Remediation of solvent-contaminated soils by aeration.
1992
Kempton H. | Davis A. | Olsen R.
A bench-scale box test was performed to evaluate the feasibility of rototilling to remediate excavated soils contaminated with tetrachloroethylene (PCE), trichloroethylene (TCE), and 1,1,1-trichloroethane (1,1,1-TCA). Two clay-rich soils (A and B) containing 0.15% organic C and different concentrations of the target analytes were placed in 15-cm thick layers under a 10 km/h wind, tilled daily, and samples collected and analyzed periodically. Soil A (25,000 microgram/kg PCE) lost 80% after 24 h and 97% after 407 h. Soil B (8881 microgram/kg PCE) lost 29% after 24 h and 92% after 407 h. Initial TCE and 1,1,1-TCA concentrations ranged from 793 to 1570 microgram/kg. Relative volatilization loss rates were similar to that of PCE. The average volatilization half-lives of the solvents were 1.2 d for PCE, 0.58 d for TCE, and 0.64 d for 1,1,1-TCA. Removal of the analytes slowed considerably after 200 h, with a small (up to 10%) amount of each analyte retained in refractory sites. Residual solvent concentrations in soils A and B after 407 h were 935 and 719 microgram/kg PCE, 38 and 95 microgram/kg TCE, and 21 and 31 microgram/kg 1,1,1-TCA. Simulations of volatilization using the pesticide root zone model (PRZM) accurately predicted the loss or PCE, TCE, and 1,1,1-TCA over the first 24 h when most of the solvent volatilized, but the model overpredicted contaminant losses at longer durations when remnant soil concentrations were less than six times the concentration bound to refractory sites.
اظهر المزيد [+] اقل [-]الكلمات المفتاحية الخاصة بالمكنز الزراعي (أجروفوك)
المعلومات البيبليوغرافية
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