Succinic acid, a low molecular weight dicarboxylic acid was used to leach out
heavy metals from Willamette Valley soil (contaminated separately with lead, copper,
and zinc) in form of water-soluble organo-metal complexes. The research tasks included
developing synthetic contaminated soils representative of those found at Superfund sites
and making heavy metal adsorption and desorption studies.
Fixed amounts of single-metal contaminated soil were treated with succinic acid
under varying conditions of pH and organic ligand concentration. Based on the total
metal mobilized into the aqueous phase, the optimum values of pH and organic acid were
established for each metal. Since the direct determination of all species solubilized by the
organic acid solution was not possible, a computer speciation program called MICROQL
was used to determine the concentration of metal species in solution containing several
metals and potential ligands.
The results indicate that succinic acid is capable of significantly altering the
partitioning of metals between the soil and the aqueous phase. Higher concentrations of
the organic acid resulted in higher removal of metal from the soil. In case of lead and
copper, low pH (3.5) succinic acid flushing solution was found to be the most effective,
while a pH range of 4.5-5.5 was deemed optimum for zinc. The results also established
that the extent of removal of any metal depended not only upon the the stability constant
of the organo-metal complex, but also on its mode of retention within the soil. / Graduation date: 1993
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37052 |
| Date | 15 September 1992 |
| Creators | Kaul, Arvind |
| Contributors | Sproull, Robert D. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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