Separation and Purification Technology

The effectiveness of electrokinetically enhanced persulfate oxidation for the destruction of trichloroethylene (TCE) in a spiked sandy clay soil was evaluated in this work. In addition, the effect of nanoscale Fe3O4 on activating persulfate oxidation was also evaluated. The TCE-spiked soil was compacted in the soil column of the electrokinetic (EK) treatment system, and both the anode and cathode reservoirs were filled with simulated groundwater. The electrode material for both the anode and cathode was graphite. An electrical potential gradient of 1 V cm−1 was applied to the EK treatment system by a DC power supply for a period of 7–14 d. Sodium persulfate (Na2S2O8) was injected daily at a dose of 0.785–10.850 g into the anode or cathode reservoir, starting from the very beginning of the treatment. To evaluate the performance of persulfate alone in chemical oxidation of TCE in the EK treatment system, EK-alone tests were also carried out for comparison. Experimental results have shown that the EK process greatly enhances the transport of injected persulfate from the anode reservoir to the cathode reservoir via the soil compartment by means of electroosmotic flow, aiding in situ chemical oxidation of TCE. In addition, nanoscale Fe3O4 was found to play a significant role in activating persulfate oxidation. Such a coupled process was found to be capable of effective destruction of TCE in the soil compartment and electrode compartments. Under optimal conditions, the residual TCE concentration in the soil compartment was found to be lower than Taiwan EPA’s regulatory threshold (i.e., 60 mg kg −1 ). The residual TCE concentrations in both electrode reservoirs (i.e., not detectable and 0.01–1.74 mg L −1 for the anode and cathode reservoirs, respectively) also met the local regulatory standards for Type II groundwater quality (i.e., <0.05 mg L −1

[1]  Yalcin B. Acar,et al.  Principles of electrokinetic remediation , 1993 .

[2]  K. S. Knaebel,et al.  Pressure swing adsorption , 1993 .

[3]  H. Freisleben,et al.  Black lipid membranes of tetraether lipids from Thermoplasma acidophilum. , 1992, Biochimica et biophysica acta.

[4]  W. Stumm.  Chemistry of the solid-water interface , 1992 .

[5]  R. Huber,et al.  Hyperthermophilic Archaea and Bacteria Occurring within Indonesian Hydrothermal Areas , 1991 .

[6]  D. Blöcher,et al.  Mixtures of tetraetherlipids from Thermoplasma acidophilum with varying degree of cyclization show a kinetic effect for a metastable phase , 1991 .

[7]  M. Dahab.  Treatment Alternatives for Nitrate Contaminated Groundwater Supplies , 1987 .

[8]  J. L. Pond,et al.  Archaebacterial ether lipids and chemotaxonomy , 1986 .

[9]  B. Henkel,et al.  Physicochemical characterization of tetraether lipids from Thermoplasma acidophilum. Calorimetric studies on miscibility with diether model lipids carrying branched or unbranched alkyl chains , 1985 .

[10]  D. E. Sanning.  In-Situ Treatment , 1985 .

[11]  B. Henkel,et al.  Physicochemical characterization of tetraether lipids from Thermoplasma acidophilum: differential scanning calorimetry studies on glycolipids and glycophospholipids , 1984 .

[12]  P. F. Smith.  Sequence and glycosidic bond arrangement of sugars in lipopolysaccharide from Thermoplasma acidophilum. , 1980, Biochimica et biophysica acta.

[13]  P. D. Goulden,et al.  Kinetics of uncatalyzed peroxydisulfate oxidation of organic material in fresh water , 1978 .

[14]  W. Fischer,et al.  Trihexosyldiacylglycerol and Acyltrihexosyldiacylglycerol as Lipid Anchors of the Lipoteichoic Acid of Lactobacillus casei DSM 20021 , 1978, Hoppe-Seyler's Zeitschrift fur physiologische Chemie.

[15]  P. F. Smith,et al.  Ultrastructure of lipopolysaccharide isolated from Thermoplasma acidophilum , 1975, Journal of bacteriology.

[16]  W. Mayberry,et al.  A new class of lipopolysaccharide from Thermoplasma acidophilum. , 1974, Biochimica et biophysica acta.

[17]  T. D. Brock,et al.  A Thermophilic, Acidophilic Mycoplasma Isolated from a Coal Refuse Pile , 1970, Science.

[18]  K. Karlsson,et al.  Studies on sphingosines. XIV. On the phytosphingosine content of the major human kidney glycolipids. , 1968, Biochimica et biophysica acta.

[19]  R. Wuthier.  Purification of lipids from nonlipid contaminants on Sephadex bead columns. , 1966, Journal of lipid research.

[20]  Alan L. Myers,et al.  Thermodynamics of mixed‐gas adsorption , 1965 .

[21]  J. Dittmer,et al.  A SIMPLE, SPECIFIC SPRAY FOR THE DETECTION OF PHOSPHOLIPIDS ON THIN-LAYER CHROMATOGRAMS. , 1964, Journal of lipid research.

[22]  D. A. House.  Kinetics and Mechanism of Oxidations by Peroxydisulfate. , 1962 .

[23]  J. Lingane.  Volumetric Analysis. Volume III. Titration Methods: Oxidation-Reduction Reactions. , 1958 .

[24]  J. Folch,et al.  A simple method for the isolation and purification of total lipides from animal tissues. , 1957, The Journal of biological chemistry.

[25]  I. Kolthoff,et al.  The Reaction between Ferrous Iron and Peroxides. IV. Reaction with Potassium Persulfate1a , 1951 .