resumo
Anthropogenic impacts have affected the coastal environment and contributed to its contamination. Mercury (Hg) is widespread in nature and has been shown to be toxic in even the smallest amounts, negatively affecting not only the marine ecosystem but also the entire trophic chain due to its biomagnification. Mercury ranks third on the Agency for Toxic Substances and Diseases Registry (ATSDR) priority list and it is therefore imperative to develop more effective methods than those currently available to avoid the persistence of this contaminant in aquatic ecosystems. The present study aimed to evaluate the effectiveness of six different silica-supported ionic liquids (SIL) in removing Hg from contaminated saline water, under realistic conditions ([Hg] = 50 & mu;g/L), and to ecotoxicologically evaluate the safety of the SIL-remedied water, using as test model the marine macroalga Ulva lactuca. The results revealed that SIL [Si][C3C1im][SCN] (250 mg/L) was the most effective in removing Hg from solution, with a efficiency up to 99 % in just 6 h, that enable to obtain < 1 & mu;g/L Hg (European guideline in drinking water). U. lactuca exposed to either the SIL and/or the remedied water showed no significant changes in relative growth rate and chlorophyll a and b levels, compared to the control condition. Biomarker analysis (LPO, GSH, GSSG, SOD, GPx, CAT and GRed) also showed no significant changes in the biochemical performance of U. lactuca. Therefore, it could be assumed that water treatment with SIL or its presence in an aqueous environment does not pose toxicity levels that could inhibit the metabolism or cause cell damage to U. lactuca.
palavras-chave
INDUCED OXIDATIVE STRESS; SCENEDESMUS-OBLIQUUS; GROWTH-INHIBITION; ULVA-PERTUSA; HEAVY-METALS; BIOACCUMULATION; GLUTATHIONE; RESPONSES; LACTUCA; ALGAE
categoria
Marine & Freshwater Biology; Toxicology
autores
Viana, T; Almeida, R; Figueira, P; Rocha, L; Neves, MC; Freitas, R; Freire, M; Henriques, B; Pereira, E
nossos autores
agradecimentos
Bruno Henriques and Marcia C. Neves thanks FCT (Fundacao para a Ciencia e Tecnologia) for funding through the Scientific Employment (Ref. CEECIND/03511/2018 and CEECIND/00383/2017 respectively), while Thainara Viana and Paula Figueira acknowledge FCT/MCTES (Fundacao para a Ciencia e Tecnologia and Ministerio da Ciencia, Tecnologia e Ensino Superior) and ESF (European Social Fund) through CENTRO 2020 (Programa Operacional Regiao Centro) for their PhD grant ref. 2022.13015.BD and SFRH/BD/139077/2018, respectively