Mecanismos de absorção e adsorção de biofiltros para biorremediação de ambientes aquáticos contaminados com SARS-CoV-2 e metais pesados.

Abstract

Aquatic environments are commonly affected by several anthropogenic activities, including the release of untreated domestic and industrial effluents, agricultural and mining activities. Among the contaminants, heavy metals are of great concern due to its toxicity and bioaccumulation property, directly affecting the environmental quality and population health. Among the alternatives for removing heavy metals, the use of plants as decontamination agents stands out, and aquatic macrophytes have been studied due to their natural ability to remove contaminants. Firstly, a comparison was made among the natural potential for removal of heavy metals by the macrophyte species E. anagallis, H. ranunculoides, H. grumosa, and S. montevidensis in a highly anthropized area in the municipality of Pelotas/RS. Among them, it was verified through the phytoremediation indices that H. ranunculoides was highlighted by the bioconcentration factor (BCF). Thus, the species H. ranunculoides was selected to the study to evaluate the mechanisms of resistance to Chromium(VI), in an exposure period of 7 days and with the evaluation of growth parameters, photosynthetic pigments, lipid peroxidation via TBARS assay, total phenolic compounds, antioxidant enzymes, FT-IR, chromium and nutrient contents, phytoremediation indices, surface and cytological observations, along with TGA analysis. It was found that the plant species demonstrated restoration of photosynthetic pigments, alteration in functional groups and in epidermal cells, along with increased concentrations of Cr(VI). In the initial comparison between species, it was also verified that H. grumosa and S. montevidensis stood out for their phytoremoval potential (g ha-1). Thus, the H. grumosa species was selected for the study to remove SARS-CoV-2, the virus that caused the COVID-19 pandemic, which had serious consequences for the world's population health, been responsible for more than 6.6 million of deaths. Coping with the pandemic demanded the development of different researches, and this work is among them, aiming to develop an adsorbent material to remove SARS-CoV-2 from wastewater. For this, the species H. grumosa was used in natura form and in the form of activated carbon for the adsorption of SARS-CoV-2. As results found, it is highlighted the excellent removal potential found: 98.44% by H. grumosa in natura, and 99.61% by activated carbon produced with H. grumosa. Considering the results found, an initial proposal of floating biofilter devices was made aiming to apply the species H. ranunculoides and H. grumosa in the decontamination of chromium and SARS-CoV-2, respectively.