Avaliação Do Uso De Biomassa Bacteriana Imobilizada Na Biossorção De Terras-Raras Leves E Médias

Abstract

A busca por fontes alternativas de recuperação e separação dos elementos puros de terras--raras (TRs) é vista como uma ação prioritária e estratégica por diversos países demandantes desses elementos. Em alternativa aos processos clássicos de extração de TRs, o processo de biossorção vem sendo avaliado, em uma combinação da biotecnologia e metalurgia extrativa. Sendo assim, o presente trabalho buscou avaliar a capacidade da biomassa imobilizada da bactéria Bacillussubtilis na biossorção de lantânio (TR leve) e samário (TR médio), visando seu uso na separação desses elementos. As maiores porcentagens de biossorção de lantânio (La) e samário (Sm) em sistemas mono--elementares corresponderam à 94,4% e 94,9%, respectivamente, a partir de concentrações iguais (C i ) à 15 mg/L. Em soluções com C i = 100 mg/L, 89,3% de La e 91,9% de Sm foram biossorvidos. O mesmo comportamento pode ser observado para a solução bi--elementar La+Sm, onde 79,9% de La e 88,8% de Sm foram biossorvidos em soluções com C i = 15 mg/L, e, 69,4% de La e 83,4% de Sm foram biossorvidos em C i =100 mg/L. A aplicação dos dados obtidos aos modelos de adsorção de Langmuir e Freundlich demonstrou que as isotermas de adsorção obtidas para La e Sm em ambos os sistemas avaliados foram satisfatórias para ambos os modelos, sugerindo a ocorrência da biossorção em monocamada assim como condições heterogêneas na superfície, onde ambas condições podem co--existir sob as condições experimentais testadas. PALAVRAS--CHAVE:Bacillussubtilis, imobilização celular, alginato de cálcio, biossorção, terras--raras EVALUATION OF THE USE OF BACTERIAL IMMOBILIZED BIOMASS IN LIGHT AND MEDIUM RARE--EARTH ELEMENTS BIOSORPTION ABSTRACTThe search for alternative sources of recovery and separation of pure rare earth elements (REE) is a priority and strategic action by several countries demanding these elements. As an alternative to classical processes of extraction of REE, the biosorption process has been evaluated in a combination between biotechnology and extractive metallurgy. Therefore, the present work aimed to evaluate the capacity of immobilized biomass of Bacillus subtilis to the biosorption of lanthanum (light REE) and samarium (medium REE), aiming its use in the separation of these elements. The highest percentages of lanthanum (La) and samarium (Sm) biosorption in single--element systems corresponded to 94.4% and 94.9%, respectively, from an initial concentration ( i C) of 15 mg/L. In solutions with i C= 100 mg/L, 89.3% of La and 91.9% of Sm were biosorbed. The same behavior can be observed for the bi--elemental solution La + Sm, where 79.9% of La and 88.8% of Sm were biosorbed in solutions of i C= 15 mg/L, and 69.4% of La and 83.4% of Sm were biosorbed in i C= 100 mg/L. The application of the data obtained to the adsorption models of Langmuir and Freundlich showed that the adsorption isotherms obtained for La and Sm in both systems were satisfactory for both models, suggesting the occurrence of monolayer biosorption as well as heterogeneous surface conditions, where bot...

Mining Applications of Immobilized Microbial Cells in an Alginate Matrix: An Overview

“…Predicting the possibility of increasing the concentration of lanthanides in effluents have been carried out using microbial cells immobilized on Ca 2+ alginate for rare earth biosorption processes. Ca 2+ alginate immobilized biomass of Bacillus subtilis was applied for La and Sm biosorption studies with high percentual of rare earth removal, 94.4 and 94.9 %, respectively (Coimbra et al 2017). The kinetic study of La biosorption, in concentrations ranging 10-100 mg/L, showed that Ca 2+ alginate microalgal immobilized biosorbents formed by Ankistrodesmus sp.…”

“…For example, the use of immobilized cells in bioleaching (Martínez and Parada 2013), heavy metals Khare 2012, Mishra 2013), mercury and rare-earth elements biosorption (Coimbra et al 2017, Corrêa et al 2017, Coimbra et al 2019, acid mine drainage (Long et al 2004), bioremediation (Zommere and Nikolajeva 2017), and H 2 S removal (Chung et al 2010) have all been examined. However, most of these investigations were perfomed at laboratorial level, and applications of immobilized cells in mining activities in the open environment and industrial scale have yet to be realized.…”

Desafios Para a Extração Sustentável De Minérios Portadores De Terras Raras

“…4.1 Interações entre micro-organismos e minerais Na última década, vários estudos têm sido publicados abordando as interações entre micro-organismos e minerais portadores de TRs, incluindo a solubilização de TRs a partir de matrizes sólidas por meio de reações com metabólitos microbianos (Zhang et al, 2018) e a imobilização de TRs de matrizes líquidas, principalmente por sorção por biomassa (Coimbra, Nascimento & Giese, 2017;Heidelmann et al, 2017;Coimbra et al, 2019;Giese, Barbosa-Dekker & Dekker, 2019;Giese & Jordão, 2019).…”

An exploratory study of recovery of rare-earth elements from monazite in mild conditions using statistical-mixture design

“…According to Kim & Osseo-Asare [6], monazite undergoes physical processing first, followed by chemical processing, which can occur through acid treatment using sulfuric acid. The sulfate (SO4 2-) ion of sulfuric acid can act as a ligand which reacts with REE as follows [7]: 2REEPO4(s) + 3H2SO4 = (REE)2(SO4)3(s) + 6H + + 2PO4 -3 In the last decade, several studies have been published addressing the interactions between microorganisms and minerals carrying REE, including the solubilization of REE from definite matrices through reactions with microbial metabolites [8] and immobilization of REE of liquid matrices, mainly by sorption by biomass [9][10][11][12][13].…”