Laboratory studies conducted at 5, 15, 25, and 35 C measured changes in gilling rates and oxygen consumption of green sunfish in response to exposure to bentonite clay suspensions. The tests indicate that gilling rates are not affected by bentonite clay suspensions below 2125 FTU at 5 C, 1012 FTU at 15 C, and 898 FTU at 25 C. At turbidity levels exceeding 1012 FTU at 15 C and 898 at 25 C, gilling rates increased 50-70%. Tests were inconclusive at 35 C. Oxygen consumption rates were found to be unaffected by turbid suspensions below 3500 FTU at all four temperatures. Evidence suggests that increased gilling rates under highly turbid conditions are a means of compensating for reduced respiratory efficiency and a strategy for maintaining a constant oxygen uptake. Evidence indicates that the cost of increased gilling rates is probably met by a reduction in activity.

The interaction between low-density lipoprotein (LDL) and glycosaminoglycans is a key factor in atherosclerosis. The present study examines the characteristics of LDL and its binding properties with the main glycosaminoglycan of the vascular wall, chondroitin 6- sulphate (C6S). The compositional characteristics that were studied for each LDL sample were phase transition temperature, phospholipid content, free cholesterol content, cholesteryl ester content, triglyceride content, and size. Correlations of these characteristics with LDL-C6S binding were analyzed using a turbidity assay. Our results showed that there is no correlation between LDL-C6S binding and phase transition temperature, triglyceride content, or size. Strong correlations were present for LDL-C6S binding and phospholipid content (P < 0.0001, r2 = 0.4591), free cholesterol content (P < 0.01, r2 = 0.2495), and cholesteryl ester content (P < 0.005, r2 = 0.2952). When values for surface (phospholipids and free cholesterol) and core (cholesteryl esters and triglycerides) lipids were determined a positive correlation was also present with LDL-C6S binding (P < 0.0005, r2 = 0.4172; P < 0.0005, r2 = 0.4282; respectively). These results indicate that large, lipid-rich LDL particles have a higher capacity to bind C6S than smaller, lipid poor LDL. Possible implications for the atherogenicity of LDL are discussed.

Thesis advisor: Gail Kineke / Turbidity maxima are areas of elevated suspended-sediment concentration commonly found at the head of the salt intrusion in partially-mixed estuaries. The suspended-sediment distribution in the Connecticut River estuary was examined to determine where turbidity maxima exist and how they form. Areas of enhanced suspended-sediment concentration were found to exist at all phases of the tide near the head of the salt intrusion as well as downstream of this point in deeper parts of the estuarine channel. These areas are locations where peaks in the longitudinal salinity gradient exist, suggesting the presence of a front, or zone of flow convergence. During flood conditions there is a layer of landward-flowing water in the middle of the water column that decelerates upon entering deep parts of the estuary; thus enhancing particle settling. During ebb conditions, stratification and therefore settling from surface waters is enhanced. The combination of processes acting throughout the tidal cycle focuses and, potentially, traps sediment in the deeper parts of the Connecticut River estuary. / Thesis (BS) — Boston College, 2012. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Geology & Geophysics Honors Program. / Discipline: Earth and Environmental Sciences.

One billion of the poorest people in the world today do not have access to improved drinking water. Without treatment, fecal contamination results in an overwhelming disease burden. A long term best practice solution will take decades to implement. In the meantime, approximately 5 million children under five die each year from gastrointestinal diseases. This tragedy can be alleviated by household water treatment. Household Water Treatment and safe Storage systems (HWTS) provide an interim solution. While many low cost and simple technologies exist, none of them are effective against high suspended solids concentrations (>50 NTU). Previous short-term field research by others has considered modifying a BioSand water Filter (BSF), to include pretreatment through an upper sand layer in order to extend the run cycle of the primary filter, enabling complete ripening to occur. In this research program, one control and twelve configurations of modified filters were setup in the laboratory. Water was chemically conditioned to provide worst case scenario treatment by adjusting pH, TDS, and particle dispersion. Sample water was passed through each filter daily, and monitored for DO, turbidity, flow rate, and E. coli concentrations. The results indicate that pretreatment is not necessarily beneficial under all water quality conditions. Recommendations include a description of conditions under which the modification may be beneficial, and optimized pretreatment design criteria. Regardless of water quality conditions, it was found that changing the operational guidelines for filter use can significantly improve treatment efficiency, without complicating the filter design. Design guidelines for an unmodified filter coupled with operational guidelines are provided, in order to obtain sufficient quantities of the best possible water quality under high turbidity conditions. This will enable the BSF to be used in high turbidity conditions and still significantly improve the drinking water quality. It is hoped that this will decrease the disease burden and loss of life in many of the world's poorest communities.

This thesis investigates the distribution and significance of stream turbidity in Victoria; specifically exploring the factors that may have influenced the pattern of regional variation in turbidity, and factors that give it significance in the regional, social, cultural and environmental context. The limits to water availability are set, not only by the quantity of water in storages or streams but, more fundamentally, by acceptable levels of water quality and catchment health. To make effective judgements of water availability managers of water resources need to know the significance of measured natural resource condition in the regional context. Stream turbidity can be considered by the agricultural community as a sign of soil erosion and a loss of agricultural potential, while from the ecological perspective it can be considered a sign of deteriorating river health. Fundamentally, levels of turbidity are closely bound with land use practice and, in the Australian context, turbidity can be considered a measure of the consequences of land management practices on soil erosion and run-off. Measured levels of turbidity in Victoria should be interpreted within the context of a unique history and geography. The spread of European colonisation and the introduction of massive land use change to the Victorian landscape have meant that over most of Victoria current levels of turbidity reflect the effects of over a hundred and fifty years of large scale intervention with its controlling factors. In Victoria current levels of turbidity are interpreted in a cultural context far different from that of early colonists or even of a few decades ago. The concept of Ecologically Sustainable Development which has dominated natural resource management in recent times brings new responsibilities to resource managers. Ecologically sustainable management means that resources must be considered in a more inclusive spatial and temporal context. In the early stage of Victoria's history sustainable management of water meant having enough water left from winter rains to supplement summer supply. However, in recent years, it has begun to have more complex associations; sustainable water use is now, almost universally considered to include maintenance of the environmental health of waterways, and by implication, the environmental health of the whole catchment. In this context, stream turbidity can be considered a useful indicator of catchment health, in particular, because levels of turbidity bear a direct physical relationship to catchment processes. New tools are needed to explore the relationship between land use and water quality at the regional scale. The results of this current research include a regional statistical model of stream turbidity, which is conceptually designed to offer useful predictions of stream turbidity and underpin sustainable resource management. The statistical model was used as input to the development of a unique map display using Geographic Information Systems (GIS). The GIS is used to display the distribution of model predictions over a large region of south-eastern Australia. The practical advantage of this modelling approach is that it provides managers with the ability to identify locations in Victoria where measured water quality differs significantly from modelled water quality and flag them for further investigation. The major project outputs are a map of Victorian Water Quality Monitoring Network (VWQMN) catchments showing catchments in Victoria where measured turbidity differs from model predictions and a raster representation of the state of Victoria in which cell values indicate predicted stream turbidity. Important to this project was the novel use of GIS technology to process large national and regional scale digital data sets using tools developed for catchment scale hydrological models.

The contribution of phytoplankton productivity to higher trophic levels in salt marshes is not well understood. My study furthers our understanding of possible mechanisms controlling phytoplankton productivity, abundance, and community composition in salt marshes. Across three consecutive springs (2001 to 2003), I sampled the upper Nueces Delta in south Texas, a shallow, turbid, salt marsh system stressed by low freshwater inflow and wide ranging salinity (<15 to >300 ppt). Water column productivity and respiration were estimated using a light-dark bottle technique, and phytoplankton biovolume and community composition were determined using inverted light microscopy. To determine their effect on the phytoplankton community, zooplankton and bacterioplankton abundance and several physical parameters were also assessed. Meaningful relationships among the numerous variables evaluated in this study were identified using principal component analysis (PCA). Despite high turbidity, phytoplankton productivity and biovolume were substantial. Resuspension appeared to play a major role in phytoplankton dynamics, as indicated by a positive relationship between ash weight and biovolume that explained up to 46% of the variation in the PCA. Negative relationships between zooplankton grazers and pennate diatoms of optimal sizes for these grazers suggested a functional grazing food chain in this system. Salinity also may have been important in phytoplankton dynamics, whereas nutrients appeared to play a minor role. Salinity increases may have been responsible for a decoupling observed between phytoplankton and grazers during late spring. Findings suggest hypotheses for future studies focused on the role of phytoplankton in salt marshes, particularly those stressed by reduced freshwater inflow and high salinities.

Extreme rainfall in raw water resource is greatly caused by climate change in Taiwan now. When typhoons are occurred, the turbidity in raw water is caused a high concentration frequently. In Taiwan the raw water, used by water treatment plants, comes from majorly river water. Most water treatment plants use chlorine disinfection; the disinfection process also produced excess disinfection by-products when raw water contains high turbidity and organic matter. In recent years, membrane method is widely being applied in water purification, but shortcomings were the higher price and not longer life. The purpose of this study is to investigate the treatment efficiency of turbidity, TOC, AOC, THMs and THMFP by using cheap nonwoven and biofilter (denoted as This System). In this study we used the base weight of 35 g/m2 nonwoven in filtration experiments for turbidity removal. Experimental results show turbidity removal by this system was nearly 90% when inlet turbidity is under moderate condition. The turbidity of treated water in effluent is all below 2 NTU that is compliance with national drinking water quality standards. Turbidity removal was about 90% using nonwoven with 21 pieces. Removal of organic matter is about 39% using biofilter when influent was in the low concentration of TOC. The removal rate is about 77% when the high TOC concentration in influent. In removal of TOC, TOC removal of raw water (I) was about 26.41%. The concentration of TOC was reduced from1169.9 £gg/L to 856.9£gg/L. The TOC removal of raw water (¢º) was about 19.65%. The concentration of TOC was reduced from 680.8£gg/L to 521£gg/L. The TOC removal of raw water (¢») was about 48.78%. The concentration of TOC was reduced from 1819 £gg/L to 936.5£gg/L. In removal of AOC, the removal rate of raw water (I) was about 50.83%. The concentration of AOC was from 59.51 £gg acetate-C/L to 28.42 £gg acetate-C/L). The removal of raw water (¢º) was about 50.97%. The concentration of AOC was from 73.08 £gg acetate-C/L to 35.8 £gg acetate-C/L. The removal of raw water (¢») was about 65.07%. The concentration of AOC was from 226.60 £gg acetate-C/L to 81.19 £gg acetate-C/L. The suggested limit level of AOC in treated water is 50£gg acetate-C/L Longer empty bed contact time of biofilter should enable the concentration below 50 £gg acetate-C/L. Removal of AOC increased with increased the empty bed contact time of biofilter . In removal of THMs and THMFP (denoted as precursors), the raw water (I) : THMs removal was about 50.22%. The concentration of THMs was reduced from 34.64 £gg/L to 17.56 £gg/L. The raw water (¢º): THMFP removal was about 46.83%. The concentration of THMs was reduced from 34.18 £gg/L to 18.27 £gg/L. The raw water (¢»): THMFP removal was about 51.81%. The concentration of THMFP was reduced from 81.49 £gg/L to 39.25 £gg/L. They were all lower than national standard of drinking water (THMs 80 £gg/L). Thus, this system can effectively remove turbidity, TOC, THMs and THMs precursors in raw water.

Submarine channels are important conduits for sediment in deep marine environments, and understanding their formation is critical to modeling basin fill processes. Most models describing channel evolution focus on turbidity currents as the erosive and constructive force in channel initiation. However, slope failure and slumping can be significant drivers of channelization, particularly in upper slope and ramp environments. Determining the relative roles of slumping and erosion by turbidity currents can provide important insight into the timing of channelization and the geometries of subsequent deposits. Samples were collected from Guadalupe Mountains National Park from two primary localities at Salt Flat Bench (Figure 2). Three vertical sections were measured at both locations. A total of 16 samples were collected for petrographic analysis and X-ray fluorescence (XRF) imaging. Spectacular outcrop quality makes the Middle Permian Brushy Canyon Formation in Guadalupe Mountains National Park an ideal location for the study of early channel evolution. A detailed facies analysis of fine-grained channel deposits was conducted in the Upper Brushy Canyon Formation in the Salt Flat Bench outcrops. After channelization, an interval of relative condensation dominated by hemipelagic settling of organic matter and silt was followed by an interval of incomplete sediment bypass by turbidity currents. This sequence of events suggests that sea level was at a relative highstand at the time of channel inception, whereas channel inception by turbidity currents is expected during a lowstand. Slumping rather than erosion by turbidity currents is the most likely mechanism to have initiated a channel at the study area. There is no evidence for the existence for high energy currents until after the interval of condensation. However, the action of weak contour currents during early channel evolution is observed in outcrop and microtextural features. Early carbonate cementation of channel-lining silts may have stabilized the slump surface with respect to erosion by later turbidity currents.

In this study, twenty-seven experiments of transport and hydrographic observations were conducted at 9 bridges along the Love River during the period between 2001/12/20 and 2003/9/10. In each experiment repeated measurements were made at each bridge every two hours for a total period of 12 hours. An additional experiment (the 28th experiment) was conducted at 2004/6/16 in the Chihsien Bridge which consists of continuous measurements of velocity, depth and turbidity with a total length of 27 hours. Our results indicate that the Love River is influenced by the incoming tides from the river mouth up to the Dingxin Bridge. The tidal range is approximately 1m during spring tides (10cm during neap tides) at river mouth. The velocity at the Chihsien Bridge has a high frequency variation with a period of approximately 1 hour and amplitude of 20 cm/s during the 28th experiment. Salinity variations are in phase with tides, while turbidity and tides are out of phase. Harmonic analysis of depth, velocity, salinity and turbidity data all indicate that K1 is the principal tidal constituent followed by M2. River transport in the lower estuary is mainly comprised of two parts: tide and river discharge. The tidal induced transport is estimated to be ¡Ó30 CMS and net river discharge is about 1~9 CMS. The upper estuary is affected by two transport mechanisms: agricultural runoff and rain precipitation. After analyzing the measurement results, the transport of the upper branches is estimated to be 0~0.5 CMS during dry seasons and 1~5 CMS during rainy seasons. The agricultural transport reaches its maximum value in January with an estimated rate of 1~2.8 CMS. For the upper branches of Love River, the ratio£\between the hydraulic depth D and hydraulic radius R is found to reach a constant value of 0.9~1.0 when the transport Q is less than 2CMS, and£\is 0.8~0.9 when Q is greater than 2 CMS. The relationship between Q and the section factor TaDb, where T is the channel width, is found to be TD5/3=7.171Q (Dingxin Bridge) and TD5/3=0.744Q (Hougang Bridge) based on Manning formula. Finally, the relationship between Q and D is found to be D=1.811Q0.2981 (Longxin bridge) and D=0.266Q0.256 (Hougang Bridge).

The contribution of phytoplankton productivity to higher trophic levels in salt marshes is not well understood. My study furthers our understanding of possible mechanisms controlling phytoplankton productivity, abundance, and community composition in salt marshes. Across three consecutive springs (2001 to 2003), I sampled the upper Nueces Delta in south Texas, a shallow, turbid, salt marsh system stressed by low freshwater inflow and wide ranging salinity (<15 to >300 ppt). Water column productivity and respiration were estimated using a light-dark bottle technique, and phytoplankton biovolume and community composition were determined using inverted light microscopy. To determine their effect on the phytoplankton community, zooplankton and bacterioplankton abundance and several physical parameters were also assessed. Meaningful relationships among the numerous variables evaluated in this study were identified using principal component analysis (PCA). Despite high turbidity, phytoplankton productivity and biovolume were substantial. Resuspension appeared to play a major role in phytoplankton dynamics, as indicated by a positive relationship between ash weight and biovolume that explained up to 46% of the variation in the PCA. Negative relationships between zooplankton grazers and pennate diatoms of optimal sizes for these grazers suggested a functional grazing food chain in this system. Salinity also may have been important in phytoplankton dynamics, whereas nutrients appeared to play a minor role. Salinity increases may have been responsible for a decoupling observed between phytoplankton and grazers during late spring. Findings suggest hypotheses for future studies focused on the role of phytoplankton in salt marshes, particularly those stressed by reduced freshwater inflow and high salinities.