The potential of utilizing a new form of chemical processing technology called SpinChem® Rotating Bed Reactor (RBR), in combination with different reactive materials, for the purpose of remediating multi-contaminated aquifers under changing environmental conditions, was investigated using laboratory studies and geochemical models. Four different reactive materials, or combinations thereof, were tested: heat-treated peat powder combined with zero-valent iron (ZVI); IronPeat, which consists of peat powder coated with a ferriferous hydrosol (FFH); and a powdered steel waste product. Results showed that the powdered steel waste was compatible with the technology while the peat-based sorbents were not. However, there were no indications that the kinetics of the sorption reactions increased. This was attributed to the fact that the rate-limiting steps, for the binding of the studied metal(loid)s onto iron oxide, are generally considered to be dependent on the later stages of the sorption process related to diffusion mechanisms and not to the rate of mass transfer through the bulk liquid phase, which is what primarily is increased through application of the SpinChem® RBR technology.

The work presented in this thesis is divided into two parts. The first part is the sorption of Ni and Eu to granitic materials, and cation exchange capacity measurements for powdered and intact samples. The second part is method development on autoradiography. In the first part, static batch sorption experiments were carried out to study the relative sorption properties of different granitic rocks and minerals. Experimental data were described using non-electrostatic correction models such as the Langmuir, Freundlich and Linear models. Sorption data obtained for sorption in a constant pH environment and variable metal concentration were used to test the Component Additive Model (CAM). Sorption test studies carried out using energy dispersive X-ray microanalysis were used to map the sorption of Eu on an intact sample. The results showed the CAM was applicable for Ni sorption to BG but that it was not applicable for Eu sorption to any of the granitic rocks studied. The sorption data fitted the CAM in the following order; BG (1) > GA (0.7) > RG (0.5) > GG (0.2), GrG (0.2) for Ni sorption and RG (0.7) > BG (0.4) > GA (0.2), GG (0.2), GrG (0.2) for Eu sorption to the different granitic rocks. Values in brackets represent the ratio of Rd-predicted/Rd-calculated. Results from the application of the CAM showed it was not possible to predict the Rd of the bulk sample from the component minerals. Desorption studies at constant pH were analysed by calculating the hysteresis H. The results showed that the higher the Rd the higher the hysteresis. Surface complexation using JChess Geochemical Code was used to obtain surface complexation parameters for the metal-solid complex for sorption in variable pH and constant metal concentration. Experimental data were described by the mass action law to obtained proton stoichiometry at which the sorption edge is defined. Results showed the presence of NaCl decreased the sorption of Ni, and increased the sorption of Eu. Sorption kinetics experiments in different carbonate complexing environments were carried out to study the effect of carbonate on Eu sorption capacity and rate of sorption. Data were fitted to first and second order kinetic models to investigate the sorption rates. Results showed the sorption to be fast initially before reaching a steady state after more than 200 hours of equilibration. Kinetic data confirmed the low sorption capacity observed for quartz. Data obtained for sorption in a mixed radionuclide system were modelled using the Linear model and the surface complexation model. The surface complexation constants are correlated to the Rd values obtained from the linear sorption isotherms. Modelling the results using Rdmix and Rdsing showed that sorption was suppressed in a mixed system, with no effect observed for sorption to feldspar in single and mixed systems. Cation exchange capacity (CEC) measurements were undertaken to deduce a correlation between the CEC of powdered rock samples and intact sample using rock beakers developed from the British Geological Survey by applying the Bascomb method in which the pH was buffered to pH 8.1. Normalising the results using the surface area showed that the CEC of the rock beakers was 6 orders of magnitude greater than that of the powdered sample. In the second part, a method for differentiating two or more radionuclides using storage phosphor imaging plates coupled with the Storm Scanner system was tested. Initial results showed that it is possible to differentiate one radionuclide from another in a mixed system using different levels of shielding.

Per- and polyfluoroalkyl substances (PFASs) have become contaminants of increasing concern to society due to the contamination of drinking water and the ecosystem. A better understanding of the sorption and transport of PFASs in soil systems is urgently needed, however there have been few studies dedicated to investigating competitive sorption among PFASs, and there is no available model to model such effects. This study investigated the sorption behaviour of PFASs of different carbon chain lengths and different functional groups to investigate potential competitive sorption effects. A multi-compound sorption model was set up based on Langmuir single sorption isotherms. By modelling the different PFASs both separately and mixed together in bi-solute and multi-solute systems, the possibility of modelling competition effects between different PFASs for sorption sites was investigated. The model could describe the general tendency of longer chained PFASs to outcompete shorter chained PFASs, and that perfluorinated sulfonic acids (PFSAs) outcompete perfluorinated carboxylic aids (PFCAs). However, the model failed to reproduce multi-solute sorption results for PFOS at concentrations near or above the critical micelle concentration (CMC), indicating micelle formation and multilayer sorption, which cannot be described by a Langmuir isotherm-based model. The study showed that it is possible to model competitive effects among some PFASs using this approach, although more advanced models may be needed to model the sorption of long-chained PFASs where micelle formation may occur, which would require further research to derive values for the parameters necessary to perform this type of modelling. / Per- och polyfluorerade alkylsubstanser (PFAS) är kolväten där alla (per-) eller vissa (poly-) avväteatomerna bytts ut mot fluoratomer. PFAS är syntetiska kemikalier som började produceras på 1950-talet och kan beså av olika långa kolkedjor och funktionella grupper vilket påverkar deras egenskaper.Den funktionella gruppen är det hydrofila (vattenälskande) ”huvudet” på molekylen vilken kan bestå avolika kemiska grupper, av vilka de två vanligast studerade grupperna är sulfonsyror (PFSA) ochkarboxylsyror (PFCA), men det finns även många andra grupper. PFAS delas också in i långa och kortaföreningar där långa PFAS har en kolkedja som är längre än 6 kol och korta PFAS har 6 kol eller färrei sin kolkedja. Den molekylära strukturen med ett hydrofilt huvud och en hydrofob (vattenhatande)fluorerad kolkedja gör att PFAS ofta används som ytaktiva ämnen. Det finns fler än 4 700 PFAS och deanvänds i många olika produkter så som vatten- och fettavstötande tyger, mattor, rengöringsmedel, plastoch non-stickbeläggningar i t.ex. stekpannor. På grund av PFAS unika egenskaper har de också använtsi brandskum där de bildar en tunn film av vatten mellan skummet och det brinnande bränslet vilketeffektivt släcker branden. Men användningen av PFAS i brandskum har visat sig särskilt problematisktdå det innebär ett direkt utsläpp av stora mängder PFAS i naturen. Kol-fluorbindningen är väldigt stark och organismer klarar inte av att bryta bindningen vilket gör attPFAS inte bryts ned utan ansamlas i naturen. Detta tillsammans med deras vattenlöslighet resulterar imånga fall i stora föroreningsplymer i grundvattnet. Livsmedelsverket har rapporterat att dricksvattnetför mer än 3,6 miljoner människor är påverkat av PFAS föroreningar i Sverige. PFAS misstänks hacancerogena och hormonstörande effekter och flera PFAS föroreningar är nu reglerade inom EU. Menäven om nya utsläpp är reglerade behöver de PFAS som redan finns i naturen åtgärdas. Det finns mångatekniker för att åtgärda PFAS-förorenade områden där man utnyttjar molekylernas förmåga att binda tillfast material (sorption). Hur starkt molekylerna binder till materialet beror på en rad faktorer så somkolkedjans längd, mängden organiskt material i vattnet och/eller materialet PFAS ska binda till,elektrostatiska interaktioner med andra närvarande joner i vattnet samt vattnets pH. I den här studien utnyttjas dessa egenskaper för att se hur effektivt olika PFAS binder till olikamaterial med hjälp av matematiska modeller. Även potentiella konkurrenseffekter undersöks då olikaPFAS binder olika starkt. Om det då finns ett begränsat antal platser för molekylerna att binda till kanen del PFAS konkurreras ut av andra PFAS som binder starkare. Det påverkar hur effektiv enåtgärdsmetod är för att rena vattnet. Studien visade att det till viss del är möjligt att modellera tävlingseffekter mellan olika PFAS, därPFAS med längre kolkedjor konkurrerar ut kortare PFAS, och PFSA är mer konkurrenskraftiga jämförtmed PFCA. Men mer avancerade modeller krävs för modellering av längre PFAS vid högrekoncentrationer då deras förmåga att bilda aggregat/miceller försvårar modelleringen. Fler studierbehövs därför för att öka mängden information som krävs för att använda dessa mer avancerademodeller.