compounds that can exhibit antimicrobial activity during fuel storage. We evaluated the antimicrobial activity of bio-oil added to diesel oil B10 by determining the minimum inhibitory concentration at different concentrations (0-10%) using oil-deteriorating microorganisms for 10 days at 30 °C. Bio-oil was separated from the aqueous phase by solid phase extraction using ultrapure water and sodium hydroxide. The aqueous phase containing the solubilized compounds of bio-oil was characterized by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection. Minimum inhibitory concentration in the range of 0.25% to 4% was observed for the tested inocula. The chromatographic analysis of both extracts allowed the identification of several oxygenated compounds, which the majority of the analytes consisted of phenolic compounds, followed by ketones.