Soil quality standards (SQSs) are one of the most important elements of management system for contaminated sites. In order to manage risks associated with soil contamination, risk based SQSs are used worldwide. However, in Turkey, the Soil Pollution Control Regulation in force was focusing mainly on the use of stabilized sludge on soil and was including standards for a limited number of parameters, mainly metals and some organic chemicals. Thus, existing SQSs were far away from providing common criteria for assessment of the soil quality. In this study, the aim was to develop human health risk based SQSs for Turkey. For derivation of risk based SQSs, the conceptual framework and technical infrastructure were established. SQSs were derived for 151 chemical substances and for three different land use types by incorporating generic site characteristics for Turkey. Since SQSs are highly sensitive to site conditions and chemical-specific data used in calculations, a Microsoft Excel based exposure model was developed as a technical tool. This tool serves for calculation of generic and site-specific SQSs and maintenance of the currency of the standards by allowing periodic update of data used in calculations. Besides, a hydrogeologic database was developed to provide information on the general soil and hydrogeologic characteristics that are used in derivation of SQSs. This database is ultimately, expected to serve for development of conceptual site models, sampling strategies, and derivation of dilution factors during risk assessment studies. As a result, this study presents a general perspective and approach for derivation of human health risk based SQSs. It is believed that the developed conceptual and technical infrastructure will contribute to contaminated site management and risk assessment studies conducted by the regulatory authorities and the other stakeholders in Turkey.

This research reports on an experimental and theoretical study of soil heating/air stripping and steam injection/vacuum extraction for remediation of MTBE and Diesel Contaminated Soils. Two one-dimensional mass transfer models were using to simulate the process of remediaction. Contaminant kinds(MTBE and Diesel)¡A contaminant concentration (152~13,912 mg/kg soil)¡Asoil temperature(38~120¢J)¡Asteam injection pressure(0.5~1.0 atm)¡A and the mass of steam used(0.379~0.730 kg/h)were employed as the experimental factors in this study. In soil heating/air stripping study, rising soil temperature will enhance the MTBE removed efficiency¡A it was shown in the concentration of effluent gas. Further, the flow rate at outlet of column was higher than that at inlet of column, it revealed MTBE transfers from liquid phase to gas phase and was removed by gas flow. The concentration of effluent gas curve in low initial MTBE concentration test was similar with high concentration test, but the mechanisms was quiet different¡Ait need advanced adsorption test to find the reasons. In medium initial MTBE concentration test¡Athe concentration of effluent gas curve showed linear shape. When using steam injection/vacuum extraction treating MTBE contaminated soil, it showed 90¢Mefficiency can be reached in one hour. In steam injection/vacuum extraction study, it showed higher initial diesel contaminant concentration¡Ahigher initial concentration of effluent gas. Further, in high initial diesel concentration test (13.912 g diesel/kg soil test and about 5g/ kg soil tests)¡Athe concentration of effluent gas curves had a dominant drop at early time in remediation, it revealed the injection steam flow was quiet large, so diesel didn¡¦t has enough time to transfer to gas phase, that the gas couldn¡¦t been saturation at outlet of column. But in low initial diesel concentration test (about 1 g diesel/kg soil tests), the concentration of effluent gas curves showed the typical NAPL remediation curve. The different with in high and low initial concentrations might from the complex composition of diesel. Because at the early time in remediaction of high initial diesel concentration, the low carbon numbers diesel could abundantly evaporate, it caused the high concentration of effluent gas. With the remediation time go by, the low carbon numbers diesel exhaust. So the main composition of effluent gas transfer to high carbon numbers diesel, that the concentration of effluent gas curve showed the slowly decline. For high initial diesel concentration test (13.912 g diesel/kg soil)¡A the efficiency was the highest (73.7¢M). For low initial diesel concentration test (about 1 g diesel/kg soil), the efficiency was the lost (about 20¢M). Further, the remediation of diesel contaminated soil exited a rapid removed period. Under the conditions of this study, the rapid removed period could remove more than 95¢Mcontaminant of diesel removed at hold remediation time. The experiment results also showed that larger the mass of steam injection, shorter the rapid removed period, and larger the steam injection pressure, longer the rapid removed period. When using soil heating/air stripping treating diesel contaminated soil, the removed efficiency was worse 10-20¢Mthan the same initial diesel contaminated concentration. In simulating remediation process, the prediction with the MTBE measured concentration yielded good agreement in NAPL model. But to get the better fit of diesel in NAPL model, it might set the ¡§could removed mass¡¨ to initial condition of model. In non-NAPL model, MTBE also showed good agreement with model, and the model enabled the prediction of the initial contaminant level in the soil.

Contamination of groundwater supplies by gasoline and other petroleum-derived hydrocarbons released from underground or aboveground storage tanks is a serious and widespread environmental problem. Corrosion, ground movement, and poor sealing can cause leaks in tanks and associated piping. Petroleum hydrocarbons contain methyl tertiary-butyl ether (MTBE) (a fuel oxygenate), benzene, toluene, ethylbenzene, and xylene isomers (BTEX), the major components of gasoline, which are hazardous substances regulated by many nations. MTBE possesses all the characteristics of a persistent compound in the subsurface: high solubility, low volatility, low sediment sorption, and resistance to biodegradation. The objectives of this study were to (1) evaluate the biodegradibility of MTBE under aerobic conditions, and (2) assess the potential of using the aerobic bioremediation technique to clean up aquifers contaminated by MTBE. In this study, microcosms were constructed to determine the feasibility of biodegrading MTBE by intrinsic microbial consortia (aquifer sediments) under aerobic and aerobic cometabolic conditions. In the cometabolic microcosms, propane, ethanol, and BTEX were applied as the primary substracts to enhance the biodegradation of MTBE. The inocula used in this microcosm study were aquifer sediments collected from the contaminated-zones of a petroleum-hydrocarbon (including MTBE) contaminated site. Microcosms were constructed with nutrient medium (or site groundwater), sediments, and MTBE solution in 70-mL serum bottles sealed with Teflon-lined rubber septa. MTBE was analyzed using purge-and-trap instrument following gas chromatography (GC)/flame ionization detector (FID). Results show that the indigenous microorganisms were able to biodegrade MTBE under aerobic conditions using MTBE as the sole primary substrate. Microcosms with site groundwater as the medium solution show higher MTBE biodegradation rate. This indicates that site groundwater might contain some trace minerals or organics, which could enhance the MTBE biodegradation rate. Results show that the addition of BTEX would also enhance the MTBE removal. However, no significant MTBE biodegradation was observed in microcosms with propane and ethanol as the primary substrates. This reveals that the supplement of the second carbon source might inhibit the degradation of MTBE due to the preferential removal of some organics over MTBE. Results from the microcosm study suggest that aerobic biodegradation plays an important role on the MTBE removal. Intrinsic bioremediation is a feasible technology to remediate the studied MTBE-contaminated site.

The purpose of this study was to evaluate the treatment efficiency of phenol contaminated soils by electrokinetic (EK) process conducted in sand boxes (60 cm¡Ñ30 cm¡Ñ30 cm; L¡ÑW¡ÑH). The electric field strength, electrode polarity reverse, and Fenton reagent were employed as the experimental factors in this study to assess the variations of soil characteristics, potential difference, and residual phenol concentration distribution during a treatment period of 20 days and after the treatment. It was found that the anode reservoir pH decreased to around 2 and the cathode reservoir pH increased to approximately 12 after 2~3 days of treatment in the no electrode polarity reverse system. However, the variation of pH in the anode and cathode reservoirs was less obvious in the case with electrode polarity reverse. No matter a constant potential system or a constant current system was employed, a general trend of a lower pH at the anode reservoir and a higher pH at the cathode reservoir would be found. The acid front generated at the anode reservoir flushed across the soil specimen toward the cathode and the base front advanced toward the anode. However, in the central region of sand box, unsaturated and saturated soil specimen maintain neutral. For EK or EK-Fenton experiments, under the constant potential conditions, the potential difference relative to the cathode versus the distance from anode was found to have a linear relationship at the beginning of the electrical potential application. As the treatment time elapsed, the potential gradient became non-linear. Nevertheless, there was no remarked potential gradient change in the case with electrode polarity reverse. Although capillarity has resulted in an increase of the moisture content of unsaturated soil (from 25.34% to 30% after 20 days), electroosmotic (EO) flow was not obvious in the unsaturated zone. For the experiments with electrode polarity reverse, they had a much greater EO flow quantity, the electroosmotic permeability coefficients for constant potential and constant current systems were 6.42¡Ñ10-6 cm2/V¡Es and 9.47¡Ñ10-6 cm2/V¡Es, respectively. It was also found that the existence of contaminants did reduce the EO flow quantity. Regardless of the employment of a constant potential or constant current system, the maximum destruction and removal efficiency (DRE) of phenol was obtained for EK-Fenton process. The maximum DRE values of phenol for both constant potential and constant current systems were found to be 78.06% and 80.11%, respectively. However, the DRE of phenol was found to be much lower for the system with electrode polarity reverse. It was postulated that the destruction efficiency of phenol was less obvious than the removal efficiency in the electrode polarity reverse system. In addition, a frequent reverse of electrode polarity also resulted in a frequent change of EO flow direction. Thus, a flow hysteresis of phenol in the soil compartment was found.

Seals are considered one of the important flow elements of a turbomachinery device. Traditional labyrinth seals have proven their performance functionality by reducing leakage rates. Significant improvements on labyrinth seal functionality were obtained through altering the design geometry of labyrinth seals to prevent contamination across a seal and maintaining small leakage flowrates. This results in a windback seal that has only one tooth which continuously winds around the shaft like a screw thread. These seals are used in gas compressors to isolate the gas face seal from bearing oil. A purge gas is passed through the seal into the bearing housing. The helical design allows the seal to clear itself of any oil contamination. Windback seal performance is controlled through changing the seal geometry. A 2D graphical design tool for calculating the total and cavity leakage flowrates for windback seals is introduced. The effectiveness of the Fluent CFD (Computational Fluid Dynamics) commercial code to accurately predict the leakage rate for windback seals was evaluated. The objective is to determine if CFD simulations can be used along with a few experimental tests to study windback seals of this design with air as the working fluid. Comparison of measurement and predictions for a windback seal using the κ-ε turbulence model with enhanced wall treatment functions show predictions and measurements comparing very well with a maximum difference of 5% for leakage rate. Similarly, the leakage rate of the tested smooth seal compares favorably with two dimensional CFD predictions, with a difference of 2%-11% and 8%-15% using laminar and κ-ε turbulent flow models, respectively. The variation of leakage with shaft speed and pressure ratio across the seals is accurately predicted by the CFD simulations. Increasing the rotor speed to 15000 rpm increases the measured leakage flowrate for the windback seal by 2% at high differential pressure and 4.5% at low differential pressure, and decreases it by 10 % for the smooth seal. The effects of seal clearance, tooth pitch, cavity depth and the tooth number of starts on leakage flowrate, velocity and pressure distributions were studied numerically for three differential pressures and four rotor speeds.

The industrial solvent trichloroethylene (TCE) and petroleum hydrocarbons (e.g., fuel oil) are among the most ubiquitous organic compounds found in subsurface contaminated environment. The developed treatment train system included the first stage of groundwater and surfactant flushing followed by the second stage of chemical oxidation such as potassium permanganate (KMnO4) and Fenton-like treatment. The third stage was the application of enhanced bioremediation for the further removal of residual contaminants after the first two treatment processes. The objectives of this study were to (1) assess the applicability of treatment train system for the remediation of organic compounds contaminated subsurface environment, (2) determine the optimal operational conditions of the three-stage treatment system, and (3) evaluate the effects of residual surfactant Simple GreenTM (SG) and hydrogen peroxide (H2O2) after chemical oxidation stage on the efficiency of bioremediation process. In this study, three different surfactants [SG, Triton X-100, and Tween 80] were evaluated in batch experiments for their feasibility on contaminants removal. Results from the surfactant biodegradation and microbial enumeration study indicate that SG was more biodegradable and was able to enhance the microbial activity of the intrinsic microorganisms. Thus, SG was applied in the following batch or column experiments of the treatment train system. Results from this study indicate that approximately 87.6% of TCE in the system (with initial concentration of 40 mg L-1) could be removed from the simulated dense non-aqueous-phase liquids (DNAPLs) system after groundwater flushing followed by biodegradable surfactant (1 g L-1 of SG) flushing, while the TCE concentrations dropped from 40 to 4.96 mg L-1 at the end of the flushing experiment. Moreover, approximately 10.7% of the remaining TCE could be removed from the system after the oxidation process using KMnO4 as the oxidant. Results from the oxidation process show that TCE was reduced from 4.96 to 0.69 mg L-1, and chloride concentation was increased from ND to 0.88 mg L-1 with the presence of 1 g L-1 of SG. The residual 1.7% of the TCE could be further remediated via the enhanced bioremediation stage, and the TCE concentrations dropped from 0.69 mg L-1 to below detection limit at the end of the bioremediation experiment. Results also indicate that the remaining KMnO4 had no significant inhibition on bacterial growth and TCE biodegradation. Thus, SG flushing and KMnO4 oxidation would not cause adverse effect on subsequent bioremediation process using intrinsic bacteria. Thus, complete TCE remediation was observed in this study using the three-stage treatment scheme. Results from the column experiment reveal that a complete TPH removal could be obtained after the application of three consecutive treatment processes. Results show that TPH concentration could be reduced from 50,000 mg kg-1 to below detection limit. This indicates that the treatment train system is a promising technology to remediate fuel-oil contaminated soils. Results from the column study indicate that approximate 80.3% of initial TPH in the soil could be removed after the SG [50 pore volumes (PVs)] followed by groundwater (30 PVs) flushing. The Fenton-like oxidation (with 6% of H2O2 addition) was able to remove another 15.0% of TPH. The observed first-order reaction rate constant of TPH oxidation was 2.74¡Ñ10-2 min-1, and the half-life was 25.3 min during the first 40 min of reaction. The residual 4.7% of the TPH could be further remediated via the aerobic bioremediation process. Thus, complete TPH removal was obtained in this study using the three-stage treatment scheme. The proposed treatment train system would be expected to provide a more efficient and cost-effective alternative to remediate chlorinated solvent and petroleum hydrocarbons contaminated sites.

La technique de croissance assistée par faisceau focalisé d'électrons offre des perspectives attrayantes pour la nano et micro-fabrication en trois dimensions. Les faisceaux d'électrons peuvent être focalisés sur des dimensions inférieures à 1 Å, ce qui permet l'observation, l'analyse et la modification d'objets à l'échelle atomique. De nombreuses applications peuvent être envisagées, mais supposent une description précise des mécanismes physico-chimiques mis en jeu.<br /><br />Une étude bibliographique montre d'abord que cette technique est dérivée du phénomène de contamination observé en microscopie électronique. Puis, afin d'en faire un outil expérimental efficace, un microscope électronique à balayage a été muni de systèmes d'approvisionnement en gaz précurseur et de condensation. De nouvelles méthodes électriques et optiques ont été mises au point pour le suivi in-situ du procédé. La démarche scientifique s'est déroulée en deux phases. La physique du phénomène a d'abord été étudiée, en déposant des films minces de carbone, d'un composite cuivre-carbone, puis d'or pur. La propagation des électrons dans ces films a été décrite grâce à la mesure en continu de la fraction du courant de sonde absorbée dans l'échantillon. Les effets des électrons diffusés sur le taux de croissance ont été étudiés. Un modèle physique a été développé pour rendre compte des résultats. La deuxième phase a été la croissance de pointes composites sous un faisceau immobile. La forme des pointes est déterminée par la diffusion des électrons. Un modèle physique décrivant les trajectoires des électrons à l'intérieur et autour des pointes a été mis au point. La troisième phase a été la construction de micro-structures tridimensionnelles, dont la forme illustre les effets de la profondeur de pénétration des électrons, qui est plus grande que l'épaisseur des dépôts.<br /><br />Pour comprendre la chimie du phénomène, les dépôts de carbone obtenus ont été analysés par plusieurs techniques de micro-sonde. Tous les dépôts obtenus à partir de précurseurs pourtant différents avaient la composition C9H2±xO1±x (x<1). La fraction d'hybridation sp2 de la phase carbone amorphe est de 90%. Le taux de croissance augmente avec la pression de vapeur, le moment dipolaire et la masse moléculaire du précurseur. Il diminue avec la température de l'échantillon. La réaction de fixation du précurseur adsorbé est une ionisation, suivie de la perte des éléments volatils H, N, O, F et Cl. L'analyse des dépôts composites de métaux a montré qu'ils peuvent être conducteurs. Des micro-dispositifs ont été démontrés, comme un contact électrique à un nanotube et un capteur de champ magnétique présentant une surface active de 500 × 500 nm2.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on December 29, 2009). Thesis advisor: Dr. Andrew D. Clarke. Includes bibliographical references.

Klövsjukdomen digital dermatit hos kor ger upphov till smärta hos djuren samt störningar i produktionen. För att förebygga och behandla klövsjukdomen används olika preparat, däribland CuSO4-lösning. Syftet med studien är att undersöka om och i så fall i vilken omfattning spridande av kopparförorenad gödsel påverkar Cu-halten i jordbruksmark. Studien genomfördes med provtagning av två oberoende jordbruksmarker där ett av områdena gödslas med kopparförorenad gödsel. Resultaten visar att jordbruksmark där förbrukad CuSO4 spridits med stallgödseln ger upphov till en signifikant ökad Cu-halt i markens översta lager, 0-25 cm. / The hoof disease digital dermatitis rise pain with the cows as well as production disruption. To prevent and treat the hoof disease different substances are used, including CuSO4 solutions. The purpose of this study is to examine if, and in that case in which incidence, the spread of copper contaminated manure affects the copper content in agricultural land. The study was performed sampling two independent agricultural areas. One of the areas was fertilized with copper contaminated manure. The results show that agricultural land where CuSO4 has been spread with the manure has a significant higher content of Cu in the upper level of the soil, 0-25 cm.

Steps on a high index metal or semiconductor surface may play a fundamental role for electronic structure, adsorption, film growth, chemical reaction and catalysis. The surface atomic and electronic structures of stepped W(110) surfaces have been investigated by a few research groups during the past 20 years. But there is still a lot of controversy. We use high resolution core level photoemission to study several different stepped tungsten surfaces. Curve fittings of the spectra permit tests of core-level binding- energy shift models that relate local atomic coordination to binding -energy differences associated with terrace and step-edge atoms. For the first time we find a well resolved W4f₂/₇ peak associated with step edge atoms. We attribute previous failure to directly detect the step-edge effects in core level photoemission to contamination by hydrogen. The well resolved peaks for surface atoms with different coordinations can serve as a “finger print” for specific atoms. Experiments in which stepped surfaces are systematically dosed by H₂ clarify the role played by H contamination. We also grow Ag nanowires on the stepped W(110) surface and use angle resolved photoemission to study the band structure. We find distinct dispersion for the nanowires along the step edge direction while there is only little dispersion perpendicular to the wires. The second part of the research is core level photoemission study on Cesium film growth on Cu(100) surface. We study the phonon broadening effect for Cs at different temperatures. We compare our data with previous theoretical models and get good results on surface and bulk Debye temperatures and zero temperature phonon broadening. The binding energy shifts for the Cs 5p₂/₇ at different temperatures have also been investigated. The results fit the lattice expansion model very well except at temperature higher than 200 K. The higher temperature deviation is caused by thermal evaporation of Cs films. This conclusion is checked by the following coverage dependent core level peaks study on the Cs/Cu(100) system. / text