Lake Burragorang, the focus of this thesis, is the main water supply source for the large population of Sydney and is a major source for the Blue Mountains residents. This study was aimed to evaluate the distribution of heavy metals and their speciation in sediments of Lake Burragorang. The principal focus is on the study of heavy metal pollution and their bioavailability to the aquatic system. Five-step sequential extraction procedure was employed to assess different geochemical forms of certain metals in sediment grabs of Lake Burragorang. This is the first study to report metal speciation data for Lake Burragorang sediments. No significant spatial variations were observed in the speciation trends. The variation in metals and nutrients in the sediments with age was established and has been compared with published historical record, rainfall records and bushfire data. / Master of Engineering (Hons)

This thesis presents analysis of the hydrodynamic and sedimentation changes of the Causeway Lake, Queensland. It was created in 1939 when a causeway and bridge construction was built across the estuary entrance. Since the construction, significant sediment retention has occurred in the lake. The sediment study presented in this thesis was undertaken based on historical data, field data measurement and numerical modelling, supported by theoretical analysis. Based on bathymetry data for the period from 1986 and 2003, an average of 2500 m3/year of sediment has settled in the estuary. To verify the sources of sedimentation, field measurements were undertaken at selected sections at two upstream boundaries (Mulambin and Shoal Creeks), and at the downstream boundary under the bridge. Four sets of field measurements with tidal elevation up to 4.5 m (0.8 m above the bridge sill) were analysed. Results showed that sediment transport in from the sea side was about 1050 m3/year and from the catchments area was in the order of 1100 m3/year (wash load was not included). Implementation of numerical modelling using RMA required calibration using field data. The predicted sediment transport was in order of 2900 m3/year. The calibrated model was used to simulate the sedimentation pattern for the next 10 years. Four scenarios were analysed, and the resulting recommendation was to dredge out about 141,000 m3 sediment from the Mulambin Creek branch area. Other solutions were also suggested: improvement of lake management and possibility to raise the sill level (water gate).

Many sediments, including the fine-grained pelagic deposits, possess polymodal grain size distributions. Resolution of individual modes show them to be related either to compositional fractions or to depositional processes or both, and sometimes permits the tracing of dispersal patterns. The Cahn sedimentation balance provides a means of obtaining continuous cumulative size distribution curves of fine-grained sediments. The resultant cumulative curve is processed by computer to yield a size frequency curve which is often found to be polymodal. This frequency curve is resolved into its individual components by means of an analog computer. The method is discussed in detail and illustrated by means of a test study of pelagic sediments from the Northwest Pacific. Samples collected nearest land have the most components and the best sorted components. Fifteen modes were decanted from five samples and X-rayed. Similar components from different samples were found to have similar compositions when plotted on a feldspar-kaolinite-mica ternary diagram. Based on like composition and nearly identical mean size values, it is possible to trace the sedimentary components from sample to sample. / Graduation date: 1972

This multidisciplinary study integrates remote sensing, stratigraphy, siliciclastic and carbonate sedimentology, tectonics, and petrography of the Nisai, Khojak and Sharankar Formations to reveal the Paleogene depositional, diagenetic and deformational history of the Katawaz Basin. Study of Landsat Thematic Mapper (TM) digital data shows that maximum discrimination of different rocks is achieved in bands 5, 4, and 2 in red, green and blue, respectively. Maximum spectral contrast of Nisai limestone lithofacies uses band ratios 7/5(R), 4/3(G)and 3/2(B). Laboratory spectral measurements suggest Nisai lithofacies are best discriminated in lower wavelength regions (TM bands 1, 2, 3, and 4). Late Paleocene to early Oligocene Nisai Formation records carbonate platform, slope and basinal deposition. Newly formed structural highs and lows, due to emplacement of ophiolites on the western passive margin of Indo-Pakistan subcontinent, controlled deposition and thickness of Nisai lithofacies. Revised age of the ophiolite emplacement, based on benthic forams, is early Paleocene. Siliciclastic Khojak Formation includes newly identified upper continental slope, prodelta, delta front, lower and upper delta plains lithofacies. These lithofacies represent prograding fluvial-dominated, wave-modified Katawaz delta that axially fed Khojak submarine-fan turbidites to the southwest. Sandstone detrital modes and paleocurrent analysis suggest derivation from the early Himalayan orogen and longitudinal dispersal down the basin axis. Decrease in quartz, and increase in total lithics from bottom to top reflect gradual uplift and unroofing of the early Himalaya. Diagenetic relationships suggest complex paragenetic sequence of chlorite-quartz-calcite cementation. Himalaya-derived molasse, delta, and turbidite fan sediments are related in time and space. Molasse sedimentation began in late Paleocene, when early Himalayan orogenic highlands formed. However, sedimentation on the modern Indus delta-fan began in the early Miocene. This age-range discrepancy implies that a major portion of the Himalayan marine record is missing. Khojak strata are that missing record. The Katawaz remnant ocean closed, scissors fashion, by the end of early Miocene and the Katawaz-Khojak complex was incorporated to the Indo-Pakistan subcontinent. The Himalaya-Katawaz system is a Paleogene analogue to the Carboniferous Appalachian-Black Warrior-Ouachita system. / Graduation date: 1998

The present work deals with the development of a direct simulation strategy for solving the motion of spherical particles in non-Newtonian liquids. The purely viscous (non-elastic) non-Newtonian liquids are described by Bingham and thixotropy models. Validation of the strategy is performed for single phase (lid driven cavity flow) and two phase flows (sphere sedimentation). Lid driven cavity flow results illustrate the flow evolution of thixotropic liquid and subtle differences between thixotropic rheology and pseudo Bingham rheology. Single sphere sedimentation in Bingham liquid is shown to be influenced by the yield stress of the liquid. Time-dependent properties such as aging prominently affect the settling of a sphere in thixotropic liquid. The hydrodynamic interactions between two spheres are also studied at low and moderate Reynolds numbers. In thixotropic liquid, an intriguing phenomenon is observed where the separation distance between the spheres first increases and then rapidly decreases. / Chemical Engineering

This research is an experimental, field and numerical study of the sedimentation and consolidation of in-line thickened oil sands fine tailings. In-line thickening is a process that adds flocculant and coagulant into a modified tailings pipeline in a multi stage fashion to improve the dewatering behaviour of oil sands fine tailings cyclone overflow. The parent untreated cyclone overflow, in-line thickened tailings and sheared in-line thickened tailings were investigated in the laboratory. In-line thickened tailings were produced in the laboratory using the same process as in the field project and sheared in-line thickened tailings were prepared by shearing the thickened tailings with a specified shearing effort to simulate tailings transportation. A combination of hindered sedimentation tests, compressibility standpipe tests and large strain consolidation tests with vane shear tests was then used to capture a full range of sedimentation, consolidation and shear strength characteristics for these materials. Results show that the in-line thickening process significantly improves hydraulic conductivity and undrained shear strength of the fine tails. Shearing damages some of the floc structure but does not cause the material to fully return to the original state of the cyclone overflow. The laboratory data of the in-line thickened tailings was compared with field performance at two in-line thickened tailings pilot scale ponds and with a validation standpipe test by utilizing a developed finite strain consolidation model. Good agreements were obtained between the field performance, the laboratory test results and the validation standpipe test. These good agreements confirmed the validity of the laboratory determined geotechnical parameters and of the developed numerical model and indicated that it is possible to model large scale field performance with small scale laboratory tests. Finally, composite tailings was made from the in-line thickened tailings and was found to have a similar segregation boundary to that of gypsum treated composite tailings made with mature fine tailings but had a much higher hydraulic conductivity and shear strength which were inherited from the flocculated fines. / Geotechnical Engineering

Thesis (M.S.)--Ohio University, June, 2006. / Title from PDF t.p. Includes bibliographical references (p. 66-73)

In the process laboratory of Metso minerals (Sala) AB, continuous tests have been made with a laboratory unit High-Rate thickener. The tests are made in order to compare three methods of thickening techniques of suspended solids. The three techniques are High-Rate thickening, conventional thickening and lamella thickening. The High-Rate and the conventional trials are based on a continuous method, while the lamella thickener is based on batch trials. Because the lamella thickener is based on batch trials and there were some optimization problems with the adding point of the flocculant at the continuous trials, it was not feasible to compare the lamella thickener with the other two thickener types. On the other hand, since the optimization problems were the same for the other two methods there was no problem comparing them. The result of the comparison between the High-Rate thickener and the conventional thickener, was, that the High-Rate thickener manages to work at a higher rise rate with a lower consumption of flocculant than the conventional thickener. Seeing to the unit area that is needed by each thickener it is apparent that the conventional thickener demands a higher unit area than the High-Rate thickener to achieve the same amount of solids in the underflow. It has also been showed that the High-Rate thickener demands a lesser quantity of flocculant at the same amount of suspended solids in the feed than the conventional thickener.

Det vatten som avrinner från hårdgjorda ytor, så kallat dagvatten, innehåller ofta en mängd olika föroreningar, så som tungmetaller och näringsämnen, som kan göra stor skada om vattnet inte renas innan det når recipienten. Ett vanligt sätt att rena detta vatten är genom öppna system, som dammar och våtmarker, eftersom de fungerar både som flödesutjämnare och som sedimentationsmagasin. I Steningedalen, Märsta, finns en dagvattenanläggning med dammar och översilningsytor, vars syfte är att rena dagvatten från ett avrinningsområde på ca 7200 ha. Vattnet leds till dammarna via en dagvattentunnel vars primära syfte var att leda vattnet förbi Märsta centrum. Tunneln är ca 3100 m lång, sprängd och delvis i betong, och har ett skibord installerat i tunnelmynningen med syfte att skapa ett sedimentationsmagasin samt att vid höga flöden leda vattnet förbi dammarna direkt till Märstaån. I denna studie har reningseffekten av denna dagvattentunnel utretts. Detta har gjorts genom provtagning av vattnet i två punkter i tunneln, den ena belägen ca 1 km uppströms tunnelmynningen och den andra i tunnelmynningen. Analyser med avseende på tungmetallerna bly, kadmium, krom, koppar, nickel och zink samt näringsämnet fosfor har därefter genomförts. Även halten suspenderat material och vattnets partikelstorleksfördelning har undersökts. För att komplettera vattenanalyserna har även tungmetall- och fosforhalten i sedimenten vid provpunkterna analyserats och sedimentmäktigheten mätts. Resultaten av vatten- och sedimentprovtagningen visar bland annat att halterna av tungmetaller i vattnet generellt är relativt höga. Speciellt zink återfinns i höga halter både i vattnet och i sedimenten och överskrider det av Naturvårdsverket uppsatta gränsvärdet för lösta halter i vatten. Vidare är fosforhalterna, enligt Naturvårdsverkets klassning för sjöar och vattendrag, extremt höga vid högt flöde och höga vid lågt flöde i tunneln.  Resultaten av filtreringsanalyserna visar på att partikelstorleken i vattnet är generellt mycket liten, vilket innebär att andelen partiklar som är stora nog att sedimentera också är mycket liten. Sedimentmäktigheten är dock högre i slutet av tunneln, vilket visar att sedimentationen ökar med ett minskat avstånd till tunnelmynningen. Detta beror sannolikt på att det installerade dämmet leder till en minskad vattenhastighet genom en ökning i tvärsnittsarea, vilket i sin tur leder till förbättrade förutsättningar för sedimentation. Resultaten visar vidare att halterna av tungmetaller och fosfor i dagvattnet inte skiljer sig avsevärt mellan provpunkterna vid lågt flöde i tunneln. Vid högt flöde är halten av tungmetaller och fosfor dock lägre vid tunnelmynningen jämfört med den övre provtagningspunkten, vilket tyder på att det sker en viss avskiljning i tunneln, sannolikt genom sedimentation av partikelbundna föroreningar. Därmed dras slutsatsen att tunnelns senare del uppvisar en god avskiljning av föroreningar vid ett relativt högt flöde, men att avskiljningseffekten minskar vid lägre flöden, vilket kan förklaras genom att partiklarna i vattnet generellt är mycket små men att både mängden partiklar och partikelstorleksfördelningen ökar vid högre flöden. / Stormwater often contains a variety of pollutants such as heavy metals and nutrients that can cause great damage if the water is not treated before it reaches the recipient. A common way to decontaminate this water is through open systems such as ponds and wetlands since they both act as a sedimentation tank and also create a more steady flow. In Steningedalen, Märsta, there is a constructed wetland system designed to clean stormwater from a catchment of about 7200 ha. The water is channeled to the ponds via a stormwater tunnel whose primary purpose was to carry water past the center of Märsta village. The tunnel is about 3100 m long, partially in concrete, and has a weir installed in the end of the tunnel. The purpose of the weir is partly to create a sedimentation basin and partly to channel water past the wetland system when high flows occur. In this study, the treatment effect of this stormwater tunnel is investigated. This has been carried out by sampling the water at two points, one about 1 km away from the end of the tunnel, and the other at the end of the tunnel, with subsequent analysis for the heavy metals lead, copper, cadmium, chrome, nickel and zinc as well as the nutrient phosphorus. Also, the concentration of suspended matter and the particle size distribution of the stormwater has been investigated. To supplement the water analysis, heavy metals and phosphorus in the sediments were analysed and thickness of the sediment was also measured. The result of the water and sediment sampling shows that the levels of heavy metals in the water are generally relatively high. Zinc in particular, is found at high concentrations both in water and in sediments and exceeds the Environmental Protection Agency’s limit. Phosphorus levels are also, according to the Environmental Protection Agency's classification of lakes and streams, extremely high at high flow rates and high at low flow rates in the tunnel. The results also show that the concentrations of heavy metals and phosphorus in surface waters do not differ significantly between the sampling points at low flow rates in the tunnel. At high flow rates, however, a reduced level of both heavy metals and phosphorus was detected in the end of the tunnel, which indicates that the level of these pollutants decreases with distance from the inlet due to sedimentation in the tunnel. Sediment thickness is greater at the end of the tunnel, which indicates that sedimentation increases towards the outlet of the tunnel which most likely is due to fact that the installed weir slows down the flow rates and creates a sedimentation basin. However, the results of the particle size distribution analysis show that the fraction of particles large enough to settle is very small. Thus it is concluded that the later part of the tunnel shows a relatively good separation capability at high flow rates, but the separation effect is reduced at lower flow rates, which can be explained by the small size of the particles in the water.

Copano Bay is a shallow (< 2-3 m), microtidal estuary in south central Texas. In an effort to both determine the distribution as well as investigate the controls on the distribution of oyster reefs, a geophysical survey of Copano Bay was conducted in June and July 2007. Surficial sediment analysis confirms that the recent sedimentation in Copano Bay is comprised of mostly estuarine mud with little sand or shell, large extents of oyster reefs and smaller areas of sand. Seismic stratigraphy analyses verify that the first oyster reefs in Copano Bay formed atop topographic highs in the Pleistocene surface. About 6 ka, sea level rise slowed to near its present rate and sediment supply decreased tremendously to Copano Bay decreasing the amount of suspended sediment. The first oyster reefs began forming around this time using these fluvial terraces as suitable substrate. Once the initial reefs were established, additional reefs began forming atop these initial reefs, or on the eroded shell hash material from the initial reefs. During this time of slow sea level rise and low sediment input to the bay, oyster reefs thrived and reef and shell hash material covered a majority of the bay surface. Once climate change increased sediment input to the bay, the reefs began to decrease in size due to siltation. The reefs have continued to decrease in size causing a 64 percent reduction in oyster reef and shell hash area from approximately 4.8 ka to today.