000168725 001__ 168725
000168725 005__ 20181203022440.0
000168725 0247_ $$2doi$$a10.1021/es104288y
000168725 02470 $$2ISI$$a000289341300038
000168725 037__ $$aARTICLE
000168725 245__ $$aEffect of Humic Substance Photoalteration on Lead Bioavailability to Freshwater Microalgae
000168725 260__ $$c2011
000168725 269__ $$a2011
000168725 336__ $$aJournal Articles
000168725 520__ $$aThe present study provides results on the influence of humic substance (HS) photoalteration on lead availability to the freshwater microalga Chlorella kesslerii. The evolution of the free lead-ion concentrations measured by the ion exchange technique [Pb](IET) and intracellular lead contents was explored in the presence of Suwannee River humic: (SRHA) and fulvic (SRFA) acids, as well as Aldrich humic acid (AHA) exposed at increasing radiance doses under a solar simulator. Modifications of HS characteristics highly relevant to Pb complexation and accumulation of HS to algal surfaces, including Fourier transform infrared spectroscopy, were followed. It was demonstrated that simulated sunlight exposure of HS increased [Pb](IET), in the medium for SRFA and SRHA, but had no effect for AHA. No clear relationship was observed between the changes in free lead-ion concentrations and intracellular content in alga for all studied HS, suggesting that HS photodegradation products also exhibit Pb complexation properties, and that direct interactions between HS and alga are affected. Indeed, photoalteration of humic substances reduced the adsorption of HS to the algal surface; the effect was more pronounced for SRFA and AHA and less significant for SRHA. The bioavailability results were consistent with the characterization of the phototransformation of humic substances: Pb speciation changes followed the modification of the relative abundance of the carboxylic groups and their molecular environment, while the reduced HS adsorption to the alga correlated with losses of the double bond abundance and aromaticity.
000168725 6531_ $$aDissolved Organic-Matter
000168725 6531_ $$aBiotic Ligand Model
000168725 6531_ $$aFulvic-Acid
000168725 6531_ $$aUv-B
000168725 6531_ $$aMetal Bioavailability
000168725 6531_ $$aChlorella-Kesslerii
000168725 6531_ $$aSuwannee River
000168725 6531_ $$aCarbon
000168725 6531_ $$aFluorescence
000168725 6531_ $$aSpeciation
000168725 700__ $$aSpierings, Julian
000168725 700__ $$aWorms, Isabelle A. M.
000168725 700__ $$aMieville, Pascal
000168725 700__ $$0240061$$aSlaveykova, Vera$$g165826
000168725 773__ $$j45$$q3452-3458$$tEnvironmental Science & Technology
000168725 909C0 $$0252030$$pGR-SLV$$xU11826
000168725 909CO $$ooai:infoscience.tind.io:168725$$particle
000168725 917Z8 $$x173008
000168725 937__ $$aEPFL-ARTICLE-168725
000168725 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000168725 980__ $$aARTICLE