Evidências da aplicabilidade dos hidróxidos duplos lamelares como agentes adsorventes em matrizes aquáticas

Abstract

Anthropogenic actions have affected the quality of water resources, causing a great impact on the environment around the world, significantly reducing its availability for consumption. In view of the priority need to remove contaminants and pollutants from aquatic matrices, the development of new technologies for this purpose becomes essential. Some decontamination processes employ solid materials for adsorption, providing low cost associated with high efficiency. The Lamellar Double Hydroxides (HDLs) besides being versatile show promise in adsorption processes. A Scoping Review and a Bibliometric Analysis were carried out in order to obtain a world overview of what has been studied on the applicability of lamellar double hydroxides as adsorbent agents for contaminants/pollutants in effluents. For the Scoping Review, data collection was performed by searching for publications by three independent reviewers on online platforms (a) Web of Science (WoS); (b) Scopus; (c) Science Direct; (d) National Library of Medicine (PubMed), (e) Google Scholar, and (f) Open Grey; through the use of keywords: lamellar double hydroxides, environment, contaminant, pollutant, wastewater and effluents. The inclusion criteria were: open access publications that contribute in a relevant way to the research question. The chronology used was from the date of origin of each platform to the year 2022. Based on the eligibility criteria, 26 studies were selected, from different nationalities, with their publication period comprised between 2005 and 2021, denoting the scientific effort from more than 100 researchers. The predominance of the origin of the studies was registered, as well as the composition of the HDLs used, the contaminants/pollutants or reaction media in which they were used, the synthesis method used and the most relevant considerations of each research. For the Bibliometric Analysis, R bibliometrix and VOSviewer were used, having retrieved 663 documents from 69 countries, with China (328), India (51) and Japan (40) being the most productive. Important journals in the environmental area and with a high impact factor such as Chemical Engineering Journal (44), Applied Clay Science (38), Journal of Hazardous Materials (35) and Chemosphere (27) were the ones that published the most. This work showed the main information that describes HDLs as promising materials and of significant relevance as adsorbents of contaminants and pollutants in aquatic matrices, highlighting the challenges identified for the emergence of new studies on the subject.