Aniline and 2,4,6-trinitrotoluene associate preferentially to low molecular weight fractions of dissolved soil organic matter.
Aniline and 2,4,6-trinitrotoluene (TNT) were equilibrated with particulate (POM) and dissolved organic matter (DOM) from an organic soil at different compositions of adsorbed major cations (Na, Al) and pH (aniline: 3.7-5.1, TNT: 4.8-5.0). After separation of POM, concentrations of (14)C-labelled aniline and TNT* (including TNT degradation products) were determined in DOM size fractions using size-exclusion chromatography (SEC) and UV-detection. Concentrations in the <3.5 kDa size fraction were 2.8-6.0 and 8.5-9.5 times higher for aniline and TNT*, respectively, as compared to the >40 kDa fraction. Thus, both aniline and TNT* were preferentially associated to the smallest DOM size fraction. The significant binding to DOM (similar extent as to POM) and the fact that the <3.5 kDa DOM fraction was less susceptible to flocculation by major metals suggests that the mobility of aniline and TNT is highly affected by the solubility of soil organic matter.
Eriksson
Johan
J
Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
Skyllberg
Ulf
U
D000327:Adsorption; D000814:Aniline Compounds / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis*; D008970:Molecular Weight; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*; D014303:Trinitrotoluene / Q000737:chemistry*
D000814:Aniline Compounds; D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D014303:Trinitrotoluene; C023650:aniline