(cest2017_01032) Evaluation of ecotoxicity of carbon nanomaterials with polyoxometalates

摘要

research has shown the potential ofnanomaterials in the environmental field, because theirhigh specific surface area provides improved efficiency toseveral processes. Although their application in soilremediation and water treatment seems promising,information about their possible toxic effects in the aquaticecosystems is still sparse. The toxicity of threepolyoxometalates ([PMo12O40]3-(PMo12), [PMo11VO40]4-(PMo11V),[PMo10V2O40]5-(PMo10V2)), graphene flakes (GF)and the three polyoxometalates immobilized on GF(PMo12@GF, PMo11V@GF, PMo10V2@GF), which weredeveloped to be used as catalysts on photo-oxidationprocesses, was evaluated towards the algaPseudokirchnerielasubcapittata, a recommended speciesfor ecotoxicity tests. The experimental evaluation wascarried out according to the inhibition test for algae (ECRegulation 440/2008, which was based on the OCDEGuideline 201). This is based on determining the effect ingrowth inhibitionof the algae culture (P. subcapitata)exposed to the nanomaterial according to the exposureconcentration of material, compared with a control culture.Determination of in vivo chlorophyll content byfluorescence, which is a fast and sensitive method, wasused to estimate cell density. The most toxic material wasthe one with higher content of vanadium (PMo10V2@GF),for which 6.5 mg/L is the effective concentration thatcauses inhibition to 50% of the alga population.