TY - JOUR
T1 - Enhanced dissolution of trichloroethene
T2 - Effect of carbohydrate addition and fermentation processes
AU - Nelson, D. K.
AU - Novak, Paige J
PY - 2009
Y1 - 2009
N2 - Remediation of source areas is challenging because lingering contaminants are often present as nonaqueous phase liquid (NAPL) and sorbed mass, and therefore difficult to remove via biodegradation or other commonly used remedial methods. Experimental results indicate that enhanced dissolution of a model NAPL, trichloroethene (TCE), can occur through the addition and/or subsequent fermentation of a dilute molasses solution. Enhanced mass transfer occurs by two mechanisms, depending upon whether the molasses solution is fresh or has fermented. The addition of fresh molasses worked to increase TCE solubility (>200%), thereby increasing mass transfer from the NAPL phase. Mixing TCE NAPL with a fermented molasses solution, however, increased TCE mass flux via the formation of a NAPL/aqueous phase emulsion. In addition, fermented liquid may have also decreased the soil partitioning coefficient (Kd) of TCE, indicating that enhanced transfer of sorbed mass to the aqueous phase could also occur in the presence of fermented molasses. These results provide guidance on how remedial systems may be optimized to increase NAPL and sorbed-mass dissolution and are therefore important, particularly when bioremediation is used to polish residual source zones.
AB - Remediation of source areas is challenging because lingering contaminants are often present as nonaqueous phase liquid (NAPL) and sorbed mass, and therefore difficult to remove via biodegradation or other commonly used remedial methods. Experimental results indicate that enhanced dissolution of a model NAPL, trichloroethene (TCE), can occur through the addition and/or subsequent fermentation of a dilute molasses solution. Enhanced mass transfer occurs by two mechanisms, depending upon whether the molasses solution is fresh or has fermented. The addition of fresh molasses worked to increase TCE solubility (>200%), thereby increasing mass transfer from the NAPL phase. Mixing TCE NAPL with a fermented molasses solution, however, increased TCE mass flux via the formation of a NAPL/aqueous phase emulsion. In addition, fermented liquid may have also decreased the soil partitioning coefficient (Kd) of TCE, indicating that enhanced transfer of sorbed mass to the aqueous phase could also occur in the presence of fermented molasses. These results provide guidance on how remedial systems may be optimized to increase NAPL and sorbed-mass dissolution and are therefore important, particularly when bioremediation is used to polish residual source zones.
KW - Biological treatment
KW - Groundwater pollution
KW - Nonaqueous phase liquids
KW - Remedial action
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U2 - 10.1061/(ASCE)EE.1943-7870.0000042
DO - 10.1061/(ASCE)EE.1943-7870.0000042
M3 - Article
AN - SCOPUS:69149110994
SN - 0733-9372
VL - 135
SP - 861
EP - 868
JO - Journal of Environmental Engineering
JF - Journal of Environmental Engineering
IS - 9
ER -