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An emplaced source of coal tar creosote within the sandy Borden research aquifer has provided an opportunity to document the long term (5140 days) natural attenuation for this complex mixture. Plumes of dissolved chemicals were produced by the essentially horizontal groundwater flowing at about 9 cm/day. Eleven chemicals were extensively sampled seven times using a monitoring network of ~280 14-point multilevel samplers. A model of source dissolution using Raoult’s Law adequately predicted the dissolution of nine of eleven compounds analysed. Mass transformation has limited the extent of the plumes as groundwater flowed more than 500 m yet the plumes are no longer than 50 m. Phenol and xylenes were removed and naphthalene was attenuated from its maximum extent on day 1357. Some compound plumes reached an apparent steady state and the plumes of other compounds (dibenzofuran and phenanthrene) are expected to continue to expand due to an increasing mass flux and limited degradation potential. Biotransformation is the major process controlling natural attenuation at the site. The greatest organic mass loss is associated with the high solubility compounds. However, the majority of the mass loss for most compounds has occurred in the source zone. Oxygen is the main electron acceptor yet the amount of organics lost cannot be accounted for by aerobic mineralization or partial mineralization alone. After 10 years the source zone was treated with permanganate in situ to reduce the flux of contaminants into the dissolved plume and to permit natural attenuation to further reduce the plume extent. A sufficient mass of permanganate was injected to oxidize ~10% of the residual source. Laboratory experiments demonstrated that eight of ten of the study compounds were readily oxidized by permanganate. Once treated oxidized compounds displayed a reduced plume mass and mass discharge while they migrated through the monitoring network. Once beyond the monitoring network the mass discharge and plume mass of these compounds returned to pre-treatment trends. Non-reactive compounds displayed no significant decrease in mass discharge or plume mass. Overall the partial in situ chemical oxidation of the coal tar creosote source produced no long-term effect on the dissolved plumes emanating from the source.

An emplaced source of coal tar creosote within the sandy Borden research aquifer has provided an opportunity to document the long term (5140 days) natural attenuation for this complex mixture. Plumes of dissolved chemicals were produced by the essentially horizontal groundwater flowing at about 9 cm/day. Eleven chemicals were extensively sampled seven times using a monitoring network of ~280 14-point multilevel samplers. A model of source dissolution using Raoult’s Law adequately predicted the dissolution of nine of eleven compounds analysed. Mass transformation has limited the extent of the plumes as groundwater flowed more than 500 m yet the plumes are no longer than 50 m. Phenol and xylenes were removed and naphthalene was attenuated from its maximum extent on day 1357. Some compound plumes reached an apparent steady state and the plumes of other compounds (dibenzofuran and phenanthrene) are expected to continue to expand due to an increasing mass flux and limited degradation potential. Biotransformation is the major process controlling natural attenuation at the site. The greatest organic mass loss is associated with the high solubility compounds. However, the majority of the mass loss for most compounds has occurred in the source zone. Oxygen is the main electron acceptor yet the amount of organics lost cannot be accounted for by aerobic mineralization or partial mineralization alone. After 10 years the source zone was treated with permanganate in situ to reduce the flux of contaminants into the dissolved plume and to permit natural attenuation to further reduce the plume extent. A sufficient mass of permanganate was injected to oxidize ~10% of the residual source. Laboratory experiments demonstrated that eight of ten of the study compounds were readily oxidized by permanganate. Once treated oxidized compounds displayed a reduced plume mass and mass discharge while they migrated through the monitoring network. Once beyond the monitoring network the mass discharge and plume mass of these compounds returned to pre-treatment trends. Non-reactive compounds displayed no significant decrease in mass discharge or plume mass. Overall the partial in situ chemical oxidation of the coal tar creosote source produced no long-term effect on the dissolved plumes emanating from the source.

In this study, potassium permanganate was used as the oxidant to remediate TCE¡Vcontaminated groundwater. The objectives of this bench-scale oxidation study include the following: (1) evaluate the overall TCE oxidation rate with the presence of KMnO4, (2) assess the consumption rate of KMnO4, (3) evaluate the effect of the oxidation by-product, manganese dioxide (MnO2), on the TCE oxidation rate. The control factors in this study include (1) four different molar ratios of KMnO4 to TCE [designated as P, (KMnO4/TCE) = 2, 5, 10, and 20]; (2) four different TCE concentration (0.5, 5, 20, and 100 ppm); (3) three different initial pH values (2.1, 6.3, and 12.5); (4) three different oscillator mix rate (0, 50, and 200 rpm); (5) four different molar ratios of dibasic sodium phosphate (Na2HPO4) to Mn2+ [designated as D, (Na2HPO4/Mn2+) = 0, 50, 100, and 300D], and (6) two different medium solutions [deionized (DI) water and groundwater]. Moreover, the effects of D values on TCE oxidation rate and KMnO4 consumption rate were also evaluated. Experimental results indicate that a second-order reaction model could be applied to express the oxidation reaction of TCE by KMnO4, and the calculated rate constant equals 0.8 M-1s-1. Results also show that the higher the P value, the higher the TCE oxidation rate. Moreover, TCE oxidation rate was not affected under low pH conditions (pH = 2.10 and 6.3). However, TCE oxidation rate dropped under high pH condition (pH 12.5) due to the transformation of KMnO4 to manganese dioxide. The following three pathways would cause the production of manganese dioxide: (1) direct oxidation of TCE by KMnO4, (2) production of Mn2+ after the oxidation of TCE by KMnO4, and Mn2+ was further oxidized by KMnO4 to form manganese dioxide, and (3) transformation of KMnO4 to manganese dioxide under high pH condition. Results also show that more manganese dioxide was produced while groundwater was used as the medium solution. Results show that the produced manganese dioxide was 47.2% - 81.5% less with the addition of dibasic sodium phosphate. Moreover, the variations in D values would not affect the TCE oxidation rate. However, the increase in D value would decrease the consumption of KMnO4. Results also reveal that significant inhibition of manganese dioxide production was observed under low pH condition. Furthermore, no TCE oxidation byproducts were detected after the oxidation reaction. Key words: KMnO4, TCE, manganese dioxide and dibasic sodium phosphate

In situ chemical oxidation using permanganate is an approach to organic contaminant site remediation. Manganese dioxide particles are products of permanganate reactions. These particles have the potential to deposit in the subsurface and impact the flow-regime in/around permanganate injection, including the well screen, filter pack, and the surrounding subsurface formation. Control of these particles can allow for improved oxidant injection and transport and contact between the oxidant and contaminants of concern. The goals of this research were to determine if MnO2 can be stabilized/controlled in an aqueous phase, and to determine the dependence of particle stabilization on groundwater characteristics. Bench-scale experiments were conducted to study the ability of four stabilization aids (sodium hexametaphosphate (HMP), Dowfax 8390, xanthan gum, and gum arabic) in maintaining particles suspended in solution under varied reaction conditions and time. Variations included particle and stabilization aid concentrations, ionic content, and pH. HMP demonstrated the most promising results, as compared to xanthan gum, gum arabic, and Dowfax 8390 based on results of spectrophotometric studies of particle behavior, particle filtration, and optical measurements of particle size and zeta potential. HMP inhibited particle settling, provided for greater particle stability, and resulted in particles of a smaller average size over the range of experimental conditions evaluated compared to results for systems that did not include HMP. Additionally, HMP did not react unfavorably with permanganate. These results indicate that the inclusion of HMP in a permanganate oxidation system improves conditions that may facilitate particle transport.

A research project assessing the effectiveness of potassium permanganate (KMnO4) for the treatment of iron (Fe) and manganese (Mn) has been conducted by the University of Central Florida (UCF) on behalf of the United States Navy with regards to the water supply on the island of Guam, located in the Marianas Islands. The study consisted of three basic investigative components: one that examined the use of potassium permanganate for iron and manganese control for Fena Lake, a second that examined the existing unit operations that comprised the Navy's water treatment plant (NWTP), and a third that examined iron and manganese field sampling analytical procedures. In the first and primary component of the research, surface water from Fena Lake located within the Naval Magazine in proximity of Santa Rita, Guam was collected at several different lake depths and initially analyzed for iron and manganese using inductively coupled plasma. Subsequent aliquots of Fena Lake collected at the various water depths were transferred to jars then dosed with varying amounts of potassium permanganate after which iron and manganese content was determined. The jars were covered to simulate actual lake to plant transfer conditions experienced at the Navy's on-island facilities. A portion of the jars was dosed with potassium permanganate prior to metals analysis in order to allow for comparisons of baseline conditions. To represent conventional treatment processes, the water samples were then coagulated with aluminum sulfate prior to filtration to remove the oxidized manganese and iron formed from the addition of the potassium permanganate. Coagulated aliquots were filtered and collected to evaluate residual dissolved iron and manganese content. Based on the results of the jar tests it was determined that manganese was reduced by 95% or greater and that iron was completely removed to below the analytical detection limit (0.001 mg/L). It was determined that the potassium permanganate dose required for oxidation of iron was 0.94 mg/mg iron and for manganese was 1.92 mg/mg manganese. It was also observed that when the jars containing aliquots that turned brown in color after potassium permanganate dosing meant that iron and manganese were present and were being oxidized; however, water samples that turned pink were found to be over-dosed with potassium permanganate. The pink water is an undesired characteristic and could result in customer complaints when distributed to the system. The second component of research focused on NWTP existing conditions. Water samples were collected after each key unit operation within the NWTP and analyzed for iron and manganese. This was to determine if pre-chlorination at Fena Lake was effective at removing iron and manganese that could be present in the source water. Analysis was conducted where pre-chlorination at Fena Lake was practiced as well as when no pretreatment was practiced prior to the NWTP. It was determined that the iron and manganese were not detected downstream of the coagulation unit operation within the NWTP even when pre-chlorination was not practiced. Consequently pre-chlorination of Fena Lake source water was not required for controlling iron and manganese under the conditions experienced in this study. A third study was also implemented to confirm that 0.1-micron filters are appropriate for use in preparing samples for analytical determination of iron and manganese analysis at various points within the NWTP. The filtration step is important to delineate between dissolved and suspended iron and manganese forms. Standard Methods 3120B recommends the use of 0.45-micron filters, although based on literature it has been shown that oxidized manganese particles may be smaller than a 0.45-micron pore size. Unless a coagulant was used, the oxidized manganese may not be fully removed via the 0.45-micron filter. To verify the effectiveness of using a 0.1-micron filter, a jar test was conducted to compare the use of a 0.1-micron filter, a 0.45-micron filter, and a 0.45-micron filter after the sample has been coagulated. It was found that the use of a 0.1-micron filter was superior to the use of 0.45-micron filters even with coagulant addition when directly comparing between dissolved and suspended iron and manganese forms. It is recommended that 0.1-microns be utilized in lieu of historically recommended 0.45-micron filters for sample preparation procedures.

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The influence of solution pH, DOC concentration, the relative molecular weight distribution of DOC, and the source of DOC were investigated for their effects on the removal of complexed Fe(II) by alum coagulation and/or KMn04 and H20 2 oxidation. The differentiation between particulate, colloidal, and soluble iron species was achieved through the use of 0.2 urn filters and 100K ultrafilters. Results from oxidation and ultrafiltration studies indicated incomplete complexation of the Fe(II) by DOC in solution. Following the addition of either oxidant, uncomplexed Fe(II) was oxidized to Fe (III) which was either complexed by high molecular weight DOC or formed colloidal iron oxides, both of which were efficiently removed by alum coagulation. Alum coagulation alone, however, was ineffective for removing Fe(II) in the presence of DOC. Results revealed the formation of particulate iron species to be a function of DOC source. The formation of colloidal iron was dependent upon DOC concentration and DOC source. The adsorption of DOC by iron oxides was observed to accompany the formation of colloidal iron species. / Master of Science

Il existe en France des centaines de friches industrielles polluées par du goudron de houille, un mélange récalcitrant de composés tels que les hydrocarbures aromatiques polycycliques. Lorsque la zone non saturée des sols est fortement contaminée, elle est usuellement excavée et remblayée. Cette thèse porte sur un traitement alternatif permettant une valorisation potentielle des sols sur site : l’oxydation chimique in situ, qui a déjà montré des résultats encourageants au laboratoire mais n’a que très peu été testée en grandeurs réelles. Les recherches ont donc été menées autour de trois échelles – bibliographie, laboratoire et pilote – afin de déterminer s’il existait un traitement oxydant répondant à des critères techniques, économiques et environnementaux acceptables pour être appliquée à l’échelle de la friche. La phase laboratoire a montré que l’ajout d’un soutien thermique augmentait significativement l’efficacité du traitement, i) par augmentation de la disponibilité de la pollution par préchauffage de la terre dans le cas du permanganate, ou ii) par activation thermique de l’oxydant dans le cas du persulfate. A l’échelle du pilote, une mise en contact homogène entre l’oxydant et la pollution n’a été possible que par noyage partiel de la terre avec les solutions oxydantes concentrées. L’activation du persulfate s’est révélée délicate à mettre en œuvre, le chauffage de solutions concentrées ayant mené à une décomposition parasite de l’oxydant. Au contraire, l’utilisation de solutions concentrées de permanganate a conduit à une dégradation des polluants encore plus élevée qu’au laboratoire grâce à la forte exothermicité de la réaction / In France, hundreds of brownfields are currently polluted with coal tar, a complex and recalcitrant mixture of organic compounds such as polycyclic aromatic hydrocarbons. When the unsaturated zone of soils is highly contaminated, it is commonly excavated and backfilled. This work deals with an alternative treatment, in situ chemical oxidation, that allows a potential reuse of soils directly on site. This technique has already provided encouraging results at the lab scale but has rarely been tested in the field. Research was made around three scales – bibliography, laboratory and pilot – in order to respond to the main problem: is there an oxidative treatment able to meet technical, economic and environmental criteria quite acceptable to be applied at brownfield level? The laboratory research phase showed that the addition of a moderate thermal support significantly increased treatment effectiveness, by i) an increase in pollutant availability by soil preheating in the case of permanganate, or ii) a thermal activation of the oxidant in the case of persulfate. At the pilot scale, a homogeneous contact between the oxidant and the pollutants was possible only by a partial flooding of the soil with the concentrated oxidizing solutions. The persulfate activation turned out to be difficult to implement because heating concentrated solutions led to a parasite decomposition of the oxidant. On the contrary, the use of concentrated solutions of permanganate led to an even higher degradation than in the laboratory, as a result of the strong exothermicity of the reaction