Aplicação de grafeno e nanocompósitos de grafeno na remoção de compostos orgânicos aromáticos de matriz aquosa: uma revisão

Abstract

Aromatic organic pollutants are potentially toxic to the human and environmental health and are considered as priority pollutants by regulatory agencies. Significant quantities of these pollutants are directly discharged into the water bodies through industrial activities and spills, among others. Managing areas contaminated with these organic pollutants is one of the major environmental challenges today and the investigations have increased with the target of developing new environmental treatment technologies. Of all technologies that have been proposed to remove these pollutants from water, adsorption is recognized worldwide as an attractive option due to its versatility, wide applicability and economic viability. Graphene, a carbon-based nanomaterial, has been considered a strategic material and the use of graphene as adsorbent has shown excellent results in the removal of organic compounds from aqueous solutions. The present review based on systematic approach has shown that graphene structures are a promising alternative to traditional adsorbent materials, due to their unique structural characteristics and great adsorption capacity for organic compounds. However, the research in this area is still in its initial stage, since the number of publications to date was found to be small, demonstrating there is a long way to go before effective practical applications become a reality. The review was carried out with focus on the use of nanoadsorbent graphene (GFNA) to treat water and wastewaters contaminated with aromatic organic compounds. After applying a set of eligibility criteria, 19 publications were selected for detailed analysis and organized in a so-called revision table. Through analysis of the review table, it was concluded that the studies did not follow the same experimental conditions, which made difficult to compare and establish correlations between them. It was also verified that the performance of the graphene structures, as well as the activated carbon, depend on the experimental conditions, as well as the structural characteristics of the adsorbent itself. The review showed that graphene structures represent a promising alternative to other traditional adsorbent materials, since they are easy to manipulate, have unique structural characteristics and great capacity to adsorb organic compounds. However, efforts should be directed to the development of methods of producing graphene in scale and with higher structural quality. Additional investigations are required for better evaluation of the mechanisms involved in the adsorption, the influence of the characteristics of the adsorption aqueous medium, adsorbent and the adsorbate characteristics.