The pH-dependent adsorption of tributyltin to charcoals and soot.
Widespread use of tributyltin (TBT) poses a serious environmental problem. Adsorption by black carbon (BC) may strongly affect its behavior. The adsorption of TBT to well characterized soot and two charcoals with specific surface area in the range of 62-111m(2)g(-1) have been investigated with main focus on pH effects. The charcoals but not soot possess acidic functional groups. TBT adsorption reaches maximum at pH 6-7 for charcoals, and at pH>6 for soot. Soot has between 1.5 and 15 times higher adsorption density (0.09-1.77μmolm(-2)) than charcoals, but charcoals show up to 17 times higher sorption affinities than soot. TBT adsorption is successfully described by a new pH-dependent dual Langmuir model considering electrostatic and hydrophobic adsorption, and pH effects on TBT speciation and BC surface charge. It is inferred that strong sorption of the TBTOH species to BC may affect TBT toxicity.
Fang
Liping
L
Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark. fang@life.ku.dk
Borggaard
Ole K
OK
Marcussen
Helle
H
Holm
Peter E
PE
Bruun Hansen
Hans Christian
HC
D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D019015:Geologic Sediments; D006863:Hydrogen-Ion Concentration; D015233:Models, Statistical; D053260:Soot / Q000737:chemistry*; D014220:Trialkyltin Compounds / Q000737:chemistry*
D053260:Soot; D014220:Trialkyltin Compounds; D002606:Charcoal; C011559:tributyltin