The manufacturing industries play a significant role in contributing to the economy of a country. Among various manufacturing industries, the semiconductor manufacturing (SM) industries is one of the fastest growing industries in the world having worldwide sales of $31 billion in the month of December 2016. Semiconductors are required by large number of industries, including Telecommunications, Medical Electronics, Automobile, Defence and Aerospace, Consumer Electronics, etc.,. Today, without semiconductors, the technology that we count on every day would not be possible. Because of these, the demand for SM industry is increased rapidly. In addition, most of the semiconductor based products‘ life is very short. Due to these, SM industry is highly competitive industry. Thus, to utilize the resources effectively, to handle the huge demand, and to deliver the product on-time, efficient scheduling is important in SM industry. SM process can be broadly classified into Wafer Fabrication (called as wafer fab), Wafer Probing, Assembly, and Final Testing. Scheduling is more important in wafer fab due to complex operations involving with multiple types of machines and re-entrant, expensive machines, and time-consuming process involved. Thus, this study concerns about scheduling in wafer fab, particularly diffusion operation. The diffusion operation, carried out on batch processing machine, heavily impacts the production rate of wafer fab and in turn the SM industry. This is due to the fact that, diffusion operation requires relatively longest processing time among all the operations in the wafer fab. Due to these, diffusion operation is the bottleneck operations in the wafer fab. Based on the detailed literature review, this study addresses a new research problem on dynamic scheduling (DS) of diffusion furnace(s) by considering together the various real-life problem characteristics: Non-identical parallel diffusion furnaces, Machine eligibility restriction, Incompatible-job families, Job and/or resource related real time events, and Non-agreeable release time and due-date. In addition, due to the importance of on-time delivery this study deals with five due-date based scheduling objectives: Total weighted tardiness (TWT), Number of tardy jobs (NT), On time delivery (OTD) rate, Total earliness and lateness (TE/L) and Maximum lateness (Lmax) as a single objective as well as multi objectives. Here, the multi objectives are developed, considering all the five due-date based scheduling objectives in a linear form by randomly assigning equal and unequal weights to each of the due-date based single objectives considered in this study. With these, the main objective of this thesis is to study the impact of job and/or resource related real time events (JR-RTE) on the relative efficiency of the proposed dynamic scheduling algorithms for diffusion furnace(s) while optimizing each of the due-date based scheduling objectives considered in this study. The research problem considered in this study is decomposed into five phases. From the analysis of the literature, it is observed that, there is no earlier study has the mathematical models for dynamic scheduling (DS) of diffusion furnaces to optimize all the due-date based scheduling objectives, considered in this study. Due to this, in the first phase, fourteen (0-1) mixed integer linear programming (MILP) models are proposed for DS of diffusion furnaces (seven models for DS of single diffusion furnace and seven models for DS of non-identical parallel diffusion furnaces) to optimize the due-date based single objectives: TWT, NT, OTD rate, TE/L, and Lmax and multi objectives: MO1 and MO2. All the proposed (0-1) MILP models are demonstrated for its workability by developing a suitable numerical example, LINGO set code (which generates each of the proposed (0-1) MILP model for any given data), and solving using LINGO solver. Further, based on the analysis of the literature a suitable experimental design is proposed and generated 15 small-scale test data. The computational complexity of each of the proposed (0-1) MILP models is discussed empirically by solving 15 small-scale test data. Due to the computational intractability of the proposed (0-1) MILP models for DS of diffusion furnaces, the second phase of the research focuses on a simple alternative approach based on dispatching rules, as the analysis of the literature reveals that dispatching rules are heavily used in the SM industry. However, there is no study in the literature presenting a comparative analysis of various dispatching rules particularly due-date based dispatching rules (DDR) for DS of diffusion furnace(s) to optimize various due-date based scheduling objectives. Accordingly, in the second phase, this study proposes a simple Greedy Algorithm (GA) based on DDR (called as GA-DDR) for Dynamic Scheduling of Single Diffusion Furnace (DS-SDF). Further, this study proposes twenty variants of GA-DDR considering various due-date based dispatching rules such as Earliest Due-Date, Flow Due-Date, Operational Due-Date, Modified Operational Due-Date, Critical Ratio, Minimum Slack First, Cost OVER Time, ten versions of Apparent Tardiness Cost (ATC) [including a new ATC rule proposed in this study] & five versions of Batch Apparent Tardiness Cost (BATC) [including a new BATC rule proposed in this study] for DS-SDF. All these twenty variants of GA-DDR are implemented in Turbo C. An experimental design is proposed in this phase for generating large-scale test data. Accordingly, 270 large-scale problem instances (representing 27 problem configurations and 10 instances per configurations) are generated. With these, a series of computational experiments are carried out to understand the relative efficiency of the twenty proposed variants of GA-DDR as follows: The efficiency of each of the twenty proposed variants of GA-DDR for DS-SDF with respect to each of the scheduling objectives considered in this study is analysed in comparison with optimal objective function value obtained from the corresponding (0-1) MILP models for 15 small-scale problem instances using the standard performance measures: Average Relative Percentage Deviation (ARPD) and Maximum Relative Percentage Deviation (MRPD). Further, for each of the 270 problem instances the efficiency of each of the twenty proposed variants of GA-DDR for DS-SDF with respect to each of the scheduling objectives is analysed in comparison with estimated objective function value, which is computed by giving the twenty feasible solutions obtained for each instances as input to Weibull distribution, (i) empirically using the performance measures: ARPD, MRPD, Integrated Rank (IRANK), & Global comparison based on Worst Solution (GCWS), and (ii) statistically by using the performance measures: Mean, Median, and 95% confidence interval. From the overall analysis, at the end of the second phase of the study, six efficient variants of GA-DDR among the twenty proposed variants of GA-DDR are identified for DS-SDF and discussed the insights for their better performance. In these six efficient variants of GA-DDR, two variants of GA-DDR uses the new ATC rule and/or BATC rule proposed by the author of this thesis. The second phase of the research considers only dynamic arrival of jobs in all the twenty variants of GA-DDR. But, in the real-life various unexpected job related real time events: rush job, due-date change, early/late arrival of job, change in job priority, and job cancellation and/or resource related real time events: machine breakdown, operator illness, tool failure, shortage of material, and defective material will occur in addition to the dynamic arrival of jobs. From the literature, it is observed that, all the studies in the dynamic scheduling of diffusion furnaces consider only future arrival of jobs and no study considering real time events. Further, to the best of our knowledge, the research studies on discrete processing machines develop various rescheduling algorithm or modify the existing algorithm whenever real time events occur while taking the scheduling decision. However, due to the longest operation time requirements at diffusion furnace and the computerized tracking system in the shop floor of wafer fab, we strongly propose a research hypothesis that modifying appropriately the work-in-process (WIP) data and/or the availability time of the corresponding diffusion furnace(s) for next scheduling depending upon the occurrence of job and/or resource related real time events respectively by utilizing the existing computerized tracking system in the shop floor is sufficient, and changing any proposed efficient algorithms for DS-SDF is not required. This hypothesis is proved both empirically and statistically in the third phase of this research, considering the twenty proposed variants of GA-DDR for DS-SDF and the proposed experimental design. Accordingly, this study propose a formal researchable hypothesis that there is no impact of JR-RTE on the relative efficiency of the twenty proposed variants of GA-DDR for DS-SDF while optimizing each of the due-date based scheduling objectives considered in this study. For testing the proposed hypothesis, this study proposed adjusted GA-DDR (with JR-RTE) for each of the proposed GA-DDR, in which there is step to update the WIP data if job related event occurs, and/or the next available time of corresponding diffusion furnace(s) for scheduling the same if resource related event occurs, before finalizing the scheduling decision. Each of the 270 large-scale problem instances generated using the proposed experimental design is solved by each of the 20 adjusted variants of GA-DDR (with JR-RTE). The comparison on the relative efficiency of each of the 20 proposed variants of GA-DDR and adjusted GA-DDR (with JR-RTE) is carried out using the performance measures: ARPD and MRPD [that is, ARPD(GA-DDR) vs. ARPD(adjusted GA-DDR with JR-RTE), and MRPD(GA-DDR) vs. MRPD(adjusted GA-DDR with JR-RTE)] while optimizing each of the seven scheduling objectives considered in this study. The empirical analysis of the comparisons reveals that there is no change in the relative efficiency of each of the 20 proposed variants of GA-DDR and the corresponding 20 adjusted variants of GA-DDR (with JR-RTE) while optimizing each of the scheduling objectives considered in this study. Further, this study proved the proposed hypothesis statistically by conducting the Spearman‘s rank order correlation between each of the 20 variants of GA-DDR and adjusted GA-DDR (with JR-RTE) for DS-SDF while optimizing each of the seven due-date based scheduling objectives considered in this study. From the empirical and statistical analyses carried out in the third phase of the study indicated that, no need to adjust the proposed variants of GA-DDR for any occurrences of real time events for obtaining efficient schedule. The SM industry normally would have more than one non-identical diffusion furnaces and that too in parallel. Due to some technical reasons, some jobs are processed only in specific diffusion furnace(s) available in the shop floor (this is called as machine eligibility restriction in scheduling theory). Hence, the impact of JR-RTE on the dynamic scheduling (DS) of non-identical parallel diffusion furnaces (NPDF) with machine eligibility restriction (MER) is addressed in the fourth phase of this study. In the fourth phase of the research study, the twenty proposed variants of GA-DDR for DS-SDF extended appropriately for DS-NPDF with MER [called as Extended GA-DDR (EGA-DDR)]. Further, a few new problem parameters required for NPDF with MER are identified from the literature and extended the proposed experimental design and generated 270 problem instances for representing NPDF with MER. For testing the proposed hypothesis on the impact of JR-RTE on DS-NPDF with MER, exactly the similar research processes carried out for comparing GA-DDR vs. adjusted GA-DDR (with JR-RTE) is followed for comparing EGA-DDR vs. adjusted EGA-DDR (with JR-RTE). Both empirical and statistical analyses clearly proved that there is no impact of JR-RTE on the relative efficiency of the twenty variants of EGA-DDR for DS-NPDF with MER while optimizing each of the due-date based scheduling objectives considered in this study and no need to adjust the variants of EGA-DDR for any occurrences of real time events for obtaining efficient schedule. So far, the study addressed the development of efficient GA-DDR and EGA-DDR for DS-SDF and DS-NPDF with MER respectively and studied the impact of JR-RTE on the relative efficiency of these proposed GA-DDR and EGA-DDR. Now, in the final phase of the research study, the impact of JR-RTE on the meta heuristics: Simulated Annealing (SA) and Tabu Search (TS), one at a time, for DS-SDF while minimizing TWT are studied. Accordingly, the required parameters for these two meta heuristics are identified from the literature and the meta heuristics: SA and TS, considering each of the six solutions obtained from the six efficient variants of GA-DDR respectively as initial solution are implemented. From the analysis of the solutions obtained, for each of the 270 problem instances, from each of the six efficient variants of GA-DDR and from each of the meta heuristics: SA and TS, it appears that the six efficient proposed variants of GA-DDR seems to be robust in terms of both quality and computational time requirements in obtaining efficient solution. Further, to study the impact of JR-RTE on meta heuristics: SA and TS, this study considers (a) six solutions obtained from each of the six efficient variants of GA-DDR for DS-SDF as the initial solution and obtained six final solutions respectively from each of the meta heuristics, and (b) six solutions obtained from each of the six adjusted variants of GA-DDR (with JR-RTE) for DS-SDF as the initial solution and obtained six final solutions respectively from each of the meta heuristics. For each of the meta heuristics, these two sets of final solutions, obtained for each of the 270 problem instances, are compared empirically and statistically, based on various performance measures considered in this study, and proved the research hypothesis defined in this study. The major research contributions of this study are as follows - By analyzing the literature on scheduling diffusion furnaces and the real-life situation in scheduling diffusion furnaces, a new research problem on dynamic scheduling (DS) of diffusion furnaces with incompatible-job families, machine eligibility restriction, non-agreeable release time and due-date, considering job and/or resource related real time events (JR-RTE) along with dynamic job arrival to optimize due-date based scheduling objectives: TWT, NT, OTD rate, TE/L, and Lmax as a single objective as well as multi objective was defined. - Seven (0-1) MILP models for each of DS-SDF and DS-NPDF were proposed for optimizing each of the seven due-date based scheduling objectives considered in this study and the computational complexity was observed. - Due to the computational complexity of the proposed (0-1) MILP models and the popularity of the dispatching rules in the semiconductor manufacturing industry, this study proposed and compared the twenty variants of (i) greedy algorithm based on due-date based dispatching rules (GA-DDR) for DS-SDF, and (ii) Extended GA-DDR for DS-NPDF with machine eligibility restriction (MER). - The impact of JR-RTE on the twenty proposed variants of (a) GA-DDR for DS-SDF, and (b) EGA-DDR for DS-NPDF with MER was studied and observed that modifying the data appropriately by utilizing the existing computerized tracking system available in the shop floor is sufficient and rescheduling or modifying the existing algorithms are not required when the occurrences of JR-RTE happens. - Finally, single solution based meta heuristics: Simulated Annealing (SA) and Tabu Search (TS), considering each of the six solution obtained from each of the six efficient variants of GA-DDR proposed in this study as initial solution respectively, were proposed for DS-SDF to minimize TWT. Performance analysis of the solution obtained from each of the six efficient variants of GA-DDR and from each of the meta heuristics were carried out and observed that efficient variants of GA-DDR seems to be robust in terms of both quality and computational time requirements in obtaining efficient solution. In addition, the impact of JR-RTE on the meta heuristics: SA and TS were studied and proved the research hypothesis proposed in this study. Although, this study considers many real-life problem characteristics, there are certain limitations in this study. Though this study proposed mathematical model for DS-NPDF, the required additional constraint on Machine Eligibility is not considered in this study. Further, the impact of JR-RTE on the meta heuristics: SA and TS were studied considering only DS-SDF and not for DS-NPDF with MER. In addition to overcoming the limitations mentioned here, there are many immediate future research directions for the problem studied in this thesis such as proposing the greedy algorithms for scheduling diffusion operation along with upstream or downstream operation, and proposing population based meta heuristics for the research problem defined in this study.

The subject of this work is to validate the possibility of managing the cast iron strength through residual Mg content and to determine methodically whether it is possible to exploit this technology in a foundry. It is another subject to determine the economics of the exchange of cupola furnace for electric induction furnace and methodically assess the possibilities of melting in the electric induction furnace.

The aluminium industry is anticipated to witness a surge in demand, with projectionsof a two to three-fold increase by 2050. Meeting environmental objectives andaddressing the growing emphasis on sustainability from both the industry andconsumers seeking eco-friendly products present significant challenges. Energyefficiency will be crucial in addressing these concerns. While primary aluminiumproduction consumes the majority of energy in the industry, the die-casting sector, asan energy-intensive segment, offers opportunities for enhancing energy efficiency. Inhousealuminium smelting in high-pressure die-casting (HPDC) foundries, primarilyemploying gas-fired shaft furnaces with preheating for improved energy efficiency, isa significant energy user.This research examines energy efficiency in High-Pressure Die Casting (HPDC)foundries, particularly in-house aluminium smelting. Utilizing literature reviewsand expert interviews, the study reveals efficient technologies, drivers and barriersto energy efficiency, and the importance of sustainability. The current absence ofwell-defined Best Available Techniques (BAT) and the absence of validated claims bymanufacturers in the HPDC sector emphasize the urgent need for extensive researchand empirical verification.The results from this study show that using gas-fired shaft furnaces is the optimalchoice for the next decade, with waste heat recovery as the primary energy efficiencymethod, supplemented by the implementation of energy management systems andstrategies. Induction furnaces may emerge as a viable future technology, contingenton significant electricity network expansion and low energy prices.

Résumé : L’auto-cicatrisation des fissures des matériaux cimentaires présente un intérêt important pour améliorer leur durabilité (propriétés de transfert par exemple). L’impact du laitier de haut-fourneau sur ce phénomène a été peu étudié bien qu’il ait été observé sur des ouvrages du Génie Civil. Dans cette étude, la cinétique et l’amplitude de l’auto-cicatrisation ont été suivies par des essais non destructifs : la tomographie aux rayons X et la perméabilité à l’air, pour une fissuration créée à 7 jours et à 28 jours. Les résultats montrent que le laitier de haut-fourneau possède un potentiel d’auto-cicatrisation intéressant pouvant dépasser les résultats obtenus pour les formulations de référence sans laitier. Ce bon potentiel dépend des caractéristiques physico-chimiques des matériaux brutes et du potentiel d’hydratation de la formulation au cours du temps. De plus pour suivre l’auto-cicatrisation, un nouvel essai a été mis en place afin de fissurer les éprouvettes de mortier par retrait gêné et d’étudier l’auto-cicatrisation d’une fissure naturelle. Cet essai s’est avéré efficace sur la formulation de référence. Une caractérisation des produits de cicatrisation par MEB-EDS témoigne de la formation de nouveaux produits dans les fissures et de l’impact important des conditions de stockage sur le type de produits formés: des C-S-H pour un stockage sous eau et des carbonates de calcium pour un stockage en chambre humide (CO2 + eau). Les résultats de migration aux chlorures de nano-indentation montrent que ces produits de cicatrisation possèdent de bonnes propriétés de durabilité et des propriétés mécaniques à l’échelle microscopique intéressantes (pour le carbonate de calcium). Enfin, une modélisation du phénomène d’auto-cicatrisation est proposée au moyen du code de calcul de géochimie PHREEQC. L’étude a révélé le potentiel intéressant de PHREEQC pour modéliser l’auto-cicatrisation et en faire un outil de prédiction du phénomène. / Abstract : Self-healing of cementitious materials presents great interest to improve the durability of concrete structure (transfer properties for example). The impact of blast-furnace slag on this phenomenon is not yet clear even if the self-healing of concrete with blast-furnace slag was observed in building sites. To understand the blast-furnace slag influence, non-destructive methods were used to follow self-healing: X-ray tomography and gas permeability test. All specimens were cracked at 7 days and 28 days. The results show that the blast furnace slag has an interesting self-healing potential that can exceed the reference formulation results. This good potential depends on the physico-chemical characteristics of the raw materials and the hydration potential of the formulation over time. In addition to follow the self-healing, a new trial was set up to crack mortar specimens by restrained shrinkage and study the self-healing of a natural crack. In addition to follow the self-healing, a new trial was set up to crack mortar specimens by restrained shrinkage and study the self-healing of a natural crack. This test has proven effective over the reference formulation.The SEM with EDS analysis showed the formation of new products in the crack and the impact of storage conditions on these products : C-S-H for specimens stored in water and calcium carbonate for specimens stored in a damp chamber (CO2 + water). Migration chlorures and nano-indentation tests results showed that self-healing products had interesting durability properties and micro-mechanical properties (for calcium carbonate). Finally, self-healing modelling is proposed by means of geochemistry PHREEQC calculation code. The study revealed interesting potential PHREEQC to model self- healing phenomenon and make it a of predictive tool.

A linear model of an annealing furnace is developed using a black-box system identification approach, and used when testing three different control strategies to improve temperature control. The purpose of the investigation was to see if it was possible to improve the temperature control while at the same time  decrease the switching frequency of the  burners. This will lead to a more efficient process as well as less maintenance, which has both economic and environmental benefits. The estimated model has been used to simulate the furnace with both the existing controller and possible new controllers such as a split range controller and a model predictive controller (MPC). A split range controller is a control strategy which can be used when more than one control signal affect the output signal, and the control signals have different range. The main advantage with MPC is that it can take limitations and constraints into account for the controlled process, and with the use of integer programming, explicitly account for the discrete switching behavior of the burners. In simulation both new controllers succeed in decreasing the switching and the MPC also improved the temperature control. This suggest that the control of the furnace can be improved by implementing one of the evaluated controllers.

Thesis (MScEng (Process Engineering))--Stellenbosch University, 2008. / The electric smelting furnace is found at the heart of the platinum recovery process where the power input from the electrodes produces a complex interplay between heat transfer and fluid flow. A fundamental knowledge of the dynamic system hosted by the electric furnace is valuable for maintaining stable and optimum operation. However, describing the character of the system hosted by the electric furnace poses great difficulty due to its aggressive environment. A full-scale threedimensional Computational Fluid Dynamics (CFD) model was therefore developed for the circular, three-electrode Lonmin smelting furnace. The model was solved as time dependent to incorporate the effect of the three-phase AC current, which was supplied by means of volume sources representing the electrodes. The slag and matte layers were both modelled as fluid continuums in contact with each other through a dynamic interface made possible by the Volume of Fluid (VOF) multi-phase model. CO-gas bubbles forming at electrode surfaces and interacting with the surrounding fluid slag were modelled through the Discrete Phase Model (DPM). To account for the effect of concentrate melting, distinctive smelting zones were identified within the concentrate as assigned a portion of the melting heat based on the assumption of a radially decreasing smelting rate from the centre of the furnace. The tapping of slag and matte was neglected in the current modelling approach but compensation was made for the heating-up of descending material by means of an energy sink based on enthalpy differences. Model cases with and without CO-gas bubbles were investigated as well as the incorporation of a third phase between the slag and matte for representing the ‘mushy’ chromite/highly viscous slag commonly found in this region. These models were allowed to iterate until steady state conditions has been achieved, which for most of the cases involved several weeks of simulation time. The results that were obtained provided good insight into the electrical, heat and flow behaviour present within the molten bath. The current density profiles showed a large portion of the current to flow via the matte layer between the electrodes. Distributions for the electric potential and Joule heat within the melt was also developed and showed the highest power to be generated within the immediate vicinity of the electrodes and 98% of the resistive heat to be generated within the slag. Heat was found to be uniformly distributed due the slag layer being well mixed. The CO-gas bubbles was shown to be an important contributor to flow within the slag, resulting in a order of magnitude difference in average flow magnitude compared to the case where only natural buoyancy is at play. The highest flow activity was observed halfway between electrodes where the flow streams from the electrodes meet. Consequently, the highest temperatures are also observed in these regions. The temperature distribution within the matte and concentrate layers can be characterized as stratified. Low flow regions were identified within the matte and bottom slag layer which is where chromite and magnitite deposits are prone to accumulate. The model results were partially validated through good agreement to published results where actual measurements were done while also falling within the typical operating range for the actual furnace. The modelling of the electric furnace has been valuably furthered, however for complete confidence in the model results, further validation is strongly recommended.

After carbon, phosphorus is the most commonly detected element in archaeological iron. The typical phosphoric iron range is 0.1wt% to 1wt%P. The predominant source of phosphorus in iron is the ore smelted. Around 60% of economic UK rock iron ore formations contain over 0.2%P. Under fully reducing conditions, both in liquid-state (cast iron) and solid-state bloomery smelting (direct reduction) processes, such rock ores would be predicted to produce phosphoric iron, and bog iron ores even more so. Ore-metal-slag phosphorus ratios for bloomery iron are derived here, by means of: laboratory experiments; full-scale experimental bloomery smelting; and analysis of remains from three Medieval and two Late Roman-Iron Age iron production sites in England and the Netherlands. Archaeological ore, slag, metal residues (gromps), and iron artefacts were analysed by metallography, SEM-EDS, EPMA, and XRD. The effects of forging and carburising on phosphoric iron were studied by experiment and artefact analysis. The ore to slag %P ratio for solid-state reduction was determined to range from 1:1.2 to 1: 1.8. The ore to metal %P ratio varied from 1:0.2 to 1:0.7-1.4, depending on furnace operating conditions. Archaeological phosphoric iron and steel microstructures resulting from non-equilibrium reduction, heat treatment, and mechanical processing are presented to define the technology of early phosphoric iron. Microstructures were identified by a combination of metallography and chemical analysis. The phosphoric iron artefacts examined appear to be fully functional objects, some cold-worked and carburised. Modern concepts of 'quality' and workability are shown to be inapplicable to the archaeological material.

<p>Four different kinds of filter-materials with reactive surfaces have been studied concerning their capacity to absorb heavy metals in leachate from a municipal waste deposit. The heavy metals studied were: lead, cadmium, copper, mercury, chromium, nickel and zinc. The leachate contains high levels of dissolved organic carbon (DOC) and has a high pH-value along with a high buffer capacity. These characteristics of the leachate make it difficult to remove pollutants and require efficient filters. The filters that were examined in the report are blast-furnace slag with CaO, sand covered with iron oxides, olivine and nepheline. The experiment was carried out in two sets, starting with batch experiments followed by a column study. The objective of the batch experiments was to find out how variations in pH affected the sorption capacity of the materials. The interval used during the test was from pH 5 to pH 10. The computer program VisualMinteq was used to evaluate the dominating sorption processes when the materials interacted with the solutions. Two different kinds of solutions were used in the batch experiment. One of them was the leachate, to which known concentrations of heavy metals were added (about 1 μM) and the other consisted of sodium nitrate, a solution without organic compounds, which was used as a reference. The sodium nitrate solution was also spiked with the same concentration of heavy metals as the leachate.</p><p>The results from the batch experiment showed that the sorption of heavy metals was lowered if the DOC level was high. No relation between pH and sorption ability could be found for the leachate, but for some metals in the sodium solution a higher pH improved the removal of heavy metals. The two materials that showed best results in the batch experiment were the blast-furnace slag and the sand with iron oxides. These materials were used in the column study. The olivine material was somewhat better than the nepheline in the batch experiment.</p><p>Four columns were used in the column study, two for each material. Leachate with heavy metals was pumped into the columns with a specific flow rate; at first a low flow rate was used and when half the experiment time had passed the flow rate was increased. The flow rates used were 0.12 m/24 h and 0.62 m/24 h. The outcome of the column experiment showed that the slag had the highest ability to adsorb metals. The metal sorption was over 60 percent for lead, cadmium and zinc, where the highest sorption was obtained for lead. No affects were noticed when the flow rate was increased.</p> / <p>I detta examensarbete har fyra olika reaktiva filtermaterials kapaciteter att ur deponilakvatten avskilja tungmetallerna bly, kadmium, koppar, kvicksilver, krom, nickel och zink testats. Deponilakvatten är ett avloppsvatten med höga halter organiskt material (DOC), högt pH och en hög buffertkapacitet. Dess sammansättning ställer stora krav på ett filter och närvaron av ligander påverkar sorptionprocesserna. Filtren som ingått i studien är kalciumoxiddopad masugnsslagg, järnoxidtäckt sand, olivin och nefelin.</p><p>Försöken utfördes i två delar, med inledande skakförsök och därefter kolonnförsök. I båda försöken användes lakvatten med en extra tillsats av tungmetaller. I skakförsöken användes även natriumnitrat; ett referensvatten utan organiska ligander, även det spikat med tungmetaller. I skakförsöken studerades avskiljningens pH-beroende för de olika filtren, med ett pH-intervall på ca 5 – 10. Därefter modellerades resultaten i jämviktsprogrammet VisualMinteq för att fastställa vilka processer som styr avskiljningen. Skakförsöken och kolonnförsöken utfördes båda i klimatrum vid 8 ºC, för att efterlikna markens naturliga temperatur.</p><p>Resultaten från skakförsöken visade att masugnsslagg och järnoxidsand gav bäst avskiljning för de flesta tungmetaller. Olivin och nefelin var sämre metallsorbenter, där olivin uppvisade något bättre resultat än nefelin. Inget tydligt pH-beroende för lakvattnet kunde utläsas, men för natriumnitratlösningen gav en pH-höjning en ökad sorption för vissa metaller. Den kemiska jämviktsmodelleringen visade att den dominerande processen i filtermaterialen var sorption på filterytorna. De två filtermaterialen som visade bäst resultat i skakförsöken (slagg och järnoxid) studerades vidare i kolonnförsök, där ett bestämt lakvattenflöde pumpades genom kolonner packade med materialen. Två olika flödeshastigheter testades (0,12 m/dygn och 0,62 m/dygn) och sorptionen av metaller analyserades. Slaggen uppvisade högst avskiljningskapacitet av de studerade filtren. De metaller som sorberades bäst var bly, kadmium och zink (över 60 % avskiljning), där den högsta sorptionen erhölls för bly. Gemensamt för både skak- och kolonnförsöken var att sorptionen försvårades då halten organiskt material (DOC) ökade, vilket beror på att DOC konkurrerar med de reaktiva ytorna på filtren om att binda den fria metalljonen. Ingen minskande avskiljningseffekt av en flödesökning kunde utläsas.</p>

<p>An excessive input of nutrients to lakes and other water bodies has created a problem with eutrophication in Sweden. Untreated, or partially treated, domestic sewage is a major source for discharge of phosphorus (P), which is the nutrient most frequently responsible for eutrophication of most fresh waters and the Baltic Sea. The waste water can be cleaned by filter materials, which have a high P-retention ability and which after saturation may be used as fertilizers. Four potentially suitable filter materials were tested in batch- and column experiments in this study. In the batch experiments, the following materials were shaken with waste water in time series ranging from 5 seconds to 60 minutes: coarse (1-4 mm) and fine (0-2 mm) Polonite® (heated bedrock from Poland); Filtralite® (light expanded clay aggregates with limestone added before burning); water cooled blast furnace slag (BF-slag) and BF-slag mixed with 10% burned limestone. In the column experiment, the phosphorus sorption capacity in BF-slag and BF-slag mixed with burned limestone was observed under saturated and unsaturated flow conditions for 10 weeks. The waste water used in both experiments originated from the full scale testing site at Ångersjön in Sweden. After the column experiment was ended, the filter materials were investigated with XRD (X-ray diffraction) and SEM (scanning electron microscope) in order to figure out which chemical reactions that had taken place.</p><p>The results from the batch experiments show that fine Polonite® and BF-slag mixed with limestone have the fastest P sorption capacity. Already after 5 seconds of shaking the materials showed effective retention of P. The coarse Polonite®, Filtralite® and BF-slag showed similar sorption capacities, although the coarse Polonite® tended to be somewhat inferior. The column studies showed that the materials used in the columns had a sorption capacity of 98 % or more. The XRD and SEM indicated that an amorphous calcium-P-compound was created in the filter material.</p> / <p>I Sverige är reningen av fosfor i vatten från enskilda avlopp ofta bristfällig, vilket bland annat kan leda till övergödning av sjöar, hav och vattendrag. Sedan några år tillbaka har olika filtermaterial med speciella reaktiva egenskaper, som bland annat avskiljer fosfor från avloppsvatten, undersökts. Tanken med filtermaterialen är att de efter mättnad med näringsämnen ska kunnas användas som jordförbättringsmedel. I denna rapport har några olika filtermaterial, lämpade för fosforavskiljning, undersökts genom skak- och kolonnförsök. I skakförsök, där skaktiderna varierade mellan 5 sekunder och 60 minuter, testades Polonite®, Filtralite®, Hyttsand och Hyttsand blandad med 10 % bränd kalk. Polonite® är en upphettad form av bergarten opoka varav två olika kornstorleksfraktioner (0-2 mm och 1-4 mm) användes. Filtralite® och Hyttsand är antropogena filtermaterial. Filtralite® tillverkas i Norge och består av kalkhaltiga kulor av expanderad lera (Leca®). Hyttsand framställs genom vattenkylning av masugnsslagg som bildas vid framställningen av råjärn vid stålverket i Oxelösund. I kolonnförsöken, som utfördes under 10 veckor, studerades Hyttsand och Hyttsand blandad med 10 % bränd kalk under omättade och mättade flödesförhållanden. I samtliga experiment användes avloppsvatten från reningsverket vid Ångersjön, där Filtralite® och Hyttsand testas i fullskala. Efter kolonnförsöken avslutats undersöktes filtermaterialen med XRD (röntgendiffraktion) och SEM (svepelektron mikroskop) för att utreda vilka mekanismer som medverkat vid avskiljningen av fosfor.</p><p>Resultaten från skakförsöken visade att finkornig Polonite® och Hyttsand blandad med kalk avskiljer fosfor effektivt redan efter skakning i 5 sekunder. Grovkornig Polonite, ren Hyttsand och Filtralite® sorberade fosfor tämligen likartat, även om den grovkorniga Poloniten® tenderade att vara aningen sämre än de övriga. Resultaten från kolonnförsöken visade att fosfor kunde avskiljas till över 98 % i alla kolonner och att det bildats amorfa fosfatföreningar, främst med kalcium, under den 2,5 månader långa experimentperioden.</p>

Lake Champlain is a major economic driver for Vermont's tourism economy, as well as a primary source of drinking water for many of the state's residents but nutrient pollution represents a potential threat to ecosystem health and economic well-being. From December 2011 to December 2012 a field trial of an EAF steel slag filter was assessed for its feasibility in treating wastewater originating from Swan Valley Cheese (SVC), in Swanton, VT. The study focuses on a period of the filter's operation from May 4 to October 10, 2012. The plant generates approximately 20,000 gallons per day of high P concentration wash water which is treated in an open aerated lagoon. The filter treated effluent from this lagoon. The major goals of this research were to conduct a field trial of an EAF steel slag filter to evaluate its effect on total P (TP), dissolved reactive P (DRP), and total suspended solids (TSS). Research was also conducted on pH reduction for filter effluent. Results indicate that the filter removed 95.83% of TP, 96.65% of DRP, and 52.25% of TSS. Average pH effluent was measured at 10.12 ±1.55. Additionally, a field study was conducted on sampling two unlined bioretention systems treating urban stormwater runoff. Methods used are presented and methodological considerations for future studies are presented to guide researchers in more effective and efficient methods for obtaining influent and effluent samples from bioretention systems that are not necessarily designed for sampling.