resumo
Ionic liquids (ILs) are often claimed to be "environmentally friendly" compounds however, the knowledge of their potential toxicity towards different organisms and trophic levels is still limited, in particular when protic ionic liquids (PILs) are addressed. This study aims to evaluate the toxicity against various microorganisms and the biodegradability of four PILs namely, N-methyl-2-hydroxyethylammonium acetate, m-2-HEAA; N-methyl-2-hydroxyethylammonium propionate, m-2-HEAPr; N-methyl-2-hydroxyethylammonium butyrate, m-2-HEAB; and N-methyl-2-hydroxyethylammonium pentanoate, m-2-HEAP. The antimicrobial activity was determined against the two bacteria, Sthaplylococcus aureus ATCC-6533 and Escherichia coli CCT-0355; the yeast Candida albicans ATCC-76645; and the fungi Fusarium sp. LM03. The toxicity of all PILs was tested against the aquatic luminescent marine bacterium Vibrio fischeri using the Microtox (R) test. The impact of the PILs was also studied regarding their effect on lettuce seeds (Lactuta sativa). The biodegradability of these PILs was evaluated using the ratio between the biochemical oxygen demand (BOD) and the chemical oxygen demand (COD). The results show that, in general, the elongation of the alkyl chain tends to increase the negative impact of the PILs towards the organisms and biological systems under study. According to these results, m-2-HEM and m-2-HEAP are the less and most toxic PILs studied in this work, respectively. Additionally, all the PILs have demonstrated low biodegradability. (C) 2016 Published by Elsevier Ltd.
palavras-chave
FISCHERI MARINE-BACTERIA; ANTIMICROBIAL ACTIVITIES; PHYSICOCHEMICAL PROPERTIES; TERRESTRIAL ECOTOXICITY; PHASE-BEHAVIOR; ALLIUM-CEPA; IMIDAZOLIUM; TOXICITY; ANION; PYRIDINIUM
categoria
Environmental Sciences & Ecology
autores
Oliveira, MVS; Vidal, BT; Melo, CM; de Miranda, RDM; Soares, CMP; Coutinho, JAP; Ventura, SPM; Mattedi, S; Lima, AS
nossos autores
Sónia Patrícia Marques Ventura
Professor Auxiliaragradecimentos
This work was developed in the scope of the project ITP - Institut of Technology and Research, financed by CNPq (Process number 404651/2013-5); CICECO-Aveiro Institute of Materials, financed by national funds through the FCT/MEC (Ref. FCT UID/CTM/50011/2013) and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. The authors are grateful for the financial support from PIBIC-FAPITEC for the grant of Rafael L. F. de Barros. The authors also thank the financial support from Fundacao para a Ciencia e a Tecnologia (FCT) under the project PTDC/AAC-AMB/119172/2010. The authors are also grateful for the financial support of FCT by the post-doctoral grant SFRH/BPD/79263/2011 of S.P.M. Ventura and CAPES of post-doctoral fellowship of R.C.M. Miranda.