P. Lafrance et al., EFFECT OF NATURAL DISSOLVED ORGANIC-MATTER FOUND IN GROUNDWATER ON SOIL ADSORPTION AND TRANSPORT OF PENTACHLOROPHENOL, Environmental science & technology, 28(13), 1994, pp. 2314-2320
Kinetic, equilibrium, and transport experiments were performed to quan
tify pentachlorophenol (PCP) adsorption and mobility in water-saturate
d soil columns. The effect of natural dissolved organic matter (NDOM,
<0.1 mg/L or 15 mg/L) found in groundwater was investigated. While the
pH was found to greatly affect the adsorption of PCP, the adsorption
rate was not affected by NDOM at either pH 5.4 or pH 6.3. For a low co
ncentration range (PCP <0.4 nmol/mL), the effect of NDOM on PCP adsorp
tion isotherms was negligeable at pH 5.2, 5.4, and 6.1. The breakthrou
gh curves (BTCs) obtained from displacement studies were fitted to the
analytical solution of a one-dimensional transport model that assumes
a linear isotherm. The BTCs (pH 6.2-6.5) showed that NDOM do not affe
ct the retardation factor for PCP. However, PCP adsorption isotherms o
btained from a higher concentration range (PCP <3 nmol/mL) showed that
NDOM may increase the adsorption of PCP on soil at pH 5.4 and 6.1.