TY - JOUR
T1 - Trace metal distribution in soluble organic matter from municipal solid waste compost determined by size-exclusion chromatography
AU - Kaschl, Arno
AU - Römheld, Volker
AU - Chen, Yona
PY - 2002/9
Y1 - 2002/9
N2 - Municipal solid waste (MSW) composts carry high amounts of trace metals and organic complexing agents that may influence metal bioavailability and mobility after application to soils. In order to assess the degree of organic complexation of trace metals in the solution phase of MSW compost and the relevance of organic ligand type, size exclusion chromatography (SEC) was applied to compost-extracted organic ligands. Adjustment of the elution conditions minimized the interaction with the gel matrix for compost humic substances and dissolved organic matter (DOM) fractions. The SEC was then used to separate the aqueous compost extract into samples with distinct differences in chemical constituents. The highest quantities of Cu, Zn, Ni, Mn, and Cd were found to coelute with the main peak of the SEC elution curve, which, as observed by Fourier-transformed infrared (FTIR) spectroscopy, also had the highest density of carboxyl groups. The ratio of aromatic to aliphatic structures was higher for eluates with low retention times, and cations such as Al, Cr, and Fe were preferably associated with these larger organic molecules. All trace metals in the compost solution phase were bound mostly to DOM rather than forming inorganic complexes.
AB - Municipal solid waste (MSW) composts carry high amounts of trace metals and organic complexing agents that may influence metal bioavailability and mobility after application to soils. In order to assess the degree of organic complexation of trace metals in the solution phase of MSW compost and the relevance of organic ligand type, size exclusion chromatography (SEC) was applied to compost-extracted organic ligands. Adjustment of the elution conditions minimized the interaction with the gel matrix for compost humic substances and dissolved organic matter (DOM) fractions. The SEC was then used to separate the aqueous compost extract into samples with distinct differences in chemical constituents. The highest quantities of Cu, Zn, Ni, Mn, and Cd were found to coelute with the main peak of the SEC elution curve, which, as observed by Fourier-transformed infrared (FTIR) spectroscopy, also had the highest density of carboxyl groups. The ratio of aromatic to aliphatic structures was higher for eluates with low retention times, and cations such as Al, Cr, and Fe were preferably associated with these larger organic molecules. All trace metals in the compost solution phase were bound mostly to DOM rather than forming inorganic complexes.
KW - Dissolved organic matter
KW - Fourier-transformed infrared spectrometry
KW - Municipal solid waste compost
KW - Size exclusion chromatography
KW - Trace metals
UR - http://www.scopus.com/inward/record.url?scp=0036707666&partnerID=8YFLogxK
U2 - 10.1002/etc.5620210903
DO - 10.1002/etc.5620210903
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C2 - 12206415
AN - SCOPUS:0036707666
SN - 0730-7268
VL - 21
SP - 1775
EP - 1782
JO - Environmental Toxicology and Chemistry
JF - Environmental Toxicology and Chemistry
IS - 9
ER -