Enhanced electrokinetic dissolution of naphthalene and 2,4-DNT from contaminated soils.
Electrokinetic soil remediation has been proven to remove heavy metals and polar organics from low hydraulic conductivity subsurface environment. In this study, carboxymethyl-beta-cyclodextrin (CMCD) was used as a carrier to assist electrokinetic treatment for removal of low polarity organic contaminants from soils (2.2% organic carbon content). Naphthalene and 2,4-dinitrotoluene (2,4-DNT) were selected as the test compounds. The results from columns experiments showed that 46 and 43% of naphthalene and 2,4-DNT, respectively, were removed using 0.01 N NaNO(3) flushing solution with 40 V electrical potential while 70 and 72% of naphthalene and 2,4-DNT were removed using 2 g/L CMCD solution. Naphthalene and 2,4-DNT removal was enhanced to 83 and 89%, respectively, by using 2 g/L CMCD with 40 V electrical potential. Findings from this study also demonstrated that cyclodextrin assisted electrokinetics can enhance the removal rate of naphthalene and 2,4-DNT. Electric potential applied has more influence on the contaminant removal than the amount of CMCD used. Higher voltage application caused increase in the removal rate of naphthalene and 2,4-DNT, and appeared to be one of the critical factors in obtaining higher contaminant removal while increasing CMCD solution concentration above 2 g/L appeared to have little effect on the contaminant removal.
Jiradecha
Chatdanai
C
Chemical and Environmental Engineering Department, Illinois Institute of Technology, Chicago, 606016, USA.
Urgun-Demirtas
Meltem
M
Pagilla
Krishna
K
D004136:Dinitrobenzenes / Q000737:chemistry* / Q000302:isolation & purification*; D004563:Electrochemistry; D007700:Kinetics; D009281:Naphthalenes / Q000737:chemistry* / Q000302:isolation & purification*; D012989:Soil Pollutants / Q000302:isolation & purification*; D012996:Solutions; D047392:beta-Cyclodextrins / Q000737:chemistry
D004136:Dinitrobenzenes; D009281:Naphthalenes; D012989:Soil Pollutants; D012996:Solutions; D047392:beta-Cyclodextrins; C031721:naphthalene; C016403:2,4-dinitrotoluene; C031215:betadex